Datasheet

4
LM138 , LM338
SNVS771C –MAY 1998–REVISED DECEMBER 2016 www.ti.com
Product Folder Links: LM138 LM338
Submit Documentation Feedback Copyright © 1998–2016, Texas Instruments Incorporated
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report.
6.3 Thermal Information
THERMAL METRIC
(1)
LM338 LM338
UNITNDS (TO-CAN) NDE (TO-220) NDS (TO-CAN)
2 PINS 3 PINS 2 PINS
R
θJA
Junction-to-ambient thermal resistance 35 22.9 35 °C/W
R
θJC(top)
Junction-to-case (top) thermal resistance 1 15.7 1 °C/W
R
θJB
Junction-to-board thermal resistance — 4.1 — °C/W
ψ
JT
Junction-to-top characterization parameter — 2.1 — °C/W
ψ
JB
Junction-to-board characterization parameter — 4.1 — °C/W
R
θJC(bot)
Junction-to-case (bottom) thermal resistance — 0.7 — °C/W
(1) These specifications are applicable for power dissipations up to 50 W for the TO-3 (NDS) package and 25 W for the TO-220 (NDE)
package. Power dissipation is specified at these values up to 15-V input-output differential. Above 15-V differential, power dissipation is
limited by internal protection circuitry. All limits (that is, the numbers in the minimum and maximum columns) are specified to TI's AOQL
(Average Outgoing Quality Level).
(2) Regulation is measured at a constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to
heating effects are covered under the specifications for thermal regulation.
6.4 Electrical Characteristics: LM138
Values apply for T
J
= 25°C; V
IN
– V
OUT
= 5 V; and I
OUT
= 10 mA (unless otherwise noted).
(1)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
V
REF
Reference voltage
3 V ≤ (V
IN
– V
OUT
) ≤ 35 V, 10 mA ≤ I
OUT
≤ 5 A, P ≤ 50 W,
T
J
= –55°C to 150°C
1.19 1.24 1.29 V
V
RLINE
Line regulation 3 V ≤ (V
IN
– V
OUT
) ≤ 35 V
(2)
T
J
= 25°C 0.005% 0.01% V
T
J
= –55°C to 150°C 0.02% 0.04% V
V
RLOAD
Load regulation 10 mA ≤ I
OUT
≤ 5 A
(2)
T
J
= 25°C 0.1% 0.3%
T
J
= –55°C to 150°C 0.3% 0.6%
Thermal regulation 20 ms pulse 0.002% 0.01% W
I
ADJ
Adjustment pin current T
J
= –55°C to 150°C 45 100 µA
ΔI
ADJ
Adjustment pin current change
10 mA ≤ I
OUT
≤ 5 A, 3 V ≤ (V
IN
– V
OUT
) ≤ 35 V,
T
J
= –55°C to 150°C
0.2 5 µA
ΔV
R/T
Temperature stability T
J
= –55°C to 150°C 1%
I
LOAD(MIN)
Minimum load current V
IN
– V
OUT
= 35 V, T
J
= –55°C to 150°C 3.5 5 mA
I
CL
Current limit
V
IN
– V
OUT
≤ 10 V
DC, T
J
= –55°C to 150°C 5 8 A
0.5-ms peak, T
J
= –55°C to 150°C 7 12 A
V
IN
– V
OUT
= 30 V 1 1 A
V
N
RMS output noise
(percent of V
OUT
)
10 Hz ≤ f ≤ 10 kHz 0.003%
ΔV
R
/ΔV
IN
Ripple rejection ratio
V
OUT
= 10 V, f = 120 Hz, C
ADJ
= 0 µF,
T
J
= –55°C to 150°C
60 dB
V
OUT
= 10 V, f = 120 Hz, C
ADJ
= 10 µF,
T
J
= –55°C to 150°C
60 75 dB
Long-term stability T
J
= 125°C, 1000 Hrs 0.3% 1%