ST LD1085DT15R, LD1085D2M18R, LD1085D2M25R, LD1085D2T33R, LD1085D2M33R User Manual

LD1085xx

3 A low drop positive voltage regulator adjustable and fixed

Features

■Typical dropout 1.3 V (at 3 A)

■Three terminal adjustable or fixed output voltage 1.5 V, 1.8 V, 2.5 V, 3.3 V, 5 V, 12 V.

■Automotive grade product: adjustable VOUT only in TO-220 full pack package

■Guaranteed output current up to 3 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, TO-220FP, DPAK, D2PAK, D2PAK/A

■Pinout compatibility with standard adjustable VREG

Description

The LD1085xx is a low drop voltage regulator able to provide up to 3 A of output current. Dropout is guaranteed at a maximum of 1.2 V at the maximum output current, decreasing at lower loads. The LD1085xx is pin to pin compatible with the older 3-terminal adjustable regulators, but has better performances in term of drop and output tolerance.

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 LD1085xx quiescent current flows

TO-220		TO-220FP
DPAK	D2PAK	D2PAK/A

into the load, so increase efficiency. Only a 10 µF minimum capacitor is need for stability.

The device is supplied in TO-220, TO-220FP, DPAK, D2PAK and D2PAK/A. On chip trimming allows the regulator to reach a very tight output voltage tolerance, within ± 1 % at 25 °C.

The LD1085xx is available as automotive grade in TO-220FP package only, for the option of adjustable output voltage whose commercial part number is shown in the Table 11: Order codes. This device is qualified according to the specification AEC-Q100 of the automotive market, in the temperature range -40 °C to

125 °C, and the statistical tests PAT, SYL, SBL are performed.

Table 1.	Device summary
		Part numbers
	LD1085XX		LD1085XX25
	LD1085XX15		LD1085XX33
	LD1085XX18		LD1085XX50

July 2009

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Contents	LD1085xx

Contents

1	Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 3
2	Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 4
3	Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	5
4	Schematic application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	6
5	Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	7
6	Typical application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	14
7	Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	18
8	Order codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	26
9	Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	27

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LD1085xx	Diagram

1 Diagram

Figure 1. Schematic diagram

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Pin configuration	LD1085xx

2 Pin configuration

Figure 2. Pin connections (top view)

TO-220	TO-220FP
D2PAK	D2PAK/A
	DPAK

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LD1085xx	Maximum ratings

3 Maximum ratings

Table 2.

Absolute maximum ratings

Symbol

Parameter

Value

Unit

VI

DC input voltage

30

V

IO

Output current

Internally limited

mA

PD

Power dissipation

Internally limited

mW

TSTG

Storage temperature range

-55 to +150

°C

TOP

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

TO-220FP

DPAK

D2PAK

Unit

D2PAK/A

RthJC

Thermal resistance junction-case

3

5

8

3

°C/W

RthJA

Thermal resistance junction-ambient

50

60

100

62.5

°C/W

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Schematic application	LD1085xx

4 Schematic application

Figure 3. Application circuit

V		=	V			R2
	O			REF		1 + ------
						R
						1

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LD1085xx			Electrical characteristics
5	Electrical characteristics
	VI = 4.5 V, CI = CO =10 µF, TA = -40 to 125 °C, unless otherwise specified.
Table 4.	Electrical characteristics of LD1085#15
Symbol	Parameter	Test condition	Min.	Typ.	Max.	Unit
V	Output voltage (1)	IO = 0 mA, TJ = 25°C	1.485	1.5	1.515	V
O		IO = 0 to 3 A, VI = 3.1 to 30 V	1.47	1.5	1.53	V
VO	Line regulation	IO = 0 mA, VI = 3.1 to 18 V, TJ = 25°C		0.2	4	mV
		IO = 0 mA, VI = 3.1 to 15 V		0.4	4	mV
VO	Load regulation	IO = 0 to 3 A, TJ = 25°C		2	10	mV
		IO = 0 to 3 A		4	20	mV
Vd	Dropout voltage	IO =3 A		1.3	1.5	V
Iq	Quiescent current	VI ≤ 30 V		5	10	mA
Isc	Short circuit current	VI - VO = 5 V	3.2	4.5		A
		VI - VO = 25 V	0.2	0.5		A
	Thermal regulation	TA = 25°C, 30ms pulse		0.008	0.04	%/W
SVR	Supply voltage rejection	f = 120 Hz, CO = 25 µF, IO = 3 A	60	72		dB
		VI = 7.5 ± 3 V
eN	RMS output noise voltage (%	TA = 25°C, f =10 Hz to 10 kHz		0.003		%
	of VO)
S	Temperature stability			0.5		%
S	Long term stability	TA = 125°C, 1000Hrs		0.5		%

