10MHz to 1050MHz Integrated

RF Oscillator with Buffered Outputs

6

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_______________________________________________________________Pin Description

NAME

FUNCTION

PIN

3

FDBK

Oscillator Feedback Circuit Connection. Connecting capacitors of the appropriate value between FDBK and

TANK and between FDBK and GND tunes the oscillator’s reflection gain (negative resistance) to peak at the

desired oscillation frequency. Refer to the Applications Information section.

2

TANK

Oscillator Tank Circuit Connection. Refer to the Applications Information section.

1

Oscillator DC Supply Voltage. Decouple VCC1 with 1000pF capacitor to ground. Use a capacitor with low

series inductance (size 0805 or smaller). Further power-supply decoupling can be achieved by adding a

10

Ω resistor in series from VCC1 to the supply. Proper power-supply decoupling is critical to the low noise

and spurious performance of any oscillator.

8

OUT

Open-Collector Output Buffer. Requires external pull-up to the voltage supply. Pull-up can be resistor,

choke, or inductor (which is part of a matching network). The matching-circuit approach provides the high-

est-power output and greatest efficiency. Refer to Table 1 and the Applications Information section. OUT

can be used with OUT in a differential output configuration.

7

Output Buffer DC Supply Voltage. Decouple VCC2 with a 1000pF capacitor to ground. Use a capacitor with

low series inductance (size 0805 or smaller).

6

GND

Ground Connection. Provide a low-inductance connection to the circuit ground plane.

5

OUT

Open-Collector Output Buffer (complement). Requires external pull-up to the voltage supply. Pull-up can be

resistor, choke, or inductor (which is part of a matching network). The matching-circuit approach provides

the highest-power output and greatest efficiency. Refer to Table 1 and the Applications Information section.

OUT can be used with OUT in a differential output configuration.

4

SHDN

Logic-Controlled Input. A low level turns off the entire circuitry such that the IC will draw only leakage current

at its supply pins. This is a high-impedance input.

_____________________________Typical Operating Characteristics (continued)

Ω, load at OUT = 50Ω, L1 = coaxial ceramic

-114

-112

-110

-108

-106

-104

-40

-20

0

20

40

60

80

PHASE NOISE vs. TEMPERATURE

TEMPERATURE (°C)

SSB @

∆f = 25kHz

L1 = 5nH INDUCTOR

C6 = 1.5pF

L1 = COAXIAL CERAMIC RESONATOR

(TRANS-TECH SR8800LPQ1357BY)

C6 = 1pF

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

0

1.3

2.6

3.9

5.2

6.5

OUTPUT SPECTRUM

FUNDAMENTAL NORMALIZED TO 0dB

FREQUENCY (GHz)

-150

-140

-130

-120

-110

-100

-90

-80

-70

-60

-50

-40

0.1

10

1000

100

SINGLE SIDEBAND PHASE NOISE

OFFSET FREQUENCY (kHz)

1

L1 = 5nH INDUCTOR

C6 = 1.5pF

L1 = COAXIAL

CERAMIC RESONATOR

(TRANS-TECH

SR8800LPQ1357BY)

C6 = 1pF