Diodes Incorporated ZXTN25020CFH

Overview

ZXTN25020CFH from Diodes Incorporated (formerly Zetex Semiconductors) is an NPN medium-power bipolar junction transistor in SOT23 package, rated for 20V V_CEO, 4.5A continuous collector current, and 1.25W power dissipation on optimized PCB layout. It delivers low 35–45 mV V_CE(sat) at 1A/100mA drive and supports high-speed switching with 185 MHz f_T, making it suitable for MOSFET gate driving and DC-DC converter primary-side switching.

For engineers reviewing the ZXTN25020CFH datasheet, ZXTN25020CFH pinout, ZXTN25020CFH application, or ZXTN25020CFH equivalent, key selection criteria include forward blocking voltage (70V BV_CEX), reverse blocking capability (5V BVECO), thermal resistance (100°C/W R_JA on 50mm×50mm 2oz copper), h_FE stability up to 4.5A, and SOT23 footprint compatibility with space-constrained motor control and power switch designs.

Technical Context

This NPN transistor employs advanced epitaxial process and optimized metallization to sustain 70V forward blocking (BV_CEX) while maintaining low saturation voltage and high gain linearity across 10mA–4.5A I_C range. Its 185 MHz transition frequency and sub-100 ns switching times (t_d=70.5 ns, t_r=88 ns, t_f=65 ns) support efficient hard-switching in DC-DC topologies.

The device features asymmetric breakdown ratings: 70V VCBO and BV_CEX, 20V V_CEO, and only 5V V_ECO, indicating intentional design for unidirectional high-side or common-emitter switching-not bidirectional or emitter-follower operation. Thermal performance is explicitly characterized for three PCB copper configurations, enabling accurate system-level thermal modeling.

Key Specifications

Pinout & Package

SOT23-3 plastic surface-mount package (JEDEC TO-236AB), 2.67–3.05 mm length, 1.20–1.40 mm width, 0.95 mm nominal height. Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector (top view, marking side up, tab left).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBT4401LT1G and ZXTN2010ZTA, ZXTN25020CFH uniquely combines 4.5A current handling, 70V forward blocking, and sub-50mV saturation in SOT23-enabling compact, high-efficiency power switching where alternatives require larger packages or sacrifice performance.

Availability

ZXTN25020CFH is available at Aetrix Electronics and suitable for MOSFET gate drivers, DC-DC converters, brushed DC motor control, and 24V industrial power switches requiring stable component supply and long-term manufacturability.

Supply support for ZXTN25020CFH 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 acquired Zetex Semiconductors in 2008 and maintains its high-performance analog and power transistor portfolio with focus on reliability, thermal optimization, and application-specific silicon design.

ZXTN25020CFH belongs to Zetex's "medium-power discrete" product line, engineered specifically for space-constrained, high-current switching applications where SOT23 footprint must deliver performance approaching larger packages.

FAQ

What is the maximum allowable base current for continuous operation?

The absolute maximum rating specifies I_B = 1 A continuous. However, for reliable 4.5A collector current operation, the datasheet recommends I_B = 90 mA (20× overdrive) or 450 mA (10× overdrive) depending on required V_CE(sat). Sustained 1A base current exceeds typical design needs and risks localized heating at the bond wire; use current-limiting resistors sized for ≤450 mA under worst-case V_BE conditions.

Can ZXTN25020CFH be used in avalanche mode?

No. The device is not rated or characterized for repetitive avalanche operation. While BV_CEX = 70V indicates robust forward-blocking capability under controlled base clamping, the datasheet provides no SOA curves, avalanche energy ratings, or test conditions for unclamped inductive switching. Use external snubbers or TVS diodes for inductive load protection.

Is the SOT23 package lead-free and RoHS compliant?

Yes. ZXTN25020CFH is manufactured with lead-free terminations and complies with EU RoHS Directive 2011/65/EU and JEDEC J-STD-020 moisture sensitivity level 1 (MSL1). The "CFH" suffix denotes halogen-free molding compound and RoHS-compliant packaging per Diodes Incorporated's product change notices issued post-2008 acquisition.

How does thermal performance vary between single-sided and double-sided PCB copper?

The datasheet specifies R_JA = 100°C/W for 50mm×50mm single-sided 2oz copper. Double-sided copper with thermal vias can reduce R_JA by 20–30%, but no official characterization is provided. For designs targeting <100°C junction rise at 4.5A, assume ≤80°C/W effective R_JA with aggressive via stitching and internal ground plane coupling-validated via IR thermography per IPC-7351B layout guidelines.