Analog Devices Inc. ADF435x Microwave Wideband Synthesizers

Analog Devices ADF435x Microwave Wideband Synthesizers can integrate fractional-N or integer-N phase-locked loop (PLL) frequency synthesizers when combined with an external loop filter and an external reference frequency. Using a series of frequency dividers, ADF435x can operate from 35MHz to 6800MHz.

The ADF435x synthesizers include an integrated VCO with a 2200MHz to 6800MHz fundamental output frequency. The VCO frequency can be divided by 1, 2, 4, 8, 16, 32, or 64 circuits. This design enables the designer to generate RF output frequencies as low as 35MHz. The ADF435x synthesizers operate using 3V to 3.6V analog and digital power supplies. The synthesizers also use 4.75V to 5.25V charge pumps and VCO supplies.

If an application requires isolation, designers can mute the RF output stage. Designers can also control the on-chip registers using a simple 3-wire interface.

The ADF435x synthesizers are ideal for wireless infrastructure, point-to-point/point-to-multipoint microwave links, satellites/VSATs, test equipment/instrumentation, and clock generation.

Features

RF output frequency range: 35MHz to 6800MHz
- Integer channel: -227dBc/Hz (ADF4356)
- Fractional channel: -225dBc/Hz (ADF4356)
Integrated RMS jitter (1kHz to 20MHz): 97fs for 6GHz output (ADF4356)
Typical rms jitter:
- <0.4ps rms (ADF4350)
- 0.3ps rms (ADF4351)
Typical EVM at 2.1GHz: 0.4% (ADF4351)
Fractional-N synthesizer and integer-N synthesizer
High resolution:
- 38-bit modulus (ADF4355)
- 52-bit modulus (ADF4356)
Phase frequency detector (PFD) operation to 125MHz (ADF4356)
Reference input frequency operation to 600MHz (ADF4356)

Maintains frequency lock over -40°C to +85°C (ADF4356)
Low phase noise, voltage controlled oscillator (VCO)
Programmable divide by 1, 2, 4, 8, 16 output (ADF4350)
Programmable divide by 1, 2, 4, 8, 16, 32, or 64 output (ADF4351, ADF4355, and ADF4356)
Analog and digital power supplies: 3V to 3.3V
Charge pump and VCO power supplies: 5V typical (ADF4356)
Logic compatibility: 1.8V
Programmable dual modulus prescaler of 4/5 or 8/9 (ADF4350, ADF4351, and ADF4355)
Programmable output power level (ADF4350, ADF4351 and ADF4356)
RF output mute function
3-wire serial interface (ADF4350, ADF4351, and ADF4355)
Analog and digital lock detect (ADF4350, ADF4351, and ADF4355)
Switched bandwidth fast-lock mode (ADF4350 and ADF4351)
Cycle slip reduction (ADF4351)