Analog Devices Inc. HMC620-SX

Overview

HMC620-SX from Analog Devices (formerly Hittite Microwave) is a GaAs MMIC I/Q mixer designed for RF front-end signal translation in 3–7 GHz systems. It functions as an Image Reject Mixer (IRM) or single-sideband upconverter, delivering 9 dB typical conversion loss, 32 dB image rejection, and +22 dBm input IP3 at +15 dBm LO drive - enabling high-fidelity downconversion in point-to-point radio transceivers.

For engineers reviewing the HMC620-SX datasheet, HMC620-SX pinout, HMC620-SX application, or HMC620-SX equivalent, this device requires attention to its 24-lead ceramic SMT package grounding scheme, DC-coupled RF/LO/IF ports, IF bandwidth extending to DC, and thermal derating above +85°C - all critical for stable operation in WiMAX and VSAT receiver designs.

Technical Context

The HMC620-SX integrates two double-balanced GaAs MESFET mixer cells with an on-die 90° hybrid to enable quadrature mixing without external phase-shifting components. Its architecture supports both IRM downconversion and SSB upconversion modes, with IF outputs at IF1 and IF2 referenced to DC.

It operates with a fixed +15 dBm LO drive for optimal performance, exhibiting 0.3 dB amplitude balance and 3° phase balance across 3–7 GHz RF input, while maintaining >43 dB LO-to-RF isolation and >30 dB LO-to-IF isolation - key for suppressing local oscillator leakage in sensitive receive chains.

Key Specifications

Pinout & Package

24-lead leadless ceramic SMT package (4×4 mm, 16 mm²), alumina body with gold-over-nickel plating, MSL3 rated, requiring soldering of all ground leads and exposed paddle to PCB RF ground per JEDEC standards.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I/Q mixer applications.

Compared with HMC1048LP4CE and ADL5375-05, the HMC620-SX offers superior image rejection and lower conversion loss within its 3–7 GHz band, making it the preferred choice for high-performance receive-side IRM applications where passive architecture, DC-coupled IF, and thermal stability are prioritized.

Availability

HMC620-SX is available at Aetrix Electronics and suitable for point-to-point radio, WiMAX infrastructure, and VSAT outdoor unit designs requiring stable component supply, long-lifecycle support, and traceable sourcing for aerospace-grade manufacturing.

Supply support for HMC620-SX 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 portfolio, specializing in precision analog, RF, and microwave ICs for communications and defense markets.

The HMC620-SX belongs to Hittite's legacy GaAs MMIC mixer family, engineered specifically for high-linearity, low-image-noise RF front-ends in licensed wireless infrastructure and satellite communication systems.

FAQ

What is the recommended LO drive level for optimal performance of the HMC620-SX?

The HMC620-SX requires a precise +15 dBm LO drive level for specified performance: at this level, it achieves 9 dB typical conversion loss, 32 dB image rejection, and +22 dBm input IP3. Deviating below +13 dBm or above +17 dBm degrades linearity and balance; the datasheet confirms +15 dBm as the calibrated reference point for all electrical specifications of the HMC620-SX.

Can the HMC620-SX operate with DC-coupled IF outputs in zero-IF receivers?

Yes - the HMC620-SX features fully DC-coupled IF1 and IF2 outputs, enabling direct interface to baseband ADCs without external blocking capacitors. However, each IF pin must not source or sink more than ±3 mA DC current; exceeding this risks non-function or permanent damage to the HMC620-SX. This DC capability is explicitly validated in the datasheet's Pin Descriptions section.

What thermal management is required for continuous operation of the HMC620-SX at +85°C ambient?

At +85°C ambient, the HMC620-SX dissipates up to 579 mW; above that temperature, power must be derated by 8.93 mW/°C. Its thermal resistance (R_TH) is 112°C/W (channel to die bottom), so effective heat sinking via the exposed paddle and ≥6 thermal vias to inner ground planes is mandatory. The datasheet specifies that all ground leads and the paddle must be soldered to PCB RF ground to maintain thermal and electrical integrity of the HMC620-SX.

Is the HMC620-SX pin-compatible with other Hittite I/Q mixers like the HMC621LC4?

No - the HMC620-SX is not pin-compatible with the HMC621LC4 or other variants. While both are 24-lead ceramic packages, their pin functions differ: the HMC620-SX assigns IF1 to pin 9 and IF2 to pin 11, whereas the HMC621LC4 swaps IF2 to pin 9 and uses pin 11 for bias control. This functional mismatch means PCB layout changes are required when substituting; the HMC620-SX pinout is unique to its internal hybrid configuration.

Does the HMC620-SX support both downconversion and upconversion modes?

Yes - the HMC620-SX supports dual-mode operation: as an Image Reject Mixer (IRM) for downconversion (RF→IF) and as a Single Sideband Upconverter (SSBU) for upconversion (IF→RF). Its internal architecture - two double-balanced mixer cells plus an integrated 90° hybrid - enables both functions without external reconfiguration. The datasheet confirms this capability in the General Description and Upconverter Performance sections for the HMC620-SX.