DS8005 Datasheet, PDF (7/20 Pages) Maxim Integrated Products – Smart Card Intergace

TOP VIEW
CLKDIV1 1
CLKDIV2 2
5V/3V 3
1_8V 4
V_CCB 5
V_DDA 6
RSTB 7
CLKB 8
CGND 9
PRESA 10
I/OA 11
I/OB 12
PRESB 13
CGND 14
Smart Card Interface
Pin Configuration
DS8005
SO
28 SEL_AB
27 OFF2
26 I/OIN
25 XTAL2
24 XTAL1
23 OFF
22 GND
21 V_DD
20 RSTIN
19 CMDVCC
18 V_DDA2
17 V_CCA
16 RSTA
15 CLKA
PIN
1, 2
3
4
5
6
7
8
9, 14
10
11
Pin Description
NAME
CLKDIV1,
CLKDIV2
5V/3V
1_8V
V_CCB
V_DDA
RSTB
CLKB
CGND
PRESA
I/OA
FUNCTION
Clock Divider. Determines the divided-down input clock frequency (presented at XTAL1 or from a
crystal at XTAL1 and XTAL2) on the CLK_ output pin. Dividers of 1, 2, 4, and 8 are available.
5V/3V Selection Pin. Allows selection of 5V or 3V for communication with an IC card. Logic-high
selects 5V operation; logic-low selects 3V operation. The 1_8V pin overrides the setting on this pin if
active. See Table 3 for a complete description of choosing card voltages.
1.8V Operation Selection. This active-high input puts the device into 1.8V smart card communication
mode. The selected interface (when activated) powers a card with a 1.8V supply and all I/O lines
operate at 1.8V.
Smart Card Supply Voltage, Interface B. Decouple to CGND (card ground) with 2 x 100nF or 100 +
200nF capacitors (ESR < 100m
).
Smart Card Interface Supply. 5V power supply for powering the card interface.
Smart Card Reset, Interface B. Card reset output from contact C2.
Smart Card Clock, Interface B. Card clock, contact C3.
Smart Card Ground
Interface A Card Presence Indicator. Active-high card presence input for the first card interface.
When the presence indicator becomes active, a debounce timeout begins. After 8ms (typ), the OFF
signal becomes active if the first card interface is selected (SEL_AB low), else the OFF2 signal
becomes active.
Smart Card Data-Line Output, Interface A. Card data communication line, contact C7. This pin is
only active if the first card interface is selected (SEL_AB low) and the interface has gone through an
activation sequence.
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