Diodes Incorporated ZXMC3A18DN8TA

Overview

ZXMC3A18DN8TA from Diodes Incorporated (formerly Zetex Semiconductors) is a complementary dual-channel SO-8 MOSFET pair comprising an N-channel (30V, 7.6A, R_DS(on) = 25 mΩ @ V_GS = 10V) and P-channel (–30V, –6.3A, R_DS(on) = 35 mΩ @ V_GS = –10V) trench MOSFET in a single low-profile SOIC-8 package. It delivers fast switching (t_d(off) = 33 ns N-ch / 60 ns P-ch), low gate charge (Q_g = 36 nC / 45 nC), and low-threshold drive for synchronous buck, half-bridge, and motor control stages.

For engineers reviewing the ZXMC3A18DN8TA datasheet, ZXMC3A18DN8TA pinout, ZXMC3A18DN8TA application, or ZXMC3A18DN8TA equivalent, key selection criteria include verified complementary channel matching, SO-8 thermal derating (R_JA = 60°C/W at 25°C, single-die condition), body diode recovery (t_rr = 20.5 ns / 32.5 ns), and gate drive compatibility with 3.3V/5V logic-level controllers.

Technical Context

This device integrates two independently optimized trench MOSFET dice-N-channel with higher transconductance (g_fs = 17.5 S) and lower R_DS(on), P-channel with robust negative threshold (V_GS(th) = –1.0 V) and matched dynamic capacitance (C_iss = 1603 pF). Both channels share identical SO-8 footprint and thermal interface but operate with opposite polarity gate control.

The dual-die structure enables true complementary switching without external level-shifting, supporting bidirectional current flow in H-bridge motor drivers and synchronous rectification in DC-DC converters. Gate charge asymmetry (Q_g = 36 nC vs. 45 nC) reflects optimized drive energy allocation per channel for balanced turn-on/turn-off timing under shared gate driver constraints.

Key Specifications

Pinout & Package

Package: SOIC-8 (SO-8), 3.9 mm × 4.9 mm × 1.75 mm profile, JEDEC MS-012AC compliant, with exposed thermal pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar complementary MOSFET applications.

Compared with DMC2038LSD-13 and SI6926DQ-T1-GE3, ZXMC3A18DN8TA offers superior switching speed (t_d(off) ≤33 ns) and tighter R_DS(on) ratio (1.4×), making it optimal for high-frequency, thermally constrained synchronous buck and motor drive applications where gate drive efficiency and thermal symmetry are critical.

Availability

ZXMC3A18DN8TA is available at Aetrix Electronics and suitable for motor drive, LCD backlighting, synchronous buck conversion, and USB-C power delivery requiring stable component supply across industrial and consumer production programs.

Supply support for ZXMC3A18DN8TA 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 legacy of high-performance analog and discrete semiconductors with ISO 9001 and IATF 16949 certification.

This device belongs to Zetex's trench MOSFET product line, engineered specifically for high-efficiency, low-voltage power management in space-constrained applications such as portable electronics and embedded power supplies.

FAQ

What is the maximum continuous drain current for each channel at 70°C ambient?

At T_amb = 70°C with V_GS = 10V, the N-channel supports 6.1 A and the P-channel supports –5.0 A. These values derive from linear derating of the 25°C ratings (7.6 A / –6.3 A) using the 17 mW/°C factor specified for SO-8 mounting on FR4 with 1 oz copper.

Can ZXMC3A18DN8TA be used in a synchronous rectifier configuration without external diodes?

Yes - both channels integrate body diodes with V_SD = 0.95 V (N-ch) and 0.82–0.95 V (P-ch) at rated current. Their fast t_rr (20.5 ns / 32.5 ns) and low Q_rr (41.5 nC / 18.4 nC) make them suitable for synchronous rectification in DC-DC converters up to 1 MHz, eliminating need for external Schottky diodes.

Is the SO-8 package thermally enhanced with an exposed pad?

No - the SO-8 outline in the datasheet shows no thermal pad or exposed metal slug. Thermal performance relies solely on lead-frame conduction and PCB copper area. The R_JA = 60°C/W rating assumes 25 mm × 25 mm FR4 with full 1 oz copper coverage on the bottom layer, not internal thermal vias or heatsinking.

How does the gate threshold voltage affect logic-level drive compatibility?

V_GS(th) = 1.0 V (N) and –1.0 V (P) ensure reliable turn-on with 3.3V or 5V microcontroller outputs. At V_GS = 3.3V, the N-channel achieves R_DS(on) ≈ 0.030 Ω and P-channel ≈ 0.050 Ω - sufficient for most low-power motor and load-switch applications without gate boosting.