SOT23, 1.8V, Nanopower, Beyond-the-Rails

Comparators With/Without Reference

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9

Pin Description

Functional Diagrams

MAX917

MAX918

IN+

OUT

REF

REF

1.245V

MAX919

MAX920

IN+

OUT

IN-

MAX917/MAX918

SO

PIN

SOT23-5

MAX919/MAX920

SOT23-5

SO

N.C.

IN-

REF

IN+

OUT

1, 5, 8

7

4

2

—

3

6

—

5

2

4

—

3

1

—

1, 5, 8

No Connection. Not internally connected.

5

7

Positive Supply Voltage

2

4

Negative Supply Voltage

—

—

Comparator Inverting Input

4

2

1.245V Reference Output and Comparator Inverting Input

3

3

Comparator Noninverting Input

1

6

Comparator Output

NAME

FUNCTION

Detailed Description

The MAX917/MAX918 feature an on-board 1.245V

±1.5% reference, yet draw an ultra-low supply current

of 750nA. The MAX919/MAX920 (without reference)

consume just 380nA of supply current. All four devices

are guaranteed to operate down to +1.8V. Their com-

mon-mode input voltage range extends 200mV

beyond-the-rails. Internal hysteresis ensures clean out-

put switching, even with slow-moving input signals.

Large internal output drivers allow rail-to-rail output

swing with up to ±8mA loads.

The output stage employs a unique design that mini-

mizes supply-current surges while switching, virtually

eliminating the supply glitches typical of many other

comparators. The MAX917/MAX919 have a push-pull

output stage that sinks as well as sources current. The

MAX918/MAX920 have an open-drain output stage that

implementing wire-ORed output logic functions.

Input Stage Circuitry

The input common-mode voltage range extends from

at any differential input voltage within these limits. Input

bias current is typically ±0.15nA if the input voltage is

between the supply rails. Comparator inputs are pro-

tected from overvoltage by internal ESD protection

diodes connected to the supply rails. As the input volt-

age exceeds the supply rails, these ESD protection

diodes become forward biased and begin to conduct.