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Fairchild Semiconductor |
www.fairchildsemi.com
FAN1539/FAN1540
1A/1.3A, LDO With Low Quiescent Current
Features
• Very Low Ground Current (IGND = 1mA)
• Excellent Line Regulation
• Excellent Load Regulation
• Very Low Transient Overshoot
• Stable with low ESR Output Capacitor (ESR = 0mΩ)
• Thermal Shutdown
• Current Limit
• Output Options: 3.3V and 1.8V
Applications
• Disk Drive Circuits
• Desktop Computers
• Laptop, Notebook Computers
• General purpose Three Terminal Regulator
Description
The FAN1539/FAN1540 series of high current LDO (1.0A
and 1.3A) has been developed for portable applications
where low quiescent current is an important requirement.
The device features excellent line and load transient response
which does not exceed 10% of nominal output value for full
operating temperature range even during power ON cycle
and short circuit removal. Internally trimmed, temperature
compensated bandgap reference guarantees 2.5% accuracy
for full range of input voltage, output current and tempera-
ture. Included on the chip are accurate current limit and ther-
mal shutdown protection. Device stability is achieved with
only two external low ESR ceramic capacitors.
The FAN1539/FAN1540 is available in thermally enhanced
3x3mm 6-lead MLP, 5x6mm 8-lead MLP package and
3-lead TO-252 packages. The 5x6mm MLP package version
features separate Kelvin sense pin for high precision applica-
tions.
Block Diagram
VIN
SRART-UP
CIRCUIT
BANDGAP
REFERENCE
ERROR
AMPLIFIER
THERMAL
SHUTDOWN
Notes:
1. No connection for FAN1540MMPX.
2. VSEN available for FAN1540MMPX.
CURRRENT
LIMIT
VOUT
X (Note1)
VSENSE
(Note2)
GND
REV. 1.0.8 3/22/04
FAN1539/FAN1540
Pin Assignments
PRODUCT SPECIFICATION
TOP VIEW
GND 1
VOUT 2
VSEN 3
VIN 4
FAN1540
8 GND
7 GND
6 GND
5 GND
5x6mm 8-Lead MLP
NC 1
6 GND
VOUT 2
VIN 3
5 NC
4 NC
FAN1539/FAN1540
3x3mm 6-Lead MLP
FAN1540
VOUT
GND
VIN
3-Lead TO-252 PACKAGE
Pin Description
Symbol
VIN
GND
VOUT
VSEN
NC
Name And Function
Input pin
Ground Pin (Tab)
Output pin: Fixed Output Voltage
Output sense pin. Connect to VOUT if Kelvin sensing is not required
No Connection
2 REV. 1.0.8 3/22/04
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