SPSB081 datasheet(26/137 Pages) STMICROELECTRONICS

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DIAGN pin can be directly connected to the microcontroller and it is pulled up to V1 voltage by internal pull-up

resistor.

DIAGN pin can be configured by DIAGN_EXT bit in normal mode or extended mode.

In default DIAGN configuration (DIAGN_EXT = 0), DIAGN pin is set low if a failure considered in fail safe mode

occurs (for example, watchdog failure; V1 failure; thermal shutdown TSD2).

As soon as the FS error source is cleared, the signal is pulled up to V1 voltage.

In extended DIAGN configuration (DIAGN_EXT = 1), DIAGN pin reflects one or more errors such as reported

in the GLOBAL STATUS BYTE register by global status bit not (GSBN) and it is set to low if at least one error

condition occurs.

A bit register is available to mask each one of GSBN flags:

•

RSTB: MASK_RSTB (0x3F)

•

PLE: MASK_PLE (0x3F)

•

FE: MASK_FE (0x3F)

•

DE: MASK_DE (0x3F)

•

GW: MASK_GW (0x3F)

Note:

DIAGN is automatically configured in normal mode (DIAGN_EXT = 0) after a reset event.

3.10

V1 overvoltage detection

SPSB081 protects the MCU against voltages over 5 V (or 3.3 V) that could harm its functionalities. For this

purpose, to sink the exceeding current accumulated in the external capacitor usually directed to the MCU, the

SPSB081 uses an internal pulldown circuit, where output current flows through the pulldown resistor to ground. If

the bit V1_OVP = 1 in CR2 the overvoltage protection circuits is enabled. If V1_OVP = 0 there is no overvoltage

protection anymore.

Figure 16. Overvoltage protection on V1

Two thresholds run the overvoltage event.

When SPSB081 detects an overvoltage event on the V1 pin:

•

If V1OV_TH1≤ V1 < V1OV_TH2 → V1_OV status flag is raised after tFILTER1 and in the same time NINT is

pulled low for 56 μs.

SPSB081

V1 overvoltage detection

DS14048 - Rev 3

page 26/137

SPSB081 датащи(PDF) 26 Page - STMicroelectronics