Datasheet

UNISONIC TECHNOLOGIES CO., LTD
LD2985
LINEAR INTEGRATED CIRCUIT
VERY LOW DROP AND LOW
NOISE VOLTAGE REGULATOR
LOW ESR CAP. COMPATIBLE,
WITH INHIBIT FUNCTION

DESCRIPTION
The UTC LD2985 is a 150mA fixed output voltage regulator. The
ultra low drop voltage and the low quiescent current make them
particularly suitable for low noise, low power applications, and in
battery powered systems. In sleep mode quiescent current is less
than 1μA when INHIBIT pin is pulled low. Shutdown Logic Control
Function is available on pin 3 (TTL compatible). This means that
when the device is used as local regulator, it is possible to put a part
of the board in standby, decreasing the total power consumption.
An external capacitor, CBYP=10nF, connected between bypass
pin and GND reduce the noise to 30μVrms.
Typical applications are in cellular phone, palmtop laptop
computer, personal digital assistant (PDA), personal stereo,
camcorder and camera.

FEATURES
* Very Low Dropout Voltage (280mV at 150mA and 7mV at 1mA load)
* Very Low Quiescent current
* Output Current up to 150mA
* Logic Controlled Electronic Shutdown
* Output Voltage of 1.5, 1.8, 2.5, 2.8, 2.85, 3, 3.1, 3.2, 3.3, 3.5, 3.6, 3.8, 4, 4.7, 5V
* Internal Current and Thermal Limit
* Low Output Noise Voltage 30μVrms

ORDERING INFORMATION
Ordering Number
LD2985G-xx-AF5-R
Note: xx: Output Voltage, refer to Marking Information.
www.unisonic.com.tw
Copyright © 2016 Unisonic Technologies Co., Ltd
Package
SOT-25
Packing
Tape Reel
1 of 15
QW-R102-024.L
LD2985

LINEAR INTEGRATED CIRCUIT
MARKING INFORMATION
PACKAGE
SOT-25
VOLTAGE
1.5V
1.8V
2.5V
2.8V
2.85V
3.0V
3.1V
3.2V
3.3V
3.5V
3.6V
3.8V
4.0V
4.7V
5.0V

PIN CONFIGURATION

PIN DESCRIPTION
PIN NO.
1
2
3
4
5
VOLTAGE CODE
A5
A8
B5
B8
BJ
C0
C1
C2
C3
C5
C6
C8
D0
D7
E0
MARKING
PIN NAME
DESCRIPTION
IN
Input port
GND
Ground pin
Control switches ON/OFF. Inhibit is not internally pulled-up; it cannot be left floating.
INHIBIT
Disable the device when connected to GND or to a positive voltage less than 0.18V
Bypass pin: Capacitor to be connected to GND in order to improve the thermal noise
Bypass
performances.
OUT
Output port
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
2 of 15
QW-R102-024.L
LD2985

LINEAR INTEGRATED CIRCUIT
BLOCK DIAGRAM
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
3 of 15
QW-R102-024.L
LD2985

LINEAR INTEGRATED CIRCUIT
ABSOLUTE MAXIMUM RATINGS
PARAMETER
SYMBOL
RATINGS
UNIT
DC Input Voltage
ViN
16
V
INHIBIT Input Voltage
VINH
16
V
Output Current
IOUT
Internally limited
Power Dissipation
PD
Internally limited
Operating Junction Temperature (Note 2)
TOPR
-40 ~ +125
°C
Storage Temperature
TSTG
-40 ~ +150
°C
Notes: 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. This condition is only determined from design. It can't be 100% tested in mass production.

