This is information on a product in full production.
May 2012 Doc ID 2149 Rev 21 1/24
24
L79xxC
Negative voltage regulators
Datasheet production data
Features
Output current up to 1.5 A
Output voltages of - 5; - 8; - 12; - 15 V
Thermal overload protection
Short circuit protection
Output transition SOA protection
Description
The L79xxC series of three-terminal negative
regulators is available in TO-220, TO-220FP and
D²PAK 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;
furthermore, having the same voltage option as
the L78xx positive standard series, they are
particularly suited for split power supplies. If
adequate heat sinking is provided, they can
deliver over 1.5 A output current. Although
designed primarily as fixed voltage regulators,
these devices can be used with external
components to obtain adjustable voltages and
currents.
TO-220FP
D²PAK
TO-220
Table 1. Device summary
Part numbers
Order codes Output
voltages
TO-220 D²PAK TO-220FP
L7905C L7905CV L7905CV-DG (1) L7905CD2T-TR L7905CP - 5 V
L7908C L7908CV L7908CV-DG (1) - 8 V
L7912C L7912CV L7912CV-DG (1) L7912CD2T-TR L7912CP - 12 V
L7915C L7915CV L7915CV-DG (1) L7915CD2T-TR L7915CP - 15 V
1. TO-220 Dual Gauge frame.
www.st.com
Contents L79xxC
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Contents
1 Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4 Test circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6 Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
7 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
8 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
L79xxC Diagram
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1 Diagram
Figure 1. Schematic diagram
Pin configuration L79xxC
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2 Pin configuration
Figure 2. Pin connections (top view)
TO220FP
TO-220
D²PAK (any type)
L79xxC Maximum ratings
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3 Maximum ratings
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. Absolute maximum ratings
Symbol Parameter Value Unit
VIDC input voltage for VO = - 5 to - 18 V -35 V
for VO = - 20 to - 24 V -40
IOOutput current Internally limited
PDPower dissipation Internally limited
TSTG Storage temperature range -65 to 150 °C
TOP Operating junction temperature range 0 to 150 °C
Table 3. Thermal data
Symbol Parameter D²PAK TO-220 TO-220FP Unit
RthJC Thermal resistance junction-case 3 5 5 °C/W
RthJA Thermal resistance junction-ambient 62.5 50 60 °C/W
Test circuit L79xxC
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4 Test circuit
Figure 3. Test circuit
L79xxC Electrical characteristics
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5 Electrical characteristics
Refer to the test circuits, TJ = 0 to 125 °C, VI = -10 V, IO = 500 mA, CI = 2.2 µF, CO = 1 µF
unless otherwise specified.
Table 4. Electrical characteristics of L7905C
Symbol Parameter Test conditions Min. Typ. Max. Unit
VOOutput voltage TJ = 25°C -4.8 -5 -5.2 V
VOOutput voltage IO = -5 mA to -1 A, PO 15 W
VI = -8 to -20 V -4.75 -5 -5.25 V
ΔVO(1) Line regulation VI = -7 to -25 V, TJ = 25°C 100 mV
VI = -8 to -12 V, TJ = 25°C 50
ΔVO(1) Load regulation IO = 5 mA to 1.5 A, TJ = 25°C 100 mV
IO = 250 to 750 mA, TJ = 25°C 50
IdQuiescent current TJ = 25°C 3 mA
ΔIdQuiescent current change IO = 5 mA to 1 A 0.5 mA
VI = -8 to -25 V 1.3
ΔVO/ΔT Output voltage drift IO = 5 mA -0.4 mV/°C
eN Output noise voltage B = 10Hz to 100kHz, TJ = 25°C 100 µV
SVR Supply voltage rejection ΔVI = 10 V, f = 120Hz 54 60 dB
VdDropout voltage IO = 1 A, TJ = 25°C, ΔVO = 100 mV 1.4 V
Isc Short circuit current 2.1 A
1. Load and line regulation are specified at constant junction temperature. Changes in VO due to heating effects must be
taken into account separately. Pulse testing with low duty cycle is used.
Electrical characteristics L79xxC
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Refer to the test circuits, TJ = 0 to 125 °C, VI = -14 V, IO = 500 mA, CI = 2.2 µF, CO = 1 µF
unless otherwise specified.
