LTC6948IUFD-2 Просмотр технического описания (PDF) - Linear Technology

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Компоненты Описание

производитель

LTC6948IUFD-2

Ultralow Noise 0.37GHz to 6.39GHz Fractional-N Synthesizer with Integrated VCO

Linear Technology 

LTC6948

Electrical Characteristics

Note 3: Valid for 1.60V ≤ V(TUNE) ≤ 2.85V with part calibrated after a

power cycle or software power-on reset (POR).

Note 4: Based on characterization.

Note 5: For 0.9V < V(CP) < (VCP+ – 0.9V).

Note 6: Measured outside the loop bandwidth, using a narrowband loop,

RFO[1:0] = 3.

Note 7: Measured inside the loop bandwidth with the loop locked.

Note 8: Reference frequency supplied by Wenzel 501-04516,

fREF = 100MHz, PREF = 10dBm.

Note 9: Reference frequency supplied by Wenzel 500-23571,

fREF = 61.44MHz, PREF = 10dBm.

Note 10: Output phase noise floor is calculated from normalized phase

noise floor by LOUT = LNORM + 10log10 (fPFD) + 20log10 (fRF/fPFD).

Note 11: Output 1/f noise is calculated from normalized 1/f phase noise by

LOUT(1/f) = L1/f + 20log10 (fRF) – 10log10 (fOFFSET).

Note 12: ICP = 5.6mA, fPFD = 61.44MHz, FILT[1:0] = 0, Loop BW = 180kHz;

fRF = 2377.7MHz, fVCO = 4755.4MHz (LTC6948-3)

Note 13: ICP = 5.6mA, fPFD = 25MHz, FILT[1:0] = 0, Loop BW = 73kHz;

fRF = 891.85MHz, fVCO = 2675Hz (LTC6948-1), fVCO = 4459MHz

(LTC6948‑2), fVCO = 5351MHz (LTC6948-3, LTC6948-4).

Note 14: Measured using DC1959.

Typical Performance Characteristics TA = 25°C. VREF+ = VD+ = VRF+ = 3.3V, VCP+ = VVCO+ =

5V, INTN = 0, DITHEN = 1, CPLE = 1, RFO[1:0] = 3, unless otherwise noted.

REF Input Sensitivity vs

Frequency

–15

–20

–25

–30

BST = 1

FILT = 0

105°C

25°C

–40°C

–35

–40

– 45

–50

0

50 100 150 200 250 300 350 400 450

FREQUENCY (MHz)

6948 G01

Charge Pump Sink Current Error

vs Voltage, Output Current

5

CPLE = 0

4

1mA

3

5.6mA

11.2mA

2

1

0

–1

–2

–3

–4

–5

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

OUTPUT VOLTAGE (V)

6948 G04

CP Hi-Z Current vs Voltage,

Temperature

5

4

ICP = 11.2mA

CPRST = 1

3 CPLE = 0

105°C

2

25°C

1

–40°C

0

–1

–2

–3

–4

–5

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

OUTPUT VOLTAGE (V)

6948 G02

Charge Pump Sink Current Error

vs Voltage, Temperature

5

4

3

2

1

0

–1

–2

ICP = 11.2mA

–3

CPLE = 0

105°C

–4

25°C

–40°C

–5

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

OUTPUT VOLTAGE (V)

6948 G05

TUNE Current vs Voltage,

Temperature

5

105°C

4

25°C

3

–40°C

2

1

0

–1

–2

–3

–4

–5

0 0.5 1.0 1.5 2.0 2.5

VOLTAGE (V)

3.0

6948 G03

Charge Pump Source Current

Error vs Voltage, Output Current

5

CPLE = 0

4

1mA

3

5.6mA

11.2mA

2

1

0

–1

–2

–3

–4

–5

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

OUTPUT VOLTAGE (V)

6948 G06

6948f

6

For more information www.linear.com/LTC6948

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