Datasheet - L79 - Negative voltage regulators

Document overview

  • Manufacturer or author: STMICROELECTRONICS
  • PDF pages: 29

Technical content

Datasheet sections

  • 1 Diagram
  • 2 Pin configuration
  • 3 Maximum ratings
  • 4 Test circuit
  • 5 Electrical characteristics
  • 6 Application information
  • 7 Package information
  • 7.1 TO-220 (single gauge) package information
  • 7.2 TO-220 (dual gauge) package information
  • 7.3 TO-220FP package information
  • 7.4 D²PAK (TO-263) type A package information
  • 7.5 D²PAK packing information
  • 8 Ordering information

Features

  • Output current up to 1.5 A
  • Output voltages: -5, -8, -12, and -5 V
  • Thermal overload protection
  • Short-circuit protection
  • Output SOA protection
  • Output tolerance 2% (AC version) or 4% (C version) at 25 °C

Description

The L79 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 L78 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. Maturity status link L79 Negative voltage regulators L79 Datasheet DS0428 - Rev 24 - January 2019 For further information contact your local STMicroelectronics sales office.

1 Diagram

Figure 1. Schematic diagram

2 Pin configuration

Figure 2. Pin connections (top view)

3 Maximum ratings

Table 1. Absolute maximum ratings operation under these condition is not implied. Table 2. Thermal data

4 Test circuit

Figure 3. Test circuit

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 3. Electrical characteristics of L7905AC

  1. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects must be taken

into account separately. Pulse testing with low duty cycle is used. Table 4. Electrical characteristics of L7905C

Electrical characteristics

Symbol Parameter Test conditions Min. Typ. Max. Unit ΔId Quiescent 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 = 10 Hz to 100 kHz, TJ = 25 °C 100 µV SVR Supply voltage rejection ΔVI = 10 V, f = 120 Hz 54 60 dB Vd Dropout voltage IO = 1 A, TJ = 25 °C, ΔVO = 100 mV 1.4 V Isc Short circuit current 1.8 A 1. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects must be taken into account separately. Pulse testing with low duty cycle is used. 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

  1. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects must be taken

into account separately. Pulse testing with low duty cycle is used.

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 L7912AC

  1. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects must be taken

into account separately. Pulse testing with low duty cycle is used. Table 7. Electrical characteristics of L7912C

Symbol Parameter Test conditions Min. Typ. Max. Unit ΔId Quiescent 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 = 10 Hz to 100 kHz, TJ = 25 °C 200 µV SVR Supply voltage rejection ΔVI = 10 V, f = 120Hz 54 60 dB Vd Dropout voltage IO = 1 A, TJ = 25 °C, ΔVO = 100 mV 1.1 V Isc Short circuit current 1.0 A 1. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects must be taken into account separately. Pulse testing with low duty cycle is used. 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 8. Electrical characteristics of L7915AC

  1. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects must be taken

into account separately. Pulse testing with low duty cycle is used.

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 9. Electrical characteristics of L7915C

  1. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects must be taken

into account separately. Pulse testing with low duty cycle is used. DS0428 - Rev 24 page 10/29

6 Application information

Figure 4. Fixed output regulator to output (1N4001 or similar) should be introduced to protect the device from momentary input short circuit. Figure 5. Split power supply (±15 V - 1 A)

Application information

DS0428 - Rev 24 page 11/29

7 Package information

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.

7.1 TO-220 (single gauge) package information

Figure 8. TO-220 (single gauge) package outline

8174627 Rev 6

Package information

DS0428 - Rev 24 page 13/29

Table 10. TO-220 (single gauge) package mechanical data

7.2 TO-220 (dual gauge) package information

Figure 9. TO-220 type A package outline

Table 11. TO-220 type A package mechanical data

7.3 TO-220FP package information

Figure 10. TO-220FP package outline

Table 12. TO-220FP package mechanical data

7.4 D²PAK (TO-263) type A package information

Figure 11. D²PAK (TO-263) type A package outline

Table 13. D²PAK (TO-263) type A package mechanical data

Figure 12. D²PAK (TO-263) recommended footprint (dimensions are in mm)

7.5 D²PAK packing information

Figure 13. D²PAK tape outline

Figure 14. D²PAK reel outline Table 14. D²PAK tape and reel mechanical data

8 Device summary

Table 15. Order codes

Revision history

Table 16. Document revision history 22-Jun-2004 9 Order codes updated Table 3. 31-Aug-2005 10 Add new order codes (TO-220 E Type) on Table 3. 19-Jan-2007 11 D²PAK mechanical data updated and add footprint data. 06-Jun-2007 12 Order codes updated. 25-Oct-2007 13 Modified: Figure 3, Figure 4, Figure 6 and Figure 7. 05-Dec-2007 14 Modified: Table 1. 18-Feb-2008 15 Modified: Table 1 on page 1. 15-Jul-2008 16 Modified: Table 1 on page 1. Figure 10 and Figure 11 on page 18. 26-May-2010 18 Modified: VI parameter Table 2 on page 5. 12-Nov-2010 19 Modified: RthJC value for TO-220 Table 3 on page 5. 15-May-2012 21 Added: order codes L7908CV-DG Table 1 on page 1. Part numbers L79xxC and L79xxAC changed to L79. Updated the features and the description in cover page. Section 7: Package mechanical data. Added Section 8: Packaging mechanical data. 15-Jan-2019 24 Updated: Section 5 Electrical characteristics.