M41ST87WMX6TR STMicroelectronics, M41ST87WMX6TR Datasheet - Page 25

• Manufacturer Part Number: M41ST87WMX6TR
• Description: IC SUPERVISOR RTC 160X8 28-SOIC
• Manufacturer: STMicroelectronics
• Type: Clock/Calendar/Supervisorr

Specifications of M41ST87WMX6TR

• 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)
• Bus Type: Serial (2-Wire, I2C)
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (max): 3.6V
• Operating Supply Voltage (min): 2.7V
• Operating Temperature Classification: Industrial
• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Pin Count: 28
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6457-2; M41ST87WMX6TR

M41ST87Y, M41ST87W
Note:
2.8
Note:
Note:
2.9
tamper connect mode bit (TCM
the tamper pin will be triggered by being connected to V
V
external switch is closed, the tamper bit will be immediately set, allowing the user to
determine if the device has been physically tampered with. If the selected switch mode is
normally closed (TCM
V
as a result of opening the external switch.
When a tamper event occurs, the tamper bits (TB1 and/or TB2) will be immediately set if
TEB
If the tamper interrupt enable bit (TIE
The IRQ/OUT output is cleared by a READ of the flags register (as seen in
page
In order to avoid an inadvertent activation of the IRQ/OUT pin due to a prior tamper event,
the flag register (0Fh) should be read prior to resetting the TEB
The tamper bits are “read only” bits and are reset only by writing the tamper enable bit
(TEB
The tamper detect function operates both under normal power, and in battery backup. Even
if the trigger event occurs during a power-down condition, the bit will be set correctly.
Sampling
As the switch mode normally closed (TCM
maintain constant monitoring, the M41ST87Y/W offers a programmable tamper detect
sampling bit (TDS
page
approximately 1 ms.
When TEB
tamper event has been detected, no additional current will be drawn.
The oscillator must be running for tamper detection to operate in the sampling mode. If the
oscillator is stopped, the tamper detection circuit will revert to constant monitoring.
Sampling in the tamper high mode (TPM
connecting the TPX
monitoring when V
on page
Internal tamper pull-up/down current
Depending on the capacitive and resistive loading of the tamper pin input (TP
may require more or less current from the internal pull-up/down used when monitoring the
normally closed switch mode. The state of the tamper current hi/tamper current low bit
(TCHI/TCLO
1 M
(see
OUT
CC
X
(if the TPM
Figure 17 on page
X
33), a reset of the TIE bit to '0,' or the RST output is enabled.
22). When enabled, the sampling frequency is once per second (1Hz), for
(depending on the state of the TPM
= '1.'
pull-up/-down resistor, while TCHI/TCLO
) to '0.'
19).
X
X
is disabled, no current will be drawn by the tamper detection circuit. After a
) determines the sizing of the internal pull-up/-down. TCHI/TCLO
X
bit is set to '1'), through the closing of the external switch. When the
X
CC
) to reduce the current drawn on V
IN
X
is “on” and revert to sampling when in battery backup (see
pin to V
= '0'), the tamper pin will be triggered by being pulled to V
23).
CC
X
). If the selected switch mode is normally open (TCM
through an external resistor. This will allow constant
X
) is set to a '1,' the IRQ/OUT pin will also be activated.
X
X
X
bit), through an internal pull-up/pull-down resistor
= '1') may be bypassed while on V
= '0') requires a greater amount of current to
X
= '0' uses a 10 M
CC
SS
or V
(if the TPM
BAT
X
(see
bit.
pull-up/-down resistor
X
Figure 16 on
bit is set to '0') or to
Operating modes
Figure 23 on
CC
XIN
X
= '1' uses a
by
), the user
Figure 13
SS
X
or to
= '1'),
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