VN5E160ASOTR-E datasheet(27/37 Pages) STMICROELECTRONICS

27 / 37 page

VN5E160ASO-E

Application information

Doc ID 022475 Rev. 5

27/37

3.4.1

Short to VCC and OFF-state open-load detection

Short to VCC

A short-circuit between VCC and output is indicated by the relevant current sense pin set to

VSENSEH during the device OFF-state. Little or no current is delivered by the current sense

during the ON-state depending on the nature of the short-circuit.

OFF-state open-load with external circuitry

Detection of an open-load in off-mode requires an external pull-up resistor (RPU) connecting

the output to a positive supply voltage (VPU).

It is preferable that VPU is switched-off during the module standby mode to avoid an

increase in overall standby current consumption in normal conditions, that is, when the load

is connected.

An external pull-down resistor (RPD) connected between output and GND is mandatory to

avoid misdetection in case of floating outputs in OFF-state (see Figure 33: Current sense

and diagnostic).

RPD must be selected in order to ensure VOUT < VOLmin unless pulled up by the external

circuitry:

Equation 3

RPD ≤ 22 KΩ is recommended.

For proper open load detection in OFF-state, the external pull-up resistor must be selected

according to the following formula:

Equation 4

For the values of VOLmin ,VOLmax, IL(off2)r and IL(off2)f (see Table 10: Open-load detection (8 V

< VCC < 18 V).

VN5E160ASOTR-E Datasheet(PDF) 27 Page - STMicroelectronics