LTC1235CS Linear Technology, LTC1235CS Datasheet - Page 7

• Manufacturer Part Number: LTC1235CS
• Manufacturer: Linear Technology

Specifications of LTC1235CS

• Number Of Elements: 1
• Monitored Voltage 1 (typ): 4.65V
• Battery Backup Switching: Yes
• Watchdog Timer: Yes
• Chip Enable Signals: Yes
• Reset Active Time: 280ms
• Manual Reset: Yes
• Package Type: SOL
• Operating Supply Voltage (min): 4.75V
• Operating Supply Voltage (max): 5.5V
• Reset Threshold Voltage (max): 4.75V
• Reset Threshold Voltage (min): 4.5V
• Power Dissipation: 500mW
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Power Fail Detection: Yes
• Mounting: Surface Mount
• Pin Count: 16
• Supply Current: 1.5mA
• Lead Free Status / Rohs Status: Not Compliant

PIN FUNCTIONS
high when ever there is a transition on the WDI pin, or
LOW LINE goes low. The watchdog timer can be disabled
by fl oating WDI (see Figure 11).
RESET (Pin 15): Logic output for μP reset control. The
LTC1235 provides three ways to generate μP reset. First,
whenever V
(4.65V, typically) or V
V
to remain active low for a minimum of 140ms. Second,
when the watchdog timer is enabled but not serviced
BLOCK DIAGRAM
CC
returns to 5V, the reset pulse generator forces RESET
CC
BACKUP
PB RST
V BATT
falls below either the reset voltage threshold
CE IN
V CC
WDI
PFI
BATT
V CC
, RESET goes active low. After
60k
1.3V
GND
LEVEL SENSE
TRANSITION
DETECTOR
DEBOUNCE
AND
+
–
–
+
C1
C2
OSC
MEMORY
LOGIC
prior to the time-out period, the reset pulse generator
also forces RESET to active low for a minimum of 140ms
for every time-out period (see Figure 11). Third, when the
PB RST pin stays active low for a minimum of 40ms,
RESET is forced low by reset pulse generator. The RESET
signal will remain active low for a minimum of 140ms from
the moment the push-button reset input is released from
logic low level.
RESET (Pin 16): RESET is an active high logic output. It
is the inverse of RESET.
–
+
RESET PULSE
M2
GENERATOR
WATCHDOG
TIMER
CHARGE
PUMP
M1
BATT ON
LOW LINE
PFO
RESET
RESET
V OUT
CE OUT
WDO
1235 BD
LTC1235
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