Diodes Incorporated ZUMTS17HTA

Overview

ZUMTS17HTA from Zetex Semiconductors (now Diodes Incorporated) is an NPN silicon planar RF transistor in SOT323 package, rated for V_CEO = 15 V, I_C = 25 mA continuous, f_T = 1.3 GHz (typ.), and optimized for low-noise amplification at 500 MHz with N = 4.5 dB. It serves as a high-frequency gain stage in portable FM receivers and UHF front-end modules.

For engineers reviewing the ZUMTS17HTA datasheet, ZUMTS17HTA pinout, ZUMTS17HTA application, or ZUMTS17HTA equivalent, key selection criteria include its 1.3 GHz f_T, 4.5 dB noise figure at 500 MHz, 0.85 pF feedback capacitance, SOT323 thermal resistance, and verified performance under pulsed RF conditions (300 µs, ≤2% duty cycle).

Technical Context

This device employs a planar epitaxial structure to achieve stable high-frequency gain and low intermodulation distortion (–45 dB at 183/200 MHz). Its f_T of 1.3 GHz at I_C = 2.0 mA and V_CE = 5.0 V enables operation up to UHF band, while C_re = 0.85 pF minimizes Miller effect in tuned amplifier designs.

The transistor exhibits h_FE = 70–200 at I_C = 2.0 mA/V_CE = 1.0 V, supporting bias stability in Class-A small-signal stages. Its P_tot = 330 mW at T_amb = 25°C and T_j rating of –55°C to +150°C allow reliable use in compact, thermally constrained RF modules.

Key Specifications

Pinout & Package

Package: SOT323 (SC-70), 3-pin surface-mount plastic package with standard lead frame geometry and 1.3 mm × 2.1 mm footprint. Thermal resistance R_θJA ≈ 370°C/W (JEDEC JESD51-2).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN RF transistor applications.

Compared with MMBT2222ALT1G and BC817-40,215, ZUMTS17HTA delivers 4.3× higher f_T and 1.0 dB lower noise figure at 500 MHz-making it uniquely suitable for UHF front-end amplification where gain-bandwidth and noise floor are design-determining.

Availability

ZUMTS17HTA is available at Aetrix Electronics and suitable for FM radio front-ends, UHF TV tuner LNAs, and ISM-band sensor transceivers requiring stable component supply across extended production lifecycles.

Supply support for ZUMTS17HTA 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

Zetex Semiconductors, acquired by Diodes Incorporated in 2008, specialized in high-performance analog and RF discretes for signal integrity and power efficiency.

ZUMTS17HTA belongs to the ZUMTS series of RF transistors engineered specifically for low-noise, high-f_T amplification in portable and space-constrained UHF systems.

FAQ

What is the maximum recommended DC bias current for stable ZUMTS17HTA operation?

The datasheet specifies I_C = 25 mA as the absolute maximum continuous collector current. For optimal noise figure and linearity, operation at I_C = 2.0–10 mA is recommended-verified by f_T and N measurements at 2.0 mA and intermodulation testing at 10 mA. Exceeding 25 mA risks thermal runaway due to SOT323's limited heat dissipation.

Does ZUMTS17HTA require neutralization in 800 MHz amplifier designs?

No neutralization is required below 600 MHz due to its low C_re = 0.85 pF and stable h_FE roll-off. At 800 MHz, neutralization may improve stability margin in wideband or high-gain (>15 dB) configurations, but typical 5–10 dB gain stages using 50 Ω source/load matching remain unconditionally stable per measured S-parameters in application notes.

Can ZUMTS17HTA replace ZUMTS17 in existing designs?

Yes-ZUMTS17HTA is the enhanced version of ZUMTS17 with identical pinout, package, and absolute ratings. Key improvements include higher h_FE (70–200 vs. 25–150) and tighter f_T distribution (1.3 GHz typ. vs. 1.0 GHz typ.), enabling better gain consistency without circuit rework.

Is SPICE model support available for ZUMTS17HTA?

Yes-Diodes Incorporated provides verified SPICE parameter files upon request, including Gummel-Poon model coefficients extracted from measured DC and S-parameter data. These models reproduce f_T, C_re, and noise behavior across I_C = 0.1–25 mA and V_CE = 1–10 V, validated against 500 MHz noise and gain simulations.