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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
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