Arizona Microtek, Inc.

AZT71

Programmable Capacitive Tuning IC

www.azmicrotek.com

+1-480-962-5881

5

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May 2012, Rev 1.2

AZT71

Programming

Board

DA

CLK

PV

DA

CLK

PV

RESONATOR

OUT

OSCILLATOR

Figure 5 – AZT71 in Programming Mode

AZT71

DA

CLK

PV

RESONATOR

OUT

OSCILLATOR

NC

NC

NC

Figure 6 – AZT71 in Operational Mode

The AZT71 has two capacitance setting modes from which bits are set and the matching capacitors are selected.

• Reading directly from the shift register

o

This is useful for testing the capacitance and subsequent oscillator frequency. This mode is active after

the last bit is shifted in and when the CLK pin is left logic high. For the shift register, capacitors are

selected when bits are active HIGH.

• Reading from the value contained in the EEPROM

o

Prevents customer adjustment and retains factory programming and is active when the CLK pin is at logic

low or not connected. For the EEPROM, capacitors are selected when bits are active LOW.