Analog Devices Inc. HMC837LP6CE

Overview

HMC837LP6CE from Analog Devices (formerly Hittite Microwave) is a fractional-N phase-locked loop frequency synthesizer with integrated tri-band VCO, delivering RF outputs at 1025–1150 MHz (fVCO/2), 2050–2300 MHz (fVCO), and 4100–4600 MHz (2fVCO), with ultra-low phase noise (−112 dBc/Hz typ. in-band), <180 fs RMS jitter, and 24-bit frequency resolution (3 Hz typ.). It serves as a high-performance clock source in cellular infrastructure transceivers.

For engineers reviewing the HMC837LP6CE datasheet, HMC837LP6CE pinout, HMC837LP6CE application, or HMC837LP6CE equivalent, this page provides verified functional identity, validated pin roles, confirmed tri-band VCO operation, exact PLL/VCO integration architecture, and real-world design constraints including loop filter configuration dependencies and supply rail segregation (3.3 V digital / 5 V analog).

Technical Context

The HMC837LP6CE integrates a low-noise delta-sigma fractional-N PLL with autocalibrating tri-band VCO, supporting three output paths-divide-by-2, fundamental, and doubler-each with independent power levels (11–13 dBm, 9–12 dBm, −3–2 dBm respectively). Its cycle-slip prevention (CSP) phase detector enables fast frequency hopping, while the precision charge pump (0.02–2.54 mA) and 19-bit N-divider (up to 524,287) support fine resolution and wide tuning range.

It requires segregated power domains: 5 V for VCO core and charge pump analog sections (VPPCP, VDDCP, VCC1, VCC2), 3.3 V for digital (DVDD3V), and 3.3 V for analog bias rails (AVDD, VCCHF, VCCPS, VCCPD, RVDD); thermal resistance is 20 °C/W junction-to-ground paddle, rated MSL1, RoHS-compliant 40-lead 6×6 mm QFN package.

Key Specifications

Pinout & Package

40-lead, 6×6 mm, RoHS-compliant QFN package with exposed ground paddle (MSL1, reflow peak 260 °C). All ground leads and paddle must be soldered to PCB RF ground per Hittite application note land pattern.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADF4372BCPZ and LMS8001-SYNTH, the HMC837LP6CE offers superior in-band phase noise and tri-band output flexibility in a smaller 6×6 mm footprint, making it optimal for cost-sensitive, high-density 4G/5G infrastructure where VCO autonomy and self-test are required.

Availability

HMC837LP6CE is available at Aetrix Electronics and suitable for cellular infrastructure, phased array radar, and high-speed data radio applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for HMC837LP6CE 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 line, specializing in microwave/mmWave ICs for defense, communications, and instrumentation.

The HMC837LP6CE belongs to Hittite's "PLLs with Integrated VCO" family, designed specifically for high-performance wireless infrastructure where low phase noise, fast settling, and multi-band flexibility replace discrete PLL+VCO solutions.

FAQ

What is the primary function of the HMC837LP6CE in a radio system?

The HMC837LP6CE functions as a fully integrated fractional-N PLL frequency synthesizer with tri-band VCO, generating precise, low-noise local oscillator signals across 1025–1150 MHz, 2050–2300 MHz, and 4100–4600 MHz bands. Its role is to provide agile, spectrally pure clock sources for up/down-conversion in cellular base stations and test equipment - the HMC837LP6CE replaces discrete PLL, VCO, and divider combinations while maintaining sub-Hz frequency resolution and <90 fs jitter.

Does the HMC837LP6CE support both integer and fractional-N modes, and how do they differ in performance?

Yes, the HMC837LP6CE supports both integer and fractional-N modes. In integer mode, it achieves a Figure of Merit (FOM) of −230 dBc/Hz and 132.5 fs RMS jitter (10 kHz–100 MHz) with 100 MHz PFD and 93 kHz loop bandwidth. In fractional mode, FOM degrades slightly to −227 dBc/Hz and jitter increases to 128.5 fs under identical conditions due to quantization noise - the HMC837LP6CE uses advanced delta-sigma modulation to minimize spurs while retaining 3 Hz typical resolution.

How is RF output configured for different frequency bands on the HMC837LP6CE?

The HMC837LP6CE provides three RF output paths from its integrated VCO: fVCO/2 (1025–1150 MHz), fVCO (2050–2300 MHz), and 2fVCO (4100–4600 MHz). The fVCO/2 and fVCO outputs are available simultaneously on differential pins RF_P (29) and RF_N (28); for 2fVCO operation, these pins must be shorted externally to enable doubler mode - the HMC837LP6CE does not require external multipliers or switches to access all three bands.

What power supply architecture is required for proper operation of the HMC837LP6CE?

The HMC837LP6CE requires six distinct supply domains: 5 V for VPPCP/VDDCP/VCC1/VCC2 (VCO core and charge pump analog), 3.3 V for DVDD3V (digital logic), and 3.3 V for AVDD/VCCHF/VCCPS/VCCPD/RVDD (analog bias rails). Each domain must be independently decoupled with 100 nF + 10 pF capacitors near respective pins - improper rail segregation causes increased phase noise and failed VCO calibration, directly impacting HMC837LP6CE system-level timing integrity.

Is the HMC837LP6CE pin-compatible with other Hittite PLL+VCO devices like the HMC830LP6CE?

No, the HMC837LP6CE is not pin-compatible with the HMC830LP6CE or other members of the LP6CE family. While both use 40-lead 6×6 mm QFN packages, pin assignments differ significantly - for example, HMC837LP6CE places VTUNE on pin 23 and RF outputs on pins 28/29, whereas HMC830LP6CE assigns VTUNE to pin 25 and RF to pins 30/31. Layout reuse is not possible; the HMC837LP6CE requires its own dedicated footprint and routing per the official evaluation PCB schematic.