Microchip Technology MCP1811BT-020/LT

Overview

MCP1811BT-020/LT from Microchip Technology is a 150 mA ultra-low quiescent current (250 nA typical) fixed-output 2.0 V low-dropout linear regulator in a 3-lead SOT-23 package, featuring shutdown mode with 5 nA typical supply current and output discharge functionality. It operates from 1.8V to 5.5V input and stabilizes with only 1.0 µF ceramic output capacitance, targeting energy-constrained systems such as hearing aids and smart wearables.

For engineers reviewing the MCP1811BT-020/LT datasheet, MCP1811BT-020/LT pinout, MCP1811BT-020/LT application, or MCP1811BT-020/LT equivalent, key selection criteria include its 2.0 V output voltage accuracy (±4%), 400 mV dropout at 150 mA, 5 nA shutdown current, output discharge capability, and compatibility with micro-power MCU domains like PIC XLP and SAM L series.

Technical Context

The MCP1811BT-020/LT belongs to the MCP1811B variant family - distinguished by no output discharge in A versions but present in A variants; however, per Table 1 and device suffix "T", this part is MCP1811B-type with output discharge enabled. Its internal error amplifier drives a PMOS pass transistor, enabling stable regulation down to 2.0 V output while maintaining sub-µA quiescent draw across –40°C to +85°C junction temperature.

It integrates foldback overcurrent protection (50 mA limit under short-circuit), a dedicated SHDN pin with 70% VIN logic-high threshold, and a discharge transistor (RDCH = 100 Ω) that actively pulls VOUT to GND during shutdown. The device requires no input capacitor for basic operation but benefits from 1 µF ceramic CIN for PSRR improvement above 1 kHz.

Key Specifications

Pinout & Package

Package: 3-Lead SOT-23 (JEDEC MO-178AA), 2.92 mm × 1.3 mm × 1.0 mm, surface-mount, lead-free and RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B202MR-G and RP111N201B-TR-F, the MCP1811BT-020/LT uniquely delivers verified output discharge, tighter dropout, and identical 250 nA IQ in the same 3-pin footprint - making it the sole choice for designs requiring deterministic VOUT collapse without layout change.

Availability

MCP1811BT-020/LT is available at Aetrix Electronics and suitable for energy harvesting nodes, medical wearable patches, and smart hearing aids requiring stable component supply with guaranteed long-term manufacturability and consistent parametric performance.

Supply support for MCP1811BT-020/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 Inc. is a leading provider of microcontroller, mixed-signal, analog, and Flash-IP solutions, serving automotive, industrial, consumer, and communications markets with vertically integrated silicon and development tools.

The MCP1811 family was designed specifically for ultra-low-power battery-operated systems demanding nanowatt-level quiescent consumption, fast wake-up, and minimal external components - targeting next-generation wearables, implantables, and ambient IoT endpoints.

FAQ

What is the output voltage tolerance of the MCP1811BT-020/LT over temperature and load?

The MCP1811BT-020/LT maintains output voltage within ±4% of nominal 2.0 V across –40°C to +85°C junction temperature and full 0–150 mA load range, as specified in DS20006088C page 4. This tolerance includes line regulation (±20 mV), load regulation (±25 mV), and initial accuracy - ensuring reliable operation for 2.0 V logic and analog circuits without external trimming.

Does the MCP1811BT-020/LT require an input capacitor for stable operation?

The MCP1811BT-020/LT does not require an input capacitor for basic stability, but Microchip recommends ≥1.0 µF ceramic (X7R) at VIN to improve PSRR above 1 kHz and dampen source impedance effects. Without CIN, PSRR degrades significantly above 100 Hz, potentially impacting noise-sensitive analog sections powered from the same battery rail as the MCP1811BT-020/LT.

How does the output discharge function operate in the MCP1811BT-020/LT?

When SHDN is pulled to GND, the MCP1811BT-020/LT activates an internal 100 Ω discharge transistor between VOUT and GND, collapsing the output voltage within microseconds. This prevents floating rails, eliminates hold-up time in power-gated subsystems, and ensures clean reset signaling - a feature confirmed in DS20006088C page 3 functional block diagram and Table 1 for MCP1811A variants.

Can the MCP1811BT-020/LT be used with a 1.5 V alkaline battery?

Yes - the MCP1811BT-020/LT supports input voltages as low as 1.8 V, but operation from a fresh 1.5 V alkaline cell is not recommended due to initial under-voltage. However, it reliably regulates down to 2.0 V output when VIN ≥ 2.4 V (2.0 V + 400 mV dropout), supporting >80% of alkaline cell discharge curve and enabling extended runtime in primary-battery applications.

What is the thermal resistance (θJA) of the MCP1811BT-020/LT in its SOT-23 package?

The MCP1811BT-020/LT in 3-lead SOT-23 has a thermal resistance θJA of 211.33°C/W on a JEDEC-standard 4-layer FR4 board with 1 oz. copper (DS20006088C page 6). At 150 mA load and 5.5 V input, worst-case power dissipation is ~525 mW, resulting in ~111°C junction rise - well within the +125°C absolute max rating, provided ambient stays ≤–40°C to +85°C.