Datasheet MAX971–MAX974 and MAX981–MAX984 (Maxim) - 9

Ultra-Low-Power, Open-Drain, Single/Dual-Supply Comparators MAX971–MAX974/MAX981–MAX984 Detailed Description Power-Supply and Input Signal Ranges
This family of devices operates from a single 2.5V to 11V The MAX971–MAX974/MAX981–MAX984 comprise various combinations of a micropower 1.182V reference power supply. The MAX9_1 and MAX9_4 have a and micropower comparators. The Typical Operating separate ground for the output driver, allowing operation Circuit shows the MAX971/MAX981 configuration, and with dual supplies ranging from ±1.25V to ±5.5V. Figures 1a–1d show the MAX9_2–MAX9_4 configurations. Connect V- to GND when operating the MAX9_1 or MAX9_4 from a single supply. The maximum total supply Internal hysteresis in the MAX9_1, MAX982, and voltage in this case is still 11V. MAX9_3 provides the easiest method for implementing hysteresis. It also produces faster hysteresis action and For proper comparator operation, the input signal can consumes much less current than circuits using external range from the negative supply (V-) to within one volt of positive feedback. the positive supply (V+ - 1V). The guaranteed common- mode input voltage range extends from V- to (V+ - 1.3V). The inputs can be taken above and below the supply rails by up to 300mV without damage. MAX9_3 MAX972 1 OUTA OUTB 8 1 (A1) OUTA OUTB 8 (A3) 2 V- V+ 7 2 (C2) V- V+ 7 (A2) 3 INA+ REF 6 3 (C1) INA+ INB+ 6 (C3) 4 INB- HYST 5 4 (B1) INA- INB- 5 (B3) V- Figure 1c. MAX973/MAX983 Functional Diagram ( ) BUMPS FOR THE UCSP (Window Comparator) Figure 1a. MAX972 Functional Diagram 1 OUTB MAX9_4 OUTC 16 2 OUTA OUTD 15 3 V+ GND 14 4 INA- IND+ 13 MAX982 1 OUTA OUTB 8 5 INA+ IND- 12 2 V- V+ 7 3 INA+ REF 6 6 INB- INC+ 11 4 INB+ HYST 5 7 INB+ INC- 10 V- 8 REF V- 9 Figure 1b. MAX982 Functional Diagram Figure 1d. MAX974/MAX984 Functional Diagram
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