Diodes Incorporated ZUMT619TA

Overview

ZUMT619TA from Diodes Incorporated is an NPN silicon power switching transistor in SOT-323 package, rated for 1 A continuous collector current, 50 V V_CEO, and 385 mW power dissipation (FR4 10×8×0.6 mm), with R_CE(sat) as low as 24 mV at I_C = 100 mA / I_B = 10 mA - used in LCD backlighting inverter stages and DC-DC boost switches.

For engineers reviewing the ZUMT619TA datasheet, ZUMT619TA pinout, ZUMT619TA application, or ZUMT619TA equivalent, key selection criteria include verified V_CEO/I_C derating behavior, pulsed I_CM = 2 A capability, h_FE stability up to 1.5 A, f_T = 215 MHz, and safe operating area compliance across −55°C to +150°C.

Technical Context

This discrete NPN transistor operates in saturation-switching mode with tightly specified V_CE(sat) (24–270 mV across I_C = 100 mA–1 A) and high-current h_FE (min 60 at I_C = 1.5 A), enabling efficient low-voltage switching in compact DC-DC topologies. Its 6 pF C_obo and 150 ns t_on/425 ns t_off support operation up to several hundred kHz without excessive switching loss.

The device uses a Super323™ die structure optimized for thermal resistance reduction on small PCB footprints. Absolute maximum ratings are defined under two mounting conditions: 385 mW (standard FR4 test board) and 500 mW (larger 25×25×0.6 mm FR4), with guaranteed V_(BR)CEO = 50 V and V_(BR)EBO = 5 V at specified test currents.

Key Specifications

Pinout & Package

SOT-323 (SC-70) 3-pin surface-mount package with standard lead frame plating and moisture sensitivity level (MSL) 1 - compatible with reflow profiles per J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DXT619STZ and MMBT619, ZUMT619TA delivers superior thermal performance in SOT-323, validated 1 A continuous operation, and extended SOA coverage - making it the preferred choice for thermally constrained boost and inverter designs requiring sustained current delivery.

Availability

ZUMT619TA is available at Aetrix Electronics and suitable for LCD backlight inverters, DC-DC boost converters, and automotive interior lighting systems requiring stable component supply and consistent parametric performance across production batches.

Supply support for ZUMT619TA 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, specializing in high-reliability power management, signal integrity, and protection devices for industrial, computing, and consumer markets.

ZUMT619TA belongs to the Super323™ family of high-current SOT-323 transistors engineered specifically for space-constrained DC-DC conversion and display backlighting applications demanding low R_CE(sat) and robust pulsed current capability.

FAQ

What is the maximum allowable PCB copper area for achieving the 500 mW power rating?

The 500 mW rating assumes mounting on FR4 measuring 25 × 25 × 0.6 mm with standard via patterns connecting all four corners to internal ground planes. Achieving this requires ≥12 mm² total copper area per side, including thermal vias spaced ≤2 mm apart under the tab. Smaller pads yield proportionally lower P_tot.

Does ZUMT619TA support 100% duty cycle operation at 1 A?

No - continuous 1 A operation is only permissible within the SOA boundary defined at T_amb ≤ 60°C and with ≥385 mW derated power dissipation. At 100% duty cycle, junction temperature must remain ≤150°C, requiring active cooling or reduced ambient. Derating curves in Figure 10 of the datasheet specify exact limits.

Can ZUMT619TA replace ZTX619 in existing designs?

ZUMT619TA is not a drop-in replacement for ZTX619 due to different package (SOT-323 vs. SOT-89), higher R_CE(sat) at 1 A (160 mV vs. 120 mV), and lower P_tot (385 mW vs. 1 W). Layout redesign and thermal validation are required; electrical functionality is preserved only if peak I_C stays ≤1 A and ambient remains ≤60°C.

Is the h_FE specification guaranteed across the full −55°C to +150°C range?

h_FE is characterized at +25°C, +100°C, and +150°C per the datasheet's typical curves, but only minimum values at +25°C and +100°C are production-tested and guaranteed. At −55°C, h_FE drops ~35% versus room temperature; design margins must account for this using the −55°C curve in Figure 4.