This small synchronous switching step-down (or buck) regulator takes an input voltage of up to 38 V and efficiently reduces it to 5 V. The board measures only 0.7″ × 0.8″, but it allows a typical continuous output current of up to 5 A. Typical efficiencies of 85% to 95% make this regulator well suited for high-power applications like powering motors or servos. High efficiencies are maintained at light loads by dynamically changing the switching frequency, and an optional shutdown pin enables a low-power state with a current draw of a few hundred microamps.

The D24V50Fx family of step-down voltage regulators generates lower output voltages from input voltages as high as 38 V. They are switching regulators (also called switched-mode power supplies (SMPS) or DC-to-DC converters) with typical efficiencies between 85% and 95%, which is much more efficient than linear voltage regulators, especially when the difference between the input and output voltage is large. The available output current is a function of the input voltage and efficiency (see the Typical Efficiency and Output Current section below), but the output current can typically be as high as 5 A.

At light loads, the switching frequency automatically changes to maintain high efficiencies. These regulators have a typical quiescent (no load) current draw of less than 1 mA, and the ENABLE pin can be used to put the boards in a low-power state that reduces the quiescent current to approximately 10 µA to 20 µA per volt on VIN.

The modules have built-in reverse-voltage protection, short-circuit protection, a thermal shutdown feature that helps prevent damage from overheating, a soft-start feature that reduces inrush current, and an under-voltage lockout.

Several different fixed output voltages are available:

Several alternatives are available for this product.

Select from the options below and click “Go” to find a particular version.

Close

Alternatives available with variations in these parameter(s): output voltage Select variant…

The different voltage versions of this regulator all look very similar, so you should consider adding your own distinguishing marks or labels if you will be working simultaneously with multiple versions. This product page applies to all versions of the D24V50Fx family.

For lower-power applications, please consider our D24V25Fx family of step-down voltage regulators; these are slightly smaller, pin-compatible versions of this regulator with typical maximum output current of 2.5 A.

Side-by-side comparison of the 2.5A D24V25Fx (left) and 5A D24V50Fx (right) step-down voltage regulators.

Two larger, higher-power, 5 V versions of this regulator are also available: one with a typical maximum output current of 6 A, and the other with a typical maximum output current of 9 A. The higher-power versions also have a few additional features, like a “power good” signal and the ability to lower their output voltage, and they include optional terminal blocks for easy removable connections.

Input voltage:

4.5 V to 38 V for the version that outputs 3.3 V

[output voltage + dropout voltage] to 38 V for output voltages of 5 V and higher (see below for more information on dropout voltage)

4.5 V to 38 V for the version that outputs 3.3 V

[output voltage + dropout voltage] to 38 V for output voltages of 5 V and higher (see below for more information on dropout voltage)

Fixed 3.3 V or 5 V (depending on regulator version) with 4% accuracy

Typical maximum continuous output current: 5 A

Integrated reverse-voltage protection, over-current protection, over-temperature shutoff, soft-start, and under-voltage lockout

Typical efficiency of 85% to 95%, depending on input voltage and load; the switching frequency automatically changes at light loads to maintain high efficiencies

Typical no-load quiescent current under 1 mA; can be reduced to 10 µA to 20 µA per volt on VIN by disabling the board* Compact size: 0.7″ × 0.8″ × 0.35″ (17.8 mm × 20.3 mm × 8.8 mm)

Two 0.086″ mounting holes for #2 or M2 screws

Connections

This buck regulator has five connection points for four different connections: enable (EN), input voltage (VIN), 2x ground (GND), and output voltage (VOUT).

The input voltage, VIN, powers the regulator. Voltages between 4.5 V and 38 V can be applied to VIN, but for versions of the regulator that have an output voltage higher than 4.5 V, the effective lower limit of VIN is VOUT plus the regulator’s dropout voltage, which varies approximately linearly with the load (see below for graphs of dropout voltages as a function of the load).

The output voltage, VOUT, is fixed and depends on the regulator version: the D24V50F3 version outputs 3.3 V and the D24V50F5 version outputs 5 V.

The regulator is enabled by default: a 100 kΩ pull-up resistor on the board connects the ENABLE pin to reverse-protected VIN. The ENABLE pin can be driven low (under 0.6 V) to put the board into a low-power state. The quiescent current draw in this sleep mode is dominated by the current in the pull-up resistor from ENABLE to VIN and by the reverse-voltage protection circuit, which will draw between 10 µA and 20 µA per volt on VIN when ENABLE is held low. If you do not need this feature, you should leave the ENABLE pin disconnected.

