ISSUED DATE :2004/12/28
REVISED DATE :2006/04/18B
GJ2138
Description
1 . 5 A C M O S L o w D ro p o u t Vo l t ag e R e g u l a t o r
The GJ2138 series of positive, linear regulators feature low quiescent current (45 A typ.) with low dropout
voltage, making them ideal for battery applications.
These rugged devices have both Thermal Shutdown, and Current Fold-back to prevent device failure under
the “Worst” of operating conditions.
The GJ2138 is stable with an output capacitance of 4.7 F or greater.
Features
&
Low Dropout Voltage
Very
Functional Block Diagram
&Guaranteed 1.5A output
&Over-Temperature Shutdown
&Current Limiting
&Short Circuit Current Fold-back
&Highly Accurate± 1.5%
&Low Temperature Coefficient
Applications
&
Battery Powered Widgets
&Instrumentation
&Wireless Devices
&PC Peripherals
&Portable Electronics
Package Dimensions
TO-252
REF.
A
B
C
D
E
F
S
Millimeter
Min.
Max.
6.40
6.80
5.20
5.50
6.80
7.20
2.40
3.00
2.30 REF.
0.70
0.90
0.60
0.90
REF.
G
H
J
K
L
M
R
Millimeter
Min.
Max.
0.50
0.70
2.20
2.40
0.45
0.55
0
0.15
0.90
1.50
5.40
5.80
0.80
1.20
Typical Application Circuit
GJ2138
Page: 1/5
ISSUED DATE :2004/12/28
REVISED DATE :2006/04/18B
Absolute Maximum Ratings
Parameter
Input Max Voltage
Output Current
Output Voltage
Operating Ambient Temperature
Junction Temperature
Maximum Junction Temperature
Thermal Resistance
Internal Power Dissipation
EDS Classification
*Measure jc on backside center of tab.
Symbol
V
IN
I
OUT
V
OUT
Topr
Tj
Tj
Max
jc
(Non-Conductive Epoxy)
*
ja
PD
Ratings
8
P
D
/( V
IN-
V
O)
1.5~5.0
-40 ~ +85
-40 ~ +125
150
30
140
1
B
Unit
V
A
V
:
:
:
: /W
: /W
W
Electrical Characteristics
V
IN
=V
OUT
(T)+2V, Ta=25 : unless otherwise noted
Parameter
Output Voltage
Output Current
Current Limit
Load Regulation
Dropout Voltage
Quiescent Current
Ground Pin Current
Line Regulation
Input Voltage
Over Temperature Shutdown
Over Temperature Hysterisis
Symbol
V
OUT
(E)
(Note1)
Condition
I
O
=1mA
V
O
>1.2V
V
O
>1.2V
V
IN
=V
OUT
(T)+2V,
I
O
=1mA to 1.5A
I
O
=1.5A
V
O
=V
OUT
(E)-2%
1.4V<V
OUT
(T) 2.0V
2.0V<V
OUT
(T) 2.8V
2.8V<V
OUT
(T)
Min
-1.5%
1.5
1.5
-1
-
-
-
-
-
-0.15
-0.1
-0.4
Note3
-
-
-
TYP
V
OUT
(T)
(Note2)
Max
1.5%
-
-
1
1300
800
600
70
-
0.15
0.1
0.4
7
-
-
-
-
-
-
-
-
Unit
V
A
A
%
mV
A
A
%
V
:
:
ppm/ :
mA
dB
Vrms
I
O
I
LIM
REG
LOAD
V
DROPOUT
I
Q
I
GND
REG
LINE
V
IN
OTS
OTH
TC
I
SC
PSRR
eN
-
2.0
0.2
-
-
-
45
45
-
0.02
-
-
150
30
30
750
70
50
20
30
V
IN
= V
OUT
(T)+2V,
I
O
=0mA
V
IN
= V
OUT
(T)+2V,
I
O
=1mA~1.5A
V
OUT
(T)<2.0V
I
O
=1mA
V
IN
=V
OUT
(T)+1 to 2.0V V
OUT
(T)<4.0V
V
OUT
(T)+2
4.0V V
OUT
(T)
Output Voltage
Temperature Coefficient
Short Circuit Current
Power Supply Rejection
Output Voltage Noise
V
IN
=V
OUT
(T)+1V, V
OUT
<0.4V
f=100Hz
f=1kHz
f=10kHz
f=10Hz~100kHz,
Io=10mA,
Co=4.7 F
Io=100mA
Co=4.7 F
-
-
-
-
-
Note 1: V
OUT
(E) =Effective Output Voltage (i.e. the output voltage when “V
OUT
(T) + 2.0V” is provided at the V
IN
pin while maintaining a
certain
I
OUT
value).
