M41T94 datasheet(21/31 Pages) STMICROELECTRONICS

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M41T94

Power-on Reset

The M41T94 continuously monitors VCC. When

VCC falls to the power fail detect trip point, the RST

pulls low (open drain) and remains low on power-

up for tREC after VCC passes VPFD (max). The RST

pin is an open drain output and an appropriate

pull-up resistor should be chosen to control rise

time.

Reset Inputs (RSTIN1 & RSTIN2)

The M41T94 provides two independent inputs

which can generate an output reset. The duration

and function of these resets is identical to a reset

generated by a power cycle. Table 13, page 21

and Figure 17, page 21 illustrate the AC reset

characteristics of this function. Pulses shorter than

tRLRH1 and tRLRH2 will not generate a reset condi-

tion. RSTIN1 and RSTIN2 are each internally

pulled up to VCC through a 100kΩ resistor.

Figure 17. RSTIN1 and RSTIN2 Timing Waveforms

Table 13. Reset AC Characteristics

Note: 1. Valid for Ambient Operating Temperature: TA = –40 to 85°C; VCC = 2.7 to 5.5V (except where noted).

2. Pulse width less than 50ns will result in no RESET (for noise immunity).

3. Pulse width less than 20ms will result in no RESET (for noise immunity).

4. Programmable (see Table 14, page 23).

Symbol

Parameter(1)

Min

Max

Unit

tRLRH1

(2)

RSTIN1 Low to RSTIN1 High

200

tRLRH2

(3)

RSTIN2 Low to RSTIN2 High

100

tR1HRH

(4)

RSTIN1 High to RST High

200

tR2HRH

(4)

RSTIN2 High to RST High

200

AI03665

RSTIN2

RST

(1)

RSTIN1

tRLRH1

tRLRH2

tR1HRH

tR2HRH

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