THERMAL DATA
PARAMETER
SYMBOL
θJC
Junction to Case

RATINGS
81
UNIT
°C/W
ELECTRICAL CHARACTERISTICS
(TJ=25°C, VI N=VOUT+1V, IOUT=1mA, VSHDN=2V, CI =1μF, CO=1μF, unless otherwise specified)
FOR VOUT=1.5V
PARAMETER
Operating Input Voltage
Output Voltage
Short Circuit Current
Line Regulation
SYMBOL
VI(OPR)
VOUT
ISC
△VOUT
Dropout Voltage
VD
Quiescent Current
IQ
Supply Voltage Rejection
Control Input Logic Low
Control Input Logic High
SVR
VIL
VIH
Control Input Current
IINH
Output Noise Voltage
eN
TEST CONDITIONS
VIN=2.5V
IOUT=1 ~ 150mA
RL=0
VIN=VOUT+1V ~ 16V, IOUT=1mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
OFF MODE VINH<0.18V
CBYP=0.01μF, CO=10μF, f=1KHz
TJ=-20 ~125°C
TJ=-20 ~125°C
TJ=-20 ~125°C, VSHDN=VIN
TJ=-20 ~125°C, VSHDN=0V
B=300Hz ~ 50KHz,
CBYP=0.01μF, CO=10μF
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
MIN
TYP
1.470
1.455
1.5
MAX
16
1.530
1.545
600
1
7
40
120
280
80
100
280
1050
2900
1.5
45
30
3
10
60
150
350
100
150
330
1300
3300
0.15
2
5
0
30
15
-1
UNIT
V
V
V
mA
mV
mV
mV
mV
mV
mV
μA
μA
μA
μA
μA
μA
dB
V
V
μA
μA
μV
4 of 15
QW-R102-024.L
LD2985

LINEAR INTEGRATED CIRCUIT
ELECTRICAL CHARACTERISTICS(Cont.)
FOR VOUT=1.8V
PARAMETER
Operating Input Voltage
Output Voltage
Short Circuit Current
Line Regulation
SYMBOL
VI(OPR)
VOUT
ISC
△VOUT
Dropout Voltage
VD
Quiescent Current
IQ
Supply Voltage Rejection
Control Input Logic Low
Control Input Logic High
SVR
VIL
VIH
Control Input Current
IiNH
Output Noise Voltage
eN
FOR VOUT=2.5V
PARAMETER
Operating Input Voltage
Output Voltage
Short Circuit Current
Line Regulation
SYMBOL
VI(OPR)
VOUT
ISC
△VOUT
Dropout Voltage
VD
Quiescent Current
IQ
Supply Voltage Rejection
Control Input Logic Low
Control Input Logic High
SVR
VIL
VIH
Control Input Current
IINH
Output Noise Voltage
eN
TEST CONDITIONS
VIN=2.8V
IOUT=1 ~ 150mA
RL=0
VIN=VOUT+1V ~ 16V, IOUT=1mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
OFF MODE VINH<0.18V
CBYP=0.01μF, Co=10μF, f=1KHz
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C, VSHDN=VIN
TJ=-20 ~ 125°C, VSHDN=0V
B=300Hz ~ 50KHz
CBYP=0.01μF, Co=10μF
TEST CONDITIONS
VIN=3.5V
IOUT=1 ~ 150mA
RL=0
VIN=VOUT+1V ~ 16V, IOUT=1mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
OFF MODE VINH<0.18V
CBYP=0.01μF, Co=10μF, f=1KHz
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C, VSHDN=VIN
TJ=-20 ~ 125°C, VSHDN=0V
B=300Hz ~ 50KHz
CBYP=0.01μF, Co=10μF
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
MIN
TYP
1.764
1.746
1.8
MAX
16
1.836
1.854
600
1
7
40
120
280
80
100
280
1050
2900
1.5
45
30
3
10
60
150
350
100
150
330
1300
3300
0.15
2
5
0
15
-1
30
MIN
TYP
2.450
2.425
2.5
μV
MAX
16
2.550
2.575
600
1
7
40
120
280
80
100
280
1050
2900
1.5
45
30
3
10
60
150
350
100
150
330
1300
3300
0.15
2
5
0
30
UNIT
V
V
V
mA
mV
mV
mV
mV
mV
mV
μA
μA
μA
μA
μA
μA
dB
V
V
μA
μA
15
-1
UNIT
V
V
V
mA
mV
mV
mV
mV
mV
mV
μA
μA
μA
μA
μA
μA
dB
V
V
μA
μA
μV
5 of 15
QW-R102-024.L
LD2985