2: V
OUT
(T) =Specified Output Voltage
3: V
IN
(MIN)
=V
OUT
+V
DROPOUT
Ordering Information ( contd. )
Part Number
GJ2138-15
GJ2138-19
GJ2138-33
GJ2138-50
XXXX
XXXX
XXXX
XXXX
Marking
8T152
Output Voltage
1.5V
1.9V
3.3V
5.0V
Part Number
GJ2138-18
GJ2138-25
GJ2138-47
XXXX
XXXX
XXXX
Marking
8T182
8T252
8T472
Output Voltage
1.8V
2.5V
4.75V
8T192
8T332
8T502
GJ2138
Page: 2/5
ISSUED DATE :2004/12/28
REVISED DATE :2006/04/18B
The GJ2138 series of COMS regulators contain a PMOS pass transistor, voltage reference, error amplifier,
over-current protection, and thermal shutdown.
The P-channel pass transistor receives data from the error amplifier, over-current shutdown, and thermal
protection circuits. During normal operation, the error amplifier compares the output voltage to a precision
reference. Over-current and Thermal shutdown circuits become active when the junction temperature exceeds
150 : , or the current exceeds 2.2A. During thermal shutdown, the output voltage remains low. Normal
operation is restored when the junction temperature drops below 120 : .
The GJ2138 behaves like a current source when the load reaches 2.2A. However, if the load impedance drops
below 0.3 , the current drops back to 600mA to prevent excessive power dissipation. Normal operation is
restored when the load resistance exceeds 0.75 .
Detailed Description
The GJ2138 is stable with an output capacitance to ground of 4.7 F or greater. Ceramic capacitors have the
lowest ESR, and will offer the best AC performance. Conversely, Aluminum Electrolytic capacitors exhibit the
highest ESR, resulting in the poorest AC response. Unfortunately, large value ceramic capacitors are
comparatively expensive. One option is to parallel a 0.1 F ceramic capacitor with a 10 F Aluminum Electrolytic.
The benefit is low ESR, high capacitance, and low overall cost.
A second capacitor is recommended between the input and ground to stabilize Vin. The input capacitor should
be at least 0.1 F to have a beneficial effect.
All capacitors should be placed in close proximity to the pins. A “Quiet” ground termination is desirable. This
can be achieved with a “Star” connection.
External Capacitors
Characteristics Curve
GJ2138
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ISSUED DATE :2004/12/28
REVISED DATE :2006/04/18B
115 :
85 :
55 :
25 :
-5 :
-45 :
GJ2138
Page: 4/5
ISSUED DATE :2004/12/28
REVISED DATE :2006/04/18B
Important Notice:
All rights are reserved. Reproduction in whole or in part is prohibited without the prior written approval of GTM.
GTM reserves the right to make changes to its products without notice.
GTM semiconductor products are not warranted to be suitable for use in life-support Applications, or systems.
GTM assumes no liability for any consequence of customer product design, infringement of patents, or application assistance.
Head Office And Factory:
Taiwan:
No. 17-1 Tatung Rd. Fu Kou Hsin-Chu Industrial Park, Hsin-Chu, Taiwan, R. O. C.
TEL : 886-3-597-7061 FAX : 886-3-597-9220, 597-0785
China:
(201203) No.255, Jang-Jiang Tsai-Lueng RD. , Pu-Dung-Hsin District, Shang-Hai City, China
TEL : 86-21-5895-7671 ~ 4 FAX : 86-21-38950165
GJ2138
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