SLVSFT8F February 2023 – December 2023 TPS7H1111-SEP , TPS7H1111-SP
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
It is recommended to compensate the TPS7H1111 by utilizing compensation as shown in Figure 8-7 with CCOMP = 4.7 nF and RCOMP = 5 kΩ. CHF is not required.
However, if a different control loop response is desired, or if a different output capacitance, ESL, or ESR is used, a different compensation network may be needed. The error amplifier is an OTA (operational transconductance amplifier); therefore, traditional compensation techniques for OTAs may be employed. While TI has found its recommended type I compensation works best, an example of a type II compensation is shown in Figure 8-7.
Note that unlike in linear regulators that use a resistive voltage divider fed to a feedback pin, a feed forward capacitor (CFF) cannot be used to modify the control loop. For resistive voltage divider LDOs, a feed forward capacitor essentially provides a high frequency short between the output voltage and the feedback pin. However, in the TPS7H1111 architecture, there is no voltage divider and instead the output voltage is fed directly to the negative input terminal of the error amplifier. Since the error amplifier operates in a unity gain configuration, it inherently obtains the potential benefits of reduced noise and increased PSRR that a feed forward capacitor would typically provide.