STMicroelectronics L78L12CD13TR

Overview

L78L12CD13TR from STMicroelectronics is a three-terminal positive fixed-voltage linear regulator delivering 12 V ±4% output at up to 100 mA, featuring internal current limiting, thermal shutdown, and short-circuit protection. It requires no external components, operates with input voltages up to 35 V (for 12 V output), and is used for local on-card regulation in industrial control modules, sensor signal conditioning circuits, and low-power microcontroller power rails.

For engineers reviewing the L78L12CD13TR datasheet, L78L12CD13TR pinout, L78L12CD13TR application, or L78L12CD13TR equivalent, this device serves as a drop-in replacement for Zener-diode/resistor regulators-offering lower quiescent current (6.5 mA typ.), improved line/load regulation (200 mV/50 mV max), and reduced output noise (80 µV RMS) in space-constrained PCB designs.

Technical Context

The L78L12CD13TR implements a monolithic silicon voltage regulator architecture with built-in thermal overload protection and foldback current limiting. Its internal circuitry maintains stable 12 V output across input voltages from 14.5 V to 27 V and load currents from 1 mA to 100 mA, with junction temperature operating range of 0 °C to 125 °C for the 'C' grade.

It achieves supply voltage rejection of 37–42 dB at 120 Hz and exhibits a dropout voltage of 1.7 V under full load. The device supports multiple package options-including SO-8 (with pins 2/3/6/7 internally tied to die attach flag for enhanced thermal performance)-and is qualified per industrial reliability standards.

Key Specifications

Pinout & Package

Supplied in SO-8 package with exposed die attach flag electrically connected to pins 2, 3, 6, and 7 for improved thermal conduction. Requires minimum 6 cm² copper area on PCB for rated power dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM78L12ACZ/NOPB and MC78L12CP, the L78L12CD13TR offers tighter output tolerance (±4%), superior supply rejection (37–42 dB), lower noise (80 µV), and SO-8 packaging-making it optimal for modern SMT-based industrial and IoT designs demanding precision and thermal efficiency.

Availability

L78L12CD13TR is available at Aetrix Electronics and suitable for industrial sensor interfaces, programmable logic modules, microcontroller power rails, and IoT edge node power systems requiring stable component supply across multi-year production cycles.

Supply support for L78L12CD13TR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, microcontroller, power, and sensing solutions for industrial, automotive, and consumer markets.

The L78L series belongs to ST's legacy linear regulator product line, engineered specifically for cost-effective, robust local regulation in space- and power-constrained embedded systems-prioritizing simplicity, reliability, and wide-temperature operation.

FAQ

What is the maximum allowable input voltage for L78L12CD13TR?

The absolute maximum DC input voltage is 35 V when regulating 12 V output, per Table 1 of DS0424 Rev 30. Operation above 27 V is not recommended for continuous use due to increased power dissipation and thermal stress; derating is required above 25 V ambient.

Does L78L12CD13TR require input and output capacitors?

Yes-ST specifies a minimum 0.33 µF ceramic capacitor at the input and 0.1 µF ceramic capacitor at the output, placed as close as possible to the respective pins. These capacitors ensure stability, suppress high-frequency noise, and improve transient response per Figure 13 and Section 6 of the datasheet.

Can L78L12CD13TR be used in parallel to increase output current?

No-parallel operation is not supported. The L78L12CD13TR lacks current-sharing circuitry, and mismatched output voltages between units will cause one device to dominate conduction, risking thermal runaway. For >100 mA, use an external pass transistor as shown in Figure 14 of DS0424.

Is L78L12CD13TR RoHS-compliant and halogen-free?

Yes-the L78L12CD13TR carries ECOPACK2 qualification per ST's environmental compliance program, meeting RoHS Directive 2011/65/EU and being halogen-free per IEC 61249-2-21. Full material declarations and compliance certificates are available via ST's official product page and Aetrix's traceability portal.