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

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Electrical characteristics	LD1085xx

VI = 4.8 V, CI = CO =10 µF, TA = -40 to 125 °C, unless otherwise specified.

Table 5.	Electrical characteristics of LD1085#18
Symbol	Parameter	Test condition	Min.	Typ.	Max.	Unit
V	Output voltage (1)	IO = 0 mA, TJ = 25°C	1.782	1.8	1.818	V
O		IO = 0 to 3 A, VI = 3.4 to 30 V	1.764	1.8	1.836	V
VO	Line regulation	IO = 0 mA, VI = 3.4 to 18 V TJ = 25°C		0.2	4	mV
		IO = 0 mA, VI = 3.4 to 15 V		0.4	4	mV
VO	Load regulation	IO = 0 to 3 A, TJ = 25°C		2	10	mV
		IO = 0 to 3 A		4	20	mV
Vd	Dropout voltage	IO = 3 A		1.3	1.5	V
Iq	Quiescent current	VI ≤ 30 V		5	10	mA
Isc	Short circuit current	VI - VO = 5 V	3.2	4.5		A
		VI - VO = 25 V	0.2	0.5		A
	Thermal regulation	TA = 25°C, 30 ms pulse		0.008	0.04	%/W
SVR	Supply voltage rejection	f = 120 Hz, CO = 25 µF, IO = 3 A	60	72		dB
		VI = 7.5 ± 3 V
eN	RMS output noise voltage (% of	T = 25°C, f =10 Hz to 10 kHz		0.003		%
	VO)	A
S	Temperature stability			0.5		%
S	Long term stability	TA = 125°C, 1000 Hrs		0.5		%

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

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LD1085xx	Electrical characteristics

VI = 5.5 V, CI = CO =10 µF, TA = -40 to 125 °C, unless otherwise specified.

Table 6.	Electrical characteristics of LD1085#25
Symbol	Parameter	Test condition	Min.	Typ.	Max.	Unit
V	Output voltage (1)	IO = 0 mA, TJ = 25°C	2.475	2.5	2.525	V
O		IO = 0 to 3 A, VI = 4.1 to 30 V	2.45	2.5	2.55	V
VO	Line regulation	IO = 0 mA, VI = 4.1 to 18 V, TJ = 25°C		0.2	4	mV
		IO = 0 mA, VI = 4.1 to 18 V		0.4	4	mV
VO	Load regulation	IO = 0 to 3 A, TJ = 25°C		2	10	mV
		IO = 0 to 3 A		4	20	mV
Vd	Dropout voltage	IO = 3 A		1.3	1.5	V
Iq	Quiescent current	VI ≤ 30 V		5	10	mA
Isc	Short circuit current	VI - VO = 5 V	3.2	4.5		A
		VI - VO = 25 V	0.2	0.5		A
	Thermal regulation	TA = 25°C, 30ms pulse		0.008	0.04	%/W
SVR	Supply voltage rejection	f = 120 Hz, CO = 25µF, IO = 3 A	60	72		dB
		VI = 7.5 ± 3 V
eN	RMS output noise voltage (%	TA = 25°C, f =10 Hz to 10 kHz		0.003		%
	of VO)
S	Temperature stability			0.5		%
S	Long term stability	TA = 125°C, 1000 Hrs		0.5		%

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

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