JAJSFE5C October 2009 – May 2018 TPS65720 , TPS65721
PRODUCTION DATA.
The DCDC1 converter and LDO1 are enabled as soon as PB_IN is pulled LOW OR input voltage at pin AC is detected (<CH_PGOOD> = 1).
There is a power-hold pin for DCDC1 (HOLD_DCDC1) and one for LDO1 (HOLD_LDO1). When HOLD_DCDC1 is pulled HIGH, DCDC1 is kept enabled after PB_IN was released HIGH. HOLD_LDO1 serves the same function and keeps LDO1 enabled after PB_IN was released HIGH. After first power-up by pulling PB_IN = LOW or applying voltage at AC, the HOLD pins HOLD_DCDC1 and HOLD_LDO1 can also be used as enable pins, such that they turn on LDO1 or DCDC1, respectively when they are pulled HIGH. This function is available as long as there is a voltage at the battery. After the battery was removed or was discharged, first power-on needs to be done by pulling PB_IN = LOW.
Disabling the DC-DC converter or LDO, forces the device into shutdown, with a shutdown quiescent current as defined in Electrical Characteristics. In this mode, the low and high side MOSFETs are turned off and the entire internal control circuitry is switched-off. For proper operation the PB_IN, HOLD_DCDC1, EN_DLO1 pins must be terminated and must not be left floating.