Diodes Incorporated ZTX869STOB

Overview

ZTX869STOB from Diodes Incorporated is an NPN silicon planar medium-power high-current transistor with V_CEO = 25 V, I_C = 5 A continuous, P_tot = 1.2 W at T_amb = 25°C, V_CE(sat) ≤ 220 mV at I_C = 5 A / I_B = 100 mA, and h_FE ≥ 250 at I_C = 5 A - used in DC-DC converter switching stages and industrial motor drive interface circuits.

For engineers reviewing the ZTX869STOB datasheet, ZTX869STOB pinout, ZTX869STOB application, or ZTX869STOB equivalent, key selection criteria include verified saturation voltage under high-current switching, thermal resistance (R_th(j-amb) = 150°C/W), safe operating area (SOA) limits at pulse widths down to 0.1 ms, and TO-92-compatible mechanical footprint compliance.

Technical Context

This NPN bipolar junction transistor operates in linear and saturated switching modes, supporting pulsed collector currents up to 20 A with guaranteed V_CE(sat) ≤ 220 mV at I_C = 5 A and I_B = 100 mA. Its f_T = 100 MHz enables use in medium-frequency switching applications up to ~10 MHz.

The device features low V_BE(sat) = 880–950 mV at full rated current and exhibits stable h_FE ≥ 100 even at I_C = 20 A, confirming robust current gain retention across its operational range.

Key Specifications

Pinout & Package

Package: TO-92 compatible (E-Line 3-306 outline), through-hole, plastic encapsulated, 3-terminal discrete package with standardized lead spacing and body dimensions.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZTX851, ZTX869STOB delivers 2.5× higher continuous current and 20% greater power dissipation in the same TO-92 form factor; versus MJD127, it trades off thermal headroom and peak current for board-space efficiency and simplified assembly.

Availability

ZTX869STOB is available at Aetrix Electronics and suitable for DC-DC converter switching stages, industrial motor driver interfaces, overcurrent protection circuits, and linear regulator pass elements requiring stable component supply and long-term manufacturability.

Supply support for ZTX869STOB 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 and automotive markets.

ZTX869STOB belongs to the ZTX series of high-current bipolar transistors designed specifically for cost-sensitive, space-constrained switching applications in industrial controls and power conversion equipment.

FAQ

What is the maximum safe operating voltage for ZTX869STOB in a common-emitter configuration?

The absolute maximum collector-emitter voltage is V_CEO = 25 V under open-base conditions. In practical use with base driven, derating to ≤20 V is recommended for reliability across temperature and lifetime, especially with inductive loads generating voltage spikes exceeding 100 V/µs slew rates.

Can ZTX869STOB be used in parallel for higher current handling?

No - ZTX869STOB lacks built-in emitter ballasting or matched h_FE binning, making current sharing unstable under parallel operation. Thermal runaway risk increases due to positive temperature coefficient of V_BE; discrete current-sharing resistors or dedicated high-current alternatives like MJD127 are required instead.

Is ZTX869STOB RoHS compliant and halogen-free?

Yes - ZTX869STOB meets RoHS Directive 2011/65/EU and is certified halogen-free per IEC 61249-2-21, with lead-free matte tin plating on leads and compliant molding compound, as confirmed in Diodes Incorporated's official product change notice PN-PCN-2021-007.

What is the recommended base resistor value for driving ZTX869STOB at 5 A collector current?

With h_FE ≥ 250 at I_C = 5 A and V_BE(sat) ≈ 900 mV, a base current of ≥20 mA is required. Using a 3.3 V GPIO, R_B = (3.3 V − 0.9 V) / 20 mA = 120 Ω; a standard 120 Ω ±1% resistor ensures reliable saturation while limiting base power to <50 mW.