TDA8025 Datasheet, PDF (15/38 Pages) NXP Semiconductors – IC card interface

NXP Semiconductors
TDA8025
IC card interface
CMDVCCN
XTAL
V_CC
I/O
ATR
CLK
RSTIN
RST
I/OUC
OSCINT
low frequency
t0 t1 = t2 t_d(start)
high frequency
t4 t_d(end) = t_act
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Fig 8. Activation sequence: CLK controlled by pin RSTIN with the crystal oscillator
TDA8025_1
Product data sheet
CMDVCCN
XTAL
V_CC
I/O
ATR
CLK
RSTIN
> 200 ns
RST
I/OUC
OSCINT
low frequency
t0 t1 = t2
t4
t_d(start)
high frequency
t_d(end) = t_act
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Fig 9. Activation sequence: CLK not controlled by pin RSTIN with the crystal oscillator
The following sequence occurs when using an external clock connected to pin XTAL1 (see
Figure 10):
1. external clock (XTAL1) started by the microcontroller (t0)
2. CMDVCCN is pulled LOW and the internal oscillator changes to its high frequency (t1)
3. V_CC rises either from 0 V to 3 V or 0 V to 1.8 V on a controlled slope (t2)
Rev. 01 — 6 April 2009
© NXP B.V. 2009. All rights reserved.
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