Dual-Channel CardBus and PCMCIA VCC/VPP
Power-Switching Networks
Logic Truth Tables (cont.)
Table 3. “Databook” Code,
CODE = Mid-Supply (VL/2)
_1VCC _0VCC _1VPP _0VPP VCC_ VPP_ MODE
0
0
0
X
GND High-Z STBY
0
0
1
X
VY 12IN ACTIVE
0
1
0
X
GND GND STBY
0
1
1
X
VX 12IN ACTIVE
1
0
0
X
VY VCC_ ACTIVE
1
0
1
X
VY GND ACTIVE
1
1
0
X
VX VCC_ ACTIVE
1
1
1
X
VX GND ACTIVE
STBY = Standby Mode
X = Don’t Care
Detailed Description
The MAX1600/MAX1603 power-switching ICs contain a
network of low-resistance MOSFET switches that deliver
selectable VCC and VPP voltages to two CardBus or
PC Card host sockets. The MAX1600/MAX1603 differ
only in the VY switch on-resistance. Figure 1 is the
detailed block diagram.
The power-input pins (VY, VX, 12IN_) are completely
independent. Low inrush current is guaranteed by con-
trolled switch rise times. VCC’s 100µs minimum 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 capacitive loads are chosen as
worst-case card-insertion parameters. The internal
switching control allows VCC and VPP rise times to be
VB12
12IN
VPPA
1/2 MAX1600
1/2 MAX1603
CHARGE
PUMP
CURRENT
LIMIT
3Ω
40Ω
VY
VB3 0.08Ω*
VY
CHARGE
PUMP
CURRENT
LIMIT
VCCA
VCCA
VX
VB5 0.14Ω
VX
CHARGE
PUMP
CURRENT
LIMIT
VCCA
20Ω
FAULT
CONTROL
INPUTS
DECODE
LOGIC
AND UVLO
SHDN
THERMAL
GND
VDD
SHUTDOWN
VL
Figure 1. Detailed Block Diagram (one channel of two)
* 0.24Ω FOR THE MAX1603
_______________________________________________________________________________________ 9