Page 1
NIKO-SEM
0.8A Fixed and Adjustable Low Dropout
Linear Regulator (LDO)
GENERAL DESCRIPTION
FEATURES
L1087 Series
SOT-89,TO-92
The L1087 Series are positive and low
dropout three-terminal voltage regulators
with 0.8A output current capability. These
devices are designed for use in low voltage
applications that offers lower dropout voltage and faster transient response.
These devices are fully protected against
over current faults, over temperature operation, reversed input polarity, reversed lead
insertion, transient voltage spike …etc.
On-Chips trimming the reference voltage to
1% and features the low dropout of maximum 1.45 volts.
The L1087 Series regulators offer fixed and
adjustable voltage options available in the
space saving SOT-89 & TO-92 package.
TYPICAL APPLICATION
Fixed 3.3V or adjustable output voltage
z
Low dropout voltage
z
Low ground current
z
Fast transient response
z
Current & thermal lim iting
z
Line regulation: 0.5% typical
z
Load regulation: 0.5% typical
z
Available in SOT-89 & TO-92 package
z
APPLICATIONS
Low voltage micro-controllers
z
Battery Chargers
z
5V to 3.3V linear regulators
z
Motherboard clock supplies
z
z
zz
Post regulator for switching supplies
z
Cin
10uF
L1087
IN OUT
ADJ
+
Iadj
Vref
R1
R2
VoutVin
Cout
+
10uF
Vin > 4.75V
Cin
10uF
+
IN
L1087-3.3
GND
OUT
Cout
10uF
+
Vo = Vref (1+R2/R1) + Iadj x R2
1. Cin needed if device is far from filter capacitors.
2. Cout required for stability.
1. Cin needed if device is far from filter capacitors.
2. Cout required for stability.
- Basic Adjustable Regulator Circuit - - Fixed Voltage Regulator -
Vout = 3.3V
RL
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AUG-30-2001
Page 2
NIKO-SEM
0.8A Fixed and Adjustable Low Dropout
Linear Regulator (LDO)
ABSOLUTE MAXIMUM RATINGS
L1087 Series
SOT-89,TO-92
Maximum Supply Voltage 15V*
z
Power Dissipation
z
Thermal Resistance
z
Junction to Case,
Thermal Resistance
z
Junction to Ambient,
* When considering short circuits to ground, the maximum input-to-output differential voltage shall not be allowed
greater than approximate 2~3V at values of supply voltage in excess of 10V, continuous short-circuits can exceed
the power dissipation ratings and cause eventual destruction.
θ
JC
θ
JA
Internally
Limited
18 °C/W
160 °C/W
Operating Junction
z
Temperature Range
Storage Temperature
z
Range
Lead Temperature
z
(Soldering, 10 Seconds)
0 to 125 °C
-40 to 150 °C
260 °C
ELECTRICAL CHARACTERISTICS
Parameter
Reference Voltage
(Adjustable version)
Symbol
V
Output Voltage
(Fixed version)
Dropout Voltage VD
Line Regulation REG
Load Regulation REG
Minimum Load
Current
Adjust Pin Current I
Current Limit ICL VIN - V
RMS Output Noise VN
Ripple Rejection
Ratio
VIN = 5V, I
REF
VO VIN = 5V, I
V
= 1%, I