Table 5. Electrical characteristics of L7908C
Symbol Parameter Test conditions Min. Typ. Max. Unit
VOOutput voltage TJ = 25°C -7.7 -8 -8.3 V
VOOutput voltage IO = -5 mA to -1 A, PO 15 W
VI = -11.5 to -23 V -7.6 -8 -8.4 V
ΔVO(1) Line regulation VI = -10.5 to -25 V, TJ = 25°C 160 mV
VI = -11 to -17 V, TJ = 25°C 80
ΔVO(1) Load regulation IO = 5 mA to 1.5 A, TJ = 25°C 160 mV
IO = 250 to 750 mA, TJ = 25°C 80
IdQuiescent current TJ = 25°C 3 mA
ΔIdQuiescent current change IO = 5 mA to 1 A 0.5 mA
VI = -11.5 to -25 V 1
ΔVO/ΔT Output voltage drift IO = 5 mA -0.6 mV/°C
eN Output noise voltage B = 10Hz to 100kHz, TJ = 25°C 175 µV
SVR Supply voltage rejection ΔVI = 10 V, f = 120Hz 54 60 dB
VdDropout voltage IO = 1 A, TJ = 25°C, ΔVO = 100 mV 1.1 V
Isc Short circuit current 1.5 A
1. Load and line regulation are specified at constant junction temperature. Changes in VO due to heating effects must be
taken into account separately. Pulse testing with low duty cycle is used.
L79xxC Electrical characteristics
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Refer to the test circuits, TJ = 0 to 125 °C, VI = -19 V, IO = 500 mA, CI = 2.2 µF, CO = 1 µF
unless otherwise specified.
Table 6. Electrical characteristics of L7912C
Symbol Parameter Test conditions Min. Typ. Max. Unit
VOOutput voltage TJ = 25°C -11.5 -12 -12.5 V
VOOutput voltage IO = -5 mA to -1 A, PO 15 W
VI = -15.5 to -27 V -11.4 -12 -12.6 V
ΔVO(1) Line regulation VI = -14.5 to -30 V, TJ = 25°C 240 mV
VI = -16 to -22 V, TJ = 25°C 120
ΔVO(1) Load regulation IO = 5 mA to 1.5 A, TJ = 25°C 240 mV
IO = 250 to 750 mA, TJ = 25°C 120
IdQuiescent current TJ = 25°C 3 mA
ΔIdQuiescent current change IO = 5 mA to 1 A 0.5 mA
VI = -15 to -30 V 1
ΔVO/ΔT Output voltage drift IO = 5 mA -0.8 mV/°C
eN Output noise voltage B = 10Hz to 100kHz, TJ = 25°C 200 µV
SVR Supply voltage rejection ΔVI = 10 V, f = 120Hz 54 60 dB
VdDropout voltage IO = 1 A, TJ = 25°C, ΔVO = 100 mV 1.1 V
Isc Short circuit current 1.5 A
1. Load and line regulation are specified at constant junction temperature. Changes in VO due to heating effects must be
taken into account separately. Pulse testing with low duty cycle is used.
Electrical characteristics L79xxC
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Refer to the test circuits, TJ = 0 to 125 °C, VI = -23 V, IO = 500 mA, CI = 2.2 µF, CO = 1 µF
unless otherwise specified.
Table 7. Electrical characteristics of L7915C
Symbol Parameter Test conditions Min. Typ. Max. Unit
VOOutput voltage TJ = 25°C -14.4 -15 -15.6 V
VOOutput voltage IO = -5 mA to -1 A, PO 15 W
VI = -18.5 to -30 V -14.3 -15 -15.7 V
ΔVO(1) Line regulation VI = -17.5 to -30 V, TJ = 25°C 300 mV
VI = -20 to -26 V, TJ = 25°C 150
ΔVO(1) Load regulation IO = 5 mA to 1.5 A, TJ = 25°C 300 mV
IO = 250 to 750 mA, TJ = 25°C 150
IdQuiescent current TJ = 25°C 3 mA
ΔIdQuiescent current change IO = 5 mA to 1 A 0.5 mA
VI = -18.5 to -30 V 1
ΔVO/ΔT Output voltage drift IO = 5 mA -0.9 mV/°C
eN Output noise voltage B = 10Hz to 100kHz, TJ = 25°C 250 µV
SVR Supply voltage rejection ΔVI = 10 V, f = 120Hz 54 60 dB
VdDropout voltage IO = 1 A, TJ = 25°C, ΔVO = 100 mV 1.1 V
Isc Short circuit current 1.3 A
1. Load and line regulation are specified at constant junction temperature. Changes in VO due to heating effects must be
taken into account separately. Pulse testing with low duty cycle is used.
L79xxC Application information
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6 Application information
1. To specify an output voltage, substitute voltage value for "XX".
2. Required for stability. For value given, capacitor must be solid tantalum. If aluminium electrolytic are used,
at least ten times value should be selected. C1 is required if regulator is located an appreciable distance
from power supply filter.
3. To improve transient response. If large capacitors are used, a high current diode from input to output
(1N4001 or similar) should be introduced to protect the device from momentary input short circuit.
(*) Against potential latch-up problems.
