LTC6995-2_15 Datasheet, PDF (1/28 Pages) Linear Technology – Long Timer, Low Frequency Oscillator

Features
n _{Period Range: 1ms to 9.5 Hours}
n _{Timing Reset by Power-On or Reset Input}
n _{Configured with 1 to 3 Resistors}
n _{<1.5% Maximum Frequency Error}
n _{Programmable Output Polarity}
n _{2.25V to 5.5V Single Supply Operation}
n _{55µA to 80µA Supply Current}
(2ms to 9.5hr Clock Period)
n _{500µs Start-Up Time}
n _{CMOS Output Driver Sources/Sinks 20mA}
n _{–55°C to 125°C Operating Temperature Range}
n _{Available in Low Profile (1mm) SOT-23 (ThinSOT™)}
and 2mm × 3mm DFN Packages
Applications
n _{Power-On Reset Timer}
n _{Long Time One Shot}
n _{“Heartbeat” Timers}
n _{Watchdog Timers}
n _{Periodic “Wake-Up” Call}
n _{High Vibration, High Acceleration Environments}
L, LT, LTC, LTM, Linear Technology, TimerBlox and the Linear logo are registered trademarks
and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
LTC6995-1/LTC6995-2
TimerBlox: Long Timer, Low
Frequency Oscillator
Description
The LTC^®6995 is a silicon oscillator with a programmable
period range of 1.024ms to 9.54 hours (29.1µHz to 977Hz),
specifically intended for long duration timing events. The
LTC6995 is part of the TimerBlox^® family of versatile
silicon timing devices.
A single resistor, R_SET , programs the LTC6995’s internal
master oscillator frequency. The output clock period
is determined by this master oscillator and an internal
frequency divider, N_DIV , programmable to eight settings
from 1 to 2²¹.
t_OUT
=
N_DIV •R_SET
50kΩ
• 1.024ms,
N_DIV
= 1,8,64,...,2²¹
When oscillating, the LTC6995 generates a 50% duty
cycle square wave output. A reset function is provided
to stop the master oscillator and clear internal dividers.
Removing reset initiates a full output clock cycle which is
useful for programmable power-on reset and watchdog
timer applications.
The LTC6995 has two versions of reset functionality. The
reset input is active high for the LTC6995-1 and active low
for the LTC6995-2. The polarity of the output when reset
is selectable for both versions.
RST/RST
0
1
0
1
POLARITY
0
0
1
1
OUTPUT (OSCILLATOR START STATE)
LTC6995-1
LTC6995-2
Oscillating (Low)
0 (Reset)
0 (Reset)
Oscillating (Low)
Oscillating (High)
1 (Reset)
1 (Reset)
Oscillating (High)
Typical Application
Active Low Power-On Reset Timer
RST
OUT
LTC6995-1
GND
V⁺
SET
DIV
118k
V⁺
V⁺
1M
0.1µF
OUT
392k
5 SECONDS
1/2 t_OUT
POWER-ON RESET
(1ms TO 4.8 HOURS)
TIMER STOPPED
699512 TA01
For more information www.linear.com/LTC6995-1
699512fa
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