ST L7905AC, L7905ACV, L7905ACV-DG, L7905ACD2T-TR, L7912AC User Manual

February 2012 Doc ID 2150 Rev 13 1/22

22

L79xxAC

2 % negative voltage regulators

Features

■ Output current to 1.5 A

■ Output voltages of -5; -12; -15 V

■ Thermal overload protection

■ Short circuit protection

■ Output transition SOA protection

Description

The L79xxAC series of three-terminal negative

regulators is available in TO-220 and D²PAK

packages and several fixed output voltages.

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 L78xxA 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.

D²PAK

TO-220

Table 1. Device summary

Part numbers

Order codes

Output

voltages

TO-220 D²PAK

L7905AC L7905ACV L7905ACV-DG

(1)

L7905ACD2T-TR -5 V

L7912AC L7912ACV L7912ACV-DG

(1)

-12 V

L7915AC L7915ACV L7915ACV-DG

(1)

-15 V

1. TO-220 Dual Gauge frame.

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Contents L79xxAC

2/22 Doc ID 2150 Rev 13

Contents

1 Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

4 Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

5 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

6 Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

7 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

8 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

L79xxAC Diagram

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1 Diagram

Figure 1. Schematic diagram

Pin configuration L79xxAC

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2 Pin configuration

Figure 2. Pin connections (top view)

D²PAK

TO-220

L79xxAC 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

V

I

DC input voltage

for V

O

= -5 to -18V -35

V

for V

O

= -20, -24V -40

I

O

Output current Internally limited

P

D

Power dissipation Internally limited

T

STG

Storage temperature range -65 to 150 °C

T

OP

Operating junction temperature range 0 to 125 °C

Table 3. Thermal data

Symbol Parameter D²PAK TO-220 Unit

R

thJC

Thermal resistance junction-case 3 5 °C/W

R

thJA

Thermal resistance junction-ambient 62.5 50 °C/W

Application L79xxAC

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4 Application

Figure 3. Application circuit

L79xxAC Electrical characteristics

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5 Electrical characteristics

Refer to the test circuits, T

J

= 0 to 125 °C, V

I

= -10 V, I

O

= 500 mA, C

I

= 2.2 µF, C

O

= 1 µF

unless otherwise specified.

Table 4. Electrical characteristics of L7905AC

Symbol Parameter Test conditions Min. Typ. Max. Unit

V

O

Output voltage T

J

= 25°C -4.9 -5 -5.1 V

V

O

Output voltage

I

O

= -5 mA to -1 A, P

O

≤ 15 W

V

I

= -8 to -20 V

-4.8 -5 -5.2 V

ΔV

O

(1)

Line regulation

V

I

= -7 to -25 V, T

J

= 25°C 100

mV

V

I

= -8 to -12 V, T

J

= 25°C 50

ΔV

O

(1)

Load regulation

I

O

= 5 mA to 1.5 A, T

J

= 25°C 100

mV

I

O

= 250 to 750 mA, T

J

= 25°C 50

I

d

Quiescent current T

J

= 25°C 3 mA

ΔI

d

Quiescent current change

I

O

= 5 mA to 1 A 0.5

mA

V

I

= -8 to -25 V 1.3

ΔV

O

/ΔT Output voltage drift I

O

= 5 mA -0.4 mV/°C

eN Output noise voltage B = 10Hz to 100kHz, T

J

= 25°C 100 µV

SVR Supply voltage rejection ΔV

I

= 10 V, f = 120Hz 54 60 dB

V

d

Dropout voltage I

O

= 1 A, T

J

= 25°C, ΔV

O

= 100 mV 1.4 V

I

sc

Short circuit current 2.1 A

I

scp

Short circuit peak current T

J

= 25°C 2.5 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.