Diodes Incorporated ZMR250CL

Overview

ZMR250CL from Zetex Semiconductors is a fixed 2.5 V positive voltage regulator in TO-92 package, featuring 30 µA quiescent current, 50 mA output capability, and input voltage range of 4.2–22.5 V. It integrates internal current limiting and thermal shutdown, making it suitable for low-power industrial sensor nodes and battery-backed memory retention circuits.

For engineers reviewing the ZMR250CL datasheet, ZMR250CL pinout, ZMR250CL application, or ZMR250CL equivalent, this device is evaluated for precision low-quiescent-current regulation in space-constrained legacy through-hole designs where dropout voltage stability across –55°C to +125°C is required.

Technical Context

The ZMR250CL implements a bandgap-referenced shunt-regulated series pass architecture with unconditionally stable operation-no external capacitor required. Its thermal shutdown activates at junction temperatures exceeding ~150°C, and internal current limit holds output short-circuit current to ≤100 mA.

It operates across full military temperature range (–55°C to +125°C) with output voltage tolerance of ±2.5% over load (0–50 mA), line (4.2–22.5 V), and temperature. Ripple rejection is 55–75 dB at 120 Hz, and output noise is 65 µV_rms (10 Hz–10 kHz).

Key Specifications

Pinout & Package

TO-92 package (4.32–4.95 mm height, 3.30–3.94 mm body width), through-hole mounting, lead pitch 2.54 mm. Pin 1 = Input (IN), Pin 2 = Ground (GND), Pin 3 = Output (OUT). Pin numbering follows standard TO-92 flat-side-down orientation with tab facing left.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV70725DBVT and LM78L25ACZ, the ZMR250CL uniquely combines TO-92 compatibility, 30 µA quiescent current, unconditional stability, and integrated thermal/current protection-making it irreplaceable in legacy low-power through-hole systems requiring robustness without redesign.

Availability

ZMR250CL is available at Aetrix Electronics and suitable for industrial sensor transmitters, smart meter backup rails, and legacy PLC I/O modules requiring stable component supply with long lifecycle visibility.

Supply support for ZMR250CL 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

Zetex Semiconductors plc was a UK-based ISO 9001 and TS16949-certified designer of high-performance analog and discrete semiconductors, acquired by Diodes Incorporated in 2008.

The ZMR series was developed specifically for ultra-low-quiescent-current, thermally robust voltage regulation in harsh-environment industrial and automotive applications where reliability outweighs cost-per-unit.

FAQ

Is ZMR250CL still in production?

No-ZMR250CL is marked "Obsolete" in Zetex's ordering information. However, Aetrix Electronics maintains legacy inventory with full traceability and offers engineering support for obsolescence mitigation, including validated drop-in alternatives and second-source recommendations for ongoing production.

What is the maximum safe power dissipation for ZMR250CL in TO-92?

The TO-92 package has a maximum power dissipation of 600 mW at 25°C ambient, derating linearly to zero at 125°C. At 50 mA load and 22.5 V input, power dissipation is (22.5 − 2.5) × 0.05 = 1.0 W-exceeding safe limits; design must ensure VIN ≤ 14.5 V at full load or implement heatsinking.

Can ZMR250CL replace LM78L25 in existing designs?

Yes-ZMR250CL shares TO-92 pinout (IN-GND-OUT), same 2.5 V output, and broader input range (4.2–22.5 V vs. 7–20 V). Key improvements include 30 µA vs. 5.5 mA quiescent current and built-in thermal shutdown, enabling direct substitution with enhanced efficiency and safety.

Does ZMR250CL require an input bypass capacitor?

While not strictly required for stability, a 100 nF ceramic capacitor placed within 5 mm of Pin 1 (IN) and Pin 2 (GND) is strongly recommended to suppress high-frequency noise from upstream switching supplies and improve transient response during load steps.