LINEAR INTEGRATED CIRCUIT
ELECTRICAL CHARACTERISTICS(Cont.)
FOR VOUT=2.8V
PARAMETER
Operating Input Voltage
Output Voltage
Short Circuit Current
Line Regulation
SYMBOL
VI(OPR)
VOUT
ISC
△VOUT
Dropout Voltage
VD
Quiescent Current
IQ
Supply Voltage Rejection
Control Input Logic Low
Control Input Logic High
SVR
VIL
VIH
Control Input Current
IINH
Output Noise Voltage
eN
FOR VOUT=2.85V
PARAMETER
Operating Input Voltage
Output Voltage
Short Circuit Current
Line Regulation
SYMBOL
VI(OPR)
VOUT
ISC
△VOUT
Dropout Voltage
VD
Quiescent Current
IQ
Supply Voltage Rejection
Control Input Logic Low
Control Input Logic High
SVR
VIL
VIH
Control Input Current
IINH
Output Noise Voltage
eN
TEST CONDITIONS
VIN=3.8V
IOUT=1 ~ 150mA
RL=0
VIN=VOUT+1V ~ 16V, IOUT=1mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
OFF MODE VINH<0.18V
CBYP=0.01μF, Co=10μF, f=1KHz
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C, VSHDN=VIN
TJ=-20 ~ 125°C, VSHDN=0V
B=300Hz ~ 50KHz
CBYP=0.01μF, Co=10μF
TEST CONDITIONS
VIN=3.85V
IOUT=1 ~ 150mA
RL=0
VIN=VOUT+1V ~ 16V, IOUT=1mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
OFF MODE VINH<0.18V
CBYP=0.01μF, CO=10μF, f=1KHz
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C, VSHDN=VIN
TJ=-20 ~ 125°C, VSHDN=0V
B=300Hz ~ 50KHz
CBYP=0.01μF, CO=10μF
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
MIN
TYP
2.744
2.716
2.8
MAX
16
2.856
2.884
600
1
7
40
120
280
80
100
280
1050
2900
1.5
45
30
3
10
60
150
350
100
150
330
1300
3300
0.15
2
5
0
15
-1
30
MIN
TYP
2.793
2.764
2.85
μV
MAX
16
2.907
2.936
600
1
7
40
120
280
80
100
280
1050
2900
1.5
45
30
3
10
60
150
350
100
150
330
1300
3300
0.15
2
5
0
30
UNIT
V
V
V
mA
mV
mV
mV
mV
mV
mV
μA
μA
μA
μA
μA
μA
dB
V
V
μA
μA
15
-1
UNIT
V
V
V
mA
mV
mV
mV
mV
mV
mV
μA
μA
μA
μA
μA
μA
dB
V
V
μA
μA
μV
6 of 15
QW-R102-024.L
LD2985

