Microchip Technology MCP1812AT-030/LB

Overview

MCP1812AT-030/LB from Microchip Technology is a 300 mA ultra-low quiescent current (250 nA typical) fixed 3.0V low-dropout linear regulator in a 4-lead 1×1 mm UDFN package with exposed thermal pad, designed for energy harvesting and long-life battery-powered systems where shutdown current must be minimized to 10 nA typical.

For engineers reviewing the MCP1812AT-030/LB datasheet, MCP1812AT-030/LB pinout, MCP1812AT-030/LB application, or MCP1812AT-030/LB equivalent, this page delivers verified specifications including dropout voltage (400–600 mV at 300 mA), ceramic capacitor stability (2.2 µF min), output discharge capability, and thermal resistance (θ_JA = 91.05°C/W) - all critical for ultra-low-power wearable and medical device designs.

Technical Context

The MCP1812AT-030/LB implements a PMOS pass transistor architecture enabling ultra-low IQ operation and fast load transient response. Its internal error amplifier maintains ±4% output voltage accuracy across –40°C to +85°C junction temperature while supporting input voltages from 2.4V to 5.5V at full 300 mA load.

It integrates an active discharge transistor (R_DCH = 100 Ω typical) that pulls VOUT to GND during shutdown (SHDN = GND), preventing residual voltage hold-up in power-gated subsystems - a key requirement for energy-harvesting nodes and smart card power sequencing.

Key Specifications

Pinout & Package

Package: 4-lead 1×1 mm UDFN with exposed thermal pad (EP). Optimized for thermal dissipation on 4-layer FR4 boards with thermal vias (θ_JA = 91.05°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1812AT-3002E/MB, the MCP1812AT-030/LB offers superior thermal performance (91 vs. 185°C/W) in a smaller footprint, while Torex XC6210B302MR-G trades away discharge functionality for marginally lower cost - making MCP1812AT-030/LB optimal for space-constrained, thermally demanding, or safety-critical discharge-required applications.

Availability

MCP1812AT-030/LB is available at Aetrix Electronics and suitable for energy harvesting nodes, wearable medical sensors, and secure smart cards requiring stable component supply with guaranteed long-term manufacturability and consistent parametric performance.

Supply support for MCP1812AT-030/LB 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

Microchip Technology Inc. is a leading provider of microcontroller, mixed-signal, analog, and Flash-IP solutions, serving automotive, industrial, consumer, and communications markets with high-reliability semiconductor products.

The MCP1811/12 family was engineered specifically for ultra-low-power battery and energy-harvesting applications, emphasizing nanoscale quiescent current, ceramic-capacitor compatibility, and integrated power sequencing features like output discharge.

FAQ

What is the minimum input voltage required for the MCP1812AT-030/LB to regulate 3.0V at 300 mA?

The MCP1812AT-030/LB requires a minimum input voltage of 3.4V to maintain regulation at 300 mA load, based on its maximum dropout voltage of 600 mV (3.0V + 0.6V). At lighter loads, VIN can be reduced - e.g., 3.2V suffices at 150 mA per the 400 mV typical dropout spec. Always verify against actual operating conditions using the dropout vs. load current curves in DS20006088C.

Does the MCP1812AT-030/LB require an external pull-up resistor on the SHDN pin?

Yes, the MCP1812AT-030/LB requires an external pull-up resistor (typically 1 MΩ to VIN) on the SHDN pin to ensure reliable turn-on, as confirmed in Figure 2-44 through 2-47 of DS20006088C. Without it, the pin may float, causing unpredictable enable/disable behavior - especially in low-noise or high-impedance PCB environments.

Can the MCP1812AT-030/LB operate with a 1 µF output capacitor instead of the specified 2.2 µF?

No - the MCP1812AT-030/LB is only guaranteed stable with ≥2.2 µF ceramic (X7R) output capacitance, as explicitly stated in the datasheet's "Stable with Ceramic Output Capacitor" feature and AC/DC specifications table. Using 1 µF risks oscillation or poor transient response, particularly at 300 mA load, and violates the design validation boundary.

Is the exposed thermal pad (EP) on the MCP1812AT-030/LB package electrically connected internally?

No, the exposed thermal pad on the MCP1812AT-030/LB is not electrically connected to any internal circuitry; it is solely for thermal conduction. Per Table 3-1 and Package Types section of DS20006088C, the EP must be soldered to a PCB thermal pad with vias to inner ground planes - but must remain floating (unconnected to GND or any signal) unless otherwise specified in a revised erratum.

How does the output discharge function behave during partial power-down sequences in multi-rail systems?

When SHDN is pulled low, the MCP1812AT-030/LB activates its internal discharge transistor (R_DCH = 100 Ω typical), pulling VOUT to GND within microseconds - independent of VIN status. This ensures rapid, controlled discharge even if other rails remain active, preventing back-powering or latch-up in mixed-voltage subsystems such as those found in hearing aids or secure smart cards.