Analog Devices Inc. HMC833LP6GETR

Overview

HMC833LP6GETR from Analog Devices (formerly Hittite Microwave) is a fractional-N phase-locked loop with integrated VCO, serving as a wideband RF synthesizer for LO generation and clock synthesis. It delivers 25–6000 MHz output frequency, supports up to 100 MHz phase detector rate, achieves –110 dBc/Hz in-band phase noise (typ), and provides <180 fs RMS jitter (fractional mode, 100 kHz loop BW). It is used in microwave radio transceivers requiring spurious-free local oscillator signals.

For engineers reviewing the HMC833LP6GETR datasheet, HMC833LP6GETR pinout, HMC833LP6GETR application, or HMC833LP6GETR equivalent, key selection criteria include its 24-bit frequency resolution (3 Hz typ), Exact Frequency Mode for zero-error output, integrated VCO divider range (1/2/4/6…/62), and ultra-low FOM of –227 dBc/Hz (fractional mode).

Technical Context

The HMC833LP6GETR integrates a fundamental VCO (1500–3000 MHz), programmable RF output divider (1/2/4/6…/62), and doubler to cover 25–6000 MHz. Its delta-sigma modulator enables fractional-N operation with 19-bit N-divider (integer/fractional) and 14-bit R-divider, supporting reference inputs up to 350 MHz.

It features dual-supply architecture: 3.3 V for digital/analog control circuitry (AVDD, DVDD3V, RVDD) and 5 V for charge pump/VCO core (VPPCP, VCC1, VCC2). The PLL includes lock detect output (LD_SDO), serial SPI interface (SEN/SDI/SCK), and VTUNE port for external loop filter connection.

Key Specifications

Pinout & Package

40-lead 6×6 mm QFN package (36 mm²) with exposed ground paddle; RoHS-compliant, MSL1, matte tin plating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADF4355BCPZ and LMS8001TR, the HMC833LP6GETR offers superior in-band phase noise (–110 dBc/Hz vs. –105 dBc/Hz) and lower FOM (–227 dBc/Hz), making it preferred for high-selectivity receiver LOs and ultra-low-jitter clocking where spectral purity is prioritized over maximum frequency or integration level.

Availability

HMC833LP6GETR is available at Aetrix Electronics and suitable for cellular infrastructure, microwave radio, and communications test equipment requiring stable component supply across extended temperature ranges (–40°C to +85°C) and long production lifecycles.

Supply support for HMC833LP6GETR 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 continues to manufacture and support high-performance RF ICs for defense, communications, and instrumentation markets.

The HMC833LP6GETR belongs to Analog Devices' high-frequency PLL/VCO product line, designed specifically for wideband, low-phase-noise frequency synthesis in demanding wireless infrastructure and test equipment applications.

FAQ

What is the absolute maximum supply voltage for the VPPCP pin on the HMC833LP6GETR?

The absolute maximum supply voltage for VPPCP is +5.5 V. Operation above this level risks permanent damage. The recommended operating range is 4.8–5.2 V. Exceeding 5.5 V violates the Absolute Maximum Ratings table and may degrade charge pump linearity or cause latch-up. Always decouple VPPCP with ≥10 µF ceramic + 100 nF low-ESR capacitor near the pin. This specification applies strictly to the HMC833LP6GETR and must be verified against the latest Analog Devices datasheet revision.

Does the HMC833LP6GETR support differential reference input?

No, the HMC833LP6GETR accepts only single-ended AC-coupled reference inputs (XREFP) with 1–3.3 V_p-p amplitude. Its reference input stage is designed for 50 Ω terminated square or sinusoidal waveforms-not LVDS or differential PECL. Attempting differential drive may cause improper biasing or lock failure. For robust operation, use a balun or single-ended buffer before XREFP. This limitation is inherent to the HMC833LP6GETR's internal input structure and is documented in the "REF Input Characteristics" section.

How does the Exact Frequency Mode function in the HMC833LP6GETR?

Exact Frequency Mode uses the delta-sigma modulator to eliminate residual fractional spur-induced frequency error, enabling true zero-Hz output frequency deviation from the target. It requires programming Register 6 [17:16] = 11 and selecting appropriate loop filter bandwidth (e.g., 100–120 kHz). Verified performance shows <1 Hz error at 2113.5 MHz and 2591 MHz outputs. This mode is unique to the HMC833LP6GETR within its family and is not available on earlier HMC830 variants.

What is the thermal resistance (R_TH) of the HMC833LP6GETR package?

The thermal resistance from junction to ground paddle (R_TH) is 9 °C/W. This value assumes proper PCB layout: soldering all ground leads and the exposed paddle to a solid thermal plane with ≥6 thermal vias (0.3 mm diameter). Junction temperature must remain ≤125 °C under continuous operation. At 185 mA total supply current and 5 V bias, power dissipation is ~0.925 W, resulting in ~8.3 °C rise above board temperature-well within safe limits when mounted per Hittite Application Note guidelines for the HMC833LP6GETR.

Can the HMC833LP6GETR generate 25 MHz output directly?

Yes, the HMC833LP6GETR generates 25 MHz directly using its VCO fundamental mode (fo/62 at 1550 MHz) without external dividers. Measured phase noise at 25 MHz is –112 dBc/Hz at 10 kHz offset, and output power is –2.5 dBm (typ). This capability is confirmed in Figure 21 ("Low Frequency Performance") and enables use as a tunable reference source-validated in HMC833LP6GETR application notes for spur reduction in cascaded PLL systems.