Pololu 5A Step-Down Voltage Regulator D24V50Fx with included hardware.

Pololu 5A Step-Down Voltage Regulator D24V50Fx, bottom view.

The five connection points are labeled on the top of the PCB and are arranged with a 0.1″ spacing for compatibility with solderless breadboards, connectors, and other prototyping arrangements that use a 0.1″ grid. Either the included 5×1 straight male header strip or the 5×1 right angle male header strip can be soldered into these holes. For the most compact installation, you can solder wires directly to the board.

Pololu 5A Step-Down Voltage Regulator D24V50Fx, side view.

The board has two 0.086″ mounting holes intended for #2 or M2 screws. The mounting holes are at opposite corners of the board and are separated by 0.53″ horizontally and 0.63″ vertically.

Typical efficiency and output current

The efficiency of a voltage regulator, defined as (Power out)/(Power in), is an important measure of its performance, especially when battery life or heat are concerns. This family of switching regulators typically has an efficiency of 85% to 95%, though the actual efficiency in a given system depends on input voltage, output voltage, and output current. See the efficiency graph near the bottom of this page for more information.

The maximum achievable output current is typically around 5 A, but this depends on many factors, including the ambient temperature, air flow, heat sinking, and the input and output voltage.

Typical dropout voltage

The dropout voltage of a step-down regulator is the minimum amount by which the input voltage must exceed the regulator’s target output voltage in order to ensure the target output can be achieved. For example, if a 5 V regulator has a 1 V dropout voltage, the input must be at least 6 V to ensure the output is the full 5 V. Generally speaking, the dropout voltage increases as the output current increases. See the “Details” section below for more information on the dropout voltage for this specific regulator version.

Switching frequency and behavior under light loads

The regulator generally operates at a switching frequency of around 600 kHz, but the frequency drops when encountering a light load to improve efficiency. This could make it harder to filter out noise on the output caused by switching.

The graphs below show the typical efficiency and dropout voltage of the 5 V D24V50F5 regulator as a function of the output current:

During normal operation, this product can get hot enough to burn you. Take care when handling this product or other components connected to it.The over-current limit of the regulator operates on a combination of current and temperature: the current threshold decreases as the regulator temperature goes up. However, there might be some operating points at low input voltages and high output currents (well over 5 A) where the current is just under the limit and the regulator might not shut off before damage occurs. If you are using this regulator in an application where the input voltage is near the lower limit and the load could exceed 5 A for sustained periods (more than five seconds), consider using additional protective components such as fuses or circuit breakers.

People often buy this product together with:

This small synchronous switching step-down (or buck) regulator takes an input voltage of up to 36 V and efficiently reduces it to 5 V. The board measures only 0.7″ × 0.7″ yet delivers a typical continuous output current of up to 2.5 A and features reverse voltage protection. Typical efficiencies of 85% to 95% make this regulator well suited for powering moderate loads like sensors or small motors. An optional shutdown pin enables a low-power state with a current draw of around 20 μA to 350 μA, depending on the input voltage, and a power-good output indicates when the regulator cannot adequately maintain the output voltage.

The D24V22Fx family of step-down voltage regulators generates lower output voltages from input voltages as high as 36 V. They are synchronous switching regulators (also called switched-mode power supplies (SMPS) or DC-to-DC converters) with typical efficiencies of 85% to 95%, which is much more efficient than linear voltage regulators, especially when the difference between the input and output voltage is large. These regulators can typically support continuous output currents of over 2 A, though the actual available output current is a function of the input voltage and efficiency (see the Typical efficiency and output current section below). In general, the available output current is a little higher for the lower-voltage versions than it is for the higher-voltage versions, and it decreases as the input voltage increases.

These regulators have a typical quiescent (no load) current draw of around 1 mA, and an enable pin can be used to put the boards in a low-power state that reduces the quiescent current to approximately 5 µA to 10 µA per volt on VIN.

The modules have built-in reverse-voltage protection, short-circuit protection, a thermal shutdown feature that helps prevent damage from overheating, and a soft-start feature that reduces inrush current.

Several different fixed output voltages are available:

Several alternatives are available for this product.

Select from the options below and click “Go” to find a particular version.

Close

Alternatives available with variations in these parameter(s): output voltage Select variant…

The different voltage versions of this regulator all look very similar, so you should consider adding your own distinguishing marks or labels if you will be working simultaneously with multiple versions. This product page applies to all versions of the D24V22Fx family.

