SBVS038V September 2003 – September 2024 TPS736
PRODUCTION DATA
The TPS736 uses an NMOS pass transistor to achieve extremely low dropout. When (VIN – VOUT) is less than the dropout voltage (VDO), the NMOS pass transistor is in the linear region of operation and the input-to-output resistance is the RDS(on) of the NMOS pass transistor.
For large step changes in load current, the TPS736 requires a larger voltage drop from VIN to VOUT to avoid degraded transient response. The boundary of this transient dropout region is approximately twice the dc dropout. Values of VIN – VOUT above this line ensure normal transient response.
Operating in the transient dropout region can cause an increase in recovery time. The time required to recover from a load transient is a function of the magnitude of the change in load current rate, the rate of change in load current, and the available headroom (VIN to VOUT voltage drop). Under worst-case conditions [full-scale instantaneous load change with (VIN – VOUT) close to dc dropout levels], the TPS736 can take a couple of hundred microseconds to return to the specified regulation accuracy.