TDA8020HL/C1 View Datasheet(PDF) - Philips Electronics

Part Name

Description

View to exact match

TDA8020HL/C1

Dual smart card interface

Philips Electronics 

Philips Semiconductors

Dual IC card interface

Product specification

TDA8020HL

FUNCTIONAL DESCRIPTION

Throughout this specification, it is assumed that the reader

is familiar with ISO 7816 terminology.

Supply

The TDA8020HL operates with a supply voltage from

2.7 to 6.5 V. An integrated voltage supervisor ensures that

no spike appears on cards contacts during power-on or off.

The supervisor also initializes the device, and forces an

automatic emergency deactivation of the contacts in the

event of a supply drop-out.

As long as the supply voltage is below the threshold

voltage Vth1, the capacitor CDEL remains uncharged. When

the supply voltage reaches Vth1 and Vhys1, then CDEL is

charged with a small current source of approximately 2 µA.

When the voltage on CDEL reaches Vth2, then the

supervisor is no longer active. As long as the supervisor is

active (pin IRQ is LOW), bit SUPL in the status register is

set. When pin IRQ goes HIGH the voltage supervisor

becomes inactive (see Fig.3).

Separate supply pins are used for the DC-to-DC converter,

allowing specific decoupling for counteracting the noise

the switching transistors may induce on the supply.

A specific reference supply voltage, VDDI, is used for the

interface signals CLKIN1, CLKIN2, I/O1uC, I/O2uC,

SAD0, SAD1, SCL, SDA and IRQ, which can be lower

than VDD (minimum 1.5 V), thus allowing direct control with

a low voltage supplied device.

Pins SCL, SDA and IRQ are open-drain outputs, and may

be externally pulled up to a voltage higher than VDD.

handbook, full pagewidth

VDD

Vth1 + Vhys1

Vth1

Vth2

VCDEL

tw

tw

IRQ

BUS NOT RESPONDING

status read

after event

BUS OK

BUS NOT

RESPONDING

BUS OK

BUS NOT

RESPONDING

FCE835

Fig.3 Voltage supervisor.

2003 Nov 06

7

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