The D24V22Fx family is intended to replace our older D24V25Fx family of step-down voltage regulators. The two designs have the same size and similar current capabilities and input voltage ranges, but they do not have the same pinout and are based on different internal circuits, so there are fundamental differences in operation. In particular, these newer D24V22Fx regulators have much lower dropout voltages and provide a “power good” signal, and the newer design allows for higher output voltages (e.g. 12 V).

Input voltage:

4 V to 36 V for the version that outputs 3.3 V

[output voltage + dropout voltage] to 36 V for output voltages of 5 V and higher (see below for more information on dropout voltage)

4 V to 36 V for the version that outputs 3.3 V

[output voltage + dropout voltage] to 36 V for output voltages of 5 V and higher (see below for more information on dropout voltage)

Fixed 3.3 V, 5 V, 6 V, 7.5 V, 9 V, or 12 V output (depending on regulator version) with 4% accuracy

Typical maximum continuous output current: >2 A

Typical efficiency of 85% to 95%, depending on input voltage, output voltage, and load

Switching frequency: ~400 kHz

Integrated reverse-voltage protection, over-current protection, over-temperature shutoff, and soft-start

1 mA typical no-load quiescent current; this can be reduced to approximately 5 µA to 10 µA per volt on VIN by disabling the board

“Power good” output indicates when the regulator cannot adequately maintain the output voltage

Compact size: 0.7″ × 0.7″ × 0.31″ (17.8 mm × 17.8 mm × 8 mm)

Two 0.086″ mounting holes for #2 or M2 screws

Connections

These buck regulators have five main connection points for five different electrical nodes: power good (PG), enable (EN), input voltage (VIN), ground (GND), and output voltage (VOUT). The board also features a second ground connection point off the main row of connections that might be convenient for applications where you are soldering wires directly to the board rather than using it in a breadboard.

The input voltage, VIN, powers the regulator. Voltages between 4 V and 36 V can be applied to VIN, but for versions of the regulator that have an output voltage higher than 4 V, the effective lower limit of VIN is VOUT plus the regulator’s dropout voltage, which varies approximately linearly with the load (see below for a graph of dropout voltages as a function of the load).

The output voltage, VOUT, is fixed and depends on the regulator version: the D24V22F3 version outputs 3.3 V, the D24V22F5 version outputs 5 V, the D24V22F6 version outputs 6 V, the D24V22F7 version outputs 7.5 V, the D24V22F9 version outputs 9 V, and the D24V22F12 version outputs 12 V.

The regulator is enabled by default: a 270 kΩ pull-up resistor on the board connects the EN pin to reverse-protected VIN. The EN pin can be driven low (under 1 V) to put the board into a low-power state. The quiescent current draw in this sleep mode is dominated by the current in the pull-up resistor from EN to VIN and by the reverse-voltage protection circuit, which altogether will draw between 5 µA and 10 µA per volt on VIN when EN is held low. If you do not need this feature, you should leave the EN pin disconnected.

The “power good” indicator, PG, is an open-drain output that goes low when the regulator’s output voltage falls below around 85% of the nominal voltage and becomes high-impedance when the output voltage rises above around 90%. An external pull-up resistor is required to use this pin.

Pololu Step-Down Voltage Regulator D24V22Fx with included hardware.

Pololu Step-Down Voltage Regulator D24V22Fx, bottom view.

The five main connection points are labeled on the top of the PCB and are arranged with a 0.1″ spacing for compatibility with solderless breadboards, connectors, and other prototyping arrangements that use a 0.1″ grid. Either the included 5×1 straight male header strip or the 5×1 right angle male header strip can be soldered into these holes. For the most compact installation, you can solder wires directly to the board.

Pololu Step-Down Voltage Regulator D24V22Fx, side view.

The board has two 0.086″ (2.18 mm) diameter mounting holes intended for #2 or M2 screws. The mounting holes are at opposite corners of the board and are separated by 0.52″ (13.21 mm) both horizontally and vertically. For all the board dimensions, see the dimension diagram (204k pdf).

Typical efficiency and output current

The efficiency of a voltage regulator, defined as (Power out)/(Power in), is an important measure of its performance, especially when battery life or heat are concerns. This family of switching regulators typically has an efficiency of 85% to 95%, though the actual efficiency in a given system depends on input voltage, output voltage, and output current. See the efficiency graph near the bottom of this page for more information.

The maximum achievable output current is typically over 2 A, but this depends on many factors, including the ambient temperature, air flow, heat sinking, and the input and output voltage.

Typical dropout voltage

The dropout voltage of a step-down regulator is the minimum amount by which the input voltage must exceed the regulator’s target output voltage in order to ensure the target output can be achieved. For example, if a 5 V regulator has a 1 V dropout voltage, the input must be at least 6 V to ensure the output is the full 5 V. Generally speaking, the dropout voltage increases as the output current increases. See the “Details” section below for more information on the dropout voltage for this specific regulator version.

