LTC1472 Datasheet, PDF (7/16 Pages) Linear Technology – Protected PCMCIA VCC and VPP Switching Matrix

BLOCK DIAGRAM
V_CC EN0
TTL-TO-CMOS
CONVERTER
V_CC EN1
TTL-TO-CMOS
CONVERTER
V_DD
SHDN
VPP EN0
TTL-TO-CMOS
CONVERTER
VPP EN1
TTL-TO-CMOS
CONVERTER
VPP_IN
+
10V
–
LTC1472
BREAK-BEFORE-
MAKE SWITCH
AND CONTROL
BREAK-BEFORE-
MAKE SWITCH
GATE CHARGE
AND
DISCHARGE
CONTROL LOGIC
5V_IN
0.14Ω
OSCILLATOR
AND BIAS
CHARGE
PUMP
CURRENT LIMIT
AND THERMAL
SHUTDOWN
V_CC(OUT)
GATE CHARGE
AND
DISCHARGE
CONTROL LOGIC
0.12Ω
3V_IN
GATE CHARGE
AND
DISCHARGE
CONTROL LOGIC
CHARGE
PUMP
VPP_IN
0.5Ω
OSCILLATOR
AND BIAS
GATE CHARGE
AND
DISCHARGE
CONTROL LOGIC
CURRENT LIMIT
AND THERMAL
SHUTDOWN
CHARGE
PUMP
1.7Ω
100Ω
VCC_(IN)
VPP_OUT
LTC1470-BD01
U
OPERATION
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.
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