Datasheet
LTC6995-1/LTC6995-2
1
699512fa
For more information www.linear.com/LTC6995-1
Typical applicaTion
FeaTures DescripTion
TimerBlox: Long Timer, Low
Frequency Oscillator
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 2
21
.
t
OUT
=
N
DIV
•R
SET
50kΩ
•1.024ms, N
DIV
= 1,8,64,...,2
21
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.
OUTPUT (OSCILLATOR START STATE)
RST/RST POLARITY LTC6995-1 LTC6995-2
0 0 Oscillating (Low) 0 (Reset)
1 0 0 (Reset) Oscillating (Low)
0 1 Oscillating (High) 1 (Reset)
1 1 1 (Reset) Oscillating (High)
applicaTions
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
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, LT C, LT M, 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.
Active Low Power-On Reset Timer
LTC6995-1
0.1µF
OUT
1M
392k
118k
RST
GND
SET
OUT
V
+
DIV
V
+
V
+
699512 TA01
5 SECONDS
1/2 t
OUT
TIMER STOPPED
POWER-ON RESET
(1ms TO 4.8 HOURS)