SLVAFO4 august   2023 TPS61299

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Overview
  5. 2Load Connected to Input Voltage
    1. 2.1 Body Diode Pass (TPS61288)
    2. 2.2 Force Pass Through (TPS61253)
    3. 2.3 Bypass (TPS61291)
    4. 2.4 Summary
  6. 3Load Disconnected to Input Voltage
    1. 3.1 Synchronous HSD FET With Switchable Body Diode (TPS61299)
    2. 3.2 Extra ISO FET to Cut-Off Leakage Path
  7. 4Summary
  8. 5References

3.1 Synchronous HSD FET With Switchable Body Diode (TPS61299)

When high-side FET is a P-MOS, the device stops switching and the high-side MOSFET is fully turned off by switching the body diode direction to realize true shutdown operation. As Figure 3-1 shows, the switchable body diode provides the completed disconnection between input and output.

GUID-20230731-SS0I-JPRP-R2NM-GRPSQRVTD9DX-low.svg Figure 3-1 Ture disconnection During Shutdown

Meanwhile, the device monitors on the VMAX (the higher voltage between input voltage and output voltage). When output voltage exceeds input voltage, the body diode direction is switched to prevent the output from feeding back into the input voltage. The TPS61299 integrates ture disconnection function. Figure 3-2 shows the shutdown waveforms of the TPS61299.

GUID-20230728-SS0I-94WS-QFJW-WXFZZM6WSGCF-low.svg Figure 3-2 TPS61299 Shutdown Waveforms