Analog Devices Inc. 108313-HMC311ST89

Overview

HMC311ST89 from Analog Devices is a GaAs InGaP HBT MMIC gain block amplifier operating from DC to 6 GHz, delivering 16 dB small-signal gain, +15.5 dBm P1dB output power, and +31.5 dBm output IP3 at +5 V supply with 54 mA quiescent current. It serves as a cascadable 50 Ω RF gain stage or LO driver for HMC mixers in microwave signal chains.

For engineers reviewing the HMC311ST89 datasheet, HMC311ST89 pinout, HMC311ST89 application, or HMC311ST89 equivalent, key selection criteria include its SOT89E package compatibility, broadband 50 Ω I/O matching, temperature-stable Darlington bias architecture, and verified performance across cellular, WLAN, and microwave radio bands.

Technical Context

The HMC311ST89 integrates a monolithic InGaP HBT Darlington feedback pair, enabling stable gain over temperature (±0.012 dB/°C max above 4 GHz) with minimal external bias components. Its DC-coupled RFIN and RFOUT pins require off-chip blocking capacitors, and all ground pins-including package bottom-must connect directly to RF ground.

Designed for +5 V operation with 22 Ω bias resistor, it achieves 54 mA I_CQ and delivers >13 dB gain from DC–6 GHz. Reverse isolation exceeds 20 dB across full bandwidth, supporting cascaded multi-stage designs without interstage filtering.

Key Specifications

Pinout & Package

Package: Industry-standard SOT89E (lead pitch 1.5 mm, body size 4.5 × 2.5 × 1.5 mm), RoHS-compliant matte tin finish, MSL1 rating, thermal resistance 191 °C/W (junction-to-lead).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RF gain block applications.

Compared with HMC311ST89E, the original HMC311ST89 offers Sn/Pb solder compatibility and 235°C reflow, while QPL9057 trades 3.5 dB lower OIP3 for +3.5 dB higher P1dB-making it suitable for non-critical linearity applications where output power dominates.

Availability

HMC311ST89 is available at Aetrix Electronics and suitable for cellular infrastructure, fixed wireless access, and microwave radio applications requiring stable component supply, consistent RF performance, and long-term obsolescence management.

Supply support for HMC311ST89 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, Inc. is a global leader in high-performance analog, mixed-signal, and RF ICs, serving communications, industrial, automotive, and instrumentation markets with precision signal processing solutions.

The HMC311ST89 belongs to Analog Devices' Hittite Microwave RF MMIC product line, engineered specifically for broadband gain blocks, driver amplifiers, and LO distribution in wireless infrastructure and test equipment.

FAQ

What is the recommended bias resistor value for HMC311ST89 to achieve nominal Icq?

The HMC311ST89 requires a 22 Ω bias resistor (R_bias) to deliver 54 mA I_CQ at +5 V supply, per the equation I_CQ = (V_s − 3.8 V)/R_bias. Using 22 Ω yields 54.5 mA, aligning with the datasheet's typical 54 mA specification. Lower values increase current and risk exceeding absolute maximum ratings.

Does HMC311ST89 require external DC blocking capacitors on both input and output?

Yes, HMC311ST89 has DC-coupled RFIN and RFOUT pins, so external DC blocking capacitors are mandatory on both ports. The evaluation board uses 0.01 µF at 50 MHz and 100 pF above 900 MHz; typical values range from 100 pF to 1 nF depending on lowest operating frequency.

Can HMC311ST89 operate from a 3.3 V supply instead of 5 V?

No-HMC311ST89 is specified only for +5 V operation. Absolute maximum collector bias voltage is +7 V, but performance parameters (gain, P1dB, IP3) are characterized exclusively at +5 V with 22 Ω bias. Operation at 3.3 V is not validated and will result in severe gain reduction and potential instability.

What is the thermal management requirement for continuous operation of HMC311ST89?

HMC311ST89 requires direct thermal connection of pins 2 and 4 and the package bottom to a low-impedance PCB ground plane. With 191 °C/W junction-to-lead thermal resistance and 340 mW max dissipation at 85°C, a minimum of six 0.3 mm vias under the exposed pad is recommended to maintain T_J < 125°C at full load.

Is HMC311ST89 pin-compatible with HMC311ST89E?

Yes-HMC311ST89 and HMC311ST89E share identical SOT89E mechanical footprint, pin numbering, and electrical functionality. The only differences are lead finish (Sn/Pb vs. matte Sn) and MSL reflow profile (235°C vs. 260°C), making them drop-in replacements in compatible assembly processes.