73S8010R-IM/F1 Maxim Integrated, 73S8010R-IM/F1 Datasheet - Page 17

• Manufacturer Part Number: 73S8010R-IM/F1
• Description: I2C Interface IC
• Manufacturer: Maxim Integrated

Specifications of 73S8010R-IM/F1

• Rohs: yes

DS_8010R_022
3.3
The Teridian 73S8010R smart card interface IC incorporates a LDO voltage regulator. The voltage
output is controlled by the digital input 5V/#V. This regulator is able to provide either 3 V or 5 V card
voltage from the power supply applied on the VPC pin.
Digital circuitry is powered by the power supply applied on the VDD pin. V
range to interface with the system controller.
Three voltage supervisors constantly check the presence of the voltages V
deactivation sequence is forced upon fault of any of these voltage supervisors. The two voltage
supervisors for V
when the voltage V
voltage when using 3 V cards only.
The voltage regulator can provide a current of at least 90 mA on V
EMV 4.0 specification. The V
standard. A third voltage supervisor monitors the V
sequencer at power-on, and to deactivate the card at power-off or upon a fault. The voltage threshold of
the V
some applications to modify this threshold value. The pin VDDF_ADJ (pin 18 in the SO package, pin 17
in the QFN package) is used to connect an external resistor R
to another value V
An alternative (more accurate) method of adjusting the V
R3 from the pin to supply and R1 from the pin to ground (see
voltage, the equivalent resistance must be determined. This resistance value will be designated Kx. Kx
is defined as R1/(R1+R3). Kx is calculated as:
Kx = (2.789 / V
To determine the values of R1 and R3, use the following formulas.
R3 = 24000 / Kx
Taking the example above, where a V
Solving for R3 gives:
Solving for R1 gives:
Using standard 1 % resistor values gives R3 = 57.6 KΩ and R1 = 42.4 KΩ.
These values give an equivalent resistance of Kx = 0.4228, a 0.6% error.
If the 2.3 V default threshold is used, this pin must be left unconnected.
Rev. 1.6
DD
Power Supply and Voltage Supervision
voltage supervisor is internally set by default to 2.3 V nominal. However, it may be desirable in
 Kx = (2.789 / 2.7) - 0.6125 = 0.42046.
TH
PC
) - 0.6125 where V
DDF
PC
and V
. The resistor value is defined as follows:
becomes lower than V
R1 = R3*(Kx / (1 – Kx))
 R3 = 24000 / 0.42046 = 57080.
 R1 = 57080 *(0.42046 / (1 – 0.42046)) = 41412.
CC
are linked so that a fault is generated to activate a deactivation sequence
PC
voltage supervisor threshold values are defined from the EMV 4.0
TH
DD
is the desired new threshold voltage.
R
EXT
fault threshold voltage of 2.7 V is desired, solving for Kx gives:
= 56 kΩ / (V
CC
. This allows the 73S8010R to operate at lower V
DD
voltage. It is used to initialize the ISO-7816-3
DDF
DD
fault voltage is to use a resistive network of
- 2.33)
Figure
EXT
to ground to raise the V
CC
4). In order to set the new threshold
which easily complies with the
DD
DD
, V
also defines the voltage
PC
and V
73S8010R Data Sheet
CC
DD
. A card
fault voltage
PC
17