LT1312 Datasheet, PDF (1/12 Pages) Linear Technology – Single PCMCIA VPP Driver/Regulator

LT1312
Single PCMCIA
VPP Driver/Regulator
FEATURES
s _{Digital Selection of 0V, VCC, 12V or Hi-Z}
s _{120mA Output Current Capability}
s _{Internal Current Limiting and Thermal Shutdown}
s _{Automatic Switching from 3.3V to 5V}
s _{Powered from Unregulated 13V to 20V Supply}
s _{Logic Compatible with Standard PCMCIA Controllers}
s _{1µF Output Capacitor}
s _{30µA Quiescent Current in Hi-Z or 0V Mode}
s _{VPP Valid Status Feedback Signal}
s _{No VPP Overshoot}
s _{8-Pin SO Packaging}
U
APPLICATIONS
s _{Notebook Computers}
s _{Palmtop Computers}
s _{Pen-Based Computers}
s _{Handi-Terminals}
s _{Bar-Code Readers}
s _{Flash Memory Programming}
DESCRIPTION
The LT^®1312 is a member of Linear Technology
Corporation’s family of PCMCIA drivers/regulators. The
LT1312 provides 0V, 3.3V, 5V, 12V and Hi-Z regulated
power to the VPP pin of a PCMCIA card slot from a single
unregulated 13V to 20V supply. When used in conjunction
with a PC card interface controller, the LT1312 forms a
complete minimum component-count interface for palm-
top, pen-based and notebook computers. The VPP output
voltage is selected by two logic compatible digital inputs
which interface directly with industry standard PC card
interface controllers.
Automatic 3.3V to 5V switching is provided by an internal
comparator which continuously monitors the PC card V_CC
supply and automatically adjusts the regulated VPP out-
put to match V_CC when the VPP = V_CC mode is selected.
An open-collector VPP VALID output is driven low when
VPP is in regulation at 12V.
The LT1312 is available in an 8-pin SO package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
Typical PCMCIA Single Slot VPP Driver
13V TO 20V
PCMCIA
CARD SLOT
CONTROLLER
V_S
EN0 VPP_OUT
EN1 LT1312
VALID SENSE
GND
VPP1
VPP2
PCMCIA
CARD SLOT
V_CC
3.3V OR 5V
+ C_OUT
1µF
TANTALUM
LT1312 TA1
LT1312 TRUTH TABLE
EN0
EN1
0
0
1
0
0
1
0
1
1
1
X = DON’T CARE
SENSE
X
X
3.0V TO 3.6V
4.5V TO 5.5V
X
VPP_OUT
0V
12V
3.3V
5V
Hi-Z
VALID
1
0
1
1
1
Linear Technology PCMCIA Product Family
DEVICE DESCRIPTION
PACKAGE
LT1312 SINGLE PCMCIA VPP DRIVER/REGULATOR 8-PIN SO
LT1313 DUAL PCMCIA VPP DRIVER/REGULATOR 16-PIN SO*
LTC^®1314 SINGLE PCMCIA SWITCH MATRIX
14-PIN SO
LTC1315 DUAL PCMCIA SWITCH MATRIX
24-PIN SSOP
LTC1470 PROTECTED V_CC 5V/3.3V SWITCH MATRIX
LTC1472 PROTECTED V_CC AND VPP SWITCH MATRIX
*NARROW BODY
8-PIN SO
16-PIN SO*
1