LMX2486

SNAS324B – JANUARY 2006 – REVISED JANUARY 2016

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Electrical Characteristics (continued)

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

IF SYNTHESIZER PARAMETERS

IF_P = 8

250

2000

Operating frequency

MHz

IF_P = 16

250

3000

IF input sensitivity

–10

5

dBm

Phase detector frequency

10

MHz

3.5

mA

IF charge pump sink current

–3.5

mA

IF charge pump TRI-STATE

0.5

2

10

nA

current magnitude

1%

8%

source mismatch

Magnitude of IF CP current vs

0.5

4%

10%

CP voltage

Magnitude of IF CP current vs

4%

temperature

OSCILLATOR PARAMETERS

OSC2X = 0

5

110

MHz

Oscillator operating frequency

OSC2X = 1

5

20

MHz

Oscillator input sensitivity

0.5

Oscillator input current

–100

100

µA

SPURS

Spurs in band

–55

dBc

PHASE NOISE

RF_CPG = 0

–202

RF_CPG = 1

–204

RF synthesizer normalized

RF_CPG = 3

–206

dBc/Hz

RF_CPG = 7

–210

RF_CPG = 15

–210

IF synthesizer normalized

–209

dBc/Hz

phase noise contribution

DIGITAL INTERFACE (DATA, CLK, LE, ENOSC, CE, Ftest/LD, FLoutRF)

High-level input voltage

1.6

V

Low-level input voltage

0.4

V

High-level input current

–1

1

µA

Low-level input current

–1

1

µA

High-level output voltage

V

Low-level output voltage

0.4

V

(3)

To measure the in-band spur, the fractional word is chosen such that when reduced to lowest terms, the fractional numerator is one.

The spur offset frequency is chosen to be the comparison frequency divided by the reduced fractional denominator. The loop bandwidth

must be sufficiently wide to negate the impact of the loop filter. Measurement conditions are: Spur Offset Frequency = 10 kHz, Loop

Bandwidth = 100 kHz, Fraction = ½000, VCO Frequency = 3 GHz, Comparison Frequency = 20 MHz, RF_CPG = 7, DITH = 0, and a 4th

Order Modulator (FM = 0). These are relatively consistent over tuning range.

(4)

phase noise measured at an offset frequency, f, in a 1 Hz Bandwidth. The offset frequency, f, must be chosen sufficiently smaller than

the PLL loop bandwidth, yet large enough to avoid substantial phase noise contribution from the reference source. Measurement

conditions are: Offset Frequency = 11 kHz, Loop Bandwidth = 100 kHz for RF_CPG = 7, Fraction = ½000, VCO Frequency = 3 GHz,

Comparison Frequency = 20 MHz, FM = 0, and DITH = 0.

6

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