General description

The TDA8025 is a cost-effective analog interface for asynchronous smart cards operating at 3 V, 1.8 V or optionally, 1.2 V. Using few external components, the TDA8025 provides integrated supply, protection and control functions for a range of applications.

Features

■ Integrated circuit smart card interface

■ 3 V, 1.8 V or 1.2 V smart card supply

■ Low power consumption in inactive mode

■ Three protected, half duplex, bidirectional buffered input/output lines (C4, C7 and C8)

■ VCC regulation:

◆ 3 V, 1.8 V or optionally 1.2 V at ± 5 using one 220 nF and one 470 nF low ESR multilayer ceramic capacitor.

◆ Current pulse handling for pulses of 40 nAs at VCC = 3 V, 15 nAs at VCC = 1.8 V or VCC = 1.2 V up to 20 MHz

■ Thermal and short-circuit protection for all card contacts

■ Automatic activation and deactivation sequences triggered by short-circuit, card take-off, overheating, falling VDD(INTF) and VDD(INTREGD)

■ Enhanced card-side ElectroStatic Discharge (ESD) protection of > 6 kV

■ Clock signal using the internal oscillator or an external crystal (≤ 26 MHz) connected to pin XTAL1

■ Card clock generation up to 20 MHz with synchronous frequency changes of fxtal, 1⁄2 fxtal, 1⁄4 fxtal or 1⁄8 fxtal using pins CLKDIV1 and CLKDIV2

■ Non-inverted control of pin RST using pin RSTIN

■ NDS certified

■ Supply supervisors during power on and off:

◆ VDD(INTREGD) using a fixed threshold

◆ VDD(INTF) using resistor bridge threshold adjustment

■ Built-in debouncing on card presence contacts (typically 4.5 ms)

■ Multiplexed status signal using pin OFFN

Applications

■ Pay TV

■ Electronic payment

■ Identification

■ Bank card readers