Figure 4. Fixed output regulator
Figure 5. Split power supply (± 15 V - 1 A)
Application information L79xxC
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C3 Optional for improved transient response and ripple rejection.
Figure 6. Circuit for increasing output voltage
VXX/R2 > 3Id
VO=VXX(R1+R2)/R2
IN OUT
GND
IN OUT
GND
Figure 7. High current negative regulator (- 5 V / 4 A with 5 A current limiting)
IN OUT
GND
IN OUT
GND
L79xxC Package mechanical data
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7 Package mechanical data
In order to meet environmental requirements, ST offers these devices in different grades of
ECOPACK® packages, depending on their level of environmental compliance. ECOPACK®
specifications, grade definitions and product status are available at:
www.st.com
.
ECOPACK® is an ST trademark.
Note: In spite of some difference in tolerances, the packages are compatible.
Table 8. TO-220 mechanical data
Dim.
Type STD - ST Dual Gauge Type STD - ST Single Gauge
mm. mm.
Min. Typ. Max. Min. Typ. Max.
A 4.40 4.60 4.40 4.60
b 0.61 0.88 0.61 0.88
b1 1.14 1.70 1.14 1.70
c 0.48 0.70 0.48 0.70
D 15.25 15.75 15.25 15.75
D1 1.27
E 10.00 10.40 10.00 10.40
e 2.40 2.70 2.40 2.70
e1 4.95 5.15 4.95 5.15
F 1.23 1.32 0.51 0.60
H1 6.20 6.60 6.20 6.60
J1 2.40 2.72 2.40 2.72
L 13.00 14.00 13.00 14.00
L1 3.50 3.93 3.50 3.93
L20 16.40 16.40
L30 28.90 28.90
P 3.75 3.85 3.75 3.85
Q 2.65 2.95 2.65 2.95
Package mechanical data L79xxC
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Figure 8. Drawing dimension TO-220 (type STD-ST Dual Gauge)
0015988_S
L79xxC Package mechanical data
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Figure 9. Drawing dimension TO-220 (type STD-ST Single Gauge)
8174627_B
Package mechanical data L79xxC
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Figure 10. Drawing dimension tube for TO-220 Dual Gauge (mm)
Figure 11. Drawing dimension tube for TO-220 Single Gauge (mm)
L79xxC Package mechanical data
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Dim. mm. inch.
Min. Typ Max. Min. Typ. Max.
A 4.40 4.60 0.1730.181
B 2.5 2.7 0.098 0.106
D 2.5 2.75 0.098 0.108
E 0.45 0.70 0.017 0.027
F 0.75 1 0.0300.039
F1 1.15 1.50 0.045 0.059
F2 1.15 1.50 0.045 0.059
G4.95 5.2 0.194 0.204
G1 2.4 2.7 0.094 0.106
H 10.0 10.40 0.393 0.409
L2 16 0.630
L328.6 30.6 1.126 1.204
L4 9.810.6 0.3850.417
L5 2.93.6 0.114 0.142
L6 15.916.4 0.626 0.645
L7 99.30.354 0.366
DIA. 33.2 0.1180.126
TO-220FP mechanical data
7012510A-
H
Package mechanical data L79xxC
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Figure 12. Drawing dimension D²PAK (type STD-ST)
0079457/L
L79xxC Package mechanical data
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Figure 13. Drawing dimension D²PAK (type WOOSEOK-subcon.)
0079457/L
Package mechanical data L79xxC
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Note: The D²PAK package coming from the subcontractor WOOSEOK is fully compatible with the
ST's package suggested footprint.
Table 9. D²PAK mechanical data
Dim.
Type STD-ST Type WOOSEOK-subcon.
mm. mm.
Min. Typ. Max. Min. Typ. Max.
A 4.40 4.60 4.30 4.70
A1 0.03 0.23 0 0.20
b 0.70 0.93 0.70 0.90
b2 1.14 1.70 1.17 1.37
c 0.45 0.60 0.45 0.50 0.60
c2 1.23 1.36 1.25 1.30 1.40
D 8.95 9.35 9 9.20 9.40
D1 7.50 7.50
E 10 10.40 9.80 10.20
E1 8.50 7.50
e2.54 2.54
e1 4.88 5.28 5.08
H 15 15.85 15 15.30 15.60
J1 2.49 2.69 2.20 2.60
L 2.29 2.79 1.79 2.79
L1 1.27 1.40 1 1.40
L2 1.30 1.75 1.20 1.60
R0.4 0.30
V2
L79xxC Package mechanical data
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Figure 14. D²PAK footprint recommended data
Table 10. Footprint data
Values
Dim. mm. inch.
A 12.20 0.480
B 9.75 0.384
C 16.90 0.665
D 3.50 0.138
E 1.60 0.063
F 2.54 0.100
G 5.08 0.200