DS8023
Smart Card Interface
EMVCo approval of the interface module (IFM) contained in this Terminal shall mean only that the IFM has been tested in accordance and for sufficient
conformance with the EMV Specifications, Version 3.1.1, as of the date of testing. EMVCo approval is not in any way an endorsement or warranty regarding
the completeness of the approval process or the functionality, quality or performance of any particular product or service. EMVCo does not warrant any
products or services provided by third parties, including, but not limited to, the producer or provider of the IFM and EMVCo approval does not under any
circumstances include or imply any product warranties from EMVCo, including, without limitation, any implied warranties of merchantability, fitness for pur-
pose, or noninfringement, all of which are expressly disclaimed by EMVCo. All rights and remedies regarding products and services which have received
EMVCo approval shall be provided by the party providing such products or services, and not by EMVCo and EMVCo accepts no liability whatsoever in
connection therewith.
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
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____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2008 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
Applications Information
Performance can be affected by the layout of the appli-
cation. For example, an additional cross-capacitance of
1pF between card reader contacts C2 (RST) and C3
(CLK) or C2 (RST) and C7 (I/O) can cause contact C2
to be polluted with high-frequency noise from C3 (or
C7). In this case, include a 100pF capacitor between
contacts C2 and CGND.
Application recommendations include the following:
• Ensure there is ample ground area around the
DS8023 and the connector; place the DS8023
very near to the connector; decouple the V
DD
and
V
DDA
lines separately. These lines are best posi-
tioned under the connector.
• The DS8023 and the host microcontroller must use
the same V
DD
supply. Pins CLKDIV1, CLKDIV2,
RSTIN, PRES, AUX1IN, I/OIN, AUX2IN, 5V/3V,
CMDVCC, and OFF are referenced to V
DD
; if pin
XTAL1 is to be driven by an external clock, also
reference this pin to V
DD
.
• Trace C3 (CLK) should be placed as far as possi-
ble from the other traces.
• The trace connecting CGND to C5 (GND) should
be straight (the two capacitors on C1 (V
CC
) should
be connected to this ground trace).
• Avoid ground loops among CGND, PGND, and
GND.
• Decouple V
DDA
and V
DD
separately; if the two
supplies are the same in the application, they
should be connected in a star on the main trace.
• Connect a 100nF capacitor (ESR < 100mΩ)
between V
CC
and CGND and place near the
DS8023’s V
CC
pin.
• Connect a 100nF or 220nF capacitor (220nF pre-
ferred, ESR < 100mΩ) between V
CC
and CGND
and place near the smart card socket’s C1 contact.
With all these layout precautions, noise should be kept
to an acceptable level and jitter on C3 (CLK) should be
less than 100ps.
Technical Support
For technical support, go to https://support.maxim-
ic.com/micro.
Selector Guide
Note: Contact the factory for availability of other variants and
package options.
+
Denotes a lead(Pb)-free/RoHS-compliant package.
