LTC1258 Series

7

1258sfb

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.

However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-

tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.

PACKAGE DESCRIPTION

Internal P-Channel Pass Transistor

The LTC1258 series features an internal P-channel MOSFET

pass transistor. This provides several advantages over

similar designs using a PNP bipolar pass transistor.

These references consume only 4μA of quiescent current

under light and heavy loads as well as in dropout; whereas,

PNP-based references waste considerable amounts of

current when the pass transistor is saturated. In addition,

the LTC1258 series provides a lower dropout voltage

(200mV max) than PNP-based references.

LTC1258-5

OUT

IN

GND

4

2

5.2V

TO

12.6V

1

5V

1258 F02

0.1μF

>1μF

DAMPING RESISTOR

<1k

OUTPUT CAPACITOR VALUE (μF)

1

10

100

1k

10k

10

100

1000

1258 F03

Figure 2. Adding a Damping Resistor with

Output Capacitors Greater Than 1μF

Figure 3. Damping Resistance vs Output Capacitor Value

APPLICATIONS INFORMATION

MS8 Package

8-Lead Plastic MSOP

(Reference LTC DWG # 05-08-1660 Rev F)

S8 Package

8-Lead Plastic Small Outline (Narrow .150 Inch)

(Reference LTC DWG # 05-08-1610)

MSOP (MS8) 0307 REV F

0.53

0.152

(.021

.006)

SEATING

PLANE

NOTE:

1. DIMENSIONS IN MILLIMETER/(INCH)

2. DRAWING NOT TO SCALE

3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.

MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE

4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.

INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE

5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX

0.18

(.007)

0.254

(.010)

1.10

(.043)

MAX

0.22 – 0.38

(.009 – .015)

TYP

0.1016

0.0508

(.004

.002)

0.86

(.034)

REF

0.65

(.0256)

BSC

0 – 6 TYP

DETAIL “A”

DETAIL “A”

GAUGE PLANE

12

3

4

4.90

0.152

(.193

.006)

8

7 6 5

3.00

0.102

(.118

.004)

(NOTE 3)

3.00

0.102

(.118

.004)

(NOTE 4)

0.52

(.0205)

REF

5.23

(.206)

MIN

3.20 – 3.45

(.126 – .136)

0.889

0.127

(.035

.005)

RECOMMENDED SOLDER PAD LAYOUT

0.42

0.038

(.0165

.0015)

TYP

0.65

(.0256)

BSC

.016 – .050

(0.406 – 1.270)

.010 – .020

(0.254 – 0.508)

45

0 – 8 TYP

.008 – .010

(0.203 – 0.254)

SO8 0303

.053 – .069

(1.346 – 1.752)

.014 – .019

(0.355 – 0.483)

TYP

.004 – .010

(0.101 – 0.254)

.050

(1.270)

BSC

1

2

3

4

.150 – .157

(3.810 – 3.988)

NOTE 3

8

7

6

5

.189 – .197

(4.801 – 5.004)

NOTE 3

.228 – .244

(5.791 – 6.197)

.245

MIN

.160 .005

RECOMMENDED SOLDER PAD LAYOUT

.045 .005

.050 BSC

.030 .005

TYP

INCHES

(MILLIMETERS)

NOTE:

1. DIMENSIONS IN

2. DRAWING NOT TO SCALE

3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.

MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)