MAX9100/MAX9101
+1.0V Micropower SOT23 Comparators
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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-
fied from 0 to (V
CC
- 0.2V), although full rail-to-rail input
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
input common-mode voltages from V
CC
- 0.2V to V
CC
,
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.
