ST LD1084V User Manual

5 A low drop positive voltage regulator adjustable

Features

■ Typical dropout 1.3 V (at 5 A)

■ Three terminal adjustable output voltage

■ Guaranteed output current up to 5 A

■ Output tolerance ± 1 % at 25 °C and ± 2 % in

full temperature range

■ Internal power and thermal limit

■ Wide operating temperature range -40 °C to

125 °C

■ Package available: TO-220

■ Pinout compatibility with standard adjustable

VREG

Description

The LD1084XX is a low drop voltage regulator
able to provide up to 5 A of output current.
Dropout is guaranteed at a maximum of 1.5 V at
the maximum output current, decreasing at lower
loads. The LD1084XX is pin to pin compatible
with the older 3-terminal adjustable regulators, but
has better performances in term of drop and
output tolerance.

LD1084XX

TO-220

The device is supplied in TO-220. On chip
trimming allows the regulator to reach a very tight
output voltage tolerance, within ± 1 % at 25 °C.

A 2.85 V output version is suitable for SCSI-2
active termination. Unlike PNP regulators, where
a part of the output current is wasted as quiescent
current, the LD1084XX quiescent current flows
into the load, so increase efficiency. Only a 10 µF
minimum capacitor is need for stability.

Table 1. Device summary

Order code Output voltage

LD1084V Adjustable

July 2009 Doc ID 9035 Rev 9 1/16

www.st.com

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Contents LD1084XX

Contents

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

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

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

4 Schematic application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

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

6 Typical application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

7 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

8 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

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LD1084XX Diagram

1 Diagram

Figure 1. Schematic diagram

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Pin configuration LD1084XX

2 Pin configuration

Figure 2. Pin connections (top view)

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LD1084XX Maximum ratings

3 Maximum ratings

Table 2. Absolute maximum ratings

Symbol Parameter Value Unit

T

P

T

V

I

I

O

D

STG

OP

DC input voltage 30 V

Output current Internally limited mA

Power dissipation Internally limited mW

Storage temperature range -55 to +150 °C

Operating junction temperature range -40 to +125 °C

Note: Absolute maximum ratings are those values beyond which damage to the device may occur.

Functional operation under these condition is not implied.

Table 3. Thermal data

Symbol Parameter TO-220 Unit

R

R

thJC

thJA

Thermal resistance junction-case 3 °C/W

Thermal resistance junction-ambient 50 °C/W

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