Datasheet
MAX1725/MAX1726
12V, Ultra-Low I
Q
, Low-Dropout
Linear Regulators
4
Maxim Integrated
Detailed Description
The MAX1725/MAX1726 are low-dropout, low-quiescent-
current linear regulators designed primarily for battery-
powered applications (Figure 1). The MAX1725 provides
an adjustable output voltage from 1.5V to 5V using an
external resistor-divider. The MAX1726 supplies preset
output voltages of 1.8V, 2.5V, 3.3V, or 5V. These devices
consist of a +1.245V error amplifier, MOSFET driver,
and p-channel pass transistor (Figure 2).
Typical Operating Characteristics (continued)
(V
OUT
= +3.3V, I
OUT
= 1mA, T
A
= +25°C, unless otherwise noted.)
NAME
MAX1725 MAX1726
1 1 IN
2 2 GND
3 3 OUT
— 4 GND
4 — FB
Pin Description
FUNCTION
Supply Voltage Input
Ground
Voltage Output
Ground
Feedback Voltage Input
5 5
SHDN
Active-Low Shutdown Input
PIN
I
OUT
20mA/div
V
OUT
100mV/div
400µs/div
LOAD TRANSIENT
MAX1725/26 toc10
C
OUT
= 1µF
I
OUT
= 1mA - 20mA
V
SHDN
2V/div
V
OUT
1V/div
4ms
TURN-ON/TURN-OFF RESPONSE
MAX1725/26 toc11
C
OUT
= 1µF
I
OUT
= 1mA
0
100
50
200
150
250
300
01051520
DROPOUT VOLTAGE vs. LOAD CURRENT
MAX1725/26 toc07
LOAD CURRENT (mA)
DROPOUT VOLTAGE (mV)
T
A
= +85°C
T
A
= +25°C
T
A
= -40°C
80
70
60
50
40
30
20
10
0
0.01 1 100.1 100
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
MAX1725/26 toc08
FREQUENCY (kHz)
PSRR (dB)
V
IN
= 5V
V
OUT
= 3.3V
R
L
= 3.3kΩ
C
OUT
= 1µF
V
IN
200mV/div
V
OUT
20mV/div
100µs/div
LINE-TRANSIENT RESPONSE
MAX1725/26 toc09
C
OUT
= 1µF
I
OUT
= 1mA