+1.0V Micropower SOT23 Comparators

6

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Detailed Description

The MAX9100/MAX9101 are low-power and ultra-low

single-supply voltage comparators. They have an oper-

ating supply voltage range between +1.0V to +5.5V

and consume only 5µA of quiescent supply current,

while achieving 4µs propagation delay.

Input Stage Circuitry and

Rail-to-Rail Operation

The devices’ input common-mode range is fully speci-

range is possible with degraded performance. These

comparators may operate at any differential input volt-

age within these limits. Input bias current is typically

±5nA if the input voltage is within the specified com-

mon-mode range. Comparator inputs are protected

from overvoltage by internal diodes connected to the

supply rails. As the input voltage exceeds the supply

rails, these diodes become forward biased and begin

to conduct. Consequently, bias currents increase expo-

nentially as the input voltage exceeds the supply rails.

True rail-to-rail input operation is also possible. For

the input bias current will typically increase to 800nA.

Additionally, the supply current will typically increase to

7µA. Otherwise, the device functions as within the

specified common-mode range. See graphs in the

Typical Operating Characteristics.

Output Stage Circuitry

The MAX9100/MAX9101 contain a unique output stage

capable of rail-to-rail operation. Many comparators

consume orders of magnitude more current during

switching than during steady-state operation. However,

with this family of comparators, the supply-current

change during an output transition is extremely small.

The Typical Operating Characteristics graph Supply

Current vs. Output Transition Frequency shows the min-

imal supply-current increase as the output switching

frequency approaches 100kHz. This characteristic

reduces the requirement for power-supply filter capaci-

tors to reduce glitches created by comparator switch-

ing currents. This feature increases battery life in

portable applications.

Push-Pull Output (MAX9100)

The MAX9100 has a push-pull CMOS output. The out-

put stage swings rail-to-rail under no-load conditions.

External load drive capability varies with supply voltage.

SWITCHING CURRENT

OUTPUT RISING

MAX9100 toc16

100mV/div

1mA/div

2

µs/div

5V/div

,

SWITCHING CURRENT,

OUTPUT FALLING

MAX9100 toc17

IN+

100mV/div

1mA/div

2

µs/div

OUT

5V/div

RESPONSE TO SLOW TRIANGLE WAVEFORM

MAX9100 toc18

5.0ms/div

IN+

OUT

50mV/div

2V/div

Typical Operating Characteristics (continued)

°C, unless otherwise noted.)

Pin Description

PIN

SOT23-5

SO-8

NAME

FUNCTION

1

6

OUT

Comparator Output

2

4

GND

Ground

3

3

IN+

Noninverting Input

4

2

IN-

Inverting Input

—

1, 5, 8

N.C.

No Connection

57

Positive Supply Voltage