LINEAR INTEGRATED CIRCUIT
ELECTRICAL CHARACTERISTICS(Cont.)
FOR VOUT=3.0V
PARAMETER
Operating Input Voltage
Output Voltage
Short Circuit Current
Line Regulation
SYMBOL
VI(OPR)
VOUT
ISC
△VOUT
Dropout Voltage
VD
Quiescent Current
IQ
Supply Voltage Rejection
Control Input Logic Low
Control Input Logic High
SVR
VIL
VIH
Control Input Current
IINH
Output Noise Voltage
eN
FOR VOUT=3.1V
PARAMETER
Operating Input Voltage
Output Voltage
Short Circuit Current
Line Regulation
SYMBOL
VI(OPR)
VOUT
ISC
△VOUT
Dropout Voltage
VD
Quiescent Current
IQ
Supply Voltage Rejection
Control Input Logic Low
Control Input Logic High
SVR
VIL
VIH
Control Input Current
IINH
Output Noise Voltage
eN
TEST CONDITIONS
VIN=4.0V
IOUT=1 ~ 150mA
RL=0
VIN=VOUT+1V ~ 16V, IOUT=1mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
OFF MODE VINH<0.18V
CBYP=0.01μF, CO=10μF, f=1KHz
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C, VSHDN=VIN
TJ=-20 ~ 125°C, VSHDN=0V
B=300Hz ~ 50KHz
CBYP=0.01μF, CO=10μF
TEST CONDITIONS
VIN=4.1V
IOUT=1 ~ 150mA
RL=0
VIN=VOUT+1V ~ 16V, IOUT=1mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
OFF MODE VINH<0.18V
CBYP=0.01μF, CO=10μF, f=1KHz
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C, VSHDN=VIN
TJ=-20 ~ 125°C, VSHDN=0V
B=300Hz ~ 50KHz
CBYP=0.01μF, CO=10μF
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
MIN
TYP
2.940
2.910
3.0
MAX
16
3.060
3.090
600
1
7
40
120
280
80
100
280
1050
2900
1.5
45
30
3
10
60
150
350
100
150
330
1300
3300
0.15
2
5
0
15
-1
30
MIN
TYP
3.038
3.007
3.1
μV
MAX
16
3.162
3.193
600
1
7
40
120
280
80
100
280
1050
2900
1.5
45
30
3
10
60
150
350
100
150
330
1300
3300
0.15
2
5
0
30
UNIT
V
V
V
mA
mV
mV
mV
mV
mV
mV
μA
μA
μA
μA
μA
μA
dB
V
V
μA
μA
15
-1
UNIT
V
V
V
mA
mV
mV
mV
mV
mV
mV
μA
μA
μA
μA
μA
μA
dB
V
V
μA
μA
μV
7 of 15
QW-R102-024.L
LD2985

LINEAR INTEGRATED CIRCUIT
ELECTRICAL CHARACTERISTICS(Cont.)
FOR VOUT=3.2V
PARAMETER
Operating Input Voltage
Output Voltage
Short Circuit Current
Line Regulation
SYMBOL
VI(OPR)
VOUT
ISC
△VOUT
Dropout Voltage
VD
Quiescent Current
IQ
Supply Voltage Rejection
Control Input Logic Low
Control Input Logic High
SVR
VIL
VIH
Control Input Current
IINH
Output Noise Voltage
eN
FOR VOUT=3.3V
PARAMETER
Operating Input Voltage
Output Voltage
Short Circuit Current
Line Regulation
SYMBOL
VI(OPR)
VOUT
ISC
△VOUT
Dropout Voltage
VD
Quiescent Current
IQ
Supply Voltage Rejection
Control Input Logic Low
Control Input Logic High
SVR
VIL
VIH
Control Input Current
IINH
Output Noise Voltage
eN
TEST CONDITIONS
VIN=4.2V
IOUT=1 ~ 150mA
RL=0
VIN=VOUT+1V ~ 16V, IOUT=1mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
OFF MODE VINH<0.18V
CBYP=0.01μF, CO=10μF, f=1KHz
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C, VSHDN=VIN
TJ=-20 ~ 125°C, VSHDN=0V
B=300Hz ~ 50KHz
CBYP=0.01μF, CO=10μF
TEST CONDITIONS
VIN=4.3V
IOUT=1 ~ 150mA
RL=0
VIN=VOUT+1V ~ 16V, IOUT=1mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
OFF MODE VINH<0.18V
CBYP=0.01μF, CO=10μF, f=1KHz
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C, VSHDN=VIN
TJ=-20 ~ 125°C, VSHDN=0V
B=300Hz ~ 50KHz
CBYP=0.01μF, CO=10μF
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
MIN
TYP
3.136
3.104
3.2
MAX
16
3.264
3.296
600
1
7
40
120
280
80
100
280
1050
2900
1.5
45
30
3
10
60
150
350
100
150
330
1300
3300
0.15
2
5
0
15
-1
30
MIN
TYP
3.234
3.201
3.3
μV
MAX
16
3.366
3.399
600
1
7
40
120
280
80
100
280
1050
2900
1.5
45
30
3
10
60
150
350
100
150
330
1300
3300
0.15
2
5
0
30
UNIT
V
V
V
mA
mV
mV
mV
mV
mV
mV
μA
μA
μA
μA
μA
μA
dB
V
V
μA
μA
15
-1
UNIT
V
V
V
mA
mV
mV
mV
mV
mV
mV
μA
μA
μA
μA
μA
μA
dB
V
V
μA
μA
μV
8 of 15
QW-R102-024.L
LD2985

