Datasheet MAX9021, MAX9022, MAX9024 (Maxim) - 5

Micropower, Ultra-Small, Single/Dual/Quad, Single-Supply Comparators MAX9021/MAX9022/MAX9024 Pin Description PIN NAME FUNCTION M A X9 0 2 1 M A X9 0 2 2 M A X9 0 2 4
1 — — IN+ Comparator Noninverting Input 2 4 11 VSS Negative Supply Voltage 3 — — IN- Comparator Inverting Input 4 — — OUT Comparator Output 5 8 4 VDD Positive Supply Voltage. Bypass with a 0.1µF capacitor to GND. — 1 1 OUTA Comparator A Output — 2 2 INA- Comparator A Inverting Input — 3 3 INA+ Comparator A Noninverting Input — 5 5 INB+ Comparator B Noninverting Input — 6 6 INB- Comparator B Inverting Input — 7 7 OUTB Comparator B Output — — 8 OUTC Comparator C Output — — 9 INC- Comparator C Inverting Input — — 10 INC+ Comparator C Noninverting Input — — 12 IND+ Comparator D Noninverting Input — — 13 IND- Comparator D Inverting Input — — 14 OUTD Comparator D Output
Detailed Description
tor’s output sets the trip voltage. Therefore, the trip volt- age is related to the output voltage. The MAX9021/MAX9022/MAX9024 are single/dual/ quad, low-cost, low-power comparators that consume These comparators have 4mV internal hysteresis. only 2.8µA and provide a propagation delay, tPD, typi- Additional hysteresis can be generated with two resis- cally 3µs. They have an operating-supply voltage from tors, using positive feedback (Figure 1). Use the follow- 2.5V to 5.5V when operating from a single supply and ing procedure to calculate resistor values: from ±1.25V to ±2.75V when operating from dual power 1) Find the trip points of the comparator using these for- supplies. Their common-mode input voltage range mulas: extends from the negative supply to within 1.1V of the positive supply. Internal hysteresis ensures clean out- VTH = VREF + ((VDD - VREF)R2) / (R1 + R2) put switching, even with slow-moving input signals. VTL = VREF(1 - (R2 / (R1 + R2))
Applications Information
where VTH is the threshold voltage at which the com- parator switches its output from high to low as VIN
Adding Hysteresis
rises above the trip point. VTL is the threshold volt- Hysteresis extends the comparator’s noise margin by age at which the comparator switches its output from increasing the upper threshold and decreasing the low to high as VIN drops below the trip point. lower threshold. A voltage-divider from the compara-
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