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Fairchild Semiconductor |
www.fairchildsemi.com
FAN1950/FAN1951
1.5A Low-Voltage Low-Dropout Regulator
Features
• 1.5A minimum guaranteed output current
• 500mV maximum dropout at 1.5A
Ideal for 2.5V to 1.8V or 1.65V conversion
Ideal for 3.0V to 2.5V conversion
• Current Limiting and Thermal shutdown
• External Shut-down control (FAN1951 only)
• Error flag output (FAN1951 only)
• Fast transient response
• Low ground current
Applications
• General purpose conversion for low-voltage CPUs,
DSP and FPGAs
• SMPS post regulator
• Cable/Satellite set-top boxes
• PCI Graphics adapter cards
General Description
The FAN1950 and FAN1951 are 1.5A low-dropout linear
regulators that provide a low voltage, high current output
with a minimum of external components. Both of these
devices use a PNP output pass element achieving a maxi-
mum 500mV dropout at 1.5A load current. In addition these
devices offer overcurrent limit and thermal shutdown
features to ensure full protection.
The FAN1951 offers a logic level enable pin and an error
flag output to indicate undervoltage and over-current condi-
tions. 1.8V and 2.5V fixed output versions are available.
3.3V, 1.65V and 1.5V options are available upon request.
Typical Application
FAN1950-2.5V
FAN1951-1.8V
3.0V
2.5V
IN OUT
GND
10µF
2.5V IN OUT
100KΩ
Error Output
On/Off
FLAG
EN
GND
1.8V
10µF
REV. 0.1.6 8/30/04
FAN1950/FAN1951
Pin Assignments
FAN1950Dx
FRONT VIEW
FAN1951Dx
FRONT VIEW
1 23
1 2 3 45
3-Lead Plastic
TO-252 (DPAK)
5-Lead Plastic
TO-252 (DPAK)
Pin Descriptions
Pin Number
FAN1950 FAN1951
NA 1
Pin Name
EN
12
IN
2 3 GND
3 4 OUT
NA 5 FLAG
Pin Function Description
Enable (Input) – TTL/CMOS compatible input. Logic HIGH enables
the output
Input Supply Voltage
Ground. This pin and TAB are ground.
Output Voltage
Error Flag (Output). Open-collector output. Active-low indicates an
output fault condition.
2 REV. 0.1.6 8/30/04
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