M41ST87WMX6 STMicroelectronics, M41ST87WMX6 Datasheet - Page 37

• 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

M41ST87Y, M41ST87W
3.6
Note:
3.7
Note:
3.8
Note:
Full-time 32 kHz square wave output
The M41ST87Y/W offers the user a special 32 kHz square wave function which defaults to
output on the F
(ST bit = '0'). This function is available within one second (typ) of initial power-up and can
only be disabled by setting the 32 kE bit to '0' or the ST bit to '1.' If not used, the F
should be disconnected and allowed to float.
The F
Power-on reset
The M41ST87Y/W continuously monitors V
point, the RST pulls low (open drain) and remains low on power-up for t
V
be chosen to control rise time.
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
Reset inputs (RSTIN1 & RSTIN2)
The M41ST87Y/W provides two independent inputs which can generate an output reset.
The function of these resets is identical to a reset generated by a power cycle.
Figure 26
t
V
triggers on the rising edge.
RSTIN2 is available only in the SOX28 (MX) package.
Figure 26. RSTIN1 & RSTIN2 timing waveforms
R2
PFD
CC
will not generate a reset condition. RSTIN1 and RSTIN2 are each internally pulled up to
through a 100 kΩ resistor. Note that RSTIN1 triggers on the falling edge while RSTIN2
(max). The RST pin is an open drain output and an appropriate pull-up resistor should
32k
RSTIN1
RSTIN2
RST
pin is an open drain which requires an external pull-up resistor.
illustrate the AC reset characteristics of this function. Pulses shorter than t
32k
pin (pin 21) as long as V
t R1
Doc ID 9497 Rev 9
CC
CC
t rec
. When V
≥ V
Hi-Z
SO
t R2
, and the oscillator is running
CC
falls to the power fail detect trip
t rec
Table 13 on page
rec
after V
Clock operation
Hi-Z
AI07072
Table 10
CC
32k
41).
passes
R1
pin
37/54
and
and