Single-Channel CardBus and PCMCIA VCC/VPP

Power-Switching Network

_______________________________________________________________________________________

9

_________Logic Truth Tables (cont.)

Table 3. “Databook” Code,

CODE = Mid-Supply (VY/2)

STBY = Standby Mode, X = Don’t Care

MODE

Active

Active

Active

Active

Active

A1VCC

STBY

AVPP

1

Active

STBY

0

1

1

1

0

0

1

1

A0VPP

1

VPP

X

VCC

X

GND

X

0

0

VCC

X

0

12IN

X

1

0

GND

0

X

X

High-Z

12IN

X

GND

VCC

VX

VY

VY

VX

VX

A0VCC

1

0

0

1

1

0

0

1

GND

VY

GND

MAX1602

CURRENT

LIMIT

6

Ω

1

Ω

0.25

Ω

0.25

Ω

VB3

VB12

40

Ω

40

Ω

DECODE

LOGIC

AND UVLO

CHARGE

PUMP

CURRENT

LIMIT

CHARGE

PUMP

CURRENT

LIMIT

THERMAL

SHUTDOWN

VCC

VCC

FAULT

GND

VCC

VCC

VPP

12IN

VY

VY

VX

CONTROL

INPUTS

VDD

SHDN

VB5

CHARGE

PUMP

Figure 1. Detailed Block Diagram

_______________Detailed Description

The MAX1602 power-switching IC contains a network of

low-resistance MOSFET switches that deliver selectable

VCC and VPP voltages to two CardBus or PC Card host

socket. Figure 1 is the detailed block diagram.

The power-input pins (VY, VX, 12IN) are completely

independent, however, power must always be applied

to VY for proper operation. Low inrush current is guaran-

teed by controlled switch rise times. VCC’s 100µs mini-

mum output rise time is 100% tested with a 1µF

capacitive load, and VPP’s 1ms minimum rise time is

guaranteed with a 0.1µF load. These respective capaci-

tive loads are chosen as worst-case card-insertion para-

meters. The internal switching control allows VCC and

VPP rise times to be controlled, and makes them nearly