The graphs below show the typical efficiency and dropout voltage of the 5 V D24V22F5 regulator as a function of the output current:

During normal operation, this product can get hot enough to burn you. Take care when handling this product or other components connected to it.

People often buy this product together with:

This small synchronous switching step-down (or buck) regulator takes an input voltage from 4 V to 36 V and efficiently reduces it to 3.3 V. The board measures only 0.7″ × 0.7″ yet delivers a typical continuous output current of up to 2.6 A and features reverse voltage protection. Typical efficiencies of 85% to 95% make this regulator well suited for powering moderate loads like sensors or small motors. An optional shutdown pin enables a low-power state with a current draw of around 20 μA to 350 μA, depending on the input voltage, and a power-good output indicates when the regulator cannot adequately maintain the output voltage.

The D24V22Fx family of step-down voltage regulators generates lower output voltages from input voltages as high as 36 V. They are synchronous switching regulators (also called switched-mode power supplies (SMPS) or DC-to-DC converters) with typical efficiencies of 85% to 95%, which is much more efficient than linear voltage regulators, especially when the difference between the input and output voltage is large. These regulators can typically support continuous output currents of over 2 A, though the actual available output current is a function of the input voltage and efficiency (see the Typical efficiency and output current section below). In general, the available output current is a little higher for the lower-voltage versions than it is for the higher-voltage versions, and it decreases as the input voltage increases.

These regulators have a typical quiescent (no load) current draw of around 1 mA, and an enable pin can be used to put the boards in a low-power state that reduces the quiescent current to approximately 5 µA to 10 µA per volt on VIN.

The modules have built-in reverse-voltage protection, short-circuit protection, a thermal shutdown feature that helps prevent damage from overheating, and a soft-start feature that reduces inrush current.

Several different fixed output voltages are available:

Several alternatives are available for this product.

Select from the options below and click “Go” to find a particular version.

Close

Alternatives available with variations in these parameter(s): output voltage Select variant…

The different voltage versions of this regulator all look very similar, so you should consider adding your own distinguishing marks or labels if you will be working simultaneously with multiple versions. This product page applies to all versions of the D24V22Fx family.

The D24V22Fx family is intended to replace our older D24V25Fx family of step-down voltage regulators. The two designs have the same size and similar current capabilities and input voltage ranges, but they do not have the same pinout and are based on different internal circuits, so there are fundamental differences in operation. In particular, these newer D24V22Fx regulators have much lower dropout voltages and provide a “power good” signal, and the newer design allows for higher output voltages (e.g. 12 V).

Input voltage:

4 V to 36 V for the version that outputs 3.3 V

[output voltage + dropout voltage] to 36 V for output voltages of 5 V and higher (see below for more information on dropout voltage)

4 V to 36 V for the version that outputs 3.3 V

[output voltage + dropout voltage] to 36 V for output voltages of 5 V and higher (see below for more information on dropout voltage)

Fixed 3.3 V, 5 V, 6 V, 7.5 V, 9 V, or 12 V output (depending on regulator version) with 4% accuracy

Typical maximum continuous output current: >2 A

Typical efficiency of 85% to 95%, depending on input voltage, output voltage, and load

Switching frequency: ~400 kHz

Integrated reverse-voltage protection, over-current protection, over-temperature shutoff, and soft-start

1 mA typical no-load quiescent current; this can be reduced to approximately 5 µA to 10 µA per volt on VIN by disabling the board

“Power good” output indicates when the regulator cannot adequately maintain the output voltage

Compact size: 0.7″ × 0.7″ × 0.31″ (17.8 mm × 17.8 mm × 8 mm)

Two 0.086″ mounting holes for #2 or M2 screws

Connections

These buck regulators have five main connection points for five different electrical nodes: power good (PG), enable (EN), input voltage (VIN), ground (GND), and output voltage (VOUT). The board also features a second ground connection point off the main row of connections that might be convenient for applications where you are soldering wires directly to the board rather than using it in a breadboard.

The input voltage, VIN, powers the regulator. Voltages between 4 V and 36 V can be applied to VIN, but for versions of the regulator that have an output voltage higher than 4 V, the effective lower limit of VIN is VOUT plus the regulator’s dropout voltage, which varies approximately linearly with the load (see below for a graph of dropout voltages as a function of the load).

