How to Use V_REG_TPS61040: Examples, Pinouts, and Specs

The TPS61040 is a high-efficiency boost converter designed to step up low input voltages to higher output voltages. It is particularly well-suited for battery-powered applications, where efficient power conversion is critical. This component integrates a power switch and requires minimal external components, making it ideal for compact designs. Its adjustable output voltage and wide input voltage range make it versatile for a variety of applications.

• Portable electronics powered by single-cell or multi-cell batteries
• LED backlighting for displays
• Low-power industrial and medical devices
• Wireless communication modules
• Sensor systems requiring higher operating voltages

The TPS61040 is available in a 6-pin SOT-23 package. Below is the pinout and description:

1. Input Voltage: Ensure the input voltage is within the range of 1.8 V to 6.0 V.
2. Output Voltage Setting: Use a resistor divider network connected to the FB pin to set the desired output voltage. The formula for the output voltage is: [ V_{OUT} = V_{REF} \times \left(1 + \frac{R1}{R2}\right) ] where ( V_{REF} ) is typically 1.233 V.
3. Inductor Selection: Choose an inductor with a suitable inductance value (e.g., 4.7 µH to 22 µH) and current rating to handle the peak current.
4. Capacitor Selection: Use low ESR capacitors for both input and output. Typical values are:
   • Input capacitor: 4.7 µF to 10 µF
   • Output capacitor: 10 µF to 22 µF
5. Diode Selection: Use a fast-recovery Schottky diode with a voltage rating higher than the output voltage and a current rating exceeding the peak inductor current.
6. Enable Pin: Connect the EN pin to VIN or a microcontroller GPIO to enable or disable the device.

Below is a basic circuit diagram for the TPS61040:

VIN ----+----+----+
        |    |    |
       C1   L1   D1
        |    |    |
       GND  SW   VOUT
             |     |
            FB    C2
             |     |
            R1    GND
             |
            R2
             |
            GND

The TPS61040 can be controlled using an Arduino UNO to enable or disable the boost converter. Below is an example code snippet:

// Define the pin connected to the EN pin of TPS61040
const int enablePin = 7;

void setup() {
  // Set the enable pin as an output
  pinMode(enablePin, OUTPUT);

  // Enable the TPS61040 by setting the pin HIGH
  digitalWrite(enablePin, HIGH);
}

void loop() {
  // Keep the TPS61040 enabled
  delay(1000);

  // Example: Disable the TPS61040 for 2 seconds
  digitalWrite(enablePin, LOW);
  delay(2000);

  // Re-enable the TPS61040
  digitalWrite(enablePin, HIGH);
}

• Thermal Management: Ensure adequate heat dissipation, especially at high output currents.
• PCB Layout: Minimize the trace lengths for the SW pin and the ground connections to reduce noise and improve efficiency.
• Startup Behavior: The device may require a minimum input voltage to start up, depending on the load.

1. No Output Voltage:

   • Verify that the EN pin is pulled high.
   • Check the input voltage to ensure it is within the specified range.
   • Inspect the feedback resistor network for proper connections and values.

2. Low Efficiency:

   • Ensure the inductor and capacitors have low ESR and are appropriately rated.
   • Minimize PCB trace resistance and ensure proper grounding.

3. Output Voltage Instability:

   • Verify the feedback resistor values and connections.
   • Check the output capacitor for sufficient capacitance and low ESR.

4. Device Overheating:

   • Ensure the load current does not exceed the maximum rating.
   • Improve thermal dissipation by using a larger copper area on the PCB.

Q1: Can the TPS61040 operate with a single AA battery?
A1: Yes, the TPS61040 can operate with a single AA battery (1.8 V to 6.0 V input range), but the output current capability will depend on the input voltage and desired output voltage.

Q2: How do I calculate the inductor value?
A2: The inductor value depends on the input voltage, output voltage, and switching frequency. A typical range is 4.7 µH to 22 µH. Refer to the datasheet for detailed calculations.

Q3: Can I use the TPS61040 to power LEDs?
A3: Yes, the TPS61040 is suitable for driving LEDs. Use a current-limiting resistor or a constant-current circuit to protect the LEDs.

Q4: What happens if the EN pin is left floating?
A4: The EN pin should not be left floating. Connect it to VIN or a GPIO pin to ensure proper operation.