m41st87w STMicroelectronics, m41st87w Datasheet - Page 31

• Manufacturer Part Number: m41st87w
• Description: 5.0, 3.3, Or 3.0v, 1280 Bit 160 X8 Secure Serial Rtc And Nvram Supervisor With Tamper Detection
• Manufacturer: STMicroelectronics

Power-on Reset
The M41ST87Y/W continuously monitors V
When V
the RST pulls low (open drain) and remains low on
power-up for t
The RST pin is an open drain output and an appro-
priate pull-up resistor should be chosen to control
rise time.
Note: A Power-on Reset will result in resetting the
following control bits to '0': OFIE, AFE, ABE,
SQWE, FT, WDS, BMB0-BMB4, RB0, RB1, TIE1,
and TIE2 (see
Figure 26. RSTIN1 & RSTIN2 Timing Waveforms
Table 10. Reset AC Characteristics
Note: 1. Valid for Ambient Operating Temperature: T
2. Pulse widths of less than 100ns will result in no RESET (for noise immunity).
3. Programmable (see
Symbol
t
t
t
rec
R1
R2
CC
(2)
(2)
(3)
falls to the power fail detect trip point,
Table 13., page
RSTIN1
RSTIN2
RST
rec
after V
RSTIN1 Low to RST Low (min pulse width)
RSTIN2 Low to RSTIN2 High (min pulse width)
RSTIN1 or RSTIN2 High to RST High
Table 12., page
CC
tR1
passes V
34).
33). Same function as Power-on Reset.
Parameter
PFD
A
= –40 to 85°C; V
(max).
CC
(1)
.
trec
CC
Reset Inputs (RSTIN1 & RSTIN2)
The M41ST87Y/W provides two independent in-
puts which can generate an output reset. The
function of these resets is identical to a reset gen-
erated by a power cycle. Table
illustrate the AC reset characteristics of this func-
tion. Pulses shorter than t
ate a reset condition. RSTIN1 and RSTIN2 are
each internally pulled up to V
resistor.
Hi-Z
tR2
= 4.5 to 5.5V or 2.7 to 3.6V (except where noted).
trec
Min
100
100
96
M41ST87Y, M41ST87W
R1
Hi-Z
and t
AI07072
CC
98
Max
200
200
10
through a 100k
R2
(3)
and Figure
will not gener-
Unit
ms
ns
ns
31/42
26