How to Use Power Multiplexer: Examples, Pinouts, and Specs

The TPS2113A, manufactured by Texas Instruments, is a power multiplexer designed to seamlessly switch between two power sources to supply a single output. This device ensures reliable power delivery by automatically selecting the most suitable power source based on priority or availability. It is particularly useful in applications requiring redundancy or uninterrupted power supply.

• Battery-powered devices with USB charging
• Systems requiring automatic power source selection (e.g., USB vs. battery)
• Portable electronics with dual power inputs
• Embedded systems and microcontroller-based designs
• Power redundancy in critical systems

The TPS2113A is a highly versatile power multiplexer with the following key specifications:

The TPS2113A is available in an 8-pin VSSOP package. The pinout and descriptions are as follows:

The TPS2113A is straightforward to use in a circuit. Below are the steps and considerations for proper implementation:

1. Connect Power Sources:
   • Connect the primary power source to the IN1 pin.
   • Connect the secondary power source to the IN2 pin.
2. Output Connection:
   • Connect the load to the OUT pin.
3. Control Logic:
   • Use the CTL pin to manually select the power source if needed.
   • Configure the PR1 and PR2 pins to set the priority between IN1 and IN2.
4. Enable the Device:
   • Pull the EN pin high to enable the device.

• Ensure that the input voltages on IN1 and IN2 are within the specified range (2.8 V to 5.5 V).
• Use appropriate decoupling capacitors (e.g., 1 µF to 10 µF) on the input and output pins to ensure stable operation.
• Avoid exceeding the maximum output current of 1.25 A to prevent damage to the device.
• If using the device with a microcontroller (e.g., Arduino UNO), ensure proper logic level compatibility for control pins.

Below is an example of how to control the TPS2113A using an Arduino UNO to manually select the power source:

// Define control pins for TPS2113A
const int ctlPin = 7;  // Connected to CTL pin of TPS2113A
const int enPin = 8;   // Connected to EN pin of TPS2113A

void setup() {
  // Initialize pins as outputs
  pinMode(ctlPin, OUTPUT);
  pinMode(enPin, OUTPUT);

  // Enable the TPS2113A
  digitalWrite(enPin, HIGH);  // Set EN pin high to enable the device
}

void loop() {
  // Example: Switch between power sources every 5 seconds
  digitalWrite(ctlPin, HIGH);  // Select IN1 as the power source
  delay(5000);                 // Wait for 5 seconds

  digitalWrite(ctlPin, LOW);   // Select IN2 as the power source
  delay(5000);                 // Wait for 5 seconds
}

1. No Output Voltage:

   • Ensure the EN pin is pulled high to enable the device.
   • Verify that the input voltages on IN1 and IN2 are within the specified range.
   • Check for proper connections and ensure the load is not drawing more than 1.25 A.

2. Unstable Output Voltage:

   • Add decoupling capacitors (1 µF to 10 µF) to the input and output pins.
   • Verify that the input power sources are stable and not fluctuating.

3. Incorrect Power Source Selection:

   • Check the logic levels on the CTL, PR1, and PR2 pins.
   • Ensure the control signals are properly configured for the desired behavior.

Q: Can the TPS2113A handle higher output currents?
A: No, the maximum output current is 1.25 A. Exceeding this limit may damage the device.

Q: What happens if both power sources are unavailable?
A: The output will be disabled, and no voltage will be supplied to the load.

Q: Can I use the TPS2113A with a 12 V power source?
A: No, the input voltage range is limited to 2.8 V to 5.5 V. Using a higher voltage may damage the device.

Q: How fast does the TPS2113A switch between power sources?
A: The typical switch-over time is 50 µs, ensuring minimal disruption to the load.

By following the guidelines and recommendations in this documentation, you can effectively integrate the TPS2113A power multiplexer into your designs for reliable and efficient power management.