The output voltage, VOUT, is fixed and depends on the regulator version: the D24V22F3 version outputs 3.3 V, the D24V22F5 version outputs 5 V, the D24V22F6 version outputs 6 V, the D24V22F7 version outputs 7.5 V, the D24V22F9 version outputs 9 V, and the D24V22F12 version outputs 12 V.

The regulator is enabled by default: a 270 kΩ pull-up resistor on the board connects the EN pin to reverse-protected VIN. The EN pin can be driven low (under 1 V) to put the board into a low-power state. The quiescent current draw in this sleep mode is dominated by the current in the pull-up resistor from EN to VIN and by the reverse-voltage protection circuit, which altogether will draw between 5 µA and 10 µA per volt on VIN when EN is held low. If you do not need this feature, you should leave the EN pin disconnected.

The “power good” indicator, PG, is an open-drain output that goes low when the regulator’s output voltage falls below around 85% of the nominal voltage and becomes high-impedance when the output voltage rises above around 90%. An external pull-up resistor is required to use this pin.

Pololu Step-Down Voltage Regulator D24V22Fx with included hardware.

Pololu Step-Down Voltage Regulator D24V22Fx, bottom view.

The five main connection points are labeled on the top of the PCB and are arranged with a 0.1″ spacing for compatibility with solderless breadboards, connectors, and other prototyping arrangements that use a 0.1″ grid. Either the included 5×1 straight male header strip or the 5×1 right angle male header strip can be soldered into these holes. For the most compact installation, you can solder wires directly to the board.

Pololu Step-Down Voltage Regulator D24V22Fx, side view.

The board has two 0.086″ (2.18 mm) diameter mounting holes intended for #2 or M2 screws. The mounting holes are at opposite corners of the board and are separated by 0.52″ (13.21 mm) both horizontally and vertically. For all the board dimensions, see the dimension diagram (204k pdf).

Typical efficiency and output current

The efficiency of a voltage regulator, defined as (Power out)/(Power in), is an important measure of its performance, especially when battery life or heat are concerns. This family of switching regulators typically has an efficiency of 85% to 95%, though the actual efficiency in a given system depends on input voltage, output voltage, and output current. See the efficiency graph near the bottom of this page for more information.

The maximum achievable output current is typically over 2 A, but this depends on many factors, including the ambient temperature, air flow, heat sinking, and the input and output voltage.

Typical dropout voltage

The dropout voltage of a step-down regulator is the minimum amount by which the input voltage must exceed the regulator’s target output voltage in order to ensure the target output can be achieved. For example, if a 5 V regulator has a 1 V dropout voltage, the input must be at least 6 V to ensure the output is the full 5 V. Generally speaking, the dropout voltage increases as the output current increases. See the “Details” section below for more information on the dropout voltage for this specific regulator version.

The graph below shows the typical efficiency of the 3.3 V D24V22F3 regulator as a function of the output current:

Since the regulator’s input voltage must be at least 4 V, dropout voltage is not a consideration for this 3.3 V version.

During normal operation, this product can get hot enough to burn you. Take care when handling this product or other components connected to it.

People often buy this product together with:

This is the SparkFun “Time-of-Flight” Range Finder, a sensor board for the VL6180 distance sensor. Unlike most distance sensors that rely on reflected light intensity or reflected angles to determine range, the VL6180 uses a precise clock to measure the time it takes light to bounce back from a surface. This affords the ToF Range Finder and VL6180 a great benefit over other methods because it can be much more accurate and more immune to noise. Does this technology sound familiar? Well it should, it’s the same means cellphones use to detect when the caller is holding their phone to their ear.

The VL6180 is actually a 3-in-1 package that combines an IR emitter, a range sensor, and an ambient light sensor together for you to easily use and communicate with via an I2C interface. The ToF Range Finder is very similar to its breakout cousin with a few important differences. What sets this board apart is this sensor is equipped with an on-board 2.8V regulator, which means if you were to plug in a voltage higher than 2.8V it will be shifted down without worry of damaging your board! Another thing to note is the form factor of the sensor itself. Many small robotics platforms have integrated hole patterns for the long time favorite Sharp IR sensor line. This allows the VL6180 Sensor to be a near drop-in replacement for most Sharp sensors.

Note: Though the datasheet states the VL6180 measures an absolute range of up to 10cm, we have successfully tested it up to 25cm. The more you know.

