Datasheet

7
LTC1472
1472fa
BLOCK DIAGRAM
W
TTL-TO-CMOS
CONVERTER
OSCILLATOR
AND BIAS
GATE CHARGE
AND
DISCHARGE
CONTROL LOGIC
CHARGE
PUMP
GATE CHARGE
AND
DISCHARGE
CONTROL LOGIC
CURRENT LIMIT
AND THERMAL
SHUTDOWN
5V
IN
0.14
0.12
V
CC(OUT)
3V
IN
BREAK-BEFORE-
MAKE SWITCH
AND CONTROL
TTL-TO-CMOS
CONVERTER
V
CC
EN0
V
CC
EN1
LTC1470-BD01
VPP
IN
VPP
IN
VCC
(IN)
VPP
OUT
100
1.7
0.5
10V
VPP EN1
VPP EN0
SHDN
V
DD
GATE CHARGE
AND
DISCHARGE
CONTROL LOGIC
OSCILLATOR
AND BIAS
CURRENT LIMIT
AND THERMAL
SHUTDOWN
CHARGE
PUMP
GATE CHARGE
AND
DISCHARGE
CONTROL LOGIC
CHARGE
PUMP
BREAK-BEFORE-
MAKE SWITCH
TTL-TO-CMOS
CONVERTER
TTL-TO-CMOS
CONVERTER
+
OPERATION
U
The LTC1472 protected switch matrix is designed to be a
complete single slot solution for V
CC
and VPP switching in
a PCMCIA compatible card system. The LTC1472 consists
of two independent functional sections: the V
CC
switching
section, and the VPP switching section.
THE V
CC
SWITCHING SECTION
The V
CC
switching section of the LTC1472 consist of the
following functional blocks:
V
CC
Switch Input TTL-CMOS Converters
The LTC1472 V
CC
inputs are designed to accommodate a
wide range of 3V and 5V logic families. The input threshold
voltage is approximately 1.4V with approximately 100mV
of hysteresis. The inputs enable the bias generator, the
gate charge pumps and the protection circuity which are
powered from the 5V
IN
supply. Therefore, when the inputs
are turned off, the entire circuit is powered down and the
5V
IN
supply current drops below 1µA.