TDA8004 View Datasheet(PDF) - Philips Electronics

Part Name

Description

View to exact match

TDA8004

IC card interface

Philips Electronics 

Philips Semiconductors

IC card interface

Product specification

TDA8004T

handbook, full pagewidth

OSC_INT/64

(T ≈ 25 µs)

CMDVCC

VUP

VCC

I/O

CLK

RSTIN

RST

tact

t1

t2

high - Z t3 t4

t5

t0

ATR

MGM177

Fig.5 Activation sequence.

Active state

When the activation sequence is completed, the

TDA8004T will be in the active state. Data is exchanged

between the card and the microcontroller via the I/O lines.

The TDA8004T is designed for cards without VPP (this is

the voltage required to program or erase the internal

non-volatile memory).

Depending on the layout and on the application test

conditions (for example with an additional 1 pF cross

capacitance between C2/C3 and C2/C7) it is possible

that C2 is polluted with high frequency noise from C3. In

this case, it will be necessary to connect a 220 pF

capacitance between C2 and CGND.

It is recommended to:

1. Keep track C3 as far as possible from other tracks

2. Have straight connection between CGND and C5 (the

2 capacitors on C1 should be connected to this ground

track)

3. Avoid ground loops between CGND, PGND and GND

4. Decouple VDDP and VDD separately; if the 2 supplies

are the same in the application, then they should be

connected in star on the main track.

With all these layout precautions, noise should be at an

acceptable level and jitter on C3 should be less than

100 ps. Refer to Application Note AN97036 for specimen

layouts

Deactivation sequence

When a session is completed, the microcontroller sets the

CMDVCC line to the HIGH state. The circuit then executes

an automatic deactivation sequence by counting the

sequencer back and ends in the inactive state (see Fig.6):

• RST goes LOW → (t11 = t10)

• CLK is stopped LOW → (t12 = t11 + 1⁄2T)

• I/O, AUX1 and AUX2 are output into high-impedance

state → (t13 = t11 + T); 10 kΩ pull-up resistor connected

to VCC

• VCC falls to zero → (t14 = t11 + 1⁄23T); the deactivation

sequence is completed when VCC reaches its inactive

state

• VUP falls to zero → (t15 = t11 + 5T) and all card contacts

become low-impedance to GND; I/OUC, AUX1UC and

AUX2UC remain pulled up to VDD via a 10 kΩ resistor.

1999 Dec 30

9

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