L99PM62XP datasheet(15/98 Pages) STMICROELECTRONICS

15 / 98 page

L99PM62XP

Description

Doc ID 16363 Rev 3

15/98

The output voltage V3 can be calculated using the following formula:

The circuit in

Figure 6 provides additional current limitation using an additional NPN

transistor and R5 which allows setting the current limit.

Alternatively, voltage regulator 1 can be used to provide the 5 V reference for this topology.

However, the additional current consumption through R3 and R4 has to be considered in

V1standby mode.

2.1.4

Voltage regulator failure

The V1, and V2 regulator output voltages are monitored.

In case of a drop below the V1, V2 – fail thresholds (V1,2 < 2 V, typ for t > 2 µs), the V1,2-fail

bits are latched. The fail bits can be cleared by a dedicated SPI command.

Short to ground detection

If 4 ms after turn on of the regulator the V1,2 voltage is below the V1,2 fail thresholds,

(independent for V1,2), the L99PM62XP identifies a short circuit condition at the related

regulator output and the regulator is switched off.

In case of V1 short to GND failure the device enters VBAT standby mode automatically. Bits

Forced VBAT STD2/SHTV1 and V1 fail were set.

In case of a V2 short to GND failure the V2short and V2 fail bit is set.

If the output voltage of the corresponding regulator once exceeded the V1,2 fail thresholds

the short to ground detection is disabled. If a short to ground condition occurs the regulator

outputs switches off due to thermal shutdown (V1 at TSD2; V2 at TSD1).

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