Data Sheet AS8118

Revision 1.8, 15-Feb-05

Page 22 of 30

Analog Readout

The analog readout can be performed by disconnecting the PROG pin from the calibration board and starting a ‘read’

sequence. At specific points in time the voltage level on the PROG pin must be sampled. These time points are shown in the

following timing diagram.

TM

DIRO

PROG

69

68

67

66

0

1

2

High

Low

High

Low

CAL

High

Low

end

read

measure

zener diode

voltage:

69

68

67

66

65

0

5V

2.4V

0.5V

The numbers at the bottom of this timing diagram indicate the sample points of the bits in the PROM table, at which the zener

diode voltage level can be measured and compared against the limits for burned and unburned zener diodes.

In general this readout is most important, when a new calibration system is installed. Variations on the burn voltage or even

the length of the cable connected to the AS8118 PROG pin may have an influence on the quality of the burn process.