Datasheet

Power sequencing L6460
44/139 Doc ID 17713 Rev 1
9 Power sequencing
As soon as V
Supply
and V
SupplyInt
are above their power on reset level, L6460 will start the
charge pump circuit; once V
Pump
voltage reaches its under voltage rising threshold, L6460
begins a sequence that starts the regulators considered system regulators.
A regulator is considered a System regulator if:
– It has to start in on state without any user action.
– It is included in the power-up sequence.
– Its under-voltage event is considered by L6460 as an error condition to be
signaled through nRESET pin.
Once V
Supply
and V
SupplyInt
, V
Pump
and all the system regulators are over their under
voltage rising threshold, L6460 enters in the normal operating state, that will release
nRESET pin and will wait for SPI commands.
L6460 will reduce the noise introduced in the system by switching out of phase all its power
circuits (switching regulators, bridges and charge pump).
The L6460's startup sequence of operation is the following:
– start V
3v3
internal linear regulator
– sample startup configuration
– wait enable if slave device
– start charge pump
– start system regulators (see order in Section 8.6)
– if master send enable to slave device
– wait until V
GPIO_SPI
becomes ok