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LTC1443/LTC1444/LTC1445

144345fe

Typical applicaTion

DescripTion

Ultralow Power Quad

Comparators with Reference

The LT C

1443/LTC1444/LTC1445 are ultralow power quad

comparators with a built-in reference. The comparators

feature less than 8.5µA supply current over temperature,

an internal reference (1.182V ±1% for LTC1443 or 1.221V

±1% for LTC1444/LTC1445), programmable hysteresis

(LTC1444/LTC1445) and TTL/CMOS output (LTC1443/

LTC1445) that sinks and sources current (open-drain

output for LTC1444). The reference output can drive a

bypass capacitor of up to 0.01µF without oscillation.

The comparators operate from a single 2V to 11V supply

or a dual ±1V to ±5.5V supply (LTC1443). Comparator

hysteresis is easily programmable using two resistors and

the HYST pin (LTC1444/LTC1445). Each comparator’s

input operates from the negative supply to within 1.3V of

the positive supply. The LTC1443/LTC1445 comparator

output stage can continuously source up to 40mA. By

eliminating the cross-conducting current that normally

happens when the comparator changes logic states, power

supply glitches are eliminated.

The LTC1443/LTC1444/LTC1445 are available in the

16-pin SO, PDIP and DFN packages.

FeaTures

applicaTions

Ultralow Quiescent Current: 8.5µA Max

Reference Output Drives 0.01µF Capacitor

Adjustable Hysteresis (LTC1444/LTC1445)

Wide Supply Range

Single: 2V to 11V

Dual: ±1V to ±5.5V

Input Voltage Range Includes the Negative Supply

TTL/CMOS Compatible Outputs

Propagation Delay: 12µs (Typ) (10mV Overdrive)

No Crowbar Current

40mA Continuous Source Current

Pin Compatible Upgrades for MAX924 (LTC1443)

Low Profile (5mm × 4mm × 0.8mm) DFN Package

Battery-Powered System Monitoring

Threshold Detectors

Window Comparators

Oscillator Circuits

Reference Settling Test Circuit

–

IN A

OUT

1.2V

10k

430Ω

2.4M

1.0µF

IN A

–

HYST

REF

TO 8V

144345 TA01

LTC1445

1.21M

3.4M

–

Reference Settling

L, LT , LT C , LT M , Linear Technology and the Linear logo are registered trademarks of Linear

Technology Corporation. All other trademarks are the property of their respective owners.

REF

144345 TA02

OUT

2ms/DIV

2mV/DIV

Summary of content (14 pages)