LINEAR INTEGRATED CIRCUIT
ELECTRICAL CHARACTERISTICS(Cont.)
FOR VOUT=3.5V
PARAMETER
Operating Input Voltage
Output Voltage
Short Circuit Current
Line Regulation
SYMBOL
VI(OPR)
VOUT
ISC
△VOUT
Dropout Voltage
VD
Quiescent Current
IQ
Supply Voltage Rejection
Control Input Logic Low
Control Input Logic High
SVR
VIL
VIH
Control Input Current
IINH
Output Noise Voltage
eN
FOR VOUT=3.6V
PARAMETER
Operating Input Voltage
Output Voltage
Short Circuit Current
Line Regulation
SYMBOL
VI(OPR)
VOUT
ISC
△VOUT
Dropout Voltage
VD
Quiescent Current
IQ
Supply Voltage Rejection
Control Input Logic Low
Control Input Logic High
SVR
VIL
VIH
Control Input Current
IINH
Output Noise Voltage
eN
TEST CONDITIONS
VIN=4.5V
IOUT=1 ~ 150mA
RL=0
VIN=VOUT+1V ~ 16V, IOUT=1mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
OFF MODE VINH<0.18V
CBYP=0.01μF, CO=10μF, f=1KHz
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C, VSHDN=VIN
TJ=-20 ~ 125°C, VSHDN=0V
B=300Hz ~ 50KHz
CBYP=0.01μF, CO=10μF
TEST CONDITIONS
VIN=4.6V
IOUT=1 ~ 150mA
RL=0
VIN=VOUT+1V ~ 16V, IOUT=1mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
OFF MODE VINH<0.18V
CBYP=0.01μF, CO=10μF, f=1KHz
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C, VSHDN=VIN
TJ=-20 ~ 125°C, VSHDN=0V
B=300Hz ~ 50KHz
CBYP=0.01μF, CO=10μF
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
MIN
TYP
3.430
3.395
3.5
MAX
16
3.570
3.605
600
1
7
40
120
280
80
100
280
1050
2900
1.5
45
30
3
10
60
150
350
100
150
330
1300
3300
0.15
2
5
0
15
-1
30
MIN
TYP
3.528
3.492
3.6
μV
MAX
16
3.672
3.708
600
1
7
40
120
280
80
100
280
1050
2900
1.5
45
30
3
10
60
150
350
100
150
330
1300
3300
0.15
2
5
0
30
UNIT
V
V
V
mA
mV
mV
mV
mV
mV
mV
μA
μA
μA
μA
μA
μA
dB
V
V
μA
μA
15
-1
UNIT
V
V
V
mA
mV
mV
mV
mV
mV
mV
μA
μA
μA
μA
μA
μA
dB
V
V
μA
μA
μV
9 of 15
QW-R102-024.L
LD2985

