UNISONIC TECHNOLOGIES CO., LTD
LD1985
VERY LOW DROP AND LOW
NOISE VOLTAGE REGULATOR
LOW ESR CAP. COMPATIBLE,
WITH INHIBIT FUNCTION
DESCRIPTION
The UTC LD1985 is a 150mA fixed output voltage regulator with
ultra low drop voltage and the low quiescent current. It is specially
designed for low noise, low power applications and in battery
powered systems, such as Cell phones, palmtop laptop computer,
PDAs, DSC.
The quiescent current in sleep mode is less than 1µA when
INHIBIT pin is pulled low. Due to Shutdown Logic Control Function
is available on pin 3 (TTL compatible), 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 Besides, an external
capacitor, C
BYP
=10nF, connected between bypass pin and GND
could reduce the noise to 30µVrms.
LINEAR INTEGRATED CIRCUIT
3
2
1
4
5
SOT-25
*Pb-free plating product number: LD1985L
FEATURES
*Very low dropout voltage (280mV at 150mA and 7mV at 1mA load)
*Very low quiescent current (2mA typ. at 150mA load and 80µA at
no load)
*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, 5.0V
*Internal current and thermal limit
*± 1% tolerance version is available.(at 25℃)
*Low output noise voltage 30µVrms
ORDERING INFORMATION
Order Number
Package
Normal
Lead Free Plating
LD1985-xx-AF5-R
LD1985L-xx-AF5-R
SOT-25
Note: xx: Output Voltage, refer to Marking Information.
LD1985L-xx-AF5-R
(1)Packing Type
(2)Package Type
(3)Output Voltage Code
(4)Lead Plating
(1) R: Tape Reel
(2) AF5: SOT-25
(3) xx: refer to Marking Information
(4) L: Lead Free Plating, Blank: Pb/Sn
Packing
Tape Reel
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Copyright © 2005 Unisonic Technologies Co., Ltd
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QW-R102-021,C
LD1985
MARKING INFORMATION
PACKAGE
VOLTAGE CODE
15:1.5V
18:1.8V
25:2.5V
28:2.8V
2J:2.85V
30:3.0V
31:3.1V
32:3.2V
33:3.3V
35:3.5V
36:3.6V
38:3.8V
40:4.0V
47:4.7V
50:5.0V
LINEAR INTEGRATED CIRCUIT
MARKING
3
2
1
Lead Plating
SOT-25
LD
Voltage Code
4
5
PIN DESCRIPTION
PIN NO.
1
2
3
4
5
PIN NAME
V
IN
GND
INHIBIT
Bypass
V
OUT
FUNCTION
Input
Ground
Control switch ON/OFF. Inhibit is not internally pulled-up; it cannot be left floating.
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
performances.
Output
THERMAL DATA
PARAMETER
Thermal Resistance Junction-Case
SYMBOL
θ
JC
RATINGS
81
UNIT
℃/W
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QW-R102-021,C
LD1985
BLOCK DIAGRAM
V
IN
CURRENT
LIMIT
START-UP
SHUTDOWN
REFERENCE
VOLTAGE
ERROR
AMPLIFIER
LINEAR INTEGRATED CIRCUIT
V
OUT
SHDN
DRIVER
BYPASS
TERM. PROTEC.
GND
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QW-R102-021,C
LD1985
ABSOLUTE MAXIMUM RATINGS
PARAMETER
(Ta=25℃)
LINEAR INTEGRATED CIRCUIT
SYMBOL
RATINGS
UNIT
DC Input Voltage
V
IN
7
V
INHIBIT Input Voltage
V
INH
7
V
Output Current
I
OUT
Internally limited
Power Dissipation
P
D
Internally limited
Operating Junction Temperature
T
OPR
-20~+125
℃
Storage Temperature
T
STG
-40~+150
℃
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. The device is guaranteed to meet performance specification within 0℃~+70
℃
operating temperature range
and assured by design from -20℃~+125℃
