www.fairchildsemi.com
FAN2534/FAN2535
150 mA CMOS LDO Regulator with Fast Start, Enable
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
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:
pin 4 – ADJ, allowing the user to adjust the
output voltage over a wide range using an external voltage
divider.
FAN2534-XX:
pin 4 – BYP, to which a bypass capacitor
may be connected for optimal noise performance. Output
voltage is fixed, as specified by the suffix XX.
FAN2535-XX:
pin 4 – ERR, a flag which indicates that the
output voltage has dropped below the specified minimum
due to a fault condition.
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.
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,
Block Diagrams
EN
VIN
Bandgap
Error
Amplifier
p
VOUT
ADJ
Thermal
Sense
FAN2534
GND
FAN2534-XX
Thermal
Sense
Thermal
Sense
FAN2535-XX
VIN
BYP
Bandgap
Error
Amplifier
p
VOUT
EN
VIN
Bandgap
p
VOUT
EN
ERR
Error
Amplifier
GND
GND
REV. 1.0.2 8/26/03
FAIRCHILD [ FAIRCHILD SEMICONDUCTOR ]
