LP8345
Low Dropout, Low IQ, 500mA CMOS Linear Regulator
General Description
The LP8345 low-dropout CMOS linear regulator are avail-
able in 5V, 3.3V, 2.5V, 1.8V or adjustable output versions.
Packaged in our 6ld LLP package and 3ld DPAK they can
deliver up to 500mA output current.
Typical dropout voltage
@
500mA is 210mV for the 5.0V
version, 270mV for the 3.3V version and 335mV for the 2.5V
version.
The devices include a zener trimmed bandgap voltage ref-
erence, foldback current limiting and thermal overload limit-
ing.
The LP8345 features a PMOS output transistor which unlike
PNP type low dropout regulators requires no base drive
current. This allows the device ground current to remain less
than 50A over operating temperature, supply voltage and
irrespective of the load current.
Features
n
1.5% Typical V
OUT
tolerance
n
210mV Typical Dropout
@
500mA (V
O
= 5V)
n
Wide Operating Range
2.7V to 10V
n
Internal 500mA PMOS Output Transistor
n
19A Typical Quiescent Current
n
Thermal Overload Limiting
n
Foldback Current Limiting
n
Zener Trimmed Bandgap Reference
n
Space saving LLP package
n
Temperature Range
-- LP8345C
0C to 125C
-- LP8345I
-40C to 125C
Applications
n
Hard Disk Drives
n
Notebook Computers
n
Battery Powered Electronics
n
Portable Instrumentation
Typical Applications
Fixed V
OUT
20064801
Adjustable V
OUT
20064802
October 2003
LP8345
Low
Dropout,
Low
IQ,
500mA
CMOS
Linear
Regulator
2003 National Semiconductor Corporation
DS200648
www.national.com
Connection Diagrams
6-Pin LLP
FIXED OUTPUT VOLTAGE
20064804
Bottom View
6-Pin LLP
ADJUSTABLE OUTPUT VOLTAGE
20064806
Bottom View
Note: V
IN
Pins (Pin 1 & 6) must be connected together externally for full 500mA operation (250mA max per pin).
V
OUT
Sense (Pin 5) must be connected to V
OUT
(Pin 4).
T0-252
20064805
Top View
LP8345
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3
Absolute Maximum Ratings
(Notes 1,
2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
V
IN
, V
OUT
, V
OUT
Sense, ADJ
-0.3V to 12V
Storage Temperature Range
-65C to 160C
Junction Temperature (T
J
)
150C
Power Dissipation
(Note 3)
ESD Rating
Human Body Model (Note 6)
2kV
Machine Model
200V
Operating Ratings
(Notes 1, 2)
Supply Voltage
2.7 to 10V
Temperature Range
LP8345C
0C to 125C
LP8345I
-40C to 125C
LP8345C Electrical Characteristics
Unless otherwise specified all limits guaranteed for V
IN
= V
O
+ 1V, C
IN
= C
OUT
= 10F, T
J
= 25C. Boldface limits apply over
the full operating temperature range of T
J
= 0C to 125C
Symbol
Parameter
Conditions
Min
(Note 5)
Typ
(Note 4)
Max
(Note 5)
Units
V
IN
Input Voltage
LP8345-ADJ,1.8, 2.5
LP8345-3.3, 5.0
2.7
10
10
V
V
OUT
Output Voltage
LP8345-ADJ, ADJ = OUT
I
OUT
= 10mA, V
IN
= 2.7V, T
J
= 25C
100A
I
OUT
500mA, 2.7V V
IN
V
OUT
+4V
1.231
1.213
1.250
1.269
1.288
V
LP8345-1.8
I
OUT
= 10mA, V
IN
= 2.8V, T
J
= 25C
100A
I
OUT
500mA, 2.8V V
IN
6V
1.773
1.746
1.800
1.827
1.854
V
LP8345-2.5
I
OUT
= 10mA, V
IN
= 3.5V, T
J
= 25C
100A
I
OUT
500mA, 3.5V V
IN
6.5V
2.463
2.425
2.500
2.538
2.575
V
LP8345-3.3
I
OUT
= 10mA, V
