UM1693 datasheet(13/196 Pages) STMICROELECTRONICS

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UM1693

General items

195

1.3

Application schematics – hybrid devices

Figure 2. Typical application schematics – hybrid devices

1.4

Application schematics – description of external

components

•

Pull-up: this resistor is optional and is needed when open-load in off state diagnostic is

required. It has to be dimensioned to pull up the output above the maximum open-load

in off state detection voltage (VOL max) and make sure that the output voltage stays

below the minimum open-load in off state detection voltage (VOL min) in case the load is

connected (for details refer to Section 7.2.11: Open load detection in off-state).

•

R5//CEXT: a low pass-filter, as an RC filter, can be placed across the RSENSE resistor to

suppress HF noise. The time constant of this filter (

τ = RC) should be long enough to

effectively suppress the noise and short enough to allow MultiSense signal stabilization

taking into account multiplexer delay and settling times. C2 should be placed close to

the MCU's A/D input. Also, the ground connection for C2 should be at the same

potential as the ground of the A/D reference. The filter resistor R5 is also used to limit

the A/D's input pin current (for details refer to Section 7.2.13: MultiSense low pass

filtering).

•

R6//CEXT: this low pass-filter and ADC input connection is optional and is

recommended for monolithic devices, when a precise chip temperature or supply

UM1693 Datasheet(PDF) 13 Page - STMicroelectronics