VN7040AS datasheet(31/55 Pages) STMICROELECTRONICS

31 / 55 page

VN7040AJ, VN7040AS

Application information

DocID027400 Rev 3

31/55

4.3

MCU I/Os protection

If a ground protection network is used and negative transients are present on the VCC line,

the control pins will be pulled negative. ST suggests to insert a resistor (Rprot) in line both to

prevent the microcontroller I/O pins from latching-up and to protect the HSD inputs.

The value of these resistors is a compromise between the leakage current of

microcontroller and the current required by the HSD I/Os (Input levels compatibility) with

the latch-up limit of microcontroller I/Os.

Equation

VCCpeak/Ilatchup ≤ Rprot ≤ (VOHµC - VIH - VGND) / IIHmax

Calculation example:

For VCCpeak = -150 V; Ilatchup ≥ 20 mA; VOHµC ≥ 4.5 V

7.5 kΩ ≤ Rprot ≤ 140 kΩ.

Recommended values: Rprot = 15 kΩ

4.4

Multisense - analog current sense

Diagnostic information on device and load status are provided by an analog output pin

(MultiSense) delivering the following signals:

•

Current monitor: current mirror of channel output current

•

VCC monitor: voltage propotional to VCC

•

TCASE: voltage propotional to chip temperature

Those signals are routed through an analog multiplexer which is configured and controlled

by means of SELx and SEn pins, according to the address map in MultiSense multiplexer

addressing Table.

VN7040AS 数据表(PDF) 31 Page - STMicroelectronics