REF
+ 1.5V) ≤ V
OUT
IN -VOUT
OUT
(LINE)
(LOAD)
IO
ADJ
Δ
(V
(V
1.5V ≤ (V
0.003%
R
f = 120Hz, C
A
V
= 5V, I
IN
Test Conditions Typical Limits
OUT
OUT
) = 2V, 10mA ≤ I
IN -VOUT
= 2V 1.2A 0.9A (Min)
OUT
(Unless otherwise specified, TA = 25 °C)
= 10mA
= 10mA
OUT
= 0.8A
15V, I
≤
IN
OUT
OUT
= 10mA
≤ 0.8A
) ≤ 5.75V
= 22µF for ADJ pin,
ADJ
= 0.8A
1.25V
VO
1.23V
1.27V
0.98V
1.02V
Min
Max
O(Min)
O(Max)
1.2V 1.45V
0.5% 2%
0.5% 2.5%
10mA
55µA 100µA
of V
OUT
72dB 60dB (Min)
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AUG-30-2001
Page 3
NIKO-SEM
0.8A Fixed and Adjustable Low Dropout
Linear Regulator (LDO)
L1087 Series
SOT-89,TO-92
ELECTRICAL CHARACTERISTICS FOR FIXED 3.3V
Parameter
Symbol
Output Voltage
(Fixed version)
Dropout Voltage VD
Line Regulation REG
Load Regulation REG
Minimum Load
Current
GND Pin Current I
Current Limit ICL VIN - V
RMS Output Noise VN
Ripple Rejection
Ratio
VO VIN = 5V, I
VO = 1%, I
Δ
(LOAD)
IO
GND
(LINE)
(V
(V
1.5V ≤ (V
+ 1.5V) ≤ V
OUT
IN -VOUT
OUT
0.003%
RA
f = 120Hz, Co=22Uf,VIN = 5V,
I
= 0.8A
OUT
Test Conditions Typical Limits
= 10mA
OUT
= 0.8A
OUT
) = 2V, 10mA ≤ I
IN -VOUT
15V, I
≤
IN
) ≤ 5.75V
OUT
OUT
= 10mA
≤ 0.8A
= 2V 1.2A 0.9A (Min)
(Unless otherwise specified, TA = 25 °C)
VO
3.234V
3.367V
(Min)
(Max)
1.2V 1.45V
0.5% 2.0%
0.5% 2.0%
10mA
55µA 100µA
of V
OUT
72dB 60dB (Min)
DEVICE SELECTION GUIDE
Device
Voltage Version
Package
Marking
L1087C L1087C-3.3 L1087N-3.3
Adjustable 3.3V 3.3V
SOT-89 SOT-89 TO-92
L1087 87-3.3 87N-3.3
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NIKO-SEM
0.8A Fixed and Adjustable Low Dropout
PIN CONFIGURATIONS
Linear Regulator (LDO)
L1087 Series
SOT-89,TO-92
Pin # Function
1 Adjust/Ground
2 Output
3 Input
Note: TAB is Output Pin
Pin # Function
1 Output
2 Adjust/Ground
3 Input
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AUG-30-2001
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NIKO-SEM
Dimension
A 4.3 4.5 4.7 H 1.4 1.5 1.6
B 1.6 1.7 1.8 I 2.8 3.0 3.2
C 0.4 0.5 0.6 J 1.3 1.5 1.7
D 2.4 2.5 2.6 K 3.8 4.2 4.6
E 0.8 1.2 1.4 L 0.3 0.4 0.5
F 0.4 0.45 0.5 M
G 0.4 0.5 0.6 N
0.8A Fixed and Adjustable Low Dropout
Linear Regulator (LDO)
SOT-89 MECHANICAL DATA
mm
Min. Typ. Max.
Dimension
Min. Typ. Max.
L1087 Series
SOT-89,TO-92
mm
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AUG-30-2001
Page 6
NIKO-SEM
0.8A Fixed and Adjustable Low Dropout
Linear Regulator (LDO)
TO-92 MECHANICAL DATA
L1087 Series
SOT-89,TO-92
Dimension
mm
mm
Dimension
Min. Typ. Max.
Min. Typ. Max.
A 4.445 5.207 H 2.413 2.540 2.667
B 4.318 5.334 I 0.356 0.533
C 12.7 15.5 J
D 0.356 0.533 K
E 1.143 1.27 1.397 L
F 3.175 4.191 M
G 0.762 1.270 N
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AUG-30-2001
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