Monolithic Power Systems Inc. MPF42797DRT-0B-0000-P

Overview

MPF42797DRT-0B-0000-P from Monolithic Power Systems is a lithium-ion battery fuel gauge IC for 2–10 series-cell packs, estimating per-cell and pack state-of-charge (SOC) and state-of-health (SOH), remaining runtime, charge time, and instantaneous available power. It features on-board lifetime logging, adaptive learning for SOH tracking, and supports common AFEs including MP279x with ±3% SOC accuracy. Used in light EVs and cordless tools requiring precise battery telemetry.

For engineers reviewing the MPF42797DRT-0B-0000-P datasheet, MPF42797DRT-0B-0000-P pinout, MPF42797DRT-0B-0000-P application, or MPF42797DRT-0B-0000-P equivalent, key selection considerations include I²C interface robustness (400 kHz with CRC), low-power operation (6 µA disabled, 135 µA avg. rest mode), TQFN-32 package thermal performance (θJA = 47°C/W), and compatibility with MP279x AFEs for <3% SOC error under defined conditions.

Technical Context

The MPF42797 operates as a host-controlled fuel gauge co-processor, relying on external AFEs (e.g., MP279x) to supply cell voltages, pack current, and temperature via I²C. Its internal algorithm fuses these inputs with adaptive learning models to compute SOC/SOH per cell and pack, using configurable execution timing (EXE_TIME) and interrupt-driven updates via IRQ.

It implements a slave-mode I²C interface (default address 0x08) supporting standard/fast modes up to 400 kHz, with mandatory CRC validation for register reads/writes. Configuration occurs in dedicated CONFIG_MODE or dynamic EDIT_CONFIG_MODE, storing settings-including cell model parameters-in non-volatile memory upon exit.

Key Specifications

Pinout & Package

The MPF42797DRT-0B-0000-P is housed in a thermally enhanced TQFN-32 (4 mm × 4 mm) package with an exposed ground pad (Pin 33) requiring solder connection to PCB ground plane for optimal thermal dissipation and noise immunity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fuel gauge applications.

Compared with BQ34Z100-G1 and MAX17055, the MPF42797DRT-0B-0000-P delivers faster system integration via MP279x plug-and-play compatibility, lower standby current for intermittent telemetry, and per-cell SOH tracking essential for modular battery packs in light EVs.

Availability

MPF42797DRT-0B-0000-P is available at Aetrix Electronics and suitable for light EVs, energy storage systems, industrial robotics, and cordless power tools requiring stable component supply, production-grade traceability, and lifecycle continuity.

Supply support for MPF42797DRT-0B-0000-P 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

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance power management ICs, with design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MPF42797 belongs to MPS's battery fuel gauge product line, engineered specifically for high-accuracy, low-power state estimation in multi-cell lithium battery packs used in mobility and industrial energy applications.

FAQ

What is the minimum required host MCU specification to interface with the MPF42797DRT-0B-0000-P?

The host MCU must provide an I²C master interface (supporting 400 kHz), one GPIO for nRST control, one GPIO for CE control, one GPIO for IRQ input, and at least 48 kB Flash and 4 kB RAM. It must execute EXE_CMD to trigger fuel gauge computation and poll FG_EXE_FLAG before reading SOC/SOH registers.

Does the MPF42797DRT-0B-0000-P require external passive components for stable operation?

Yes: VDD requires a 2.2 µF ceramic capacitor to GND; VCC requires a 2.2 µF ceramic capacitor to GND; LDO pin (Pin 9) requires both 2.2 µF and 100 nF ceramics to GND; SCL/SDA require 10 kΩ pull-up resistors to VCC; and the exposed pad (Pin 33) must be soldered to a solid GND plane.

How does the MPF42797DRT-0B-0000-P achieve ±3% SOC accuracy, and what conditions are required?

This accuracy is achieved only when paired with an MP279x-series AFE, at ambient temperatures between 10°C and 50°C, with charge/discharge currents ≤1C, and using the default configuration. It is validated on Samsung INR18650-25R 10S1P packs and requires proper EXE_TIME synchronization and IRQ-driven update timing.

Can the MPF42797DRT-0B-0000-P operate without an external AFE?

No. The MPF42797 is a fuel gauge processor only and has no integrated ADCs or cell voltage/current sensing. It relies entirely on an external AFE (e.g., MP279x, or other compatible monitors) to supply VRDG_CELLx, IRDG_CELLx, and TRDG_TSx register values via I²C.

What is the purpose of the CE pin, and how does it affect power consumption?

The CE (chip enable) pin is an active-low control that halts all fuel gauge computation and disables the I²C interface when asserted. In CE-low mode, total current drops to 6 µA while retaining all internal state variables in memory - enabling zero-config wake-up when CE is deasserted.

Is the default I²C address configurable, and how is CRC enabled?

Yes: the default slave address is 0x08 but can be changed via the CONFIG_MODE_CMD sequence. CRC is enabled by writing to the appropriate configuration register; when active, the last 4 bytes of each I²C transaction are CRC-32 checksums covering register address, length, and data payload.

Does the MPF42797DRT-0B-0000-P support battery chemistries beyond standard NMC/NCA?

Yes: it supports LFP, LCO, and custom lithium chemistries via programmable cell model parameters. However, achieving specified SOC accuracy requires characterization and model tuning for each chemistry - only NMC/NCA with MP279x AFEs deliver the documented ±3% performance out-of-box.