Diodes Incorporated ZXTR2008K-13

Overview

ZXTR2008K-13 from Diodes Incorporated is a monolithic high-voltage linear regulator transistor integrating an NPN pass transistor, 8.2V Zener reference, and 150kΩ current-limiting resistor in a single TO252 (DPAK) package. It delivers a regulated 8.2V ±10% output at up to 15mA continuous load, supports 12–100V input range, and operates across –40°C to +125°C junction temperature. It serves as a compact startup supply for DC-DC converters in Power over Ethernet (PoE) injectors.

For engineers reviewing the ZXTR2008K-13 datasheet, ZXTR2008K-13 pinout, ZXTR2008K-13 application, or ZXTR2008K-13 equivalent, key selection criteria include its integrated emitter-follower topology, 100V absolute max input rating, 8.2V output tolerance, thermal resistance (R_θJA = 44°C/W on 50mm × 50mm copper), and AEC-Q101 qualification for high-reliability industrial use.

Technical Context

The ZXTR2008K-13 implements a series linear regulator using an internal emitter-follower stage with built-in Zener biasing and current limiting. Its regulation relies on fixed 8.2V Zener voltage drop across the base-emitter junction of the integrated NPN transistor, enabling stable output without external feedback components.

It operates only when VIN ≥ 12V; below that, VOUT follows VIN minus ~1.5V. The 150kΩ internal resistor sets quiescent current (275–900µA depending on VIN), while safe operating area is defined by pulsed (900mA @ 100µs) and continuous (55mA @ VIN=48V) output current limits under specified PCB copper conditions.

Key Specifications

Pinout & Package

Package: TO252 (DPAK), with exposed VIN pad thermally connected to the collector of the internal NPN transistor. Molded plastic case meets UL 94V-0 flammability rating and J-STD-020 Level 1 moisture sensitivity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage linear regulator applications.

Compared with TL783CP and LT3080IM#PBF, the ZXTR2008K-13 offers plug-and-play 8.2V regulation in minimal area, lower IQ, and guaranteed 100V survivability-making it optimal for PoE startup and telecom auxiliary rails where integration and ruggedness outweigh adjustability.

Availability

ZXTR2008K-13 is available at Aetrix Electronics and suitable for Power over Ethernet (PoE) injector designs, telecom line card power supplies, and industrial networking equipment requiring stable component supply with AEC-Q101 reliability and 100V input tolerance.

Supply support for ZXTR2008K-13 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, automotive, and communications markets.

The ZXTR series targets high-voltage linear regulation needs in space- and thermal-constrained applications, with design focus on eliminating discrete bias networks in PoE, telecom, and industrial power subsystems.

FAQ

What is the minimum input voltage required for regulation?

The ZXTR2008K-13 requires VIN ≥ 12V to maintain regulated 8.2V output. Below 12V, VOUT tracks VIN minus approximately 1.5V (e.g., VIN = 10V yields VOUT ≈ 8.5V, unregulated). This threshold is defined by the internal Zener voltage and transistor V_BE drop, and is confirmed in the datasheet's "Minimum Value of Input Voltage Required to Maintain Line Regulation" specification.

Can ZXTR2008K-13 drive a 50mA load continuously?

No-continuous output current is limited to 55mA only at VIN = 48V and with 50mm × 50mm 1oz copper PCB; at higher input voltages (e.g., 100V), power dissipation exceeds 2.3W even at 15mA. Driving 50mA continuously would exceed thermal limits unless VIN ≤ 20V and PCB copper area is maximized. The datasheet specifies 15mA as the nominal regulated output current.

Is an external capacitor required on VOUT?

Yes-a minimum 10µF ceramic or tantalum capacitor must be placed between VOUT and GND, as stated in the "Typical Application Circuit" and "Pin Functions" sections. This capacitor stabilizes regulation, suppresses load transients, and prevents oscillation due to the device's internal impedance profile. Omitting it risks output instability and excessive ripple under dynamic load conditions.

Does ZXTR2008K-13 support reverse-polarity input protection?

No-the device has no intrinsic reverse-polarity protection. Absolute maximum rating for VIN is –0.3V relative to GND; applying negative voltage beyond this damages the internal NPN transistor and Zener. External series diode or MOSFET-based reverse-blocking circuitry must be added if the application risks input polarity reversal, as confirmed by the Absolute Maximum Ratings table.