UNISONIC TECHNOLOGIES CO., LTD
LD3870
LOW DROPOUT VOLTAGE
REGULATOR
DESCRIPTION
The UTC
LD3870
is low dropout voltage regulator designed
for cellular phone application.
LINEAR INTEGRATED CIRCUIT
FEATURES
* High Ripple Rejection: 56dB≤RR(DC<f<60kHz)
66dB typ. (f=100Hz)
60dB typ. (f=1kHz)
* Output Noise Voltage:
e
N
=30ΜV , Cp=0.01μF
* Output Current: I
O(MAX)
=150mA
* High Precision Output: V
O
±2%
* Low Dropout Voltage: V
D
=0.12V typ.
(I
O
=60mA,Vo≥1.8V)
* Input Voltage range: +2~+14V(V
O
=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
Lead Free
LD3870L-xx-AF5-R
Halogen Free
LD3870G-xx-AF5-R
Package
SOT-25
Packing
Tape Reel
www.unisonic.com.tw
Copyright © 2013 Unisonic Technologies Co., LTD
1 of 5
QW-R105-028,E
LD3870
MARKING INFORMATION
PACKAGE
VOLTAGE CODE
15:1.5V
18:1.8V
25:2.5V
27:2.7V
30:3.0V
33:3.3V
50:5.0V
5
LINEAR INTEGRATED CIRCUIT
MARKING
4
L: Lead Free
G: Halogen Free
SOT-25
MXX□
Voltage Code
3
1
2
PIN CONFIGURATION
V
IN
5
V
OUT
4
3
2
CONT GND NOISE
BYPASS
1
BLOCK DAGRAM
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
2 of 5
QW-R105-028,E
LD3870
PARAMETER
LINEAR INTEGRATED CIRCUIT
ABSOLUTE MAXIMUM RATINGS
(T
A
=25°C, unless otherwise specified)
SYMBOL
RATINGS
UNIT
Input Voltage
V
IN
+14
V
Control Voltage
V
CONT
+14(Note 2)
V
Power Dissipation
P
D
200
mW
Operating Temperature
T
OPR
-40 ~ +85
°C
Storage Temperature
T
STG
-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
(V
IN
=V
OUT
+1V, C
IN
=0.1μF, C
OUT
=4.7μF, Cp=0.01μF, T
A
=25°C)
PARAMETER
SYMBOL
TEST CONDITONS
MIN
TYP
MAX
UNIT
Output Voltage
V
OUT
I
OUT
=30mA
-2%
+2%
V
Quiescent Current
I
Q
I
OUT
=0mA, expect l
CONT
200
300
μA
Quiescent Current
I
Q(OFF)
V
CONT
=0V
100
nA
At Control OFF
Output Current
I
OUT
V
OUT
-0.3V
150
200
mA
Line Regulation
△
V
OUT
/
△
V
IN
V
IN
=V
OUT
+1V ~ V
OUT
+6V, I
OUT
=30mA
0.10
%/V
Load Regulation
△
V
OUT
/
△
I
OUT
I
OUT
=0 ~ 100mA
0.03 %/mA
Dropout Voltage
V
D
I
OUT
=60mA
0.12
0.2
V
e
IN
=200mVrms, f=1kHz, I
OUT
=10mA,
60
dB
Ripple Rejection
RR
V
IN
=V
OUT
+2V, V
OUT
=3V Version
T
A
=0~85
℃
, I
OUT
=10mA,
Average Temperature
△
V
OUT
/
△
T
A
0.2
mV/°C
Coefficient of Output Voltage
V
OUT
=3V Version
f=10Hz ~ 80kHz, I
OUT
=10mA,
30
μVrms
Output Noise Voltage
e
N
V
OUT
=3V Version
ON
V
CONT(ON)
1.6
V
Control Voltage
OFF
V
CONT(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
3 of 5
QW-R105-028,E
LD3870
TEST CIRCUIT
LINEAR INTEGRATED CIRCUIT
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
4 of 5
QW-R105-028,E
LD3870
TYPICAL APPLICATON
For ON/OFF Control is not required:
V
IN
0.1
μF
V
OUT
LINEAR INTEGRATED CIRCUIT
V
OUT
4.7
μF
(ceramic or tantalum)
UTC LD3870
R
(0~300kΩ)
NOISE
BYPASS
GND
CONTROL
Cp=0.01
μF
Connect control terminal to V
IN
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:
V
IN
0.1
μF
V
IN
V
OUT
V
OUT
4.7
μF
(ceramic or tantalum)
UTC LD3870
R
CONTROL
NOISE
BYPASS
GND
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
5 of 5
QW-R105-028,E
京公网安备 11010802033920号
EEWORLD
