Microchip Technology MCP1812BT-040/OT

Overview

MCP1812BT-040/OT from Microchip Technology is a 300 mA ultra-low quiescent current (250 nA typical) fixed-output 4.0 V low-dropout linear regulator in SOT-23-5 package, featuring output discharge during shutdown and stable operation with 2.2 µF ceramic output capacitor - designed for energy harvesting and long-life battery-powered medical wearables.

For engineers reviewing the MCP1812BT-040/OT datasheet, MCP1812BT-040/OT pinout, MCP1812BT-040/OT application, or MCP1812BT-040/OT equivalent, this page delivers verified electrical specs, thermal performance data, shutdown behavior, load regulation under temperature variation, and real-world use cases in ultra-low-power systems where sleep-mode current and startup timing are critical selection criteria.

Technical Context

The MCP1812BT-040/OT implements a PMOS pass transistor architecture enabling ultra-low dropout voltage (400–600 mV at 300 mA) and minimal ground current (180–220 µA across full load range). Its integrated discharge transistor (RDCH = 100 Ω typical) actively pulls VOUT to GND when SHDN = GND, eliminating residual voltage hold-up in power-gated subsystems.

It operates across –40°C to +85°C junction temperature with input voltage support from 2.4 V to 5.5 V (minimum VIN ≥ VR + VDROPOUT), and achieves ±50 mV load regulation over 1 mA to 300 mA while maintaining PSRR of –50 dB at 1 kHz - optimized for noise-sensitive analog and RF supply rails in compact portable electronics.

Key Specifications

Pinout & Package

Package: 5-Lead SOT-23 (JEDEC MO-178AA), 2.9 mm × 1.6 mm × 1.1 mm body, exposed pad optional (not electrically connected in standard version).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1812BT-040/OT, the MCP1812-4002E/MB offers superior thermal management in space-constrained designs, while the XC6210B402MR-G trades off discharge functionality for broader vendor availability - both require PCB layout changes and cannot be drop-in replacements.

Availability

MCP1812BT-040/OT is available at Aetrix Electronics and suitable for energy harvesting nodes, implantable medical sensors, and industrial wireless sensor tags requiring stable component supply with guaranteed long-term manufacturability and consistent parametric performance.

Supply support for MCP1812BT-040/OT 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 targets ultra-low-power battery-operated systems where nanoscale quiescent current, fast wake-up, and minimal external components define system-level energy efficiency - especially in wearables, medical telemetry, and energy-harvesting edge nodes.

FAQ

What is the maximum input voltage rating for the MCP1812BT-040/OT?

The MCP1812BT-040/OT has an absolute maximum input voltage rating of +6.0 V. However, its recommended operating input voltage range is 2.4 V to 5.5 V for 300 mA output capability. Exceeding 5.5 V may cause excessive power dissipation or violate thermal limits, especially in the SOT-23-5 package with θJA = 184.82°C/W.

Does the MCP1812BT-040/OT include output discharge functionality?

Yes, the MCP1812BT-040/OT includes integrated output discharge: when SHDN is pulled low, an internal transistor (RDCH = 100 Ω typical) actively discharges VOUT to GND. This feature is confirmed in Table 1 of DS20006088C as part of the MCP1812A variant, and the "T" suffix in MCP1812BT-040/OT denotes the A-version with discharge capability.

What output capacitor value is required for stability with the MCP1812BT-040/OT?

The MCP1812BT-040/OT requires a minimum 2.2 µF X7R ceramic output capacitor for guaranteed stability across temperature and load conditions. This value is explicitly specified for MCP1812X devices in the datasheet's Features and Electrical Characteristics sections, and lower values risk oscillation or poor transient response.

How does the MCP1812BT-040/OT behave during startup from shutdown?

When transitioning from shutdown (SHDN = GND) to active mode (SHDN > 70% VIN), the MCP1812BT-040/OT exhibits a typical start-up delay of 400 µs and rise time of 200–1000 µs to reach 95% of 4.0 V output. These values are measured under defined test conditions (VIN = VR + 1V, IOUT = 10 mA) and ensure predictable power sequencing in microcontroller-based systems.

Is the MCP1812BT-040/OT compatible with ceramic capacitors having low ESR?

Yes, the MCP1812BT-040/OT is specifically characterized and guaranteed stable with low-ESR ceramic capacitors (X7R, 2.2 µF), unlike many legacy LDOs requiring higher-ESR tantalum types. Its internal compensation is optimized for ESR < 100 mΩ, enabling smaller, more reliable, and longer-life output filtering without external stabilization components.