Datasheet

UNISONIC TECHNOLOGIES CO., LTD
LD3870
LINEAR INTEGRATED CIRCUIT
LOW DROPOUT VOLTAGE
REGULATOR

DESCRIPTION
The UTC LD3870 is low dropout voltage regulator
designed for cellular phone application.

FEATURES
* High Ripple Rejection: 56dB≤RR(DC<f<60kHz)
66dB typ. (f=100Hz)
60dB typ. (f=1kHz)
* Output Noise Voltage: eN=30ΜV , Cp=0.01μF
* Output Current: IO(MAX)=150mA
* High Precision Output: VO±2%
* Low Dropout Voltage: VD=0.12V typ.
(IO=60mA,Vo≥1.8V)
* Input Voltage range: +2~+14V(VO =1.5V Version)
* ON/OFF Control: Active High
* Output capacitor with 4.7uF ceramic capacitor
* Internal Short Circuit Current Limit
* Internal Thermal Overload Protection

ORDERING INFORMATION
Ordering Number
LD3870G-xx-AF5-R
www.unisonic.com.tw
Copyright © 2014 Unisonic Technologies Co., LTD
Package
SOT-25
Packing
Tape Reel
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QW-R102-027.G
LD3870
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LINEAR INTEGRATED CIRCUIT
MARKING INFORMATION
PACKAGE
VOLTAGE CODE
SOT-25
15:1.5V
18:1.8V
25:2.5V
27:2.7V
30:3.0V
33:3.3V
50:5.0V
MARKING
4
5
MXXG
1
2
Voltage Code
3
PIN CONFIGURATION
VIN
5
VOUT
4
3
1
2
CONT GND NOISE
BYPASS

BLOCK DAGRAM
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www.unisonic.com.tw
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LINEAR INTEGRATED CIRCUIT
ABSOLUTE MAXIMUM RATINGS (TA=25°C, unless otherwise specified)
PARAMETER
SYMBOL
RATINGS
UNIT
Input Voltage
VIN
+14
V
Control Voltage
VCONT
+14(Note 2)
V
Power Dissipation
PD
200
mW
Operating Temperature
TOPR
-40 ~ +85
°C
Storage Temperature
TSTG
-40 ~ +125
°C
Note 1: Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Absolute maximum ratings are stress ratings only and functional device operation is not implied.
2. When input voltage is less than +14V, the absolute maximum control voltage is equal to the input voltage.

ELECTRICAL CHARACTERISTICS
(VIN=VOUT+1V, CIN=0.1μF, COUT=4.7μF, Cp=0.01μF, TA=25°C)
PARAMETER
SYMBOL
TEST CONDITONS
MIN
TYP
MAX
UNIT
Output Voltage
VOUT
IOUT=30mA
-2%
+2%
V
Quiescent Current
IQ
IOUT=0mA, expect lCONT
200
300
μA
Quiescent Current
IQ(OFF)
VCONT=0V
1000
nA
At Control OFF
Output Current
IOUT
VOUT-0.3V
150
200
mA
Line Regulation
△VOUT/△VIN VIN=VOUT+1V ~ VOUT+6V, IOUT=30mA
0.10
%/V
Load Regulation
△VOUT/△IOUT IOUT=0 ~ 100mA
0.03 %/mA
Dropout Voltage
VD
IOUT=60mA
0.12
0.2
V
eIN=200mVrms, f=1kHz, IOUT=10mA,
60
dB
Ripple Rejection
RR
VIN=VOUT+2V, VOUT=3V Version
TA=0~85℃, IOUT=10mA,
Average Temperature
0.2
mV/°C
△VOUT/△TA
Coefficient of Output Voltage
VOUT=3V Version
f=10Hz ~ 80kHz, IOUT=10mA,
30
μVrms
Output Noise Voltage
eN
VOUT=3V Version
ON
VCONT(ON)
1.6
V
Control Voltage
OFF
VCONT(OFF)
0.6
V
Note: The above specification is a common specification for all output voltages. Therefore, it may be different from
the individual specification for a specific output voltage.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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QW-R102-027.G
LD3870
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LINEAR INTEGRATED CIRCUIT
TEST CIRCUIT
UNISONIC TECHNOLOGIES CO., LTD
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LD3870
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LINEAR INTEGRATED CIRCUIT
TYPICAL APPLICATON
For ON/OFF Control is not required:
VIN
4.7 μF
(ceramic or tantalum)
0.1 μF
UTC LD3870
R
(0~300kΩ)
VOUT
VOUT
NOISE
BYPASS
GND
CONTROL
Cp=0.01 μF
Connect control terminal to VIN terminal
The quiescent current can be reduced by using a resistance “R”. Instead, it increases the minimum operating
voltage. For further information, please refer to Figure ”Output Voltage vs. Control Voltage”.
For In use of ON/OFF CONTROL:
VIN
VIN
VOUT
0.1 μF
UTC LD3870
VOUT
4.7 μF
(ceramic or tantalum)
R
NOISE
BYPASS
GND
CONTROL
Cp=0.01 μF
State of control terminal:
* ”H”  Output is enables.
* ”L”or “open”  Output is disabled.
* Noise bypass Capacitance Cp
- Noise bypass capacitance Cp reduces noise generated by hand-gap reference circuit.
- Noise level and ripple rejection will be improved when larger Cp is used.
- Use of smaller Cp value may cause oscillation.
- Use the Cp value of 0.01uF greater to avoid the problem.
UTC assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or
other parameters) listed in products specifications of any and all UTC products described or contained
herein. UTC products are not designed for use in life support appliances, devices or systems where
malfunction of these products can be reasonably expected to result in personal injury. Reproduction in
whole or in part is prohibited without the prior written consent of the copyright owner. The information
presented in this document does not form part of any quotation or contract, is believed to be accurate
and reliable and may be changed without notice.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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