Features

2.8V Regulator - Provides the required 2.8V for the sensor

I2C Level Shifter - Provides logic level conversion from 2.8V to VCC

3-in-1 Module

IR Emitter

Range Sensor

Ambient Light Sensor

IR Emitter

Range Sensor

Ambient Light Sensor

Measures absolute range up to 10cm

Gesture Recognition

I2C Interface

Two Programmable GPIO

Sharp Sensor Board Layout

Filling out our accelerometer offerings, we now have the really lovely digital ADXL345 from Analog Devices, a triple-axis accelerometer with digital I2C and SPI interface breakout. We added an on-board 3.3V regulator and logic-level shifting circuitry, making it a perfect choice for interfacing with any 3V or 5V microcontroller such as the Arduino.The sensor has three axes of measurements, X Y Z, and pins that can be used either as I2C or SPI digital interfacing. You can set the sensitivity level to either +-2g, +-4g, +-8g or +-16g. The lower range gives more resolution for slow movements, the higher range is good for high speed tracking. The ADXL345 is the latest and greatest from Analog Devices, known for their exceptional quality MEMS devices. The VCC takes up to 5V in and regulates it to 3.3V with an output pin.Fully assembled and tested. Comes with 9 pin 0.1" standard header in case you want to use it with a breadboard or perfboard. Two 2.5mm (0.1") mounting holes for easy attachment.Get started in a jiffy with our detailed tutorial!

ADXL345 - Triple-Axis Accelerometer (+-2g/4g/8g/16g) w/ I2C/SPI (16:05)

This precision sensor from Bosch is the best low-cost sensing solution for measuring barometric pressure and temperature. Because pressure changes with altitude you can also use it as an altimeter! The sensor is soldered onto a PCB with a 3.3V regulator, I2C level shifter and pull-up resistors on the I2C pins.The BMP180 is the next-generation of sensors from Bosch, and replaces the BMP085. The good news is that it is completely identical to the BMP085 in terms of firmware/software - you can use our BMP085 tutorial and any example code/libraries as a drop-in replacement. The XCLR pin is not physically present on the BMP180 so if you need to know that data is ready you will need to query the I2C bus.This board is 5V compliant - a 3.3V regulator and a i2c level shifter circuit is included so you can use this sensor safely with 5V logic and power.Using the sensor is easy. For example, if you're using an Arduino, simply connect the VIN pin to the 5V voltage pin, GND to ground, SCL to I2C Clock (Analog 5) and SDA to I2C Data (Analog 4). Then download our BMP085/BMP180 Arduino library and example code for temperature, pressure and altitude calculation. Install the library, and load the example sketch. Immediately you'll have precision temperature, pressure and altitude data. Our detailed tutorial has all the info you need including links to software and installation instructions. It includes more information about the BMP180 so you can understand the sensor in depth including how to properly calculate altitude based on sea-level barometric pressure.

BMP180 Barometric Pressure/Temperature/Altitude Sensor- 5V ready (4:40)

This compact board breaks out the pins of a microSD card connector necessary to interface with the card through SPI (Serial Peripheral Interface), and it can be directly integrated into 5 V systems thanks to its on board 3.3 V regulator and level shifting circuits. The 0.1″ pin spacing allows compatibility with standard perfboards, solderless breadboards, and 0.1" connectors.

This carrier board makes it easy to interface a microSD memory card (originally known as TransFlash) with an SPI-capable microcontroller, offering a convenient and inexpensive way to add gigabytes of non-volatile storage to an embedded project. It includes a 3.3 V regulator and level shifters on the four SPI lines, enabling direct integration into 5 V systems, and it provides access to the all of the connections through single 1×9 row of 0.1″-spaced through-holes. A breakaway 0.1″ male header strip is included, which can be soldered in to use the board with breadboards, perfboards, or 0.1″ female connectors, and the board has two mounting holes for #2 or M2 screws.

Breakout Board for microSD Card with 3.3V Regulator and Level Shifters with included header pins.

Breakout Board for microSD Card with 3.3V Regulator and Level Shifters plugged into a breadboard with microSD card (not included) inserted.

For 3.3 V projects, we carry a smaller Breakout Board for MicroSD Card without the 3.3 V regulator, level shifters, and mounting holes. This more basic module (shown in the right picture below) breaks out all of the microSD pins (including the ones used for the SD bus mode interface) rather than just the SPI-interface pins.

Breakout Board for microSD Card with 3.3V Regulator and Level Shifters.

Breakout Board for microSD Card.

For a microSD socket and user-programmable microcontroller on a single board, consider our A-Star 32U4 Prime controllers, which essentially use the same level-shifting circuits to interface a microSD card with an Arduino-compatible ATmega32U4 MCU running at 5 V.

Since many microcontrollers have built-in SPI interfaces, most hobbyist projects communicate with Secure Digital cards in SPI bus mode; this is the only mode supported by this board. (The alternative SD bus mode is proprietary, and a license from the SD Association is required for access to the full specifications.) The pins on this board are labeled according to their functions in SPI mode.

