
www.fairchildsemi.com
REV. 1.0.2 8/26/03
Features
 70dB Ripple rejection ( >45dB up to 1MHz)
 150μsec Power On Time
 150μsec Enable Time
 Low noise - 50μVrms 
 Enable optimized for CDMA time slices
 180 mV dropout voltage at 150 mA
 Enable/Shutdown Control
 Enable time independent of noise bypass capacitor value
 SOT23-5 package
 Thermal limiting
 300 mA trimmed current limit
Applications
 Cellular Phones and accessories
 PDAs
 Portable cameras and video recorders
 Laptop, notebook and palmtop computers
Description
The FAN2534/FAN2535 family of micropower low-dropout 
voltage regulators utilize CMOS technology to offer a new 
level of cost-effective performance in GSM, TDMA, and 
CDMA cellular handsets, laptop and notebook computers, 
and other portable devices.
Proprietary design technics 
ensure high ripple rejection. Other features include low 
noise, short circuit current limit, thermal shutdown circuit, 
low dropout voltage, fast enable required in CDMA handset 
applications, exceptional loop stability to accommodate a 
wide variety of external capacitors, and a compact SOT23-5
surface-mount package. These products offer significant 
improvements over older Bipolar and CMOS designs and are 
pin-compatible with many popular devices. 
The FAN2534 and FAN2535 devices are distinguished by 
the assignment of pin 4:
FAN2534:
output voltage over a wide range using an external voltage 
divider.
 pin 4 – ADJ, allowing the user to adjust the 
FAN2534-XX:
may be connected for optimal noise performance. Output 
voltage is fixed, as specified by the suffix XX. 
 pin 4 – BYP, to which a bypass capacitor 
FAN2535-XX: 
output voltage has dropped below the specified minimum 
due to a fault condition. 
pin 4 – ERR, a flag which indicates that the 
The standard fixed output voltages available are 2.6V, 2.85V, 
and 3.0V . Custom output voltages are also available: please 
contact your local Fairchild Sales Office for information.
FAN2534/FAN2535
150 mA CMOS LDO Regulator with Fast Start, Enable
Block Diagrams
FAN2534
EN
ADJ
GND
Thermal 
Sense
p
VIN
VOUT
Bandgap
Error
Amplifier
FAN2534-XX
EN
BYP
GND
GND
Bandgap
Thermal 
Sense
p
Error
Amplifier
VIN
VOUT
FAN2535-XX
EN
ERR
Bandgap
Thermal 
Sense
p
Error
Amplifier
VIN
VOUT