M41ST87WMX6 STMicroelectronics, M41ST87WMX6 Datasheet - Page 38

• Manufacturer Part Number: M41ST87WMX6
• Description: IC SUPERVISOR RTC 160X8 28-SOIC
• Manufacturer: STMicroelectronics
• Type: Clock/Calendar/Supervisorr

Specifications of M41ST87WMX6

• Memory Size: 160B
• Time Format: HH:MM:SS:hh (24 hr)
• Date Format: YY-MM-DD-dd
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 2.7 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-SOIC, 28-SOH (8.48mm Width)
• Function: Clock/Calendar/Alarm/Timer Interrupt
• Rtc Memory Size: 160 Byte
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 2.7 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Rtc Bus Interface: Serial (2-Wire, I2C)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-5370-5; M41ST87WMX6

Clock operation
3.9
3.10
Note:
38/54
Table 10.
1. Valid for ambient operating temperature: T
2. Pulse widths of less than 100 ns will result in no RESET (for noise immunity).
3. Programmable (see
Power-fail comparators (1 and 2)
Two power-fail inputs (PFI
If either PFI
output (PFO
detector to signal a failing power supply. Typically PFI
external voltage dividers (see
available) or the regulated output of the V
such that the voltage at PFI
regulated V
operating voltage, thus providing an early warning of power failure.
During battery back-up, the power-fail comparator turns off and PFO
remain) low. This occurs after V
PFO
from V
comparator is enabled and PFO
unused, PFI
unconnected.
Power-fail outputs
The PFO
full-CMOS output drivers. By setting the power-fail output open drain bit (PFOD) to a '1,' the
output will be configured as open drain (with I
PFOD is set to '0,' the outputs will be configured as full-CMOS (sink and source current as
specified in
When configured as open drain (PFOD = '1'), PFO
up resistor.
where noted).
Symbol
2
t
t
t
R1
R2
rec
are forced high, irrespective of V
PFD
(2)
(2)
(3)
1
(max) until the inputs are recognized. At the end of this time, the power-fail
and PFO
CC
1
Table 17 on page
1
1
Reset AC characteristics
or PFI
or PFI
or PFO
input to the M41ST87Y/W or the microprocessor drops below the minimum
RSTIN1 low to RST low (min pulse width)
RSTIN2 low to RSTIN2 high (min pulse width)
RSTIN1 or RSTIN2 high to RST high
2
Table 12 on page
2
2
is less than the power-fail threshold (V
2
outputs are programmable as N-channel, open drain output drivers, or
should be connected to V
) will go low. This function is intended for use as an under-voltage
1
and PFI
1
or PFI
Figure 5 on page
23).
Doc ID 9497 Rev 9
CC
1
Parameter
and PFO
40). Same function as power-on reset.
2
drops below V
2
) are compared to an internal reference voltage (1.25V).
falls below V
A
= –40 to 85 °C; V
PFI
CC
for the write protect time (t
2
(1)
follow PFI
regulator. The voltage divider can be set up
OL
SS
11) to either the unregulated DC input (if it is
as specified in
PFD
PFI
and the associated PFO
1
and PFO
CC
(min). When power returns, PFO
several milliseconds before the
1
1
and PFI
= 4.5 to 5.5 V or 2.7 to 3.6 V (except
and PFI
PFI
2
), the associated power-fail
2
Table 17 on page
will require an external pull-
2
are connected through
. If the comparator is
Min
100
100
96
M41ST87Y, M41ST87W
1
rec
and PFO
), which is the time
1
or PFO
98
Max
200
200
2
(3)
go (or
44). When
2
left
1
Unit
ms
ns
ns
and