Analog Devices Inc. ADRF6755ACPZ

Overview

ADRF6755 from Analog Devices is a fully integrated I/Q modulator with on-chip fractional-N PLL, VCO, and 47 dB digitally controlled attenuator, operating from 100 MHz to 2400 MHz. It delivers 8 dBm P1dB at 1800 MHz, −161 dBm/Hz noise floor, and 20.5 dBm output IP3, enabling direct RF upconversion in satellite transceivers, LTE base stations, and broadband wireless infrastructure.

For engineers reviewing the ADRF6755 datasheet, ADRF6755 pinout, ADRF6755 application, or ADRF6755 equivalent, this device supports SPI/I2C configuration, offers 1 Hz frequency resolution, integrates baseband bandwidth up to 600 MHz, and provides programmable RF output disable with 350 ns turn-off settling time-critical for TDD systems and fast-hopping transmitters.

Technical Context

The ADRF6755 combines a high-modulus fractional-N synthesizer (10–40 MHz PFD, 25 MHz/V KVCO) with a wideband quadrature modulator featuring differential 500 mV dc-biased IBB/QBB inputs and single-ended 50 Ω RFOUT. Its third-order fractional interpolator enables sub-Hz resolution while maintaining low in-band phase noise (0.17° rms integrated from 1 kHz–8 MHz at 1800 MHz).

Baseband signal path supports 600 MHz 3 dB bandwidth and 450 mV p-p nominal swing per differential pair; RF output gain flatness is ±0.5 dB across any 40 MHz span at 300–2400 MHz, and LO carrier feedthrough is suppressed to −45 dBc at 1800 MHz with full 47 dB attenuation range.

Key Specifications

Pinout & Package

ADRF6755 is housed in a 56-lead, 8 mm × 8 mm LFCSP package with exposed paddle (EP), requiring low-impedance ground connection. Power domains are segregated: VCC1–VCC4 (5 V analog supplies), VREG1–VREG6 and REGOUT (3.3 V PLL/digital supplies), AGND/DGND (separate analog/digital ground planes).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I/Q modulator with integrated synthesizer applications.

Compared with ADRF6755, ADRF6780 offers extended frequency coverage at the expense of LO monitoring capability and linearity, while TRF372017 reduces integration level but lowers BOM cost where external synthesis is acceptable.

Availability

ADRF6755 is available at Aetrix Electronics and suitable for satellite communications transmitters, 4G/5G small cell base stations, and broadband wireless access equipment requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for ADRF6755 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving precision instrumentation, communications, and industrial markets since 1965.

The ADRF6755 belongs to Analog Devices' RadioVerse™ family of highly integrated RF transceivers and front-end ICs, designed specifically for next-generation wireless infrastructure requiring single-chip RF upconversion, frequency synthesis, and digital control.

FAQ

What is the maximum baseband input bandwidth supported by the ADRF6755?

The ADRF6755 supports a 600 MHz 3 dB baseband bandwidth on its differential IBB/QBB inputs. This enables handling of wide instantaneous signal bandwidths such as those required for 100 MHz 5G NR carriers or multi-carrier LTE-A deployments. The input stage is dc-biased at 500 mV and accepts 450 mV p-p differential sine waves, requiring external biasing and low-impedance drive sources. Performance remains stable across temperature and supply variations.

Does the ADRF6755 include an integrated voltage-controlled oscillator (VCO)?

Yes, the ADRF6755 integrates a high-performance VCO as part of its fractional-N PLL subsystem. The VCO exhibits a tuning sensitivity (KVCO) of 25 MHz/V and operates across the full 100 MHz–2400 MHz RF output range. VTUNE is provided as an accessible pin for external loop filter connection, and the VCO's phase noise contributes directly to the device's specified −133 dBc/Hz at 1 MHz offset (1800 MHz LO). No external VCO is required.

How does the ADRF6755 handle RF output power control?

The ADRF6755 implements a 47 dB digitally controlled attenuator with 1 dB step resolution, programmable via SPI or I²C interface registers. Absolute step accuracy is ±2.0 dB at full 47 dB attenuation, and relative step accuracy is ±1.5 dB across the full frequency range above 300 MHz. Output settling time is 15 µs to ±0.2 dB, enabling fast power ramping in TDD systems. The attenuator operates independently of the I/Q input amplitude.

Can the ADRF6755 be configured for both SPI and I²C interfaces simultaneously?

No, the ADRF6755 supports either SPI or I²C mode, selected by the logic state of the CS pin: CS high configures I²C (slave address 0x60), while CS low selects SPI mode. Both interfaces share SDI/SDA and CLK/SCL pins but use different protocols and timing-SPI supports up to 20 MHz clocking and register readback via SDO, whereas I²C operates at ≤400 kHz and is bidirectional on SDI/SDA. Mode selection is hardware-defined and not runtime-switchable.

What is the purpose of the LOMON pins on the ADRF6755?

The LOMON and LOMON pins provide a differential, open-collector replica of the internal local oscillator signal at four programmable output power levels (−6, −12, −18, or −24 dBm). These outputs are intended for external monitoring, feedback, or spectrum analysis and must be terminated to REGOUT (3.3 V) with external resistors. They can be disabled via serial port programming and should be tied to REGOUT if unused. Unlike RFOUT, LOMON carries only the LO tone-not the modulated signal.