stm1404c STMicroelectronics, stm1404c Datasheet - Page 14

• Manufacturer Part Number: stm1404c
• Description: Security Supervisor With Battery Switchover
• Manufacturer: STMicroelectronics

V
V
Note:
V
V
V
14/36
OUT
TPU
CC
BAT
SS
This is the Supply Voltage Output. When V
Voltage), V
V
(~2.4V), or V
connected externally to a capacitor that will retain a charge for a period of time, in case an
intruder forces V
terminal of the battery to the V
capacitor.
Three variations of parts will be offered with the following options:
1.
2.
3.
For STM1404B and STM1404C, this pin provides pull-up voltage for the physical tamper
pins (TP1-4). This pin is not to be used as voltage supply source for any other purpose.
V
This is the Supply voltage (2.2V to 3.6V).
This is the secondary (backup battery) supply voltage. The pin is connected to the positive
terminal of the battery with a rectifying diode like the BAT54J from STMicroelectronics for
reverse charge protection. Voltage at this pin, after diode rectification, will be approximately
0.2V less than the battery voltage, and will depend on the type of battery used as well as the
I
required.) If no battery is used, connect the V
Ground, V
BAT
CC
TPU
being drawn. (A capacitor of at least 1.0µF connected between the V
through a p-channel MOSFET switch. When V
STM1404A: V
operate in normal mode (see
STM1404B: V
High when this occurs; and
STM1404C: V
High when this occurs.
is the internally switched supply voltage from either the V
SS
OUT
, is the reference for the power supply. It must be connected to system ground.
BAT
is supplied from V
, V
CC
OUT
OUT
OUT
OUT
or V
is supplied from V
remains ON when SAL is active-low; Vccsw pin will continue to
is taken to High-Z when SAL is active-low; Vccsw pin will be set to
is driven to Ground when SAL is active-low; Vccsw pin will be set to
BAT
to Ground. The rectifying diode connected from the positive
BAT
CC
pin of the STM1404 will prevent discharge of the
Section : Vccsw, V
. In this condition, V
BAT
CC
. It is recommended that the V
BAT
rises above V
pin to the V
CC
CC
falls below the lower value of V
OUT
switch output on page
SO
may be connected externally to
CC
CC
(Battery Backup Switchover
pin.
pin or the V
BAT
OUT
pin and V
BAT
pin be
12);
pin.
SW
SS
is