ELECTRICAL CHARACTRISTICS
(T
J
=25
℃
, V
IN
=V
OUT
+1V, I
OUT
=1mA, V
SHDN
=2V, C
IN
=1µF, C
OUT
=1µF, unless otherwise specified)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP MAX UNIT
Operating Input Voltage
V
IN(OPR)
2.5
7.0
V
1.0% 1.485
1.515
V
IN
=2.5V
1.5
V
1.5% 1.477
1.523
1.0% 1.462
1.538
I
OUT
=1 ~ 150mA
V
Output Voltage
V
OUT
1.5% 1.455
1.545
1.0% 1.447
1.553
I
OUT
=1 ~ 150mA, T
J
=-20 ~ 125℃
V
1.5% 1.440
1.560
1.0% 1.782
1.818
V
IN
=2.8V
1.8
V
1.5% 1.773
1.827
1.0% 1.755
1.845
Output Voltage
V
OUT
I
OUT
=1 ~ 150mA
V
1.5% 1.746
1.854
1.0% 1.737
1.863
I
OUT
=1 ~ 150mA, T
J
=-20 ~ 125℃
V
1.5% 1.728
1.872
1.0% 2.475
2.525
V
IN
=3.5V
2.5
V
1.5% 2.4625
2.5375
1.0% 2.4375
2.5625
Output Voltage
V
OUT
I
OUT
=1 ~ 150mA
V
1.5% 2.425
2.575
1.0% 2.4125
2.5875
I
OUT
=1 ~ 150mA, T
J
=-20 ~ 125℃
V
1.5%
2.4
2.6
1.0% 2.772
2.828
V
IN
=3.8V
2.8
V
1.5% 2.758
2.842
1.0% 2.730
2.870
Output Voltage
V
OUT
I
OUT
=1 ~ 150mA
V
1.5% 2.716
2.884
1.0% 2.702
2.898
I
OUT
=1 ~ 150mA, T
J
=-20 ~ 125℃
V
1.5% 2.688
2.912
1.0% 2.821
2.879
V
IN
=3.85V
2.85
V
1.5% 2.807
2.893
1.0% 2.778
2.921
Output Voltage
V
OUT
I
OUT
=1 ~ 150mA
V
1.5% 2.764
2.935
1.0% 2.750
2.950
I
OUT
=1 ~ 150mA, T
J
=-20 ~ 125℃
V
1.5% 2.736
2.964
1.0% 2.970
3.030
V
IN
=4.0V
3.0
V
1.5% 2.955
3.045
1.0% 2.925
3.075
Output Voltage
V
OUT
I
OUT
=1 ~ 150mA
V
1.5% 2.91
3.09
1.0% 2.895
3.105
I
OUT
=1 ~ 150mA, T
J
=-20 ~ 125℃
V
1.5% 2.88
3.12
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QW-R102-021,C
LD1985
ELECTRICAL CHARACTRISTICS(Cont.)
PARAMETER
SYMBOL
V
IN
=4.1V
Output Voltage
V
OUT
I
OUT
=1 ~ 150mA
LINEAR INTEGRATED CIRCUIT
TEST CONDITIONS
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
1.0%
1.5%
I
OUT
=1 ~ 150mA, T
J
=-20 ~ 125℃
V
IN
=4.2V
Output Voltage
V
OUT
I
OUT
=1 ~ 150mA
I
OUT
=1 ~ 150mA, T
J
=-20 ~ 125℃
V
IN
=4.3V
Output Voltage
V
OUT
I
OUT
=1 ~ 150mA
I
OUT
=1 ~ 150mA, T
J
=-20 ~ 125℃
V
IN
=4.5V
Output Voltage
V
OUT
I
OUT
=1 ~ 150mA
I
OUT
=1 ~ 150mA, T
J
=-20 ~ 125℃
V
IN
=4.6V
Output Voltage
V
OUT
I
OUT
=1 ~ 150mA
I
OUT
=1 ~ 150mA, T
J
=-20 ~ 125℃
V
IN
=4.8V
Output Voltage
V
OUT
I
OUT
=1 ~ 150mA
I
OUT
=1 ~ 150mA, T
J
=-20 ~ 125℃
V
IN
=5.0V
Output Voltage
V
OUT
I
OUT
=1 ~ 150mA
I
OUT
=1 ~ 150mA, T
J
=-20 ~ 125℃
V
IN
=5.7V
Output Voltage
V
OUT
I
OUT
=1 ~ 150mA
I
OUT
=1 ~ 150mA, T
J
=-20 ~ 125℃
MIN
3.069
3.0535
3.022
3.007
2.9915
2.976
3.168
3.152
3.120
3.104
3.088
3.072
3.267
3.2505
3.2175
3.201
3.1845
3.168
3.465
3.447
3.412
3.395
3.377
3.360
3.564
3.546
3.510
3.492
3.474
3.456
3.762
3.743
3.705
3.686
3.667
3.648
3.96
3.94
3.9
3.88
3.86
3.84
4.653
4.6295
4.582
4.559
4.5355
4.512
TYP
3.1
3.2
3.3
3.5
3.6
3.8
4.0
4.7
MAX UNIT
3.131
V
3.1465
3.1775
V
3.193
3.2085
V
3.224
3.232
V
3.248
3.280
V
3.296
3.312
V
3.328
3.333
V
3.3495
3.3825
V
3.399
3.4155
V
3.432
3.535
V
3.552
3.587
V
3.605
3.622
V
3.640
3.636
V
3.654
3.690
V
3.708
3.726
V
3.744
3.838
V
3.857
3.895
V
3.914
3.933
V
3.952
4.04
V
4.06
4.1
V
4.12
4.14
V
4.16
4.747
V
4.7705
4.817
V
4.841
4.8645
V
4.888
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QW-R102-021,C
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