2003 Nov 06 8
Philips Semiconductors Product specification
Dual IC card interface TDA8020HL
DC-to-DC converter
VCC1 is the supply voltage for card 1 contacts and VCC2 is
the supply voltage for card 2 contacts. Card 1 and card 2
may be independently powered-down, powered at 5 V or
poweredat3 V.Acapacitortype step-up converter is used
for generating these voltages. This step-up converter acts
either as a doubler, tripler or follower. An hysteresis of
100 mV is present on the different threshold voltages.
If VCC is the maximum value of VCC1 and VCC2, then there
are 5 possible situations:
•VDD < 3.4 V and VCC = 3 V: in this case, the DC-to-DC
converter acts as a doubler with a regulation of
approximately 4.0 V
•VDD < 3.4 V and VCC = 5 V: in this case, the DC-to-DC
converter acts as a tripler with a regulation of
approximately 5.5 V
•VDD > 3.5 V and VCC = 3 V: in this case, the DC-to-DC
converter acts as a follower: VDD is applied on VUP
•5.8V>V
DD > 3.5 V and VCC = 5 V: in this case, the
DC-to-DC converter acts as a doubler with a regulation
of approximately 5.5 V
•VDD > 5.9 V and VCC = 5 V: in this case, the DC-to-DC
converter acts as a follower and VDD is applied on VUP.
The output voltage, VUP, is fed internally to the VCC
generators. VCC1,V
CC2 and CGND1, CGND2 are used as
a reference for all other cards contacts.
The sum of ICC1 and ICC2 shall not exceed 80 mA, which
means that when a card is drawing its maximum current
(around 60 mA at VCC = 5 V, 55 mA at VCC = 3 V), the
other card should be set in low power consumption mode
(less than 20 or 25 mA). Note that during the card Advice
to Receive (ATR) process, the current may be maximum;
so, a card should only be activated if the other card draws
lessthan20 or25 mA. TheDC-to-DC converterissupplied
via separate supply pins VDDA and AGND to allow
decoupling separate from the other supply pins.
Duringnormaloperationoractivation,each cardis allowed
to draw independently a current of up to 60 mA at
VCC = 5 V or up to 55 mA at VCC = 3 V, with a supply
voltage from 2.7 V up to 6.5 V provided the sum of
ICC1 and ICC2 does not exceed 80 mA.
If VDD > 3 V, for 5 V cards, then both cards can draw up to
60 mA at the same time.
If VDD > 3 V, for 3 V cards, then both cards can draw up to
55 mA at the same time.
I2C-bus
A 400 kHz I2C-bus slave interface is used for configuring
the device and reading the status.
I2C-BUS PROTOCOL
The I2C-bus is for 2-way, 2-line communication between
different ICs or modules. The serial bus consists of two
bidirectional lines; one for data (SDA), and one for the
clock (SCL).
Both the SDA and SCL lines must be connected to a
positive supply voltage via a pull-up resistor.
The following protocol has been defined:
•Data transfer may be initiated only when the bus is not
busy
•During data transfer, the data line must remain stable
whenever the clock line is HIGH. Changes in the data
line while the clock line is HIGH will be interpreted as
control signals.
BUS CONDITIONS
The following bus conditions have been defined:
•Bus not busy: both data and clock lines remain HIGH
•Start data transfer: a change in the state of the data line,
fromHIGH-to-LOW, while the clockis HIGH, defines the
START condition
•Stop data transfer: a change in the state of the data line,
fromLOW-to-HIGH, while the clockis HIGH, defines the
STOP condition
•Data valid: the state of the data line represents valid
data when, after a START condition, the data line is
stable for the duration of the HIGH period of the clock
signal. There is one clock pulse per data bit.
DATA TRANSFER
Each data transfer is initiated with a START condition and
terminated with a STOP condition.
Data transfer is unlimited in the read mode. The
information is transmitted in bytes and each receiver
acknowledges with a ninth bit.
The TDA8020HL operates in standard mode (100 kHz
clock rate) and fast mode (400 kHz clock rate) defined in
the I2C-bus specification.
By definition, a device that sends a signal is called a
transmitter, and the device which receives the signal is
called a receiver. The device which controls the signal is