LT138A/LT338A
LM138/LM338
ELECTRICAL CHARACTERISTICS
SYMBOL
I
SC
PARAMETER
Current Limit
CONDITIONS
(V
IN
– V
OUT
)
≤
10V
DC
0.5ms Peak
(V
IN
– V
OUT
) = 30V, T
J
= 25°C
∆V
OUT
∆Temp
∆V
OUT
∆Time
e
n
θ
JC
Temperature Stability
Long-Term Stability
T
A
= 125°C, 1000 Hours
q
q
q
The
q
denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 2)
MIN
5
6
LT138A
TYP
MAX
8
12
1
1
0.3
0.001
1
2
2
1
MIN
5
6
LM138
TYP
8
12
1
1
0.3
0.003
1
1
MAX
UNITS
A
A
A
%
%
%
°C/W
RMS Output Noise (% of V
OUT
) 10Hz
≤
f
≤
10kHz
Thermal Resistance
Junction-to-Case
K Package
The
q
denotes specifications which apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C. (Note 2)
SYMBOL
V
REF
PARAMETER
Reference Voltage
CONDITIONS
I
OUT
= 10mA
3V
≤
(V
IN
– V
OUT
)
≤
35V,
10mA
≤
I
OUT
≤
5A, P
≤
50W
∆V
OUT
∆V
IN
∆V
OUT
∆I
OUT
Line Regulation
Load Regulation
3V
≤
(V
IN
– V
OUT
)
≤
35V, (Note 3)
q
q
MIN
1.238
1.225
LT338A
TYP
MAX
1.250
1.250
0.005
0.02
5
0.1
1.262
1.270
0.01
0.04
15
0.3
30
0.6
0.02
MIN
1.19
LM338
TYP
1.24
0.005
0.02
5
0.1
20
0.3
0.002
60
75
45
0.2
3.5
MAX
1.29
0.03
0.06
25
0.5
50
1
0.02
UNITS
V
V
%/V
%/V
mV
%
mV
%
%/W
dB
dB
10mA
≤
I
OUT
≤
5A, (Note 3)
V
OUT
≤
5V
V
OUT
≥
5V
V
OUT
≤
5V
V
OUT
≥
5V
q
q
20
0.3
0.002
Thermal Regulation
Ripple Rejection
20ms Pulse
V
OUT
= 10V, f = 120Hz
C
ADJ
= 0µF
C
ADJ
= 10µF
10mA
≤
I
OUT
≤
5A,
3V
≤
(V
IN
– V
OUT
)
≤
35V
(V
IN
– V
OUT
) = 35V
(V
IN
– V
OUT
)
≤
10V
DC
0.5ms Peak
(V
IN
– V
OUT
) = 30V, T
J
= 25°C
q
q
q
q
q
q
q
60
60
75
45
0.2
3.5
100
5
10
60
I
ADJ
∆I
ADJ
Adjust Pin Current
Adjust Pin Current Change
Minimum Load Current
100
5
10
µA
µA
mA
A
A
A
%
I
SC
Current Limit
5
6
8
12
1
2
2
1
1
0.3
0.001
1
5
6
8
12
1
1
0.3
0.003
1
1
∆V
OUT
∆Temp
∆V
OUT
∆Time
e
n
θ
JC
Temperature Stability
Long-Term Stability
RMS Output Noise (% of V
OUT
)
Thermal Resistance
Junction-to-Case
T
A
= 125°C, 1000 Hours
10Hz
≤
f
≤
10kHz
K Package
q
%
%
°C/W
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.
Note 2:
Unless otherwise specified, these specifications apply:
V
IN
– V
OUT
= 5V and I
OUT
= 2.5A. These specifications are applicable for
power dissipations up to 50W.
Note 3:
See thermal regulation specifications for changes in output voltage
due to heating effects. Load and line regulation are measured at a constant
junction temperature by low duty cycle pulse testing.
138afb
3
LINER [ LINEAR TECHNOLOGY ]
