19-2599; Rev 0; 10/02
500mA, Low-Voltage Linear Regulator
in Tiny QFN
An internal PMOS pass transistor allows low 210µA
supply current, making this device ideal for portable
equipment such as personal digital assistants (PDAs),
cellular phones, cordless phones, and other equipment, including base stations and docking stations.
Other features include an active-low, power-OK output
that indicates when the output is out of regulation, a
0.02µA shutdown mode, short-circuit protection, and
thermal-shutdown protection. The MAX1935 comes in a
tiny 1.9W, 8-pin 3mm x 3mm thin QFN package.
Features
o Guaranteed 500mA Output Current
o Output Down to 0.8V
o Low 175mV Dropout at 500mA
o ±1.5% Output Voltage Accuracy
Preset at 1.5V
Adjustable from 0.8V to 4.5V
o Power-OK Output
o Low 210µA Ground Current
o 0.02µA Shutdown Current
o Thermal-Overload Protection
o Output Current Limit
o Tiny 1.9W, 8-Pin 3mm x 3mm Thin QFN Package
Ordering Information
Cellular and Cordless Telephones
PDAs
Palmtop Computers
PIN-PACKAGE
-40°C to +85°C
8 Thin QFN
3mm x 3mm
MAX1935ETA15*
Notebook Computers
TEMP RANGE
MAX1935ETA*
Applications
PART
-40°C to +85°C
8 Thin QFN
3mm x 3mm
*Contact factory for preset output voltages.
Base Stations
Selector Guide
USB Hubs
Docking Stations
OUTPUT
VOLTAGE
PART
MAX1935ETA
Adjustable
ADB
1.5V
ADB
MAX1935ETA15
Pin Configuration
Typical Operating Circuit
RPOK
100kΩ
VOUT
0.8V TO 4.5V
TOP VIEW
OUT
POK
TO µC
COUT
10µF
VIN
2.25V TO 5.5V
TOP MARK
SET
8
2
7
OUT
3
6
SET
SHDN
IN
CIN
1µF
1
POK
MAX1935
IN
IN
R1
4
5
GND
MAX1935
OUT
R2
ON
SHDN
GND
THIN QFN
3mm x 3mm
OFF
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX1935
General Description
The MAX1935 low-dropout linear regulator operates
from a 2.25V to 5.5V supply and delivers a guaranteed
500mA load current with low 175mV dropout. The highaccuracy (±1.5%) output voltage is preset at an internally trimmed voltage or can be adjusted from 0.8V to
4.5V with an external resistive-divider.