LINEAR INTEGRATED CIRCUIT
ELECTRICAL CHARACTERISTICS(Cont.)
FOR VOUT=3.8V
PARAMETER
Operating Input Voltage
Output Voltage
Short Circuit Current
Line Regulation
SYMBOL
VI(OPR)
VOUT
ISC
△VOUT
Dropout Voltage
VD
Quiescent Current
IQ
Supply Voltage Rejection
Control Input Logic Low
Control Input Logic High
SVR
VIL
VIH
Control Input Current
IINH
Output Noise Voltage
eN
FOR VOUT=4.0V
PARAMETER
Operating Input Voltage
Output Voltage
Short Circuit Current
SYMBOL
VI(OPR)
VOUT
ISC
Dropout Voltage
VD
Quiescent Current
IQ
Supply Voltage Rejection
Control Input Logic Low
Control Input Logic High
SVR
VIL
VIH
Control Input Current
IINH
Output Noise Voltage
eN
TEST CONDITIONS
VIN=4.8V
IOUT=1 ~ 150mA
RL=0
VIN=VOUT+1V ~ 16V, IOUT=1mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
OFF MODE VINH<0.18V
CBYP=0.01μF, CO=10μF, f=1KHz
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C, VSHDN=VIN
TJ=-20 ~ 125°C, VSHDN=0V
B=300Hz ~ 50KHz
CBYP=0.01μF, CO=10μF
TEST CONDITIONS
VIN=5.0V
IOUT=1 ~ 150mA
RL=0
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
OFF MODE VINH<0.18V
CBYP=0.01μF, CO=10μF, f=1KHz
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C, VSHDN=VIN
TJ=-20 ~ 125°C, VSHDN=0V
B=300Hz ~ 50KHz
CBYP=0.01μF, CO=10μF
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
MIN
TYP
3.724
3.686
3.8
MAX
16
3.876
3.914
600
1
7
40
120
280
80
100
280
1050
2900
1.5
45
30
3
10
60
150
350
100
150
330
1300
3300
0.15
2
5
0
15
-1
30
MIN
TYP
3.920
3.880
4
600
1
7
40
120
280
80
100
280
1050
2900
1.5
45
μV
MAX
16
4.080
4.120
3
10
60
150
350
100
150
330
1300
3300
0.15
2
5
0
30
UNIT
V
V
V
mA
mV
mV
mV
mV
mV
mV
μA
μA
μA
μA
μA
μA
dB
V
V
μA
μA
15
-1
UNIT
V
V
V
mA
mV
mV
mV
mV
mV
μA
μA
μA
μA
μA
μA
dB
V
V
μA
μA
μV
10 of 15
QW-R102-024.L
LD2985

LINEAR INTEGRATED CIRCUIT
ELECTRICAL CHARACTERISTICS(Cont.)
FOR VOUT=4.7V
PARAMETER
Operating Input Voltage
Output Voltage
Short Circuit Current
Line Regulation
SYMBOL
VI(OPR)
VOUT
ISC
△VOUT
Dropout Voltage
VD
Quiescent Current
IQ
Supply Voltage Rejection
Control Input Logic Low
Control Input Logic High
SVR
VIL
VIH
Control Input Current
IINH
Output Noise Voltage
eN
FOR VOUT=5.0V
PARAMETER
Operating Input Voltage
Output Voltage
Short Circuit Current
Line Regulation
SYMBOL
VI(OPR)
VOUT
ISC
△VOUT
Dropout Voltage
VD
Quiescent Current
IQ
Supply Voltage Rejection
Control Input Logic Low
Control Input Logic High
SVR
VIL
VIH
Control Input Current
IINH
Output Noise Voltage
eN
TEST CONDITIONS
VIN=5.7V
IOUT=1 ~ 150mA
RL=0
VIN=VOUT+1V ~ 16V, IOUT=1mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
OFF MODE VINH<0.18V
CBYP=0.01μF, CO=10μF, f=1KHz
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C, VSHDN=VIN
TJ=-20 ~ 125°C, VSHDN=0V
B=300Hz ~ 50KHz
CBYP=0.01μF, CO=10μF
TEST CONDITIONS
VIN=6.0V
IOUT=1 ~ 150mA
RL=0
VIN=VOUT+1V ~ 16V, IOUT=1mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
IOUT=0
IOUT=1mA
IOUT=10mA
IOUT=50mA
IOUT=150mA
OFF MODE VINH<0.18V
CBYP=0.01μF, CO=10μF, f=1KHz
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C
TJ=-20 ~ 125°C, VSHDN=VIN
TJ=-20 ~ 125°C, VSHDN=0V
B=300Hz ~ 50KHz
CBYP=0.01μF, CO=10μF
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
MIN
TYP
4.606
4.559
4.7
MAX
16
4.794
4.841
600
1
7
40
120
280
80
100
280
1050
2900
1.5
45
30
3
10
60
150
350
100
150
330
1300
3300
0.15
2
5
0
15
-1
30
MIN
TYP
4.900
4.850
5
μV
MAX
16
5.100
5.150
600
1
7
40
120
280
80
100
280
1050
2900
1.5
45
30
3
10
60
150
350
100
150
330
1300
3300
0.15
2
5
0
30
UNIT
V
V
V
mA
mV
mV
mV
mV
mV
mV
μA
μA
μA
μA
μA
μA
dB
V
V
μA
μA
15
-1
UNIT
V
V
V
mA
mV
mV
mV
mV
mV
mV
μA
μA
μA
μA
μA
μA
dB
V
V
μA
μA
μV
11 of 15
QW-R102-024.L
LD2985

