STM32F769AI datasheet(168/255 Pages) STMICROELECTRONICS

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Electrical characteristics

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DocID029041 Rev 4

5.3.21

NRST pin characteristics

The NRST pin input driver uses CMOS technology. It is connected to a permanent pull-up

resistor, RPU (see Table 65: I/O static characteristics).

Unless otherwise specified, the parameters given in Table 68 are derived from tests

performed under the ambient temperature and VDD supply voltage conditions summarized

in Table 17.

Figure 40. Recommended NRST pin protection

1. The reset network protects the device against parasitic resets.

2. The user must ensure that the level on the NRST pin can go below the VIL(NRST) max level specified in

Table 68. Otherwise the reset is not taken into account by the device.

Table 68. NRST pin characteristics

Symbol

Parameter

Conditions

Min

Typ

Max

Unit

RPU

Weak pull-up equivalent resistor(1)

VIN = VSS

VF(NRST)(2) NRST Input filtered pulse

100

VNF(NRST)(2) NRST Input not filtered pulse

VDD > 2.7 V

300

TNRST_OUT Generated reset pulse duration

Internal Reset source

μs

1. The pull-up is designed with a true resistance in series with a switchable PMOS. This PMOS contribution to the series

resistance must be minimum

(~10% order)

2. Guaranteed by design.

STM32F769AI Datasheet(PDF) 168 Page - STMicroelectronics