Diodes Incorporated ZTX601ASTZ

Overview

ZTX601ASTZ from Diodes Incorporated is an NPN silicon planar medium-power Darlington transistor with V_CEO = 160 V, I_C = 1 A continuous, h_FE ≥ 5 k at I_C = 1 A, P_tot = 1 W at T_amb = 25°C, and TO-92 compatible package - used in high-gain switching and linear amplification stages of industrial power supplies and relay drivers.

For engineers reviewing the ZTX601ASTZ datasheet, ZTX601ASTZ pinout, ZTX601ASTZ application, or ZTX601ASTZ equivalent, key selection criteria include verified V_CEO/V_CBO ratings, h_FE group B performance at 1 A, V_CE(sat) ≤ 1.2 V under I_C = 1 A / I_B = 10 mA, thermal derating slope (5.7 mW/°C), and TO-92 terminal assignment compatibility.

Technical Context

This Darlington pair integrates two NPN transistors monolithically to deliver high DC current gain (up to 100 k) while maintaining defined saturation characteristics. It operates with a base-emitter turn-on voltage of 1.5–1.7 V and exhibits f_T = 150–250 MHz at I_C = 100 mA, enabling use in medium-speed switching and analog amplification up to ~100 kHz.

The device supports pulsed operation up to I_CM = 4 A with t_on = 0.75 µs and t_off = 2.2 µs under specified test conditions. Its safe operating area (SOA) is defined for single-pulse operation at T_amb = 25°C, with voltage derating dependent on source resistance and V_CE.

Key Specifications

Pinout & Package

Supplied in E-Line TO-92 compatible package (3-206 outline), with lead configuration: Pin 1 = Collector, Pin 2 = Base, Pin 3 = Emitter - verified per Diodes Incorporated mechanical drawing 3-206 and electrical marking "ZTX601ASTZ" on top surface.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZTX601 and MJD122G, ZTX601ASTZ uniquely balances TO-92 form factor, 160 V rating, and guaranteed 5 k h_FE at full 1 A - making it optimal for compact, medium-voltage, high-gain switching where thermal mass is limited.

Availability

ZTX601ASTZ is available at Aetrix Electronics and suitable for relay drivers, DC motor controls, linear regulator pass elements, and sensor signal amplifiers requiring stable component supply across industrial and embedded design cycles.

Supply support for ZTX601ASTZ 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 centers and manufacturing facilities across Asia and the Americas.

ZTX601ASTZ belongs to the ZTX series of high-gain silicon transistors designed specifically for medium-power linear and switching applications in industrial control, power management, and signal conditioning systems.

FAQ

What is the maximum allowable base current for ZTX601ASTZ?

The absolute maximum base current is not explicitly specified, but electrical characteristics confirm reliable operation at I_B = 10 mA for full 1 A collector current. Exceeding this may cause localized heating or accelerated degradation. Derating guidelines recommend limiting I_B to ≤ 10 mA under continuous DC conditions and verifying thermal margin using the 5.7 mW/°C derating curve.

Can ZTX601ASTZ replace ZTX600 in existing designs?

ZTX601ASTZ has higher V_CBO (180 V vs. 160 V) and V_CEO (160 V vs. 140 V) than ZTX600, making it a functional upgrade in most cases. However, h_FE distribution differs: ZTX601 guarantees ≥5 k at 1 A, while ZTX600 specifies only ≥1 k. Verify gain requirements and thermal margins before substitution, especially in linear applications.

Is ZTX601ASTZ suitable for PWM motor control?

Yes - its t_on = 0.75 µs and t_off = 2.2 µs support PWM frequencies up to ~200 kHz, though practical use is typically limited to ≤ 20 kHz due to thermal constraints. For 1 A average current, ensure duty cycle and ambient temperature stay within SOA limits shown in Figure 3-207, and avoid sustained operation above 50°C without airflow.

Does ZTX601ASTZ require a base resistor in switching applications?

Yes - a base resistor is mandatory to limit I_B and prevent damage. For 1 A I_C, assuming h_FE = 5 k, I_B ≈ 0.2 mA is theoretically sufficient, but datasheet test conditions use I_B = 10 mA for guaranteed V_CE(sat). A 470 Ω resistor from 5 V logic yields ~10 mA and is commonly used; adjust based on drive voltage and required saturation margin.