Datasheet LTC1042 (Analog Devices)

LTC1042 Window Comparator
U FEATURES DESCRIPTIO
■ Micropower 1.5µW (1 Sample/Second) The LTC®1042 is a monolithic CMOS window comparator ■ Wide Supply Range — 2.8V to 16V manufactured using Linear Technology’s enhanced ■ High Accuracy LTCMOS™ silicon gate process. Two high impedance Center Error ±1mV Max voltage inputs, CENTER and WIDTH/2, define the middle Width Error ±0.15% Max and width of the comparison window. Whenever the input voltage, V ■ Wide Input Voltage Range IN, is inside the window the WITHIN WINDOW output is high. The ABOVE WINDOW output is high V+ to Ground whenever VIN is above the window. By interchanging VIN ■ TTL Outputs with 5V Supply and CENTER, the ABOVE WINDOW output becomes ■ Two Independent Ground-Referred Control Inputs BELOW WINDOW and is high if VIN is below the window. ■ Small Size 8-Pin MiniDIP Sampling techniques provide high impedance voltage inputs that can common mode to both supply rails
U APPLICATIO S
(V+ and GND). An important feature of the inputs is their non-interaction. Also the device is effectively “chopper ■ Fault Detectors stabilized,” giving it extremely high accuracy over ■ Go/No-Go Testing all conditions of temperature, power supply and input ■ Microprocessor Power Supply Monitor voltage range. , LTC and LT are registered trademarks of Linear Technology Corporation. Another benefit of the sampling techniques used to design LTCMOS is a trademark of Linear Technology Corp. the LTC1042 is the extremely low power consumption. When the device is strobed, it internally turns on the power to the comparators, samples the inputs, stores the outputs in CMOS latches and then turns off power to the compara- tors. This all happens in about 80µs. Average power can be made small, almost arbitrarily, by lowering the strobe rate. The device can be self-strobed using an external RC network or strobed externally by driving the OSC pin with a CMOS gate.
U TYPICAL APPLICATIO Battery-Powered Remote Freezer Alarm Total Supply Current vs Sampling Frequency
V+ 10000 “HI” = TEMPERATURE V+ = 6V IT 150k 150k 1 8 BETWEEN 10M ±5% A) 1000 26°F AND 31°F µ ( I 2 7 T ±1°F T 3 LTC1042 6 100 “HI” = TEMPERATURE 3V TO 16V 4 5 T ABOVE 31°F R1* 10 ±1°F 7.5k LTC1042 SUPPLY 0.05µF CURRENT 1 R2* 576Ω FOR THIS APPLICATION TOTAL SUPPLY CURRENT, I 0.1 fS ≈ 1HZ 0.01 T = YELLOW SPRINGS INSTRUMENT CO., INC. P/N 44007 0.1 1 10 100 1000 10000 ALL RESISTORS ±1% UNLESS OTHERWISE SPECIFIED SAMPLING FREQUENCY, fS (Hz) *OTHER TEMPERATURE BANDS MAY BE SELECTED BY CHOOSING APPROPRIATE VALUES FOR R1 AND R2 LTC1042 • TA02 LTC1042 • A01 1042fa 1