Renesas UPD121W18AT1F-E1-AT

Overview

UPD121W18AT1F-E1-AT from Renesas Electronics is a fixed-output 1.8 V, 1.5 A CMOS low-dropout linear regulator in TO-252 (MP-3ZK) package, featuring 1.0 V max dropout at full load, ±2.0% output voltage tolerance at 25°C, and integrated thermal shutdown and over-current protection. It powers large-scale ASICs in digital consumer equipment requiring stable, low-noise local regulation.

For engineers reviewing the UPD121W18AT1F-E1-AT datasheet, UPD121W18AT1F-E1-AT pinout, UPD121W18AT1F-E1-AT application, or UPD121W18AT1F-E1-AT equivalent, this page delivers verified electrical specs, validated package mapping, confirmed thermal performance, and real-world use context for power supply design in high-current embedded systems.

Technical Context

The UPD121W18AT1F-E1-AT implements a CMOS-based error amplifier with internal reference voltage trimming, constant-current buffer, and on-chip protection logic. Its architecture supports stable operation with ≥10 μF laminated ceramic output capacitors and tolerates input voltages from 2.8 V to 5.5 V.

It features active ON/OFF control with 1 μA standby current, 150 μA typical quiescent current at zero load, and ripple rejection of 65 dB at 1 kHz. The device operates across −40°C to +85°C ambient and shuts down thermally above +150°C junction temperature.

Key Specifications

Pinout & Package

UPD121W18AT1F-E1-AT uses a 5-pin TO-252 (MP-3ZK) surface-mount package with exposed thermal pad (Pin 6, common to GND). Pin 3 is cut and non-functional; Pin 4 is NC for fixed-output variants.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with UPD121W18AT1F-E1-AT, TPS7A4700RGWR offers superior noise performance but cannot deliver 1.5 A, while MCP1703T-1802E/MB sacrifices current and thermal robustness for ultra-low I_Q and small footprint - neither matches the original's balance of high current, thermal resilience, and CMOS efficiency in TO-252.

Availability

UPD121W18AT1F-E1-AT is available at Aetrix Electronics and suitable for industrial control interfaces, digital consumer equipment, embedded communication modules, and ASIC power supply designs requiring stable component supply with long-term lifecycle support.

Supply support for UPD121W18AT1F-E1-AT 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

Renesas Electronics Corporation is a global semiconductor leader formed in 2010 via merger of NEC Electronics and Renesas Technology, specializing in microcontrollers, analog, power, and timing solutions for industrial, automotive, and consumer markets.

The UPD121WxxA series was designed as a high-current, CMOS-based LDO family targeting power integrity in digital appliances - emphasizing low dropout, ceramic-capacitor compatibility, and integrated protection for ASIC and FPGA core voltage regulation.

FAQ

What is the minimum input voltage required for UPD121W18AT1F-E1-AT to regulate 1.8 V output?

The UPD121W18AT1F-E1-AT requires a minimum input voltage of 2.8 V to maintain regulation at full 1.5 A load, based on its maximum 1.0 V dropout specification. At lighter loads, it can operate down to VO + VDIF(typical) = 1.8 V + 0.6 V = 2.4 V, but design margin mandates using 2.8 V as the guaranteed minimum per recommended operating conditions.

Can UPD121W18AT1F-E1-AT be used with only ceramic capacitors?

Yes - the UPD121W18AT1F-E1-AT is explicitly qualified for use with laminated ceramic output capacitors of 10 μF or greater, as confirmed in the datasheet's "Available for laminated ceramic capacitor" feature and COUT stability guidelines. Input capacitor must be ≥0.1 μF ceramic.

Does UPD121W18AT1F-E1-AT have built-in short-circuit protection?

Yes - the UPD121W18AT1F-E1-AT includes an on-chip over-current protection circuit that limits short-circuit current to 1.0 A maximum, preventing damage during output faults. This is documented in both the Features and Electrical Characteristics sections of the datasheet.

What is the thermal resistance from junction to case (Rth(J-C)) for UPD121W18AT1F-E1-AT?

The thermal resistance from junction to case for UPD121W18AT1F-E1-AT is 12.5°C/W, measured with the exposed thermal pad (Pin 6) properly soldered to a PCB copper plane. This value enables accurate junction temperature estimation under load using TC measurements.

Is UPD121W18AT1F-E1-AT RoHS compliant?

Yes - the UPD121W18AT1F-E1-AT is Pb-free, with no lead in external electrodes or other package parts, as explicitly stated in the Ordering Information section and marked "Pb-free" in the datasheet's notes.