SLVAFW0 December   2025 TPS61381-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2TPS61381-Q1 Schematic Guideline
    1. 2.1 GND Connection
    2. 2.2 Driver Design
    3. 2.3 IO Configuration
    4. 2.4 Output Capacitor
    5. 2.5 Compensation Design
      1. 2.5.1 Small Signal Analysis
      2. 2.5.2 Step by Step Loop Compensation Design
  6. 3TPS61381-Q1 Layout Guide Line
    1. 3.1 Identification of the Critical Switching Loops
      1. 3.1.1 Low Side Driver Loop
      2. 3.1.2 Boost Leg Switching Loop
      3. 3.1.3 High Side Driver Loop
    2. 3.2 Power Component Placement
    3. 3.3 Layout Example
      1. 3.3.1 Optimizing Low Side Driver Loop Example
      2. 3.3.2 Optimizing Boost Leg Switching Loop Example
      3. 3.3.3 Optimizing High Side Driver Loop Example
      4. 3.3.4 Signal Circuit Routing Example
  7. 4Summary
  8. 5References

2.1 GND Connection

TPS61381 features in high current limit, fast start-up strategy to make sure the system voltage can be taken over instantly when a power failure is detected. The current can reach up to 25A (Set by I2C) during boost start-up. Vout changes by I2C or short circuit protection-reboot conditions. So GND connection is very important to avoid switching noise form affecting the IC. There is a risk that the IC internal circuit can lose control or even sustain damage if AGND is not connected correctly. The typical schematic is shown in Figure 2-1.

TPS61381-Q1 GND Connection Figure 2-1 TPS61381-Q1 GND Connection

Make sure that there is a separate AGND from PGND and connect VCC, COMP, AGND pin, and the thermal pad to AGND.

AGND must be connected to PGND by a single point (net-tie, 0Ω resistor or wire with 10mil width). Do not connect AGND with PGND by a wide polygon.