IN
= 4.3V T
J
= 25C
100A
I
OUT
500mA, 4.3V V
IN
7.5V
3.250
3.201
3.300
3.350
3.399
V
LP8345-5.0
I
OUT
= 10mA, V
IN
= 6V, T
J
= 25C
100A
I
OUT
500mA, 6V V
IN
9V
4.925
4.850
5.000
5.075
5.150
V
V
O
Load Regulation
LP8345-ADJ, ADJ=OUT
I
OUT
= 1mA to 500mA, V
IN
= 2.7V
6
20
mV
LP8345-1.8
I
OUT
= 1mA to 500mA, V
IN
= 2.8V
7
20
LP8345-2.5
I
OUT
= 1mA to 500mA, V
IN
= 3.5V
9
30
LP8345-3.3
I
OUT
= 1mA to 500mA, V
IN
= 4.3V
12
35
LP8345-5.0
I
OUT
= 1mA to 500mA, V
IN
= 6V
14
40
V
O
Line Regulation
V
OUT
+ 0.5V
V
IN
10V, I
OUT
= 25mA
(Note 7)
4
15
mV
V
IN
- V
O
Dropout Voltage
(Note 7) (Note 8)
LP8345-2.5
I
OUT
= 500mA
335
650
mV
LP8345-3.3
LP8345-ADJ, V
OUT
= 3.3V, I
OUT
= 500mA
270
500
LP8345-5.0
I
OUT
= 500mA
210
400
I
Q
Quiescent Current
V
IN
10V
19
50
A
Minimum Load Current
V
IN
- V
OUT
4V
100
A
LP8345
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4
LP8345C Electrical Characteristics
(Continued)
Unless otherwise specified all limits guaranteed for V
IN
= V
O
+ 1V, C
IN
= C
OUT
= 10F, T
J
= 25C. Boldface limits apply over
the full operating temperature range of T
J
= 0C to 125C
Symbol
Parameter
Conditions
Min
(Note 5)
Typ
(Note 4)
Max
(Note 5)
Units
I
LIMIT
Foldback Current Limit
V
IN
- V
OUT
>
5V
450
mA
V
IN
- V
OUT
<
4V
1200
Ripple Rejection Ratio
V
IN
(dc) = V
OUT
+ 2V
V
IN
(ac) = 1V
P-P
@
120Hz
48
55
dB
T
SD
Thermal Shutdown
Temp.
Thermal Shutdown Hyst.
160
10
C
ADJ Input Leakage
Current
V
ADJ
= 1.5V or 0V
0.01
100
nA
V
OUT
Leakage Current
LP8345-ADJ
ADJ = OUT, V
OUT
= 2V, V
IN
= 10V
10
A
LP8345-1.8, V
OUT
= 2.5V, V
IN
= 10V
10
LP8345-2.5, V
OUT
= 3.5V, V
IN
= 10V
10
LP8345-3.3, V
OUT
= 4V, V
IN
= 10V
10
LP8345-5.0, V
OUT
= 6V, V
IN
= 10V
10
e
n
Output Noise
10Hz to 10kHz, R
L
= 1k
, C
OUT
= 10F
250
Vrms
LP8345I Electrical Characteristics
Unless otherwise specified all limits guaranteed for V
IN
= V
O
+ 1V, C
IN
= C
OUT
= 10F, T
J
= 25C. Boldface limits apply over
the full operating temperature range of T
J
= -40C to 125C
Symbol
Parameter
Conditions
Min
(Note 5)
Typ
(Note 4)
Max
(Note 5)
Units
V
IN
Input Voltage
LP8345-ADJ,1.8, 2.5
LP8345-3.3, 5.0
2.7
10
10
V
V
OUT
Output Voltage
LP8345-ADJ, ADJ = OUT
I
OUT
= 10mA, V
IN
= 2.7V, T
J
= 25C
100A
I
OUT
500mA, 2.7V V
IN
V
OUT
+4V
1.231
1.213
1.250
1.269
1.288
V
LP8345-1.8
I
OUT
= 10mA, V
IN
= 2.8V, T
J
= 25C
100A
I
OUT
500mA, 2.8V V
IN
6V
1.773
1.746
1.800
1.827
1.854
V
LP8345-2.5
I
OUT
= 10mA, V
IN
= 3.5V, T
J
= 25C
100A
I
OUT
500mA, 3.5V V
IN
6.5V
2.463
2.425
2.500
2.538
2.575
V
LP8345-3.3
I
OUT
= 10mA, V
IN
= 4.3V T
J
= 25C
100A
I
OUT
500mA, 4.3V V
IN
7.5V
3.250
3.201
3.300
3.350
3.399
V
LP8345-5.0
I
OUT
= 10mA, V
IN
= 6V, T
J
= 25C
100A
I
OUT
500mA, 6V V
IN
9V
4.925
4.850
5.000
5.075
5.150
V
V
O
Load Regulation
LP8345-ADJ, ADJ=OUT
I
OUT
= 1mA to 500mA, V
IN
= 2.7V
6
20
mV
LP8345-1.8
I
OUT
= 1mA to 500mA, V
IN
= 2.8V
7
20
LP8345-2.5
I
OUT
= 1mA to 500mA, V
IN
= 3.5V
9
30
LP8345-3.3
I
OUT
= 1mA to 500mA, V
IN
= 4.3V
12
35
LP8345-5.0
I
OUT
= 1mA to 500mA, V
IN
= 6V
14
40
LP8345
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