TDA8000 Datasheet, PDF (16/24 Pages) NXP Semiconductors – Smart card interface

Philips Semiconductors
Smart card interface
Product specification
TDA8000; TDA8000T
SYMBOL
PARAMETER
CONDITIONS
MIN.
TYP.
MAX. UNIT
t₅
t_st
t_d(clk)
end of the window for sending CLK see Fig.6
to the card
maximum pulse width on START
before V_CC starts rising
delay between RSTIN and CLK
see Fig.6
160
−
−
µs
−
−
30
µs
−
−
2
µs
Notes
1. START, WRITE, CLKDIV and PRES are active LOW; RSTIN and PRES are active HIGH.
2. The transition time and duty factor definitions are shown in Fig.12; δ = -t-₁----t₊--¹---t--₂- .
3. P is the card programming voltage set by pins PSEL1 and PSEL2.
4. This condition ensures correct start-up of the oscillator with crystals having series resistance up to 100 Ω.
5. The path between I/O and I/O(µC) is as follows (see Fig.13):
a) Clamp to V_CC.
b) 20 kΩ pull-up resistor to V_CC; thus V_OH on I/O.
c) Two opposite npn transistors with sensing pnp transistor.
d) Clamp to V_SUP; thus V_OH on I/O(µC).
e) The base current of the npn transistor is decreasing when their collector current increases. This means the
voltage drop is very low for small currents and becomes maximum for some mA. Thus V_OL on I/O and I/O(µC),
current limits, and high impedance feature. The output current from I/O and I/O(µC) when the line is open-circuit
is the sum of the pull-up current and the base currents.
handbook, full pagewidth
tr
90%
10%
t1
tf
90%
10%
t2
Fig.12 Definition of transition times.
VOH
1.5 V
VOL
MBH856
1996 Dec 12
16