TPS2113A Power Multiplexer Carrier with USB Micro-B Connector Pololu

DESCRIPTION

This breakout board from Texas Instruments TPS2113A auto-switching power multiplexer allows you to select which of two power sources is connected to a load while blocking reverse current into either of the sources. It has an adjustable current limit that can be set as high as 2 A and an adjustable switching threshold. Each input power rail on the multiplexer can be supplied with 2.8 V to 5.5 V, and the board also breaks out a USB Micro-B connector that can be used to supply one of the rails.

The Texas Instruments TPS2113A auto switching power multiplexer allows you to switch seamlessly between two power sources of 2.8 V to 5.5 V while blocking reverse current into either source. The power multiplexer (or mux) has an adjustable current limit that can be set as high as 2 A and an adjustable switching threshold that helps reduce output voltage droop when switching. Each input channel is controlled by an internal MOSFET switch, so the mux avoids the voltage drop that occurs when diodes are used to OR multiple power supplies together.

The TPS2113A makes a great addition to any project that needs to be able to transition between two sources like USB and external power, but its small size makes it difficult for a student or hobbyist to use. This carrier breaks out all of the chip’s features to 0.1″-spaced pins, making it easy to use with standard solderless breadboards. In addition, the board serves as a breakout for a USB Micro-B connector that can be used to supply one of the input power rails.

By default, the TPS2113A operates in auto switching mode, which means that it will automatically select the source that has a higher voltage, but the VSNS pin can be used to maintain IN1 as the selected source until it falls below a configurable switching threshold, making IN1 the primary or preferred source. The board ships with USB power connected to IN1, which enables the common application of having a device that can be powered by USB or an external power supply, automatically choosing the appropriate source based on what is connected. USB power can be switched from IN1 to IN2 by cutting a trace and configuring a surface-mount jumper.

Since this board is a carrier for the TPS2113A, we recommend careful reading of the TPS2113A datasheet.

FEATURES

• Size: 1″ × 0.55″ × 0.15″
• Weight: 0.9 g
• Minimum operating voltage: 2.8 V
• Maximum operating voltage: 5.5 V
• Maximum output current: 2 A

RESOURCES

Pinout

Pin	Description
IN1	Primary power switch input. Can be connected to a 2.8 V to 5.5 V power source. Connected to VBUS by default through surface-mount jumper. The multiplexer will function with IN1 as low as 1.5V as long as IN2 is above 2.8 V.
IN2	Secondary power switch input. Can be connected to a 2.8 V to 5.5 V power source.
VBUS	USB 5 V supply. Connected to IN1 by default through surface-mount jumper.
OUT	Multiplexed power output.
GND	Common ground for power supplies, load, and USB. (All of the board’s GND pins are internally connected with each other and with GND from the USB connector.)
VSNS	Switching control input. An internal power FET connects OUT to IN1 if the VSNS voltage is greater than 0.8 V. Otherwise, the FET connects OUT to the higher of IN1 and IN2. This pin is pulled low through an onboard 20kΩ pull-down resistor, setting the board to auto switching mode by default. See the Control inputs section below for more details on using this pin to set a switching threshold.
EN	Enable input. When driven high, OUT is disconnected from both IN1 and IN2. This pin is pulled low through an onboard 100 kΩ pull-down resistor so the IC is enabled by default.
ILIM	Current limit input. An onboard 1kΩ resistor from ILIM to GND sets the default current limit to 0.5 A nominally, but an external resistor can be added in parallel with it to increase the limit to a maximum of 2 A.
STAT	The status output indicates which input is currently connected to the output. This pin drives low when IN1 is selected and is pulled up to OUT through an onboard 100 kΩ pull-up resistor when IN2 is selected.
D− D+ ID	Signals are broken out from the USB connector.

Control inputs

The TPS2113A has three control inputs that can optionally be used to override the default behaviour of the device: VSNS (switching operation control), EN (enable), and ILIM (current limit control).

Power connections with USB and without USB.

The board can be powered by both USB and by a power source via the pins on the board. More information on how to power the device can be found on the manufacturers’ product page.

Included hardware

The included 1×15 strip of 0.1″ header pins can be broken into smaller pieces and soldered in to use the board with perfboards, breadboards, or 0.1″ female connectors. The board has two mounting holes that work with #2 and M2 screws (not included).