LTC1843_15 Datasheet, PDF (1/12 Pages) Linear Technology – Ultralow Power Dual Comparators with Reference

LTC1841/LTC1842/LTC1843
Ultralow Power Dual
Comparators with Reference
FEATURES
s _{Ultralow Quiescent Current: 3.5µA Typ}
s _{Open-Drain Outputs Typically Sink}
Greater Than 20mA
s _{Wide Supply Range: (LTC1841)}
Single: 2V to 11V
Dual: ±1V to ±5.5V
s _{Input Voltage Range Includes the Negative Supply}
s _{Reference Output Drives 0.01µF Capacitor}
s _{Adjustable Hysteresis}
s _{12µs Propagation Delay with 10mV Overdrive}
s _{No Current Spike When Switching}
U
APPLICATIONS
s _{Battery-Powered System Monitoring}
s _{Threshold Detectors}
s _{Window Comparators}
s _{Oscillator Circuits}
, LTC and LT are registered trademarks of Linear Technology Corporation.
DESCRIPTION
The LTC^®1841/LTC1842/LTC1843 are ultralow power dual
comparators with built-in reference (LTC1842/LTC1843).
The comparators feature less than 5.7µA supply current
over temperature, a 1.182V ±1% reference, program-
mable hysteresis and open-drain outputs that sink cur-
rent. The reference output can drive a bypass capacitor of
up to 0.01µF without oscillation.
The LTC1841 operates from a single 2V to 11V supply or
a dual ±1V to ±5.5V supply. The LTC1842/LTC1843
operate from a single 2.5V to 11V supply or a dual ±1.25V
to ±5.5V supply. The LTC1842/LTC1843 hysteresis is
easily programmed by using two resistors and the HYST
pin. The comparators’ input operates from the negative
supply to within 1.3V of the positive supply. The compara-
tors’ output stage can typically sink greater than 20mA. By
eliminating the cross-conduction current that normally
happens when the comparators change logic states, power
supply glitches are eliminated.
The LTC1841/LTC1842/LTC1843 are available in SO-8
packages.
TYPICAL APPLICATION
Single Li-Ion Cell to 5V Supply
1-CELL
Li-Ion
BATTERY
R1
1.5M
+ _C1
100µF
4 IN B ^–
7
V_CC
–
R2
+
100k
3 IN A⁺
+
R3
1M
6 REF
–
R4
20k
V^–
R5
2
1.1M
R6
25k
L1
10µH ^D1
LTC1843
OUT B 8
OUT A 1
6
7
V_IN
SW
3 ^LT1302-5
Si9924DY
SHDN
8
I_{T 4}
PGND SENSE
V_C
GND
2
1
R_C
20k
C_C
0.0µF
OUTPUT
5V
600mA
+
C2
100µF
R7
500k
HYST
5
C1, C2: SANYO OS-CON
D1: MOTOROLA MBRS130LT3
L1: COILTRONICS CTX10-3
LBO
1841/43 TA01
LTC1843 Supply Current
vs Supply Voltage
5
T_A = 25°C
4
3
2
1
0
0
2
4
6
8 10 12
SUPPLY VOLTAGE (V)
1841/43 TA02
1