Diodes Incorporated ZTX601BSTOA

Overview

ZTX601BSTOA from Diodes Incorporated is an NPN silicon planar medium-power Darlington transistor in TO-92 package, rated for 160 V_CEO, 1 A continuous collector current, and 1 W power dissipation at 25°C ambient. It delivers DC current gain (h_FE) up to 100 k at I_C = 50 mA and supports switching applications requiring low saturation voltage (V_CE(sat) ≤ 1.2 V at I_C = 1 A, I_B = 10 mA).

For engineers reviewing the ZTX601BSTOA datasheet, ZTX601BSTOA pinout, ZTX601BSTOA application, or ZTX601BSTOA equivalent, key selection criteria include verified V_CEO = 160 V, guaranteed h_FE ≥ 5 k at I_C = 1 A, TO-92 mechanical compatibility, thermal derating slope of 5.7 mW/°C, and documented switching times (t_on = 0.75 µs, t_off = 2.2 µs under pulsed conditions).

Technical Context

This Darlington pair integrates two NPN transistors in cascade to achieve high current gain while maintaining single-package simplicity. Its structure enables low base drive requirements (I_B = 10 mA for 1 A output) and stable operation across −55°C to +200°C junction temperature range.

The device features a V_BE(sat) of 1.7–1.9 V and V_CE(sat) of 0.75–1.2 V depending on operating point, with f_T = 150–250 MHz confirming suitability for medium-speed switching rather than RF amplification. Input capacitance (C_ibo = 60–90 pF) and output capacitance (C_obo = 10–15 pF) are specified at standard bias conditions.

Key Specifications

Pinout & Package

Supplied in E-Line TO-92 compatible package (case style 3-206), with leads arranged as Emitter (E), Base (B), Collector (C) from left to right when viewing the flat side with leads downward.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Darlington transistor applications.

Compared with ZTX601BSTOA, ZTX601 offers identical performance with relaxed mechanical tolerances, while MPSA13 trades voltage headroom and high-current gain for broader availability-making ZTX601BSTOA optimal for 160 V, 1 A industrial switching where reliability and thermal margin are critical.

Availability

ZTX601BSTOA is available at Aetrix Electronics and suitable for relay drivers, DC motor controls, power supply sequencing, and lamp dimming circuits requiring stable component supply and long-term industrial lifecycle support.

Supply support for ZTX601BSTOA 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 components for industrial, automotive, and computing markets.

ZTX601BSTOA belongs to the ZTX series of medium-power bipolar transistors designed specifically for robust, cost-effective switching in harsh-environment industrial controls and power management subsystems.

FAQ

What is the maximum junction temperature for ZTX601BSTOA?

The absolute maximum junction temperature is +200°C, with storage temperature matching this range (−55°C to +200°C). This rating is validated per JEDEC JESD22-A108 and enables operation in high-ambient environments such as enclosed motor drives or industrial enclosures without active cooling.

Can ZTX601BSTOA be used in linear amplifier applications?

No-it is optimized for switching, not linear amplification. Its Darlington structure introduces significant V_BE nonlinearity and thermal drift, and its f_T specification (150–250 MHz) reflects small-signal behavior under pulsed test conditions, not broadband analog gain stability.

Is ZTX601BSTOA RoHS compliant and halogen-free?

Yes-ZTX601BSTOA meets RoHS Directive 2011/65/EU and is certified halogen-free per IEC 61249-2-21. Full compliance documentation, including substance declarations and test reports, is available upon request from Diodes Incorporated's quality portal.

How does thermal derating work above 25°C ambient?

Power dissipation must be reduced by 5.7 mW for every 1°C rise in ambient temperature above 25°C. For example, at 75°C ambient, P_tot is limited to 1 W − (50 × 5.7 mW) = 715 mW. This linear derating is defined in the Absolute Maximum Ratings table and confirmed by the voltage derating graph in the datasheet.