PAGE 1
LTC1443/LTC1444/LTC1445 Ultralow Power Quad Comparators with Reference Features Description Ultralow Quiescent Current: 8.5µA Max n Reference Output Drives 0.01µF Capacitor n Adjustable Hysteresis (LTC1444/LTC1445) n Wide Supply Range Single: 2V to 11V Dual: ±1V to ±5.
PAGE 2
LTC1443/LTC1444/LTC1445 Absolute Maximum Ratings (Note 1) Voltage: V + to V –, V + to GND, GND to V –............ 12V to –0.3V IN +, IN –, HYST...................(V + + 0.3V) to (V – – 0.3V) REF....................................(V + + 0.3V) to (V – – 0.3V) OUT (LTC1443)................(V + + 0.3V) to (GND – 0.3V) OUT (LTC1444/LTC1445).........(V + + 0.3V) to (V – – 0.3V) Current: IN +, IN –, HYST.................................................. 20mA REF..................................................
PAGE 3
LTC1443/LTC1444/LTC1445 Order Information LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE LTC1443CN#PBF LTC1443CN#TRPBF LTC1443CN 16-Lead PDIP 0°C to 70°C LTC1443CS#PBF LTC1443CS#TRPBF LTC1443CS 16-Lead Plastic SO 0°C to 70°C LTC1443IN#PBF LTC1443IN#TRPBF LTC1443IN 16-Lead PDIP –40°C to 85°C LTC1443IS#PBF LTC1443IS#TRPBF LTC1443IS 16-Lead Plastic SO –40°C to 85°C LTC1444CN#PBF LTC1444CN#TRPBF LTC1444CN 16-Lead PDIP 0°C to 70°C LTC144
PAGE 4
LTC1443/LTC1444/LTC1445 Electrical Characteristics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. V+ = 5V, V – = GND = 0V, unless otherwise noted. SYMBOL VOH VOL PARAMETER Output High Voltage Output Low Voltage CONDITIONS IO = – 15mA; LTC1443/LTC1445 IO = 1.8mA; LTC1443 IO = 1.
PAGE 5
LTC1443/LTC1444/LTC1445 Typical Performance Characteristics LTC1444/LTC1445 Hysteresis Control Supply Current vs Supply Voltage 5.2 80 60 20 0 –20 –40 4.8 4.6 4.4 4.2 –60 10 0 20 30 VREF – VHYST (mV) 40 4.0 50 1.0 1.186 1.5 2.0 2.5 SUPPLY VOLTAGE (V) 1.212 1.184 1.180 1.178 1.176 1.174 1.170 –60 –40 –20 1.184 0 20 40 60 80 100 120 140 TEMPERATURE (°C) 5 10 15 20 25 30 35 LOAD CURRENT (µA) 40 1.178 45 144345 G07 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.
PAGE 6
LTC1443/LTC1444/LTC1445 Typical Performance Characteristics Comparator Response Time vs Input Overdrive 10mV 50mV 2 20mV 1 0 0 100 –1 0 2 4 6 RESPONSE TIME (µs) 5 8 10 200 TA = 25°C 4 100mV 3 50mV 160 20mV 10mV 2 1 0 140 100 80 60 40 0 20 0 2 OUT CONNECTED TO V+ 120 100 –1 TA = 25°C 180 0 4 6 8 10 12 14 16 18 RESPONSE TIME (µs) 144345 G10 0 1 2 3 4 5 6 7 8 SUPPLY VOLTAGE (V) 9 10 144345 G12 144345 G11 Comparator Response Time vs Load Capacitance Comparator Short-Ci
PAGE 7
LTC1443/LTC1444/LTC1445 Pin Functions LTC1443 16 1 OUT B OUT D 15 2 OUT A 14 3 V+ 13 4 IN A– IN D+ 13 12 5 IN A+ IN D– 12 11 6 IN B – IN C+ 11 IN B+ IN C– 10 OUT B 2 OUT A 3 V+ 4 IN A– IN D+ 5 IN A+ IN D– 6 IN B – IN C+ IN B+ IN C– GND – – 7 8 + – + REF – 1.2V +– LTC1444/LTC1445 OUT C 1 + – V– 10 9 7 8 REF 16 15 HYST – + OUT C OUT D + – + – 1.2V +– 14 + + V– 9 144345 PF OUT B (Pin 1): Comparator B Output.
PAGE 8
LTC1443/LTC1444/LTC1445 Applications Information The LTC1443/LTC1444/LTC1445 is a family of quad micropower comparators with a built-in reference (1.182V for the LTC1443 and 1.221V for the LTC1444/LTC1445). Features include programmable hysteresis (LTC1444/ LTC1445), wide supply voltage range (2V to 11V) and the ability of the reference to drive up to a 0.01µF capacitor without oscillation.
PAGE 9
LTC1443/LTC1444/LTC1445 Applications Information Bypassing the reference can help prevent false tripping of the comparators by preventing glitches on the V + or the reference output voltage. Figure 3 shows the bypassed reference output with a square wave applied to the V + pin. Resistors R1 and R2 set 10mV of hysteresis, while R3 damps the reference response. Note that the comparator output doesn’t trip. 3 5V TO 8V V+ 5 IN A+ 4 IN A– + 2 OUT – 14 HYST R1 10k 8 R2 2.
PAGE 10
LTC1443/LTC1444/LTC1445 Applications Information Level Detector The LTC1444 is ideal for use as a multisupply micropower level detector as shown in Figure 5. R1 and R2 form a voltage divider from V1 to the noninverting comparator A input. R6 and R7 are used to divide down V2, while R8 is the output pull-up resistor for the comparator outputs. R3 and R4 set the hysteresis voltage and R5 and C1 bypass the reference output. 5V 3 V2 V+ R6 1.82M 1% 7 IN B+ – 6 IN B V1 R2 3.
PAGE 11
LTC1443/LTC1444/LTC1445 Package Description N Package 16-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510 Rev I) .770* (19.558) MAX 16 15 14 13 12 11 10 9 1 2 3 4 5 6 7 8 .255 ±.015* (6.477 ±0.381) .300 – .325 (7.620 – 8.255) .130 ±.005 (3.302 ±0.127) .020 (0.508) MIN .008 – .015 (0.203 – 0.381) ( +.035 .325 –.015 +0.889 8.255 –0.381 NOTE: 1. DIMENSIONS ARE .045 – .065 (1.143 – 1.651) .065 (1.651) TYP .120 (3.048) MIN ) .018 ±.003 (0.457 ±0.076) .100 (2.
PAGE 12
LTC1443/LTC1444/LTC1445 Package Description DHD Package 16-Lead Plastic DFN (5mm × 4mm) (Reference LTC DWG # 05-08-1707 Rev Ø) 0.70 ±0.05 4.50 ±0.05 3.10 ±0.05 2.44 ±0.05 (2 SIDES) PACKAGE OUTLINE 0.25 ±0.05 0.50 BSC 4.34 ±0.05 (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS 5.00 ±0.10 (2 SIDES) R = 0.20 TYP 4.00 ±0.10 (2 SIDES) 9 R = 0.115 TYP 0.40 ±0.10 16 2.44 ±0.10 (2 SIDES) PIN 1 TOP MARK (SEE NOTE 6) PIN 1 NOTCH 8 0.200 REF 1 0.25 ±0.05 0.50 BSC 0.75 ±0.05 0.00 – 0.
PAGE 13
LTC1443/LTC1444/LTC1445 Revision History (Revision history begins at Rev D) REV DATE DESCRIPTION PAGE NUMBER D 4/11 Minor update to Figure 5 in the Applications Information section E 5/12 Internal Voltage Reference Symbol Updated 10 1, 7, 8, 9, 10, 14 DFN Package Description Corrected 2 DFN Storage Temperature Range Increased to 150°C 2 Order Information Corrected 3 Related Parts Updated 14 144345fe Information furnished by Linear Technology Corporation is believed to be accurate and r
PAGE 14
LTC1443/LTC1444/LTC1445 Typical Application Single Cell to 5V Supply R1 1.1M 5% 5 R2 82.5k 1% 1 CELL LITHIUMION BATTERY 4 6 + V+ A 1/4 LTC1444 – R7 51k 5% – + 6 7 VIN SW C2 100µF 3 1 14 NC NC R5 51k 5% R4 2.4M 5% D1 1N5817 2 B 1/4 LTC1444 7 + HYST R3 1M 1% L1 10µH SUMIDA CD54-100 3 5 2 SENSE 4 1 SHDN 3 LT1300 ILIM + SEL PWR GND 8 GND C3 100µF 1 8 REF R6 430Ω 5% + – C1 1µF 1.