tda8004at-c1 NXP Semiconductors, tda8004at-c1 Datasheet - Page 9

• Manufacturer Part Number: tda8004at-c1
• Description: Ic Card Interface
• Manufacturer: NXP Semiconductors

Philips Semiconductors
TDA8004AT_3
Product data sheet
8.7 Active state
The clock may be applied to the card in the following way:
If this feature is not needed, then CMDVCC may be set LOW with RSTIN LOW. In this
case, CLK will start at t
To Request (ATR) from the card.
When the activation sequence is completed, the TDA8004AT will be in the active state.
Data is exchanged between the card and the microcontroller via the I/O lines.
The TDA8004AT is designed for cards without V
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 capacitor between C2 and CGND.
It is recommended to:
1. Keep track C3 as far as possible from other tracks
Fig 5. Activation sequence
•
•
•
Set RSTIN HIGH before setting CMDVCC LOW, and reset it LOW between t
CLK will start at this moment. RST will remain LOW until t
the copy of RSTIN. After t
precise count of CLK pulses before toggling RST.
I/O, AUX1 and AUX2 are enabled (t
CLK is applied to the C3 contact (t
RST is enabled (t
OSC_INT/64
CMDVCC
RSTIN
VUP
CLK
RST
V
I/O
CC
5
Rev. 03 — 9 February 2006
3
= t
, and after t
1
t
t
1
0
+ 7T).
5
, RSTIN has no further action on CLK. This is to allow a
t
2
5
, RSTIN may be set HIGH in order to get the Answer
4
)
3
= t
high - Z
1
+ 4T)
t
act
PP
t
3
(this is the voltage required to program
t
4
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
5
, where RST is enabled to be
t
5
TDA8004AT
IC card interface
ATR
fce662
3
and t
9 of 25
5
;