Diodes Incorporated ZUMT491TC

Overview

ZUMT491TC from Diodes Incorporated is an NPN small-signal surface-mount transistor in SOT323 package, rated for 60 V V_CEO, 1 A continuous collector current, and 500 mW power dissipation. It delivers low 250–500 mV V_CE(sat) at I_C = 500 mA–1 A with I_B = 50–100 mA, and features h_FE = 100–300 across 1 mA–1 A. It is AEC-Q101 qualified and used in automotive load switching and space-constrained DC-DC bias circuits.

For engineers reviewing the ZUMT491TC datasheet, ZUMT491TC pinout, ZUMT491TC application, or ZUMT491TC equivalent, key selection criteria include verified V_CE(sat) at high I_C, thermal resistance (R_θJA = 250 °C/W), SOT323 footprint compatibility, and AEC-Q101 qualification for automotive-grade reliability.

Technical Context

This NPN bipolar junction transistor operates in linear or saturated switching mode with base-driven control logic. Its 7 V V_EBO rating supports stable turn-on under moderate base drive, while the 80 V V_CBO enables safe operation in inductive load snubbing applications.

The device uses a planar epitaxial die structure optimized for low saturation voltage and high current gain consistency. Thermal performance is characterized on 25 mm × 25 mm FR4 PCB with 1 oz copper, where R_θJL = 350 °C/W confirms effective heat conduction through soldered leads.

Key Specifications

Pinout & Package

Package: SOT323 - ultra-compact 3-pin surface-mount plastic package (2.10 mm × 1.30 mm × 0.90 mm), lead-free, halogen-free, and RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBT4401LT1G, ZUMT491TC offers 50% higher V_CEO and 2× I_C with lower V_CE(sat); versus DXTN200100, it trades 0.5 A headroom for 30% smaller footprint and identical voltage ratings-critical for space-constrained automotive modules.

Availability

ZUMT491TC is available at Aetrix Electronics and suitable for automotive lighting control, industrial sensor biasing, and consumer appliance motor drive applications requiring stable component supply and AEC-Q101 compliance.

Supply support for ZUMT491TC 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and the Americas.

The ZUMT series targets high-reliability, space-constrained switching applications in automotive and industrial markets, emphasizing low saturation voltage, AEC-Q101 qualification, and ultra-small SOT323 packaging.

FAQ

What is the maximum operating temperature for ZUMT491TC?

The ZUMT491TC is rated for junction and storage temperatures from −55 °C to +150 °C. Its AEC-Q101 qualification includes extended high-temperature life testing at 150 °C, confirming stable electrical parameters-including h_FE and V_CE(sat)-under sustained thermal stress typical of automotive underhood environments.

Can ZUMT491TC be used in linear amplifier configurations?

Yes, ZUMT491TC supports linear operation with verified h_FE = 100–300 across 1 mA–1 A and V_CE = 5 V. However, its 500 mW power dissipation limit and 250 °C/W thermal resistance require careful derating above 25 °C ambient-linear use is viable only at low quiescent currents (<100 mA) and moderate voltage swings.

Is ZUMT491TC pin-compatible with standard SOT323 NPN transistors?

Yes, ZUMT491TC uses the industry-standard SOT323 pinout (C–E–B, left-to-right top view), matching MMBT4401, PN2222A-S, and other SOT323-packaged NPN transistors. Mechanical dimensions and pad layout comply with JEDEC MO-203AA, enabling direct footprint reuse in existing designs.

Does ZUMT491TC require external base protection diodes in inductive load switching?

No external base protection diode is required for standard operation, as the device's 7 V V_EBO rating exceeds typical base-emitter reverse voltages induced by inductive kickback. However, a 10 kΩ base-emitter resistor is recommended to ensure fast turn-off and prevent leakage-induced false triggering in noisy environments.