Diodes Incorporated AZ78L05RTR-E1

Overview

AZ78L05RTR-E1 from BCD Semiconductor Manufacturing Limited is a fixed-output +5 V, 100 mA three-terminal positive linear regulator in SOT-89 package. It features ±5% output voltage tolerance over −40°C to +125°C, internal short-circuit current limiting, thermal shutdown protection, and requires no external components. It delivers stable local regulation for microprocessor I/O power supplies and post-regulation of switching supplies.

For engineers reviewing the AZ78L05RTR-E1 datasheet, AZ78L05RTR-E1 pinout, AZ78L05RTR-E1 application, or AZ78L05RTR-E1 equivalent, key selection criteria include dropout voltage (1.6 V), quiescent current (3–5 mA), ripple rejection (47–62 dB at 120 Hz), and thermal resistance (θ_JC = 29.8°C/W) - all critical for low-noise, thermally constrained embedded power rails.

Technical Context

The AZ78L05RTR-E1 implements a monolithic series pass transistor with bandgap reference, error amplifier, and thermal shutdown circuitry in a single silicon die. Its architecture provides inherent line and load regulation without external compensation components.

It operates across an input voltage range of 7.0 V to 15 V for the 5 V variant, maintaining regulation down to a minimum input of 6.7 V. The device sustains 100 mA continuous output while limiting peak current to 150 mA and rejecting 120 Hz ripple by ≥47 dB under typical conditions.

Key Specifications

Pinout & Package

SOT-89 package: 3-pin surface-mount plastic package with exposed thermal pad (pin 2 connected to GND for thermal conduction). Compact footprint (4.4 × 2.6 mm) optimized for space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC78L05ACDR2G and TL78L05ACDR, the AZ78L05RTR-E1 delivers best-in-class thermal resistance (29.8°C/W), lowest output noise (40 μV), and highest ripple rejection (62 dB), making it optimal for noise-sensitive, space-constrained, and thermally demanding 5 V regulation tasks.

Availability

AZ78L05RTR-E1 is available at Aetrix Electronics and suitable for microprocessor I/O power supplies, post-regulation of switching supplies, high-efficiency linear regulators, and mother board I/O power supplies requiring stable component supply, RoHS-compliant packaging, and industrial temperature support.

Supply support for AZ78L05RTR-E1 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

BCD Semiconductor Manufacturing Limited is a Shanghai-based fabless analog IC designer specializing in power management, LED drivers, and high-voltage process technologies since 2003.

The AZ78LXX series was developed for cost-sensitive, space-constrained embedded systems requiring robust, no-compromise linear regulation - targeting industrial control, consumer audio, and automotive body electronics.

FAQ

What is the minimum input voltage required for the AZ78L05RTR-E1 to maintain regulation?

The AZ78L05RTR-E1 requires a minimum input voltage of 6.7 V to sustain regulated +5 V output under full load (100 mA) and across its operating temperature range (−40°C to +125°C), as specified in the Electrical Characteristics table on page 6 of the datasheet.

Does the AZ78L05RTR-E1 require input and output capacitors?

Yes - a minimum 0.33 μF ceramic capacitor is required at the INPUT pin and a minimum 0.1 μF ceramic capacitor at the OUTPUT pin, placed as close as possible to the device. These ensure stability, reduce high-frequency noise, and improve transient response per Figure 10 and Note 4 in the datasheet.

How does thermal protection operate in the AZ78L05RTR-E1?

When internal power dissipation causes junction temperature to approach ~150°C, the thermal shutdown circuit activates, disabling the pass transistor until temperature falls below the hysteresis threshold (~135°C). This prevents permanent damage and enables automatic recovery without external intervention.

Is the AZ78L05RTR-E1 pin-compatible with legacy 78L05 devices in SOT-89?

Yes - the AZ78L05RTR-E1 uses standard SOT-89 pinout (Pin 1: INPUT, Pin 2: GND, Pin 3: OUTPUT), matching industry-standard 78L05 SOT-89 variants including MC78L05ACDR2G and TL78L05ACDR, enabling direct replacement without PCB modification.