Functional description

L9758

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Doc ID 14273 Rev 3

external resistor divider at the feedback pin (VCORE_FDBK).

Once programmed to a value at power-up, this value cannot change during the power cycle.

the product.

All the linear regulators start with a controlled slew rate when the pre-regulated voltage

linear regulator are short circuit protected with a limited current.

5.4

Tracking regulators

Four low drop-out tracking regulators (VSA, VSB, VSC and VSD) are supplied by the output

of the switching pre-regulator. They track the output voltage of the VDD5 linear regulator

with the accuracy as specified in the electrical characteristic table.

The VSA regulator also tracks an external voltage reference (TRACK_REF pin) and the

tracking voltage is selected by the REF_SEL pin.

tracked. There is an internal pull-down on REF_SEL.

The tracking supplies are intended to drive loads that are external to the ECU so they are

short circuit protected with the current limited. The outputs of the tracking regulators also

withstand short circuit to the battery.

A short circuit to GND, continuous or intermittent on one tracking supply will not affect any

all sensor supplies shall be capable of operating with up to a 15µF load on the supply line.

This load may be present during initial startup, or be applied after the supply has been

powered up. In either case, the application of this load shall not cause the tracking

regulators to be permanently disabled.

VSB, VSC and VSD regulators can be disabled with VS_EN pin.

5.5

VKAM and VSTBY linear regulators

These two outputs are fully integrated low quiescent current low drop out regulators. The

input VBAT is used as the source of these supplies. These outputs are operational during

present).

The VKAM regulator has two programmable levels: 1.0V (VPROG1 pin connected to GND)

or 1.5V (if this pin is left open, an internal pull-up is present).

or 3.3V (if this pin is left open, an internal pull-up is present).

indicated in the electrical characteristic table). Once driven low it should stay low for a

minimal amount of time allowing external circuitry to latch.