5

Multisense operation

5.1

Multisense analog current monitoring

Diagnostic information on device and load status is provided by an analog output pin (Multisense) delivering the

current mirror of high-side output current.

The signal is routed through an analog multiplexer, which is configured and controlled by means of SELx pins,

according to the address map in Multisense multiplexer addressing table.

5.1.1

Current sense signal generation principle

Figure 17. Current sense block diagram

INPUT

Vcc

OUT

To uC ADC

RPROT

RSENSE

Main MOS

Sense MOS

Fault

CS

Current sense Switch Block

Current sense

Current sense

The output is capable of providing:

•

Current mirror proportional to the load current in normal operation, delivering current proportional to the

load according to a known ratio named K

•

Diagnostics flag in fault conditions delivering a current ISENSEH converted into a voltage (VSENSEH) by

using an external sense resistor

The current delivered by the current sense circuit, ISENSE, can be easily converted into a voltage VSENSE by using

an external sense resistor, RSENSE, allowing continuous load monitoring and abnormal condition detection.

Normal operation (channel ON, no fault)

While the device is operating in normal conditions (no fault intervention), VSENSE calculation can be done using

simple equations.

Current provided by MultiSense output: ISENSE = IOUT/K

Voltage on RSENSE: VSENSE = RSENSE · ISENSE = RSENSE · IOUT/K

Where:

•

VSENSE is the voltage measurable on the RSENSE resistor

•

ISENSE is the current provided from current sense pin in current output mode

•

IOUT is the current flowing through output

VNH9030AQ

Multisense operation

DS13967 - Rev 8

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