Microchip Technology MCP1825ST-0802E/DB

Overview

MCP1825ST-0802E/DB from Microchip Technology is a 500 mA, fixed 0.8 V low-dropout (LDO) linear regulator in SOT-223-5 package with active-low shutdown (SHDN), power-good (PWRGD) output, and 210 mV typical dropout at full load. It operates from 2.1 V to 6.0 V input, delivers ±0.5% output voltage tolerance, and stabilizes with only 1.0 µF ceramic output capacitor - ideal for sub-1.0 V core supply in portable computing and high-speed chipset applications.

For engineers reviewing the MCP1825ST-0802E/DB datasheet, MCP1825ST-0802E/DB pinout, MCP1825ST-0802E/DB application, or MCP1825ST-0802E/DB equivalent, key selection considerations include its 0.8 V fixed output, PWRGD timing (110 µs delay), SHDN leakage (<0.1 µA), thermal shutdown at 150°C, and compatibility with ceramic capacitors for compact, low-noise power delivery.

Technical Context

The MCP1825ST-0802E/DB implements a PMOS pass transistor architecture enabling ultra-low dropout and fast transient response. Its internal error amplifier compares VOUT against a precision 0.41 V reference, while the PWRGD comparator monitors output regulation at 92% of nominal voltage with 2% hysteresis and fixed 110 µs delay.

It integrates overtemperature protection (150°C trip, 10°C hysteresis), short-circuit current limiting (~1.2 A peak), undervoltage lockout, and soft-start functionality. The SHDN pin controls enable/disable with logic thresholds at 45% VIN (high) and 15% VIN (low), reducing quiescent current to 0.1 µA in shutdown mode.

Key Specifications

Pinout & Package

SOT-223-5 surface-mount package with exposed thermal pad (GND-connected); footprint compatible with JEDEC TO-223 standard; thermal resistance θ_JA = 62°C/W on 4-layer board.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A0508PDBVR and ADP125ARHZ-0.8-R7, the MCP1825ST-0802E/DB uniquely combines 500 mA capability, 0.8 V fixed output, integrated PWRGD with 110 µs delay, and active-low SHDN - making it the only option among the three that satisfies full power-sequencing requirements in compact, battery-sensitive designs.

Availability

MCP1825ST-0802E/DB is available at Aetrix Electronics and suitable for notebook computers, networking backplane cards, and high-speed driver chipset power applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MCP1825ST-0802E/DB 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 leading provider of microcontroller, analog, and mixed-signal semiconductors, serving automotive, industrial, consumer, and communications markets with high-reliability, low-power solutions.

The MCP1825 product line delivers high-current, low-dropout linear regulators optimized for portable and battery-powered systems demanding sub-1.0 V outputs, ultra-low quiescent current, and integrated power management features like PWRGD and SHDN.

FAQ

What is the minimum input voltage required for stable operation of the MCP1825ST-0802E/DB?

The MCP1825ST-0802E/DB requires VIN ≥ 2.1 V and VIN ≥ VOUT + VDROPOUT. With a fixed 0.8 V output and 210 mV typical dropout at 500 mA, the absolute minimum functional input is 1.01 V - but per datasheet specification, the guaranteed operational minimum is 2.1 V to ensure full parameter compliance across temperature and process variation. Below 2.1 V, regulation and PWRGD behavior are not characterized.

Does the MCP1825ST-0802E/DB require an external resistor divider to set the output voltage?

No. The MCP1825ST-0802E/DB is a fixed-output variant delivering 0.8 V without external feedback components. Unlike adjustable MCP1825 versions (e.g., MCP1825-ADJ), this part integrates internal resistors to set VOUT, eliminating the need for R1/R2 networks and simplifying layout and BOM. The ADJ pin is absent in this 5-pin SOT-223-5 configuration.

How does the PWRGD output behave during power-up and shutdown of the MCP1825ST-0802E/DB?

During power-up, PWRGD remains low until VOUT reaches 92% of 0.8 V (≈0.736 V), then asserts high after a fixed 110 µs delay. During shutdown (SHDN pulled low), PWRGD is actively driven low within microseconds. The output is open-drain, requiring an external pull-up resistor (typically 10 kΩ to VIN or VCC) to interface with host logic or reset controllers.

Can the MCP1825ST-0802E/DB be used with aluminum-electrolytic output capacitors?

Yes, but with constraints: aluminum-electrolytic capacitors must have ESR ≤ 1 Ω and are not recommended below –25°C due to impedance rise. The MCP1825ST-0802E/DB is optimized for 1.0 µF ceramic (X7R/X5R), which guarantees stability, lower noise, and wider temperature performance. Electrolytics may compromise transient response and long-term reliability in high-temperature environments.

What thermal management guidance applies to the MCP1825ST-0802E/DB in SOT-223-5 package?

The SOT-223-5 package has θ_JA = 62°C/W on a 4-layer board. To maintain TJ ≤ 125°C at 500 mA, maximum ambient must stay ≤ 85°C with adequate copper pour under the exposed pad. Thermal vias (≥4× 0.3 mm) connecting the pad to inner ground planes are mandatory. Derating is required above 85°C ambient - consult Figure 2-20 in DS22056B for temperature-dependent dropout curves.