ZHCSJW0D June 2019 – March 2020 TPS62840
The TPS6284x includes the STOP input pin, allowing the user to temporarily stop the switching of the regulator. The STOP pin function does not depend on the setting of the MODE pin. The STOP pin is only present on the DLC package.
When a logic high level is applied to the STOP pin, the regulator is forced to stop switching after the current switching cycle. The application is powered by the charge available in the output capacitor. No switching noise is generated, which can be beneficial in noise-sensitive sampled applications.
An MCU controlling this pin needs to take care to turn the device back on before the output voltage reaches a system critical level. Should this not happen, the output voltage is clamped to about 0.5 V below the set output voltage. In STOP mode, the device consumes typically 70 µA operating quiescent current from the input supply.
When a logic low level is applied to the STOP pin, the regulator immediately resumes switching operation without a start-up delay or soft start. To avoid a floating input, an internal 450-kΩ resistor pulls the STOP pin to GND. A control circuit disconnects the pulldown resistor at the STOP pin once a high level has been detected (similar to the EN pin).