Fremont Micro Devices
Ultra Low Noise, High PSRR, 250mA LDO
FEATURES
Ultra-Low Noise for RF Application
Ultra-Fast Response in Line/Load Transient
Quick Start-Up (Typically 100uS)
Low Quiescent Current: 36uA
Less than 0.1uA Standby Current When
Shutdown
Low Dropout Voltage: 120mV @ 100mA
Wide Operating Voltage Ranges : 2.5V to 6V
TTL-Logic-Controlled Shutdown Input
Low Temperature Coefficient
Current Limiting Protection
Only 1uF Output Capacitor Required
High Power Supply Rejection Ratio
ROHS Compliant and 100% Lead (Pb)-Free
Custom Voltage Available
Custom Options for CE Logic and Build-in
Pull-up/down Available
FT531xx
DESCRIPTION
The FT531xx is designed
for portable RF and
wireless applications with demanding performance
and space requirements. The FT531xx performance is
optimized for battery powered systems to deliver
ultra low noise and low quiescent current. Regulator
ground current increases only slightly in dropout,
further prolonging the battery life.
The FT531xx also works with low-ESR ceramic
capacitors, reducing the amount of board space
necessary
for
power
applications,
critical
in
hand-held wireless devices. The FT531xx consumes
less than 0.1uA in shutdown mode and has fast
turn-on time less than 100uS. The other features
include low dropout voltage, high output accuracy,
current limiting protection, and high ripple rejection
ratio. The FT531xx is available in the 5-lead of
SOT-23-5(L),
SC-70
and the 3-lead of SOT-23-3(L),
SOT-89-3(L), SOT-23 packages.
APPLLICATIONS
CDMA/GSM Cellular Handsets
Battery-Powered Equipment
Laptop, Palmtops, Notebook Computers
Hand-Held Instruments
PCMCIA Cards
Portable Information Appliances
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Page 1 of 23
DS531-A8
Fremont Micro Devices
TYPICAL APPLICATION CIRCUIT
FT531xx
Typical Application Circuit
ABSOLUTE MAXIMUM RATINGS
Supply Input Voltage --------------------------------------------------------------------------------------- 6V
Power Dissipation, PD@ TA=27
SOT-23-5(L) ----------------------------------------------------------------------------------------------- 400mW
SOT-23-3(L) ----------------------------------------------------------------------------------------------- 400mW
SOT-89-3(L) ----------------------------------------------------------------------------------------------- 600mW
SC-70 ---------------------------------------------------------------------------------------------------- 300mW
SOT-23 --------------------------------------------------------------------------------------------------- 250mW
Package Thermal Resistance
SOT-23-5(L)------------------------------------------------------------------------------------------------ 250
SOT-23-3(L)------------------------------------------------------------------------------------------------ 250
SOT-89-3(L)------------------------------------------------------------------------------------------------ 170
SC-70 ------------------------------------------------------------------------------------------------------- 330
SOT-23 ----------------------------------------------------------------------------------------------------- 380
Lead Temperature (Soldering, 10sec.) ----------------------------------------------------------------- 260
Storage Temperature Range -------------------------------------------------------------------------
ESD Susceptibility
60
to 150
HBM(Human Body Mode) -------------------------------------------------------------------------------4kV
MM(Machine Mode) --------------------------------------------------------------------------------------200V
*
Stresses exceed those listed under “Absolute Maximum Ratings” may cause permanent damage to the
device. Functional operation of the device at conditions beyond those listed in the specification is not
guaranteed. Prolonged exposure to extreme conditions may affect device reliability or functionality.
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Fremont Micro Devices
PIN CONFIGURATION
FT531xx
TERMINAL FUNCTION
Pin Name
EN
VIN
VOUT
NC
GND
Pin Function
Chip Enable (Active High). No Pull-Down Resistor Build-in
For package SOT-23-3(L) ,SOT-89-3(L) and SOT-23
VIN
Power Input Voltage
Output Voltage
No Connection
Ground
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Page 3 of 23
，
the EN is internally connected to
DS531-A8
Fremont Micro Devices
ORDERING INFORMATION
FT531xx
FT531
DESIGNATOR SYMBOL OUTPUT VOLTAGE
A
B
C
D
E
F
G
H
I
J
K
L
1.2V
1.3V
1.5V
1.8V
2.5V
2.7V
2.8V
2.85V
3.0V
3.3V
3.6V
4.2V
DESIGNATOR SYMBOL
a
b
c
d
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②①
②
①
PIN CONFIGURATION
SOT-23-5A
SOT-23-5B
SOT-23-5C
SC-70A
SC-70B
SC-70C
SOT-23-3A
SOT-23A
SOT-89-3A
PACKAGE TYPE
SOT-23-5(L)
e
f
g
h
i
SC-70 / SOT-353
SOT-23-3(L)
SOT-23
SOT-89-3(L)
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DS531-A8
Fremont Micro Devices
MARKING RULE
FT531xx
Represent Product Series
SYMBOL
6
PRODUCT SERIES
FT531xx
~ 85
Represent Output Voltage and operating temperature range
G represent the output voltage is 2.8V, operating temperature is –40
For internal reference
.
BLOCK DIAGRAM
Block Diagram
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