Document
Features
Output current up to 100 mA Output voltages of -5; -8;-12; -15 V Thermal overload protection Short-circuit protection No external components are required Output tolerance + 4%
L79L
Negative voltage regulators
Datasheet - production data
Description
The L79L series of three-terminal negative regulators employ internal current limiting and thermal shutdown, making them essentially indestructible. If adequate heat-sink is provided, they can deliver up to 100 mA output current. They are intended as fixed voltage regulators in a wide range of applications including local or oncard regulation for elimination of noise and distribution problems associated with single-point regulation. In addition, they can be used with power pass elements to make high-current voltage regulators. The L79L series used as Zener diode/resistor combination replacement, offers an effective output impedance improvement of typically two orders of magnitude, along with lower quiescent current and lower noise.
December 2017
DocID2511 Rev 19
This is information on a product in full production.
1/23
www.st.com
Contents
L79L
Contents
1 Diagram ............................................................................................ 3
2 Pin configuration ............................................................................. 4
3 Maximum ratings ............................................................................. 5
4 Electrical characteristics ................................................................ 6
5 Package information ....................................................................... 9
5.1 TO-92 package information............................................................... 9
5.2 TO-92 packing information .............................................................. 10
5.3 TO-92 Ammopak packing information ............................................. 12 5.4 SO-8 package information .............................................................. 14 5.5 SO-8 packing information................................................................ 16
5.6 SOT-89 package information .......................................................... 17 5.7 SOT-89 packing information............................................................ 20
6 Ordering information..................................................................... 21
7 Revision history ............................................................................ 22
2/23
DocID2511 Rev 19
L79L
1
Diagram
Figure 1: Schematic diagram
Diagram
DocID2511 Rev 19
3/23
Pin configuration
2
Pin configuration
Figure 2: Pin connection (top view, bottom view for TO-92)
L79L
Figure 3: Test circuit
4/23
DocID2511 Rev 19
L79L
3
Maximum ratings
Maximum ratings
Table 1: Absolute maximum ratings
Symbol
Parameter
Value
Unit
VI
IO PD TSTG
TOP
DC input voltage
Output current Power dissipation Storage temperature range
Operating junction temperature range
VO = -5 to -9 V
-30
V
VO = -12 to -15 V
-35
100
mA
Internally limited (1) mW
-40 to 150
°C
For L79LXXAC For L79LXXAB
0 to 125 °C
-40 to 125
Notes:
(1) Our SO-8 package used for Voltage Regulators is modified internally to have pins 2, 3, 6 and 7 electrically communed to the die attach flag. This particular frame decreases the total thermal resistance of the package and increases its ability to dissipate power when an appropriate area of copper on the printed circuit board is available for heat-sinking. The external dimensions are the same as for the standard SO-8.
Symbol RthJC RthJA
Table 2: Thermal data
Parameter
SO-8
Thermal resistance junction-case (max.) Thermal resistance junction-ambient (max.)
20 55 (1)
TO-92 200
SOT-89 15 115
Unit °C/W °C/W
Notes: (1) Considering 6 cm2 of copper Board heat-sink.
DocID2511 Rev 19
5/23
Electrical characteristics
L79L
4
Electrical characteristics
Refer to the test circuits, VI = - 10 V, IO = 40 mA, CI = 0.33 μF, CO = 0.1 μF, TJ = 0 to 125 °C for L79L05AC, TJ = -40 to 125 °C for L79L05AB, unless otherwise specified.
Table 3: Electrical characteristics of L79L05AC and L79L05AB
Symbol
Parameter
Test conditions
Min. Typ. Max. Unit
VO Output voltage VO Output voltage
TJ = 25 °C IO = 1 to 40 mA, VI = -7 to -20 V IO = 1 to 70 mA, VI = -10 V
-4.8 -5 -5.2 V
-
-
4.75
5.25
V
-
-
4.75
5.25
ΔVO
ΔVO
Id
ΔId eN SVR Vd
Line regulation
Load regulation
Quiescent current
Quiescent current change Output noise voltage Supply voltage rejection Dropout voltage
VI = -7 to -20 V, TJ = 25 °C VI = -8 to -20 V, TJ = 25 °C IO = 1 to 100 mA, TJ = 25 °C IO = 1 to 40 mA, TJ = 25 °C TJ = 25 °C TJ = 125 °C IO = 1 to 40 mA VI = -8 to -20 V B = 10 Hz to 100 kHz, TJ = 25 °C VI = -8 to -18 V, f = 120 Hz IO = 40 mA, TJ = 25 °C
150 mV
100
60 mV
30
6 mA
5.5 mA
0.1 mA
1.5
40
µV
41 49
dB
1.7
V
Refer to the test circuits, VI = - 14 V, IO = 40 mA, CI = 0.33 μF, CO = 0.1 μF, TJ .