Analog Devices Inc. HMC701LP6CE

Overview

HMC701LP6CE from Analog Devices (formerly Hittite Microwave) is a SiGe BiCMOS fractional-N PLL synthesizer with integrated 8 GHz 16-bit RF N-divider, 24-bit delta-sigma modulator, and ultra-low-noise PFD/charge pump. It delivers 3 Hz typical frequency step resolution, -103 dBc/Hz @ 20 kHz offset (fractional mode, 6 GHz VCO, 50 MHz reference), and supports fast settling via Cycle Slip Prevention for radar and wireless infrastructure applications.

For engineers reviewing the HMC701LP6CE datasheet, HMC701LP6CE pinout, HMC701LP6CE application, or HMC701LP6CE equivalent, key selection criteria include its 8 GHz RF input capability, 24-bit fractional resolution, dual-reference-path architecture (XREFP/XSIN), programmable PFD gain, and integrated linear sweeper for FMCW chirp generation.

Technical Context

The HMC701LP6CE implements a multi-modulus prescaler-based RF path with 16-bit N-divider operating up to 9 GHz in integer mode and 8 GHz in fractional mode, paired with a 14-bit R-divider supporting reference inputs up to 250 MHz. Its delta-sigma modulator enables fine frequency resolution while suppressing fractional spurs.

It features dual reference input paths (square-wave XREFP and sinusoidal XSIN), independent power domains (3.3 V analog/digital, 5 V charge pump/PFD), and a 3-wire GPO interface supporting real-time waveform monitoring-including lock detect, frac strobe, and Δ∑ accumulator outputs-enabling closed-loop debugging and auxiliary clock distribution.

Key Specifications

Pinout & Package

40-pin, 6 mm × 6 mm LFCSP package (36 mm² footprint) with exposed paddle; RoHS-compliant, reflow-compatible (260°C peak).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fractional-N PLL synthesizer applications.

Compared with ADF4159BCPZ and LMS8001TR, the HMC701LP6CE uniquely combines 8 GHz RF input capability, dual-reference-path optimization, on-chip linear sweeper, and real-time GPO waveform visibility-making it the preferred choice for demanding microwave infrastructure and FMCW radar where reference noise, chirp fidelity, and debug observability are critical.

Availability

HMC701LP6CE is available at Aetrix Electronics and suitable for base station radios, automotive radar modules, phased-array beamformers, and communications test equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for HMC701LP6CE 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 acquired Hittite Microwave in 2014 and maintains its high-frequency RF product portfolio, emphasizing precision analog, RF, and microwave ICs for communications, defense, and instrumentation.

The HMC701LP6CE belongs to Hittite's legacy high-performance PLL family, designed specifically for microwave frequency synthesis in infrastructure and radar systems where phase noise, spurious suppression, and fast settling are non-negotiable.

FAQ

What reference input type delivers the lowest phase noise with the HMC701LP6CE?

The XSIN (sinusoidal) reference input delivers the lowest phase noise floor-approximately -159 dBc/Hz-because its common-emitter bipolar buffer minimizes additive noise compared to the square-wave XREFP path. For best performance, use a clean 0 dBm, 50 Ω sine source AC-coupled to XSIN and disable XREFP via register configuration (rfp_buf_sq_en=0, rfp_buf_sin_en=1). The HMC701LP6CE datasheet confirms this advantage applies directly to the HMC701LP6CE under typical operating conditions.

Does the HMC701LP6CE support both fractional and integer-N modes, and how do they differ in performance?

Yes, the HMC701LP6CE supports both modes. In integer-N mode, it achieves -110 dBc/Hz phase noise @ 20 kHz offset (6 GHz VCO, 50 MHz PFD), slightly better than fractional mode (-103 dBc/Hz), due to absence of delta-sigma modulation noise. Integer mode also supports higher PFD frequencies (up to 100 MHz vs 70 MHz) and wider N-divider range (32–65,535). The HMC701LP6CE allows seamless switching between modes via SPI register control without hardware change.

How does the Cycle Slip Prevention (CSP) feature improve settling time in the HMC701LP6CE?

Cycle Slip Prevention in the HMC701LP6CE dynamically adjusts PFD gain and phase comparison behavior during large frequency hops, reducing cycle slips that cause extended lock time. This cuts settling time by ~50% versus conventional PFDs-demonstrated in HMC701LP6CE evaluation plots for 5200 MHz → 3950 MHz hops. The feature is enabled by default and requires no external configuration, making it intrinsic to the HMC701LP6CE's architecture.

Can the HMC701LP6CE generate FMCW chirps without external controllers?

Yes-the HMC701LP6CE includes a fully integrated linear sweeper subsystem that generates precise frequency chirps autonomously using internal registers and triggers. Sweep parameters (start/stop frequency, dwell, polarity, trigger source) are programmable via SPI. When configured, the HMC701LP6CE executes chirps independently, eliminating need for FPGA or MCU intervention-confirmed in the HMC701LP6CE functional description and Figure 6 timing diagrams.

What are the power supply requirements for the HMC701LP6CE charge pump and why are they separate from analog rails?

The HMC701LP6CE requires dedicated +5 V supplies (VPPCP, VPPDRV, VDDPD, etc.) for the charge pump and phase detector to achieve high output current (up to 4 mA) and wide compliance voltage range (0.4 V to VPPCP−0.4 V), ensuring robust loop filter drive across temperature. These 5 V rails are isolated from the +3.3 V analog supplies (VCCHF, RVDD) to prevent digital/charge-pump switching noise from modulating the RF/reference paths-a design requirement explicitly validated in the HMC701LP6CE electrical specifications table.