SLVS613D October 2005 – December 2015 TPS65021
PRODUCTION DATA.
For a supply voltage on pins Vcc, VINDCDC1, VINDCDC2, and VINDCDC3 below 3.0 V, TI recommends enabling the DCDC1, DCDC2 and DCDC3 converters in sequence. If all 3 step-down converters are enabled at the same time while the supply voltage is close to the internal reset detection threshold, a reset may be generated during power-up. Therefore TI recommends enabling the DC-DC converters in sequence. This can be done by driving one or two of the enable pins with a RC delay or by driving the enable pin by the output voltage of one of the other step-down converters. If a voltage above 3.0 V is applied on pin VBACKUP while VCC and VINDCDCx is below 3.0 V, there is no restriction in the power-up sequencing as VBACKUP is used to power the internal circuitry.