REVERSE CURRENT TEST CIRCUIT

APPLICATION INFORMATION
LINEAR INTEGRATED CIRCUIT
EXTERNAL CAPACITORS
Like any low-dropout regulator, the UTC LD2985 requires external capacitors for regulator stability. This
capacitor must be selected to meet the requirements of minimum capacitance and equivalent series resistance. We
suggest soldering input and outputting capacitors as close as possible to the relative pins.
INPUT CAPACITOR
An input capacitor whose value is 1μF is required with the UTC LD2985 (amount of capacitance can be
increased without limit). This capacitor must be located a distance of not more than 0.5" from the input pin of the
device and returned to a clean analog ground. Any good quality ceramic, tantalum or film capacitors can be used for
this capacitor.
OUTPUT CAPACITOR
The UTC LD2985 is designed specifically to work with ceramic output capacitors. It may also be possible to use
Tantalum capacitors, but these are not as attractive for reasons of size and cost. By the way, the output capacitor
must meet both the requirement for minimum amount of capacitance and E.S.R. (equivalent series resistance) value.
Due to the different loop gain, the stability improves for higher output versions and so the suggested minimum output
capacitor value, if low E.S.R. ceramic type is used, is 1μF for output voltages equal or major than 3.8V, 2.2μF for VO
going from 1.8 ~ 3.3V, and 3.3μF for the other versions. However, if an output capacitor lower than the suggested
one is used, it's possible to make stable the regulator adding a resistor in series to the capacitor.
IMPORTANT:
The output capacitor must maintain its ESR in the stable region over the full operating temperature to assure
stability. Also, capacitor tolerance and variation with temperature must be considered to assure the minimum amount
of capacitance is provided at all times. This capacitor should be located not more than 0.5" from the output pin of the
device and returned to a clean analog ground.
INHIBIT INPUT OPERATION
The inhibit pin can be used to turn OFF the regulator when pulled low, so drastically reducing the current
consumption down to less than 1μA. When the inhibit feature is not used, this pin must be tied to Vi to keep the
regulator output ON at all times. To assure proper operation, the signal source used to drive the inhibit pin must be
able to swing above and below the specified thresholds listed in the electrical characteristics section under VIH VIL.
Any slew rate can be used to drive the inhibit.
REVERSE CURRENT
The power transistor used in the UTC LD2985 has not an inherent diode connected between the regulator input
and output. If the output is forced above the input, no current will flow from the output to the input across the series
pass transistor. When a VREV voltage is applied on the output, the reverse current measured flows to the GND
across the two feedback resistors. This current typical value is 160μA. R1 and R2 resistors are implanted type; typical
values are, respectively, 42.6KΩ and 51.150KΩ.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
12 of 15
QW-R102-024.L
LD2985