The board is powered by applying 5 V to the VDD pin, and all of the logic pins can be interfaced directly with 5 V systems thanks to integrated level shifters. The output of the integrated 3.3 V regulator can be accessed through the 3V3 pin, and the regulator can be disabled to turn off the microSD card and save power by driving the EN pin low.

By default, the EN and CD (Card Detect) pins are each pulled up to VDD through 100 kΩ resistors. However, there are cuttable traces on the underside of the board to allow you to disconnect each pull-up as desired. These traces are located between pairs of pads (labeled “EN” and “CD” on the board’s silkscreen) that can be bridged with solder to reconnect the pull-up resistor. Alternatively, the neighboring EN and CD pads of these surface-mount jumpers (highlighted in the picture below) can be connected if you want the regulator to automatically be enabled when the microSD card is inserted and disabled when it is removed.

Communicating with a microSD card

The SD Association publishes a set of simplified specifications for SD cards containing information on interfacing with them. However, there are a number of ways to get started without understanding the specifications or writing your own code from scratch, since many microcontroller development platforms provide libraries for communicating with SD cards. For example:

The SD library for Arduino provides functions for accessing files and directories on an SD card. (It also works with Arduino-compatible boards like our A-Star programmable controllers.)

The SD Card File System library for mbed allows similar filesystem access.

Schematic

Breakout Board for Micro SD Card with 3.3V Regulator and Level Shifter schematic diagram.

This schematic is also available as a downloadable pdf (106k pdf).

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This sensor is a carrier/breakout board for ST’s VL53L0X laser-ranging sensor, which measures the range to a target object up to 2 m away. The VL53L0X uses time-of-flight measurements of infrared pulses for ranging, allowing it to give accurate results independent of the target’s color and surface. Distance measurements can be read through a digital I²C interface. The board has a 2.8 V linear regulator and integrated level-shifters that allow it to work over an input voltage range of 2.6 V to 5.5 V, and the 0.1″ pin spacing makes it easy to use with standard solderless breadboards and 0.1″ perfboards.

The VL53L0X from ST Microelectronics is a time-of-flight ranging system integrated into a compact module. This board is a carrier for the VL53L0X, so we recommend careful reading of the VL53L0X datasheet (1MB pdf) before using this product.

The VL53L0 uses ST’s FlightSense technology to precisely measure how long it takes for emitted pulses of infrared laser light to reach the nearest object and be reflected back to a detector, so it can be considered a tiny, self-contained lidar system. This time-of-flight (TOF) measurement enables it to accurately determine the absolute distance to a target without the object’s reflectance greatly influencing the measurement. The sensor can report distances of up to 2 m (6.6 ft) with 1 mm resolution, but its effective range and accuracy (noise) depend heavily on ambient conditions and target characteristics like reflectance and size, as well as the sensor configuration. (The sensor’s accuracy is specified to range from ±3% at best to over ±10% in less optimal conditions.)

Ranging measurements are available through the sensor’s I²C (TWI) interface, which is also used to configure sensor settings, and the sensor provides two additional pins: a shutdown input and an interrupt output.

The VL53L0X is a great IC, but its small, leadless, LGA package makes it difficult for the typical student or hobbyist to use. It also operates at a recommended voltage of 2.8 V, which can make interfacing difficult for microcontrollers operating at 3.3 V or 5 V. Our breakout board addresses these issues, making it easier to get started using the sensor, while keeping the overall size as small as possible.

The carrier board includes a low-dropout linear voltage regulator that provides the 2.8 V required by the VL53L0X, which allows the sensor to be powered from a 2.6 V to 5.5 V supply. The regulator output is available on the VDD pin and can supply almost 150 mA to external devices. The breakout board also includes a circuit that shifts the I²C clock and data lines to the same logic voltage level as the supplied VIN, making it simple to interface the board with 3.3 V or 5 V systems, and the board’s 0.1″ pin spacing makes it easy to use with standard solderless breadboards and 0.1″ perfboards. The board ships fully populated with its SMD components, including the VL53L0X, as shown in the product picture.

For for similar alternatives to this sensor, see our shorter-range 60 cm VL6180X carrier and longer-range 400 cm VL53L1X carrier. Both of these are physical drop-in replacements for the VL53L0X carrier, but they have different APIs, so software for the VL53L0X will need to be rewritten to work with the VL6180X or VL53L1X.

VL53L0X datasheet graph of typical ranging performance (in default mode).

