Document Title Here
Document Title Here
Document Title Here
ACR33U-A1 SmartDuo Reference Manual
Version 1.00
Page 6 of 56
www.acs.com.hk
4.0. Smart Card Interface
The interface between the ACR33U-A1 SmartDuo Smart Card Reader and the inserted smart card
follows the specifications of ISO 7816-3 with certain restrictions or enhancements to increase the
practical functionality of the ACR33U-A1 SmartDuo.
4.1. Smart Card Power Supply VCC (C1)
The current consumption of the inserted card must not be higher than 50 mA.
4.2. Programming Voltage VPP (C6)
According to ISO 7816-3, the smart card contact C6 (VPP) supplies the programming voltage to the
smart card. Since all common smart cards in the market are EEPROM based and do not require the
provision of an external programming voltage, the contact C6 (VPP) has been implemented as a
normal control signal in the ACR33U-A1 SmartDuo. The electrical specifications of this contact are
identical to those of the signal RST (at contact C2).
4.3. Card Type Selection
The controlling PC must always select the card type through the proper command sent to the
ACR33U-A1 SmartDuo prior to activating the inserted card. This includes both the memory cards and
MCU-based cards.
For MCU-based cards the reader allows to select the preferred protocol, T=0 or T=1. However, this
selection is only accepted and carried out by the reader through the PPS when the card inserted in
the reader supports both protocol types. Whenever an MCU-based card supports only one protocol
type, T=0 or T=1, the reader automatically uses that protocol type, regardless of the protocol type
selected by the application.
4.4. Interface for Microcontroller-based Cards
For microcontroller-based smart cards only the contacts C1 (VCC), C2 (RST), C3 (CLK), C5 (GND)
and C7 (I/O) are used. A frequency of 4 MHz is applied to the CLK signal (C3).
4.5. Card Tearing Protection
The ACR33U-A1 SmartDuo provides a mechanism to protect the inserted card when it is suddenly
withdrawn while it is powered up. The power supply to the card and the signal lines between the
ACR33U-A1 SmartDuo and the card is immediately deactivated when the card is removed. However,
as a rule to avoid any electrical damage, a card should only be removed from the reader while it is
powered down.
Note:
ACR33U-A1 SmartDuo does not switch on the power supply to the inserted card by itself. This
can be done by the controlling computer through the proper command sent to the reader.
