STMicroelectronics LD1585Cxx Technical data

5 A low dropout fast response positive voltage regulator

Features

■ Typical dropout 1.2 V

■ Fast transient response

■ Three terminal adjustable or fixed output

voltage 1.5 V, 2.5 V, 2.85 V, 5 V, 8 V, 9 V

■ 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

0 °C to 125 °C

■ Package available: TO-220, D

■ Pinout compatibility with standard adjustable

VREG

Description

The LD1585C is a LOW DROP voltage regulator
able to provide up to 5 A of output current.
Dropout is guaranteed at a maximum of 1.4 V at
the maximum output current, decreasing at lower
loads. The device has been improved to be
utilized in low voltage applications where transient
response and minimum input voltage are critical.

2

PAK/A

LD1585Cxx

adjustable and fixed

TO-220

The most important feature of the device consist
in lower dropout voltage and very fast transient
response. 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 LD1585C quiescent current
flows into the load, so increase efficiency. Only a
10 µF minimum capacitor is need for stability.

The device is supplied in TO-220, D

2

D

PAK/A. On chip trimming allows the regulator to
reach a very tight output voltage tolerance, within
±1% at 25 °C.

D2PAK/A

2

PAK and

Table 1. Device summary

Order codes

Part number

TO-220 D

LD1585CXX15 LD1585CD2M15R 1.5 V

LD1585CXX25 LD1585CD2M25R 2.5 V

LD1585CXX28 LD1585CD2M28R 2.85 V

LD1585CXX50 LD1585CV50 LD1585CD2M50R 5.0 V

LD1585CXX80 LD1585CD2M80R 8.0 V

LD1585CXX90 LD1585CD2M90R 9.0 V

LD1585CXX LD1585CV ADJ

November 2007 Rev 6 1/23

2

PAK/A (T&R) Output voltage

www.st.com

23

Contents LD1585Cxx

Contents

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

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

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

4 Typical application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

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

6 Typical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

7 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

8 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

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LD1585Cxx Diagram

1 Diagram

Figure 1. Schematic diagram

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Pin configuration LD1585Cxx

2 Pin configuration

Figure 2. Pin connections (top view)

TO-220

D2PAK/A

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LD1585Cxx 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 0 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 D2PAK/A Unit

R

R

thJC

thJA

Thermal resistance junction-case 3 3 °C/W

Thermal resistance junction-ambient 50 62.5 °C/W

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Typical application LD1585Cxx

4 Typical application

Figure 3. Application circuits

VO = V

(1+R2/R1)

REF

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LD1585Cxx Electrical characteristics

5 Electrical characteristics

Table 4. Electrical characteristics of LD1585C#15 (VI = 4.5 V, CI = CO =10 µF, TJ = 0 to 125 °C,

unless otherwise specified.)

Symbol Parameter Test conditions Min. Typ. Max. Unit

I

= 0 mA, TJ = 25°C 1.485 1.5 1.515 V

V

Output voltage

O

ΔV

ΔV

Line regulation

O

Load regulation

O

V

Dropout voltage IO = 5 A 1.2 1.4 V

d

Quiescent current VI ≤ 25V 5 10 mA

I

q

Short circuit current VI - VO = 5V 5.5 7 A

I

sc

Thermal regulation T

SVR Supply voltage rejection

O

I

= 0 to 5A, VI = 3 to 25V

O

I

= 0 mA, VI = 3 to 15V TJ = 25°C 0.005 0.2 %

O

I

= 0 mA, VI = 3 to 15V 0.005 0.2 %

O

I

= 0 to 5A, TJ = 25°C 0.05 0.3 %

O

= 0 to 5A 0.05 0.5 %

I

O

= 25°C, 30ms pulse 0.004 0.02 %/W

J

f = 120 Hz, C

= 25µF, IO = 5A

O

VI - VO = 3 ± 1V

(1)

1.47 1.5 1.53 V

60 75 dB

RMS output noise voltage

eN

(% of V

)

O

= 25°C, f =10Hz to 10kHz 0.003 %

T

J

S Temperature stability 0.5 %

S Long term stability T

1. See short-circuit current curve for available output current at fixed dropout.

= 125°C, 1000Hrs 0.03 1 %

J

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