How to Use TPS22908EVM: Examples, Pinouts, and Specs

The TPS22908EVM is an evaluation module designed to demonstrate the performance and functionality of the TPS22908, a low RON load switch from Texas Instruments. This module is ideal for evaluating the TPS22908 in power management applications, particularly in portable and battery-powered devices. The TPS22908 features a small footprint, low quiescent current, and fast turn-on time, making it suitable for applications requiring efficient power delivery and minimal power loss.

• Smartphones and tablets
• Wearable devices
• Portable medical equipment
• Battery-powered IoT devices
• Power distribution in low-voltage systems

• Input Voltage Range: 0.8 V to 5.5 V
• Maximum Continuous Current: 2 A
• On-Resistance (RON): 44 mΩ at 1.8 V
• Quiescent Current: 29 µA (typical)
• Turn-On Time: 85 µs at 1.8 V
• Operating Temperature Range: -40°C to 85°C
• Package: 4-pin WCSP (0.8 mm x 0.8 mm)

The TPS22908EVM includes test points and connectors for easy evaluation of the TPS22908. Below is the pin configuration for the TPS22908 IC:

The evaluation module provides additional test points for monitoring input/output voltages and currents, as well as for controlling the ON pin.

1. Power Supply Connection:

   • Connect the input voltage source to the VIN test point.
   • Ensure the input voltage is within the range of 0.8 V to 5.5 V.
   • Connect the ground of the power supply to the GND test point.

2. Load Connection:

   • Connect the load to the VOUT test point.
   • Ensure the load does not exceed the maximum continuous current of 2 A.

3. Enable the Load Switch:

   • Use the ON test point to control the load switch.
   • Apply a voltage of 1.0 V or higher to the ON pin to enable the switch.
   • Pull the ON pin to ground to disable the switch.

4. Monitor Performance:

   • Use the test points to measure input/output voltages and currents.
   • Evaluate the switch's performance under different load conditions.

• Ensure the input voltage does not exceed the maximum rating of 5.5 V to avoid damaging the device.
• Use low-resistance connections to minimize voltage drops and ensure accurate measurements.
• Avoid exceeding the maximum continuous current of 2 A to prevent overheating or damage.
• For fast switching applications, ensure the ON pin is driven with a clean and stable signal.

The TPS22908EVM can be controlled using an Arduino UNO to toggle the load switch. Below is an example code snippet:

// Define the ON pin connected to the Arduino
const int onPin = 7; // Connect Arduino pin 7 to the ON pin of TPS22908EVM

void setup() {
  pinMode(onPin, OUTPUT); // Set the ON pin as an output
}

void loop() {
  digitalWrite(onPin, HIGH); // Turn on the load switch
  delay(1000);               // Keep the switch on for 1 second
  digitalWrite(onPin, LOW);  // Turn off the load switch
  delay(1000);               // Keep the switch off for 1 second
}

Note: Ensure the Arduino's output voltage is compatible with the ON pin's logic level requirements (1.0 V or higher to enable the switch).

1. The load switch does not turn on:

   • Verify that the ON pin is receiving a voltage of 1.0 V or higher.
   • Check the input voltage at the VIN test point to ensure it is within the specified range.
   • Ensure the ground connections are secure.

2. Output voltage is lower than expected:

   • Check for excessive load current that may cause a voltage drop.
   • Verify the input voltage and ensure it is stable.
   • Inspect the connections for high resistance or loose contacts.

3. The device overheats:

   • Ensure the load current does not exceed the maximum continuous current of 2 A.
   • Verify that the input voltage is within the specified range.
   • Check for short circuits at the output.

4. No output voltage when the switch is enabled:

   • Confirm that the load is properly connected to the VOUT test point.
   • Check the ON pin signal to ensure it is correctly toggled.

Q1: Can the TPS22908EVM handle inrush current during startup?
A1: Yes, the TPS22908 is designed to handle inrush current during startup. However, ensure the load capacitance is within the recommended range to avoid excessive inrush current.

Q2: What is the maximum load capacitance supported by the TPS22908?
A2: The TPS22908 can support load capacitances up to 100 µF. For higher capacitances, additional precautions such as inrush current limiting may be required.

Q3: Can the TPS22908EVM be used with a 3.3 V logic system?
A3: Yes, the ON pin is compatible with 3.3 V logic levels, making it suitable for use with most microcontrollers and logic systems.

Q4: Is the TPS22908EVM suitable for high-frequency switching applications?
A4: The TPS22908 has a fast turn-on time of 85 µs, making it suitable for many low-frequency switching applications. For high-frequency switching, ensure the ON pin signal is stable and noise-free.

This concludes the documentation for the TPS22908EVM. For further details, refer to the official Texas Instruments datasheet and user guide.