LTC695CSW-3.3#PBF Linear Technology, LTC695CSW-3.3#PBF Datasheet - Page 15

• Manufacturer Part Number: LTC695CSW-3.3#PBF
• Description: IC MPU SUPRVSRY CIRC 3.3V 16SOIC
• Manufacturer: Linear Technology
• Type: Simple Reset/Power-On Resetr

Specifications of LTC695CSW-3.3#PBF

• Number Of Voltages Monitored: 1
• Output: Open Drain or Open Collector
• Reset: Active High/Active Low
• Reset Timeout: 140 ms Minimum
• Voltage - Threshold: 2.9V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (0.300", 7.5mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

TYPICAL APPLICATION
Table 2. LTC695-3.3 Reset Active Time and Watchdog Timeout Selections
*The nominal internal frequency is 10.24kHz. The nominal oscillator frequency with external capacitor is f
TYPICAL APPLICATION
the internal oscillator is enabled and the reset active time
is fixed at 140ms minimum for the LTC695-3.3. OSC IN
selects between the 1 second and 70ms minimum normal
watchdog timeout periods. In both cases, the timeout period
immediately after a reset is at least 1 second.
Push-Button Reset
The LTC694-3.3/LTC695-3.3 do not provide a logic input
for direct connection to a push-button. However, a push-
button in series with a 100Ω resistor connected to the
RESET output pin (Figure 13) provides an alternative for
manual reset. Connecting a 0.1μF capacitor to the RESET
pin debounces the push-button input.
Floating or High
Floating or High
OSC SEL
Low
Low
External Clock Input
External Capacitor*
Floating or High
OSC IN
Low
R1
10k
R2
30k
1
Capacitor Back-Up with 74HC4016 Switch
7
10
74HC4016
11
12
NORMAL (SHORT PERIOD)
13
14
100μF
0.1μF
3.3V
2
1024 CLKs
400ms
+
70pF
1.6 sec
100ms
The 100Ω resistor in series with the push-button is re-
quired to prevent the ringing, due to the capacitance and
lead inductance, from pulling the RESET pins of the MPU
and LTC69X below ground.
WATCHDOG TIMEOUT PERIOD
• C
V
V
CC
BATT
3.3V
LTC695-3.3
GND
LOW LINE
LTC694-3.3/LTC695-3.3
Figure 13. The External Push-Button Reset
V
CC
V
LTC694-3.3
LTC695-3.3
OUT
RESET (LONG PERIOD)
GND
IMMEDIATELY AFTER
RESET
OSC
4096 CLKs
694/5-3.3 TA03
70pF
1.6s
1.6 sec
1.6 sec
0.1μF
(Hz) =
• C
C(pF) • 1025
0.1μF
184,000
100Ω
RESET ACTIVE TIME
LTC695-3.3
2048 CLKs
800ms
70pF
RESET
(e.g. 68HC05)
200ms
200ms
MPU
694/5-3.3 F13
• C
15
69453fb