Specifications

Dimensions: 0.5″ × 0.7″ × 0.085″ (13 mm × 18 mm × 2 mm)

Weight without header pins: 0.5 g (0.02 oz)

Operating voltage: 2.6 V to 5.5 V

Supply current: 10 mA (typical average during active ranging)

Varies with configuration, target, and environment. Peak current can reach 40 mA.

Varies with configuration, target, and environment. Peak current can reach 40 mA.

Output format (I²C): 16-bit distance reading (in millimeters)

Distance measuring range: up to 2 m (6.6 ft); see the graph at the right for typical ranging performance.

Effective range depends on configuration, target, and environment.

The datasheet does not specify a minimum range, but in our experience, the effective limit is about 3 cm.

Effective range depends on configuration, target, and environment.

The datasheet does not specify a minimum range, but in our experience, the effective limit is about 3 cm.

Included components

A 1×7 strip of 0.1″ header pins and a 1×7 strip of 0.1″ right-angle header pins are included, as shown in the picture below. You can solder the header strip of your choice to the board for use with custom cables or solderless breadboards, or you can solder wires directly to the board itself for more compact installations.

VL53L0X Time-of-Flight Distance Sensor Carrier with included header pins.

VL53L0X Time-of-Flight Distance Sensor Carrier in a breadboard.

The board has two mounting holes spaced 0.5″ apart that work with #2 and M2 screws (not included).

Important note: This product might ship with a protective liner covering the sensor IC. The liner must be removed for proper sensing performance.

Connections

At least four connections are necessary to use the VL53L0X board: VIN, GND, SCL, and SDA. The VIN pin should be connected to a 2.6 V to 5.5 V source, and GND should be connected to 0 volts. An on-board linear voltage regulator converts VIN to a 2.8 V supply for the VL53L0X IC.

The I²C pins, SCL and SDA, are connected to built-in level-shifters that make them safe to use at voltages over 2.8 V; they should be connected to an I²C bus operating at the same logic level as VIN.

The XSHUT pin is an input and the GPIO1 pin is an open-drain output; both pins are pulled up to 2.8 V by the board. They are not connected to level-shifters on the board and are not 5V-tolerant, but they are usable as-is with many 3.3 V and 5 V microcontrollers: the microcontroller can read the GPIO1 output as long as its logic high threshold is below 2.8 V, and the microcontroller can alternate its own output between low and high-impedance states to drive the XSHUT pin. Alternatively, our 4-channel bidirectional logic level shifter can be used externally with those pins.

Pinout

Schematic diagram

The above schematic shows the additional components the carrier board incorporates to make the VL53L0 easier to use, including the voltage regulator that allows the board to be powered from a 2.6 V to 5.5 V supply and the level-shifter circuit that allows for I²C communication at the same logic voltage level as VIN. This schematic is also available as a downloadable PDF (110k pdf).

I²C communication

The VL53L0X can be configured and its distance readings can be queried through the I²C bus. Level shifters on the I²C clock (SCL) and data (SDA) lines enable I²C communication with microcontrollers operating at the same voltage as VIN (2.6 V to 5.5 V). A detailed explanation of the I²C interface on the VL53L0X can be found in its datasheet (1MB pdf), and more detailed information about I²C in general can be found in NXP’s I²C-bus specification (1MB pdf).

The sensor’s 7-bit slave address defaults to 0101001b on power-up. It can be changed to any other value by writing one of the device configuration registers, but the new address only applies until the sensor is reset or powered off. ST provides an application note (196k pdf) that describes how to use multiple VL53L0X sensors on the same I²C bus by individually bringing each sensor out of reset and assigning it a unique address.

The I²C interface on the VL53L0X is compliant with the I²C fast mode (400 kHz) standard. In our tests of the board, we were able to communicate with the chip at clock frequencies up to 400 kHz; higher frequencies might work but were not tested.

Sensor configuration and control

In contrast with the information available for many other devices, ST has not publicly released a register map and descriptions or other documentation about configuring and controlling the VL53L0X. Instead, communication with the sensor is intended to be done through ST’s VL53L0X API (STSW-IMG005), a set of C functions that take care of the low-level interfacing. To use the VL53L0X, you can customize the API to run on a host platform of your choice using the information in the API documentation. Alternatively, it is possible to use the API source code as a guide for your own implementation.

Sample Code

We have written a basic Arduino library for the VL53L0X, which can be used as an alternative to ST’s official API for interfacing this sensor with an Arduino or Arduino-compatible controller. The library makes it simple to configure the VL53L0X and read the distance data through I²C. It also includes example sketches that show you how to use the library.

People often buy this product together with: