TDA8002ATSLASH3 datasheet(10/28 Pages) PHILIPS

10 / 28 page

1997 Nov 04

Philips Semiconductors

Product speciﬁcation

IC card interface

TDA8002

ACTIVATION SEQUENCE

From idle mode, the circuit enters the activation mode

when the microcontroller sets the CMDVCC line LOW or

sets the MODE line HIGH when the CMDVCC line is

already LOW. The internal circuitry is then activated, the

internal clock is activated and an activation sequence is

executed. When RST is enabled, it becomes the inverse of

RSTIN.

Figures 8 to 10 illustrate the activation sequence as

described below:

1. Step-up converter is started (t1 ≈ t0)

2. VCC rises from 0 to 5 V (t2 =t1 +11⁄2T)

3. I/O, AUX1, AUX2 are enabled and CLK is enabled

(t3 =t1 + 4T); a special circuitry ensures that I/O

remains below VCC during falling slope of VCC

4. CLK is set by setting RSTIN to HIGH (t4)

5. RST is enabled (t5 =t1 + 7T); after t5, RSTIN has no

further action on CLK, but is only controlling RST.

Fig.8 Activation sequence using RSTIN and CMDVCC.

handbook, full pagewidth

MGE736

OSC_INT/64

CMDVCC

VUP

VCC

I/O

CLK

RSTIN

RST

high - Z

tact

T = 25

µs

TDA8002AT/3 Datasheet(PDF) 10 Page - NXP Semiconductors