Microchip Technology MCP73853-I/ML

Overview

MCP73853-I/ML from Microchip Technology is a linear lithium-ion/lithium-polymer battery charge management controller with integrated P-channel MOSFET pass transistor, current sensing, and reverse blocking protection. It delivers ±0.5% voltage regulation accuracy at 4.1V or 4.2V, supports programmable fast-charge current up to 400 mA, and includes automatic preconditioning, thermal regulation, and dual open-drain status outputs (STAT1/STAT2). It is used in USB-powered portable devices such as Bluetooth headsets and digital cameras.

For engineers reviewing the MCP73853-I/ML datasheet, MCP73853-I/ML pinout, MCP73853-I/ML application, or MCP73853-I/ML equivalent, this page provides verified technical context, real-world design meaning of key specs, validated 16-pin QFN package mapping, confirmed temperature-sensing capability via THREF/THERM, and two field-validated alternative parts for Li-ion charging systems.

Technical Context

The MCP73853-I/ML implements a complete linear charging algorithm: qualification → preconditioning (trickle charge at ~10% IREG) → constant-current fast charge → constant-voltage regulation → automatic termination at ≤7% IREG. It uses internal ratiometric thermistor monitoring (THREF = 2.55 V, THERM thresholds at VTHREF/2 and VTHREF/4) and scales safety timers (tPRECON, tFAST, tTERM) proportionally to CTIMER/0.1 µF.

Thermal regulation dynamically reduces charge current above ~125°C to prevent die overheating, while thermal shutdown suspends charging at 155°C with 10°C hysteresis. UVLO (4.45 V start / 4.40 V stop) prevents operation below valid USB supply, and EN pin enables/disables the device with <0.3 µA sleep current.

Key Specifications

Pinout & Package

Package: 16-lead, 4 mm × 4 mm QFN with exposed pad (EP) connected to VSS. Thermal resistance θJA = 37°C/W on 4-layer board.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar linear Li-ion charge management applications.

Compared with BQ24075RGTR and MCP73831T-2DCI/OT, the MCP73853-I/ML uniquely provides dual-status signaling, ratiometric thermistor monitoring, programmable 4.1/4.2 V regulation, and three independent safety timers - making it the only choice among the three for thermally qualified, dual-LED-feedback USB Li-ion charging in space-limited industrial or medical portable devices.

Availability

MCP73853-I/ML is available at Aetrix Electronics and suitable for USB-powered portable devices, industrial hand-held instruments, digital cameras, and cradle chargers requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for MCP73853-I/ML 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 microcontrollers, analog, and interface ICs, with deep expertise in power management and battery charging solutions for embedded systems.

The MCP7385X product line was designed specifically for USB-compliant, space-constrained Li-ion/Li-Po charging applications - integrating precision regulation, thermal safety, and status feedback in minimal QFN packages.

FAQ

What is the function of the THREF and THERM pins on the MCP73853-I/ML?

The THREF pin provides a stable 2.55 V reference to bias an external NTC or PTC thermistor, while the THERM pin monitors the thermistor's divided voltage. The MCP73853-I/ML performs ratiometric comparison against THREF/2 (1.25 V) and THREF/4 (0.62 V) to detect out-of-range temperatures. This architecture makes the MCP73853-I/ML immune to VDD fluctuations and enables reliable cell temperature qualification before and during charging.

How does the MCP73853-I/ML handle deeply depleted lithium-ion batteries?

The MCP73853-I/ML automatically enters preconditioning mode when VBAT falls below 2.80 V (±0.10 V), applying a controlled 5–15 mA trickle charge (IPREG ≈ 10% of IREG) to safely recover the cell. This prevents lithium plating and thermal instability. If VBAT does not exceed the threshold before the tPRECON timer expires (e.g., 60 minutes with 0.1 µF), the MCP73853-I/ML asserts a fault and halts charging - ensuring safety for severely discharged cells.

Can the MCP73853-I/ML be used without a microcontroller?

Yes, the MCP73853-I/ML is designed for fully autonomous operation. It executes the complete CC/CV charge algorithm - including qualification, preconditioning, fast charge, constant-voltage regulation, termination, and automatic recharge - using only passive components (PROG resistor, TIMER capacitor, VSET tie-off). Its dual open-drain STAT1/STAT2 outputs drive LEDs directly, eliminating the need for host MCU control in standalone USB chargers.

What is the purpose of the VBAT3 pin on the MCP73853-I/ML?

The VBAT3 pin is a dedicated high-impedance battery voltage sense input connected directly to the positive battery terminal. It feeds an internal precision resistor divider that establishes the feedback reference for the ±0.5% accurate voltage regulation loop. Unlike VBAT1/VBAT2 (which are power outputs), VBAT3 enables accurate closed-loop control independent of IR drop across PCB traces or MOSFET RDS(on), ensuring regulation fidelity even under high-current conditions.

How does thermal regulation affect timing behavior in the MCP73853-I/ML?

When thermal regulation activates (typically above ~125°C), the MCP73853-I/ML reduces charge current and proportionally slows down all safety timers (tPRECON, tFAST, tTERM) to prevent premature timeout. For example, if current drops to 50% of nominal, the timers run at half speed - extending their effective duration. This ensures the full charge cycle completes safely despite thermal derating, unlike fixed-timer ICs that may terminate prematurely under thermal stress.