Diodes Incorporated ZTX853STOB

Overview

ZTX853STOB from Diodes Incorporated is an NPN silicon planar medium-power high-current transistor with V_CEO = 100 V, I_C = 4 A continuous, and P_tot = 1.2 W at T_amb = 25°C; it delivers low V_CE(sat) (140 mV typ. at I_C = 2 A), h_FE ≥ 100 at I_C = 10 mA, and f_T = 130 MHz - used in industrial DC-DC converter switching stages.

For engineers reviewing the ZTX853STOB datasheet, ZTX853STOB pinout, ZTX853STOB application, or ZTX853STOB equivalent, key selection criteria include verified V_CEO/I_C derating behavior, TO-92-compatible thermal resistance (R_th(j-amb) = 150 °C/W), saturation voltage under pulsed 4 A loads, and h_FE stability across 10 mA–4 A collector current range.

Technical Context

This NPN bipolar junction transistor operates in linear and switching modes with guaranteed breakdown ratings: V_(BR)CEO ≥ 100 V (I_C = 10 mA), V_(BR)CBO ≥ 200 V (I_C = 100 µA), and V_(BR)EBO ≥ 6 V (I_E = 100 µA). Its safe operating area supports single-pulse I_C up to 10 A with t_P ≤ 300 µs and duty cycle ≤ 2%.

Thermal design relies on R_th(j-amb) = 150 °C/W (PCB-mounted, 1-inch² copper) and R_th(j-case) = 50 °C/W. Switching performance is characterized by t_on = 50 ns and t_off = 1650 ns at I_C = 1 A, V_CC = 10 V, and specified base drive conditions.

Key Specifications

Pinout & Package

Package: TO-92 compatible (E-Line TO92 Compatible, case outline 3-297), through-hole mounting, epoxy molded plastic body with 3 leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZTX853STOB, ZTX851STOB trades 40 V/2 A/0.4 W headroom for smaller footprint and cost, while BCX56-16 offers tighter h_FE spread but cannot sustain the 4 A continuous or 10 A pulsed loads critical in industrial switching roles.

Availability

ZTX853STOB is available at Aetrix Electronics and suitable for industrial motor control, DC-DC converter design, and programmable logic controller (PLC) I/O modules requiring stable component supply and long-term manufacturability.

Supply support for ZTX853STOB 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 and manufacturing operations across Asia and the Americas.

ZTX853STOB belongs to the ZTX series of high-reliability silicon bipolar transistors engineered for industrial-grade switching and linear regulation in harsh-temperature environments.

FAQ

What is the maximum allowable junction temperature for ZTX853STOB?

The absolute maximum junction temperature is +200°C, and the storage temperature range matches this limit. Operation at T_j > 150°C requires careful thermal modeling using R_th(j-amb) = 150 °C/W and confirmed PCB copper area. Derating begins at T_amb > 25°C per the published thermal curve.

Can ZTX853STOB replace a BC337 in a 5 V logic interface?

No - ZTX853STOB is optimized for medium-power switching (up to 4 A), not low-current logic interfacing. Its higher base drive requirement (400 mA for 4 A) and slower turn-off (1650 ns) make it inefficient and potentially unstable in 5 V microcontroller GPIO applications where BC337's 0.5 A rating and faster response are better matched.

Is ZTX853STOB lead-free and RoHS compliant?

Yes - ZTX853STOB is manufactured in compliance with RoHS Directive 2011/65/EU and is lead-free. The device uses matte tin-plated leads and halogen-free molding compound, meeting JEDEC J-STD-020 moisture sensitivity level (MSL) 1 requirements for reflow soldering.

Does ZTX853STOB require a heatsink in standard TO-92 mounting?

Not for ≤0.8 W continuous dissipation at T_amb ≤ 50°C on a 1-inch² copper pad. At full 1.2 W, junction temperature exceeds 150°C without additional thermal relief. For sustained 4 A operation, consider thermal vias or localized copper pour, but a discrete heatsink is impractical due to TO-92 mechanical constraints.