Document
L78
Datasheet
Positive voltage regulator ICs
TO-220 DPAK
TO-220FP D²PAK
Features
• Output current up to 1.5 A • Output voltages of 5; 6; 8; 8.5; 9; 12; 15; 18; 24 V • Thermal overload protection • Short circuit protection • Output transition SOA protection • 2 % output voltage tolerance (A version) • Guaranteed in extended temperature range (A version)
Description
The L78 series of three-terminal positive regulators is available in TO-220, TO-220FP, D²PAK and DPAK packages and several fixed output voltages, making it useful in a wide range of applications.
These regulators can provide local on-card regulation, eliminating the distribution problems associated with single point regulation. Each type embeds internal current limiting, thermal shut-down and safe area protection, making it essentially indestructible. If adequate heat sinking is provided, they can deliver over 1 A output current. Although designed primarily as fixed voltage regulators, these devices can be used with external components to obtain adjustable voltage and currents.
Maturity status link L78
DS0422 - Rev 36 - September 2018 For further information contact your local STMicroelectronics sales office.
www.st.com
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Diagram
Figure 2. Block diagram
L78
Diagram
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Pin configuration
Figure 3. Pin connections (top view)
L78
Pin configuration
TO-220
TO-220FP
D²PAK
Figure 4. Schematic diagram
DPA K
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L78
Maximum ratings
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Maximum ratings
Table 1. Absolute maximum ratings
Symbol
Parameter
VI
DC input voltage
IO PD TSTG
Output current Power dissipation Storage temperature range
TOP
Operating junction temperature range
for VO= 5 to 18 V for VO= 20, 24 V
for L78xxC, L78xxAC for L78xxAB
Value
Unit
35 V
40
Internally limited
Internally limited
-65 to 150
°C
0 to 125 °C
-40 to 125
Note:
Absolute maximum ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied.
Table 2. Thermal data
Symbol RthJC RthJA
Parameter Thermal resistance junction-case Thermal resistance junction-ambient
D²PAK 3
62.5
DPAK 8
100
TO-220 5 50
TO-220FP 5 60
Unit °C/W °C/W
Figure 5. Application circuits
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Test circuits
Figure 6. DC parameter
L78
Test circuits
Figure 7. Load regulation
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Figure 8. Ripple rejection
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L78
Electrical characteristics
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Electrical characteristics
VI = 10 V, IO = 1 A, TJ = 0 to 125 °C (L7805AC), TJ = -40 to 125 °C (L7805AB), unless otherwise specified.
Symbol VO VO VO
∆VO (1)
∆VO (1)
Iq
Parameter Output voltage Output voltage Output voltage
Line regulation
Load regulation
Quiescent current
Table 3. Electrical characteristics of L7805A
Test conditions TJ = 25 °C
IO = 5 mA to 1 A, VI = 7.5 to 18 V IO = 1 A, VI = 18 to 20 V, TJ = 25.