LMX2331A datasheet(13/17 Pages) NSC

Part #	LMX2331A

Description	PLLatinum??Dual Frequency Synthesizer for RF Personal Communications

PDF	17 Pages

Scroll/Zoom	100%

Manufacturer	NSC [National Semiconductor (TI)]

Direct Link	http://www.national.com

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13 / 17 page

Functional Description (Continued)

PHASE DETECTOR POLARITY

Depending upon VCO characteristics, R16 bit should be set

accordingly: (see figure right)

When VCO characteristics are positive like (1), R16 should

be set HIGH;

When VCO characteristics are negative like (2), R16 should

be set LOW.

SERIAL DATA INPUT TIMING

PHASE COMPARATOR AND INTERNAL CHARGE PUMP CHARACTERISTICS

VCO Characteristics

DS012331-16

DS012331-17

Notes: Parenthesis data indicates programmable reference divider data.

Data shifted into register on clock rising edge.

Data is shifted in MSB first.

Test Conditions: The Serial Data Input Timing is tested using a symmetrical waveform around VCC/2. The test waveform has an edge rate of 0.6V/ns with

amplitudes of 2.2V @ VCC = 2.7V and 2.6V @ VCC = 5.5V.

DS012331-18

Notes: Phase difference detection range: −2

π to +2π

The minimum width pump up and pump down current pulses occur at the Do pin when the loop is locked.

R16 = HIGH

LMX2331A Datasheet(PDF) 13 Page - National Semiconductor (TI)