M41ST85WMX6E STMICROELECTRONICS [STMicroelectronics], M41ST85WMX6E Datasheet - Page 20

• Manufacturer Part Number: M41ST85WMX6E
• Description: 3.0/3.3V I2C Combination Serial RTC, NVRAM Supervisor and Microprocessor Supervisor
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

M41ST85W
Power-on Reset
The M41ST85W 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.
Figure 19. RSTIN1 & RSTIN2 Timing Waveforms
Note: With pull-up resistor
Table 5. Reset AC Characteristics
Note: 1. Valid for Ambient Operating Temperature: T
20/34
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
t
t
t
t
Symbol
R1HRH
R2HRH
RLRH1
RLRH2
CC
RSTIN1
RSTIN2
RST
falls to the power fail detect trip point,
(2)
(3)
(4)
(4)
(1)
rec
after V
RSTIN1 Low to RSTIN1 High
RSTIN2 Low to RSTIN2 High
RSTIN1 High to RST High
RSTIN2 High to RST High
Table 6., page
CC
passes V
Parameter
22).
tRLRH1
tR1HRH
PFD
A
= –40 to 85°C; V
(1)
(max).
CC
.
tRLRH2
CC
Reset Inputs (RSTIN1 & RSTIN2)
The M41ST85W 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.
19.
function. Pulses shorter than t
will not generate a reset condition. RSTIN1 and
RSTIN2 are each internally pulled up to V
through a 100k
= 2.7 to 3.6V (except where noted).
illustrate the AC reset characteristics of this
Min
200
100
40
40
tR2HRH
resistor.
Max
200
200
Table 5.
RLRH1
AI03665
and t
and
Unit
ms
ms
ms
ns
Figure
RLRH2
CC