LTC6995-1 Datasheet, PDF (1/28 Pages) Linear Technology – TimerBlox: 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
= ^{NDIV • RSET}
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/6995
699512f
1