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Fairchild Semiconductor |
www.DataSheet4U.com
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
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: 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.
Block Diagrams
VIN
Bandgap
FAN2534
EN
Error
p
Amplifier
VOUT
Thermal
Sense
ADJ
GND
VIN
Bandgap
EN
Error
Amplifier
p
Thermal
Sense
FAN2534-XX
BYP
VIN
Bandgap
VOUT
EN
Error
Amplifier
p
ERR
VOUT
GND
Thermal
Sense
FAN2535-XX
GND
REV. 1.0.2 8/26/03
FAN2534/FAN2535
www.DataSheet4U.com
Pin Assignments
PRODUCT SPECIFICATION
VIN 1 FB
SHDN
GND 2
CAP+
EN 3 CAP-
5 VOUT
4 ADJ/BYP/ERR
Pin No.
1.
2.
3.
4.
5.
FAN2534
VIN
GND
EN
ADJ
VOUT
FAN2534-XX
VIN
GND
EN
BYP
VOUT
FAN2535-XX
VIN
GND
EN
ERR
VOUT
Pin Descriptions
Pin Name Pin No.
Type
ADJ 4 Input
BYP
ERR
4 Passive
4 Open drain
EN 3 Digital Input
VIN
VOUT
GND
1 Power in
5 Power out
2 Power
Pin Function Description
FAN2534 Adjust. Ratio of potential divider from VOUT to ADJ
determines output voltage.
FAN2534-XX Bypass. Connect 10 nF capacitor for noise reduction.
FAN2535-XX Error. Error flag output.
LOW when Vout< 95% of nominal; HIGH when Vout> 95% of nominal.
Enable.
LOW in Shutdown Mode; HIGH in Enable Mode
Voltage Input. Supply voltage input.
Voltage Output. Regulated output voltage.
Ground.
Absolute Maximum Ratings (Note 1)
Parameter
Power Supply Voltages
VIN (Measured to GND); Enable Input (EN);
ERR Output;
Power Dissipation
Operating Junction Temperature
Lead Soldering (5 seconds)
Storage
Electrostatic Discharge (Note 2)
Min.
0
-65
-65
4
Typ.
Max.
7
Internally limited
150
260
150
Unit
V
°C
°C
°C
kV
2 REV. 1.0.2 8/26/03
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