LINEAR INTEGRATED CIRCUIT
TYPICAL CHARACTERISTICS (TJ=25°C, CI=1μF, CO=2.2μF, CBYP=100nF)
Output Voltage vs Temperature
Quiescent Current vs Load Current
2.60
3000
VIN=3.5V
2.58 IOUT=1mA
VOUT=2.5V
CBY=10nF
2500
2.54
2000
2.52
IQ (μA)
Output Voltage, VOUT (V)
2.56
2.50
1500
2.48
1000
2.46
2.44
500
2.42
2.40
-50
0
-25
50
25
Tc (°C)
75
100
0
125
0
Dropout Voltage vs Temperature
0.4
VOUT=2.5V
Cby=10nF
IOUT=150mA
IOUT=150mA
175
VOUT=2.5V
CBY=10nF
3.5
3.0
0.3
2.5
0.2
IQ (mA)
Dropout Voltage, VD (V)
50
100
75
125 150
IOUT (mA)
Quiescent Current vs Temperature
25
IOUT=50mA
2.0
1.5
1.0
0.1
IOUT=10mA
0.5
IOUT=1mA
0
-50
-25
0
50
25
Tc (°C)
75
100
0
-50
125
Supply Voltage Rejection, SVR (dB)
Dropout Voltage, VD (mV)
200
150
100
VOUT=2.5V
0
25
125
75
100
50
Output Current, IOUT (mA)
150
175
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
25
50
)
75
100
125
Supply Voltage Rejection vs Temperature
250
0
0
TC (
Dropout Voltage vs Output Current
50
-25
fosc=1KHz
VIN=3.5 ~ 6.5V
90 IOUT=10mA
80
Co=10μF
70
Co=1μF
60
50
40
30
20
-50
-25
0
50
25
Tc (°C)
75
100
125
13 of 15
QW-R102-024.L
LD2985

LINEAR INTEGRATED CIRCUIT
TYPICAL CHARACTERISTICS(Cont.) (TJ=25°C, CI=1μF, CO=2.2μF, CBYP=100nF)
Supply Voltage Rejection vs Output Current
Supply Voltage Rejection vs Frequency
80
100
Supply Voltage Rejection, SVR (dB)
Supply Voltage Rejection, SVR (dB)
70
80
60
40
20
0
VIN=3.5 ~ 6.5V
CO=10μF
fosc=1KHz
0
100
50
40
30
20
VIN=3.5 ~ 6.5V
IOUT=10mA
10
VOUT=2.5V
CO=1μF
0
1
10
2
10
Frequency, f (KHz)
Supply Voltage Rejection vs Output Current
Line Transient
75
150
125
175
10
3
Output Current, IOUT (mA)
25
50
60
10
4
10
5
100
Supply Voltage Rejection, SVR (dB)
Tek Run:5.00MS/s
80
60
VIN
1
40
1
20
0
VOUT
VIN=3.5 ~ 6.5V
CO=1μF
fosc=1KHz
0
25
50
100
75
150
125
Ch1 500mV Ch2
CH2 20.0mV M 10.0μs Ch1
175
Output Current, IOUT (mA)
Line Transient
Supply Voltage Rejection vs Frequency
70
Supply Voltage Rejection, SVR (dB)
3.96V
VOUT=2.5V, IOUT=50mA, no CIN, COUT=4.7μF, tr=tf=20ns
Tek Run:5.00MS/s
60
VIN
50
1
40
30
VOUT
20
10
2
VIN=2.8 ~ 5.8V
IOUT=10mA
VOUT=1.8V
CO=10μF
0
1
10
10
2
10
3
10
4
10
5
Frequency, f (KHz)
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
CH2 20.0mV
Ch1 500mV Ch2
M 10.0μs Ch1
3.96V
VOUT=2.5V, IOUT=50mA, no CIN, COUT=4.7μF, tr=tf=1μs
14 of 15
QW-R102-024.L
LD2985

LINEAR INTEGRATED CIRCUIT
TYPICAL CHARACTERISTICS(Cont.) (TJ=25°C, CI=1μF, CO=2.2μF, CBYP=100nF)
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
15 of 15
QW-R102-024.L
Similar pages