ds8023-rrx Maxim Integrated Products, Inc., ds8023-rrx Datasheet - Page 14

• Manufacturer Part Number: ds8023-rrx
• Description: Smart Card Interface
• Manufacturer: Maxim Integrated Products, Inc.

Smart Card Interface
The DS8023 supports three smart card V
1.8V, 3V, and 5V. The power select is controlled by the
1_8V and 5V/3V signals as shown in Table 3. The 1_8V
signal has priority over 5V/3V. When 1_8V is asserted
high, 1.8V is applied to V
active. When 1_8V is deasserted, 5V/3V dictates V
power range. V
high state, and V
Table 3. V
Figure 9. Smart Card Power Select
14
______________________________________________________________________________________
V
1_8V
CC
CMDVCC
0
0
0
0
1
1
1
1
SELECT
5V/3V
1_8V
CC
Smart Card Power Select
CC
Select and Operation Mode
is 5V if 5V/3V is asserted to a logic-
CC
is 3V if 5V/3V is pulled to a
5V/3V
1.8V
CC
0
0
1
1
0
0
1
1
when the smart card is
CMDVCC
CC
3V
0
1
0
1
0
1
0
1
voltages:
CC
V
5V
CC
logic-low state. Care must be exercised when switching
from one V
and 5V/3V are high with CMDVCC high at the same
time, the DS8023 enters stop mode. To avoid acciden-
tal entry into stop mode, the state of 1_8V and 5V/3V
must not be changed simultaneously. A minimum delay
of 100ns should be observed between changing the
states of 1_8V and 5V/3V. See Figure 9 for the recom-
mended sequence of changing the V
SELECT (V)
1.8
1.8
1.8
1.8
3
3
5
5
CC
3V
power selection to the other. If both 1_8V
CARD INTERFACE STATUS
Not Applicable—Stop Mode
1.8V
Reserved (Activated)
Deactivated
Deactivated
Deactivated
Activated
Activated
Activated
STOP MODE
CC
range.