Advance Data Sheet

December 1999

W3000 PLL Dual-Band Frequency Synthesizer

Lucent Technologies Inc.

13

Table 13. D5: Phase Detector Polarity (Bit 17)

D5

Phase Detector Polarity

0

Negative slope

1

Positive slope

The phase detector can be programmed for either a negative or positive slope to accommodate the VCO and

low-pass filter characteristics. (See Figure 7.)

LOOP

FILTER

REFERENCE

W3000

VCO

1

0

VCO INPUT CONTROL

VOLTAGE

Figure 7. Programming the Phase Detector Slope

Table 14. RE: Reset (Bit 20)

RE

Response

0

Operation mode

1

Reset MAIN and secondary registers

After the power supply is turned on, the REF register must be programmed with a reset. This must be followed by

a programming of the MAIN register before or at the enabling of the PLL circuit.

The RE bit will clear itself, and is required to ensure correct initialization of the IC. This results in the following

conditions:

+

The RE bit is cleared back to 0.

+

The device is in powerdown mode, since the EN[1:2] bits are also cleared.

+

Previous reference and main counter values are maintained.