LTC6995-1/LTC6995-2
TimerBlox: Long Timer, Low
Frequency Oscillator
FeaTures
DescripTion
The LTC®6995 is a silicon oscillator with a programmable
periodrangeof1.024msto9.54hours(29.1µHzto977Hz),
specifically intended for long duration timing events. The
LTC6995 is part of the TimerBlox® family of versatile
silicon timing devices.
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Period Range: 1ms to 9.5 Hours
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Timing Reset by Power-On or Reset Input
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Configured with 1 to 3 Resistors
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<1.5% Maximum Frequency Error
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Programmable Output Polarity
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2.25V to 5.5V Single Supply Operation
A single resistor, R , programs the LTC6995’s internal
SET
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55µA to 80µA Supply Current
master oscillator frequency. The output clock period
is determined by this master oscillator and an internal
(2ms to 9.5hr Clock Period)
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500µs Start-Up Time
frequency divider, N , programmable to eight settings
DIV
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CMOS Output Driver Sources/Sinks 20mA
21
from 1 to 2 .
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–55°C to 125°C Operating Temperature Range
NDIV •RSET
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Available in Low Profile (1mm) SOT-23 (ThinSOT™)
tOUT
=
•1.024ms, NDIV = 1,8,64,...,221
and 2mm × 3mm DFN Packages
50kΩ
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.
applicaTions
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Power-On Reset Timer
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Long Time One Shot
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“Heartbeat” Timers
Watchdog Timers
Periodic “Wake-Up” Call
High Vibration, High Acceleration Environments
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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.
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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.
OUTPUT (OSCILLATOR START STATE)
RST/RST POLARITY
LTC6995-1
Oscillating (Low)
0 (Reset)
LTC6995-2
0 (Reset)
0
1
0
1
0
0
1
1
Oscillating (Low)
1 (Reset)
Oscillating (High)
1 (Reset)
Oscillating (High)
Typical applicaTion
Active Low Power-On Reset Timer
+
RST
GND
SET
OUT
V
LTC6995-1
+
+
V
V
5 SECONDS
1/2 t
0.1µF
OUT
TIMER STOPPED
1M
OUT
DIV
POWER-ON RESET
(1ms TO 4.8 HOURS)
118k
392k
699512 TA01
699512f
1
For more information www.linear.com/6995