SLUAAV6 September   2024 TPS56837 , TPS56837H

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 USB Type-C Power Delivery Introduction
    2. 1.2 TPS56837HA Introduction
    3. 1.3 Block Diagram of TPS56837HA in USB Type-C Power Delivery Application
  5. 2PD Controller GPIO to Configure TPS56837HA Dynamically Output Change
    1. 2.1 Typical Application
    2. 2.2 Test Results
      1. 2.2.1 Dynamically Change Waveforms
      2. 2.2.2 Efficiency Curves
      3. 2.2.3 Thermal Pictures
  6. 3PD Controller Dedicated FB Pin to Control TPS56837HA Dynamic Output Change
    1. 3.1 FB Current Injection PD Controller
    2. 3.2 Rfb Integrated PD Controller
  7. 4Summary
  8. 5References

2.1 Typical Application

The typical application schematic in Figure 2-1 shows using GPIO to switch TPS56837HA feedback bottom resistor to dynamically change output voltage.

PD Controller GPIO Control for TPS56837HA Dynamically Output Change Reference SchematicFigure 2-1 PD Controller GPIO Control for TPS56837HA Dynamically Output Change Reference Schematic

Table 2-1 shows GPIO configuration logic for different output voltage.

  • When all GPIO signal is low, no switch is open, the output is configured by R6 and R7 to default 5V.
  • When GPIO1 is changed from low to high, Q1 switch is conducted, the output is configured by R6 and R7 parallel R11 changed from 5V to 9V. Other scenario is the same mechanism.
Table 2-1 GPIO Configuration Logic
GPIO_1 GPIO_2 GPIO_3 Vout_set/V Rfb_top/ohm Rfb_bot/ohm Vout/V
0 0 0 5 30k 4.07k 5.02
1 0 0 9 30k 2.119k 9.10
1 1 0 15 30k 1.244k 15.08
1 1 1 20 30k 0.928k 20.01

The switch Q1, Q2 and Q3 gate RC filters are used to regulate the GPIO edge slew rate so that the output voltage changing slew rate can meet PD3.1 specifications of voltage transitions vSrcSlew.

The application BOM selection guide can refer to the detailed design procedure in TPS56837Hx 4.5V to 28V Input, 8A, Synchronous Buck Converter, data sheet.