Analog Devices Inc. HMC828LP6CE

Overview

HMC828LP6CE from Analog Devices (formerly Hittite Microwave) is a fully integrated Fractional-N Phase-Locked Loop (PLL) with on-die VCO, operating from 1285 to 1415 MHz. It delivers +7 to +13 dBm RF output power, achieves <180 fs RMS jitter, and supports 24-bit fractional resolution (3 Hz typ). It serves as a high-performance frequency synthesizer in cellular infrastructure and test equipment.

For engineers reviewing the HMC828LP6CE datasheet, HMC828LP6CE pinout, HMC828LP6CE application, or HMC828LP6CE equivalent, key selection criteria include its −227 dBc Figure of Merit, cycle-slip prevention for fast hopping, ultra-low in-band phase noise (−108 dBc/Hz typ), and 40-lead 6×6 mm QFN package with exposed ground paddle.

Technical Context

The HMC828LP6CE integrates a low-noise VCO with divide-by-2 differential RF output, autocalibration for VCO tuning voltage, and a precision charge pump with 20 µA gain step resolution. Its delta-sigma modulator enables fine frequency resolution while suppressing spurs, and its phase detector includes cycle-slip prevention for sub-µs frequency settling.

It supports three operational modes-integer, fractional feedback, and fractional feedforward-with maximum PFD frequencies up to 125 MHz, 100 MHz, and 80 MHz respectively. The architecture separates analog (5 V) and digital (3.3 V) supply domains across nine dedicated rails to minimize noise coupling and ensure stable VCO operation.

Key Specifications

Pinout & Package

40-lead, 6×6 mm QFN package with exposed ground paddle (MSL1, RoHS-compliant, matte Sn finish); thermal resistance 20 °C/W junction-to-paddle; requires soldering all ground leads and paddle to PCB RF ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADF4351BCPZ and HMC703LP4E, the HMC828LP6CE offers superior phase noise performance within its 1285–1415 MHz band, integrated autocal for production stability, and optimized power rail partitioning-making it the preferred choice for fixed-frequency 4G infrastructure and test gear where spectral purity and repeatability are critical.

Availability

HMC828LP6CE is available at Aetrix Electronics and suitable for cellular infrastructure, communications test equipment, and phased array radar systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for HMC828LP6CE 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 timing, microwave synthesis, and mmWave signal chain components.

The HMC828LP6CE belongs to Hittite's PLLs with Integrated VCOs product line, designed specifically for demanding wireless infrastructure and instrumentation applications requiring low phase noise, fast frequency agility, and high integration.

FAQ

What is the operating frequency range of the HMC828LP6CE?

The HMC828LP6CE operates with an integrated VCO from 1285 MHz to 1415 MHz. This range is fixed and cannot be extended using external components. The device outputs a divide-by-2 differential RF signal within this band, delivering +7 to +13 dBm into 50 Ω. Its design targets narrowband applications such as LTE Band 17/18/19 infrastructure, where stable, low-noise synthesis in this specific window is essential. The HMC828LP6CE does not support frequency multiplication or division outside its native VCO range.

Does the HMC828LP6CE require external loop filter components?

Yes, the HMC828LP6CE requires an external passive loop filter connected to the CP (Pin 4) output. The filter topology and component values depend on the desired loop bandwidth, phase margin, and PFD frequency-typical configurations use third-order passive networks. Hittite's application note provides recommended values for ~80 kHz loop bandwidth with 50 MHz reference; designers must recalculate for other conditions. The HMC828LP6CE does not integrate loop filter components, and omitting them will prevent stable lock.

How does the autocalibration subsystem function in the HMC828LP6CE?

The HMC828LP6CE autocalibration subsystem measures VCO tuning sensitivity and adjusts the VTUNE (Pin 23) voltage to center the VCO frequency within its 1285–1415 MHz range, compensating for process, voltage, and temperature variations. It executes automatically on power-up or when triggered via register write, requiring no external circuitry. Calibration completes in under 1 ms and stores results in internal registers. This eliminates manual trimming and ensures consistent start-up behavior across units-critical for high-volume 4G femtocell production where the HMC828LP6CE is deployed.

What are the power supply requirements for the HMC828LP6CE?

The HMC828LP6CE requires nine separate supply connections: four 5 V rails (VPPCP, VDDCP, VCC1, VCC2) and five 3.3 V rails (RVDD, DVDD3V, AVDD, VCCHF, VCCPS, VCCPD, BIAS). Each rail has defined current draw-e.g., VCC2 draws 56 mA for VCO core, DVDD3V draws 6.5 mA for digital logic. Decoupling capacitors (0.1 µF + 10 µF per rail) are mandatory. Failure to properly isolate and decouple these supplies increases phase noise and risks instability. The HMC828LP6CE datasheet specifies absolute max ratings and recommended sequencing.

Can the HMC828LP6CE be used in place of a discrete PLL + VCO solution?

Yes, the HMC828LP6CE replaces discrete PLL ICs and external VCOs in 1.285–1.415 GHz applications, reducing component count, board area, and tuning complexity. Its integrated VCO features autocal, low pushing (<1.5 MHz/V), and 15 MHz/V tuning sensitivity at 2 GHz-validated across temperature. Unlike discrete solutions, the HMC828LP6CE guarantees phase noise and jitter specs over full operating conditions because the VCO and PLL are co-designed and characterized as a single unit. For new designs targeting this band, the HMC828LP6CE is a drop-in functional replacement with superior repeatability.