TDA8002AT PHILIPS [NXP Semiconductors], TDA8002AT Datasheet - Page 7

• Manufacturer Part Number: TDA8002AT
• Description: IC card interface
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
FUNCTIONAL DESCRIPTION
Power supply
The supply pins for the chip are V
DGND1 and DGND2. V
in the range of 3.0 to 6.5 V. All card contacts remain
inactive during power-up or power-down.
On power-up, the logic is reset by an internal signal.
The sequencer is not activated until V
V
automatic deactivation sequence of the contacts is
performed.
Supply voltage supervisor (V
This block surveys the V
of 10 ms minimum (t
on the ALARM outputs during power-up or power-down of
V
spikes on card contacts during power-up or power-down.
When V
started. The ALARM outputs are active until this delay has
expired. When V
and a deactivation sequence of the contacts is performed.
For 3 V supply, the supervisor option must be chosen at
3 V. For 5 V supply, both options (3 or 5 V) may be chosen
depending on the application.
1997 Nov 04
handbook, full pagewidth
th2
DD
IC card interface
+ V
(see Fig.5). This signal is also used for eliminating the
hys2
DD
reaches V
(see Fig.5). When V
DD
falls below V
W
th2
) can be retriggered and is delivered
DDA
+ V
DD
ALARM
ALARM
and V
supply. A defined reset pulse
V DD
hys2
DD
, an internal delay is
DD
th2
Fig.5 Alarm as a function of V
DDD
DDA
)
, ALARM is activated
falls below V
, V
(i.e. V
DD
DDD
reaches
DD
, AGND,
) should be
th2
, an
t W
7
Clock circuitry
The TDA8002 supports both synchronous and
asynchronous cards (I
acknowledge signal from the master are not supported).
There are three methods to clock the circuitry:
When CLKSEL is HIGH, the clock should be applied on the
STROBE pin, and when CLKSEL is LOW, one of the
internal oscillators is used.
When an internal clock is used, the clock output is
available on pin CLKOUT. The RC oscillator is selected by
making CLKDIV1 HIGH and CLKDIV2 LOW. The clock
output to the card is available on pin CLK. The frequency
of the card clock can be the input frequency divided by
2 or 4, STOP LOW or 1.25 MHz, depending on the states
of CLKDIV1 or CLKDIV2 (see Table 1).
Do not change CLKSEL during activation. When in
low-power (sleep) mode, the internal oscillator frequency
which is available on pin CLKOUT is lowered to
approximately 16 kHz for power-economy purposes.
DD
Apply a clock signal to pin STROBE
Use of an internal RC oscillator
Use of a quartz oscillator which should be connected
between pins XTAL1 and XTAL2.
(pulse width 10 ms).
t W
2
MGE734
V th2
V th2
C-bus memories requiring an
V hys2
Product specification
TDA8002