1

LT1106

Micropower Step-Up

DC/DC Converter for

PCMCIA Card Flash Memory

S

FEATURE

DESCRIPTIO

designed for use on Type I and Type II PCMCIA cards. The

device senses the VPP1 and VPP2 lines at the PCMCIA

socket and generates a regulated 12V, 60mA program-

ming supply if the socket does not provide it. Internal logic

simplifies the interface to PCMCIA card microcontrollers.

One input selects a 12V or 5V regulated output, while

another input controls micropower shutdown. Two logic

outputs indicate when the selected programming voltage

is valid and whether the input supply is 3.3V or 5V.

300mV switch for efficiency up to 85%. High frequency

500kHz switching permits the use of small value, flat

inductors that fit neatly on PCMCIA cards. The device

requires just 1

µF of output capacitance.

Quiescent current is 750

µA which drops to 350µA when

the card runs off the socket supply. The shutdown pin

reduces supply current to only 10

µA. The device includes

a soft start feature which limits supply current transients

when the card is inserted into a hot socket.

S

APPLICATI

I

PCMCIA Card Flash Memory VPP Generator

I

Portable Computers

I

Portable Instruments

I

DC/DC Converter Module Replacements

I

60mA Output Current at 12V from 3V Supply

I

Shutdown to 10

µA

I

Programmable 12V or 5V Output

I

Up to 85% Efficiency

I

Quiescent Current: 750

µA

I

I

Uses Low Value, Thin, Surface Mount Inductors

I

Ultra-Thin 20-Lead TSSOP Package

, LTC and LT are registered trademarks of Linear Technology Corporation.

Burst Mode is a trademark of Linear Technology Corporation.

LOAD CURRENT (mA)

1

70

72

74

76

78

86

10

100

LT1106 • TA02

80

82

84

D1 = MBR0530

D1 = 4 BAT54Cs

IN PARALLEL

12V Output Efficiency

12V, 60mA Flash Memory Programming Supply

APPLICATI

TYPICAL

VPP1

G1

VPP2

G2

ON/OFF

GND

PGND

SW

D

S

BSS84

D

S

BSS84

POWER ON

DALE ILS-3825-01 OR

COILTRONICS CTX02-11238-3

MOTOROLA MBR0530

*

**

LT1106 • TA01

12/5

SOFT START

AVPP

1M

0.1

µF

3/5 DETECT

VPP VALID

1

µF

D1**

L1*

10

µH

0.1

µF

4.7

µF

TANT

ALUM

VPP1

VPP2

3.3V/5V

LT1106

VPP VALID

3/5

12V/60mA

0.1

µF

0.1

µF

470pF

+

FOR INFORMATION PURPOSES ONLY

OBSOLETE:

Contact Linear Technology for Potential Replacement