7.5.9 Loop Compensation
The TPS53681 provides several options for tuning the output voltage feedback and response to transients. These may be configured by programming the MFR_SPECIFIC_07, VOUT_DROOP, and MFR_SPECIFIC_14. Several such parameters may be configured through these commands:
- DC Load Line - Selects the DC shift in output voltage corresponding to increased output current. The DC load line affects both the final value the output voltage settles to, as well as the settling time. Use the VOUT_DROOP command to select the DC load line.
- Integration Time Constant - In order to maintain DC accuracy, the control loop includes an integration stage. Use MFR_SPECIFIC_07 to select the integration time constant.
- Integration Path Gain - The gain of the integration and AC paths may be selected independently. The AC and DC gains both affect the small-signal bandwidth of the converter. Use MFR_SPECIFIC_07 to select the integration path gain.
- AC Load Line - Selects the AC response to output voltage error. The AC load line affects the settling and response time following a load transient event. Use the MFR_SPECIFIC_07 command to select the AC load line.
- AC Path Gain - The gain of the integration and AC paths may be selected independently. The AC and DC gains both affect the small-signal bandwidth of the converter. Use MFR_SPECIFIC_07 to select the AC path gain.
- Ramp Amplitude - Smaller ramp settings result in faster response, but may also lead to increased frequency jitter. Likewise, large ramp settings result in lower frequency jitter, but may be slightly slower to respond to changing conditions. The ramp setting also affects the small-signal bandwidth of the converter. Use MFR_SPECIFIC_14 to select the ramp heigh setting.