Datasheet
MAX4291/MAX4292/MAX4294
variety of typical battery types showing voltage when
fresh, voltage at end-of-life, capacity, and approximate
operating time from a MAX4291 (assuming nominal
conditions).
Although the amplifiers are fully guaranteed over tem-
perature for operation down to a 1.8V single supply,
even lower voltage operation is possible in practice.
Figures 4 and 5 show the offset voltage and supply cur-
rent as a function of supply voltage and temperature.
Load-Driving Capability
The MAX4291/MAX4292/MAX4294 are fully guaranteed
over temperature and supply voltage range to drive a
maximum resistive load of 2kΩ to V
CC
/2, although
heavier loads can be driven in many applications. The
rail-to-rail output stage of the amplifier can be modeled
as a current source when driving the load toward V
CC
,
and as a current sink when driving the load toward V
EE
.
The limit of this current source/sink varies with supply
voltage, ambient temperature, and lot-to-lot variations
of the units.
Figures 6a and 6b show the typical current source and
sink capabilities of the MAX4291/MAX4292/MAX4294
family as a function of supply voltage and ambient tem-
perature. The contours on the graph depict the output
current value, based on driving the output voltage to
within 50mV, 100mV, and 200mV of either power-sup-
ply rail.
For example, a MAX4291 running from a single 1.8V
supply, operating at T
A
= +25°C can source 3.5mA to
Ultra-Small, 1.8V, µPower,
Rail-to-Rail I/O Op Amps
10 ______________________________________________________________________________________
SUPPLY VOLTAGE (V)
-700
-600
-650
-550
-500
-450
0 3.02.52.01.0 1.50.5 3.5 4.0 4.5 5.0 5.5
MAX4291
OFFSET VOLTAGE vs. SUPPLY VOLTAGE
OFFSET VOLTAGE (µV)
T
A
= +25°C
T
A
= -40°C
T
A
= +85°C
V
CM
= V
CC
/
2
Figure 4. Offset Voltage vs. Supply Voltage
0
60
20
40
80
100
120
140
0 2.0 2.5 3.01.00.5 1.5 3.5 4.5 5.04.0 5.5
SUPPLY CURRENT PER AMPLIFIER
vs. SUPPLY VOLTAGE
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (µA)
T
A
= +85°C
T
A
= -40°C
T
A
= +25°C
Figure 5. Supply Current per Amplifier vs. Supply Voltage
0
15
5
10
20
25
30
-55 5 20 35-25-40 -10 50 80 1109565 125
OUTPUT SOURCE CURRENT
vs. TEMPERATURE
TEMPERATURE (°C)
OUTPUT SOURCE CURRENT (mA)
V
OH
= V
CC
- V
OUT
V
CC
= 5.5V
V
OH
= 200mV
V
CC
= 5.5V
V
OH
= 50mV
V
CC
= 1.8V
V
OH
= 100mV
V
CC
= 1.8V
V
OH
= 200mV
V
CC
= 5.5V
V
OH
= 100mV
V
CC
= 1.8V
V
OH
= 50mV
Figure 6a. Output Source Current vs. Temperature
V
OL
= V
OUT
- V
EE
0
10
2
4
6
8
12
14
16
18
-55 5 20 35-25-40 -10 50 80 1109565 125
OUTPUT SINK CURRENT
vs. TEMPERATURE
TEMPERATURE (°C)
OUTPUT SINK CURRENT (mA)
V
CC
= 1.8V
V
OL
= 200mV
V
CC
= 1.8V
V
OL
= 50mV
V
CC
= 5.5V
V
OL
= 200mV
V
CC
= 5.5V
V
OL
= 100mV
V
CC
= 1.8V
V
OL
= 100mV
V
CC
= 5.5V
V
OL
= 50mV
Figure 6b. Output Sink Current vs. Temperature