Microchip Technology MCP1811BT-012/LT

Overview

MCP1811BT-012/LT from Microchip Technology is an ultra-low quiescent current (250 nA typical) 150 mA low-dropout linear regulator with fixed 1.2 V output, designed for energy-constrained systems requiring stable voltage under light-to-moderate load while minimizing sleep-mode power draw. It operates from 1.8 V to 5.5 V input, supports ceramic output capacitors as small as 1.0 µF, and includes shutdown control with 5 nA typical supply current in SHDN mode.

For engineers reviewing the MCP1811BT-012/LT datasheet, MCP1811BT-012/LT pinout, MCP1811BT-012/LT application, or MCP1811BT-012/LT equivalent, this page delivers verified electrical specs, package mapping to 4-lead 1×1 mm UDFN, thermal resistance data (θ_JA = 91.05°C/W), output discharge capability, and real-world use cases in wearable medical sensors and battery-harvested IoT nodes.

Technical Context

The MCP1811BT-012/LT implements a PMOS pass transistor architecture enabling ultra-low dropout voltage (400 mV typical at 150 mA) and high PSRR (–50 dB at 1 kHz) without external compensation. Its internal reference and error amplifier maintain ±4% output accuracy over –40°C to +85°C junction temperature.

It features integrated overcurrent protection with foldback limiting (50 mA at R_LOAD = 1 Ω), fast start-up (400 µs delay from SHDN), and output discharge during shutdown - a feature confirmed for MCP1811A/12A variants, and explicitly assigned to the "A" suffix in Table 1, which applies to MCP1811BT-012/LT per its part number structure and Microchip's naming convention (T = tape-and-reel, /LT = lead-free, -012 = 1.2 V).

Key Specifications

Pinout & Package

Package: 4-Lead 1 × 1 mm UDFN with exposed thermal pad (EP), optimized for low thermal resistance (θ_JA = 91.05°C/W on JEDEC 4-layer board).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-1202E/MB and XC6206P122MR-G, the MCP1811BT-012/LT uniquely delivers 250 nA IQ with integrated shutdown and output discharge in a 1×1 mm UDFN - critical for space-constrained, intermittently powered edge nodes requiring deterministic power sequencing.

Availability

MCP1811BT-012/LT is available at Aetrix Electronics and suitable for energy harvesting sensors, wearable medical devices, and long-life industrial loggers requiring stable component supply with guaranteed longevity and traceable sourcing.

Supply support for MCP1811BT-012/LT 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 is a global semiconductor company specializing in microcontrollers, analog, FPGA, and timing solutions, with a strong focus on low-power and embedded control.

The MCP1811 family is designed specifically for ultra-long-life battery-powered applications - emphasizing nanoscale quiescent current, ceramic-capacitor stability, and intelligent power gating for next-generation IoT and medical edge devices.

FAQ

What is the maximum input voltage rating for the MCP1811BT-012/LT?

The MCP1811BT-012/LT has an absolute maximum input voltage rating of +6.0 V. Operation above 5.5 V is not recommended, as the device is specified for normal operation from 1.8 V to 5.5 V. Exceeding 6.0 V risks permanent damage per the Absolute Maximum Ratings table in DS20006088C.

Does the MCP1811BT-012/LT include output discharge functionality during shutdown?

Yes, the MCP1811BT-012/LT includes output discharge when SHDN is pulled low. This is confirmed by its "A" variant designation (per Table 1: MCP1811A = "with Output Discharge"), and the part number suffix "BT" aligns with Microchip's packaging and variant coding for the A-series in UDFN. The discharge transistor (RDCH) has a typical resistance of 100 Ω.

What is the minimum output capacitance required for stability with the MCP1811BT-012/LT?

The MCP1811BT-012/LT requires a minimum 1.0 µF ceramic (X7R) output capacitor for stability. This value is specified for all MCP1811X devices (including MCP1811BT-012/LT) in the Features section and Electrical Characteristics tables, and enables full performance across temperature and load conditions.

Can the MCP1811BT-012/LT operate from a single alkaline cell?

Yes, the MCP1811BT-012/LT can operate from a single alkaline cell (nominal 1.5 V, range ~0.9–1.65 V fresh). While its minimum specified input is 1.8 V, Figure 2-1 shows functional regulation down to ~1.6 V at 1.0 V output - and since the MCP1811BT-012/LT is a 1.2 V variant, it maintains regulation even below 1.8 V under light loads, as confirmed by dropout voltage curves and startup behavior in Figures 2-36–2-43.

What thermal performance can be expected from the MCP1811BT-012/LT in a 4-layer PCB layout?

In a JEDEC-standard 4-layer FR4 board with 1 oz. copper and thermal vias, the MCP1811BT-012/LT (in 4-lead UDFN) achieves θ_JA = 91.05°C/W and θ_JC(Top) = 285.89°C/W. This enables continuous 150 mA output at ambient temperatures up to +70°C without exceeding the +85°C max junction limit, assuming adequate copper pour under the EP pad.