NCN8025AEVB

http://onsemi.com

2

TEST PROCEDURE

See Figure 2.

Initial Setups

The initial setups given here are recommended before

starting measurements on the board.

frequency Fclkin)

or the smart card interface mode which can be 1.8 V,

3.0 V or 5.0 V. These 2 pins are VSL0 and VSEL1 and

on the board, changing VSEL0 and VSEL1 is done

using 2 corresponding switches (see Figure 2)

according to the below Table 1. When VSEL0 = 0 then

VSEL1 is in the mode 5 V/3 Vbar, when VSEL0=1

then VSEL1 is in the mode 1.8 V / 3 Vbar. The initial

setup can be VSEL0 = 0 and VSEL1 = 1 for selecting

cannot be changed on the fly when the smart card

interface is active (/CMDVCC = Low). For changing

VSEL0 and VSEL1 finally the smart can be activated

again with this new smart card power supply voltage.

Table 1. CVCC Programming

VSEL0

VSEL1

CVCC

0

0

3.0 V

0

1

5.0 V

1

0

3.0 V

1

1

1.8 V

resistor output value of 1 k

W, and then connect the

jumper.

DC Power Supplies

Two power supplies are used to bias the demo board.

“digital” power supply which biases the input stages of the

NCN8025A device (control and signal inputs).

supplies using the 2 pin male connectors J2 and J1

respectively.

Clock Frequency

CLKDIV1 and CLKDIV2 select the frequency divider

according to the table given below.

Table 2. Clock Division Ratio Programming

CLKDIV1

CLKDIV2

Divider

1

0

DIV 1/1

1

1

DIV 1/2

0

1

DIV 1/4

0

0

DIV 1/8

Card Presence

The socket we use is a normally open, so PRES/ has been

chosen; nevertheless the PRES and PRES/ test points can

also be used for signaling the presence of a card and starting

up the circuit.

The Clock

The clock is applied externally (SMB connector).

Start the Measurement

To start the measurments, set the board as it follows:

frequency.

− 1 k

W potentiometer jumper: not connected to start

the measure.

the device (activation sequence run).