Monolithic Power Systems Inc. MP6420GJ-P

Overview

MP6420GJ-P from Monolithic Power Systems is a battery protection IC designed for 2- or 3-series Li-ion battery packs, integrating a 24V/100mΩ protective MOSFET, ±25mV over-charge threshold accuracy, and PTC interface in TSOT23-8. It monitors cell voltages (VB1–VB2, VB2–VB3, VB3–VSS), triggers OVP with 3.8s typical response delay, and supports external control via CTL pin for safe assembly and test.

For engineers reviewing the MP6420GJ-P datasheet, MP6420GJ-P pinout, MP6420GJ-P application, or MP6420GJ-P equivalent, key selection factors include its fixed 4.45V over-charge threshold (±25mV), integrated MOSFET with 4.5A current capability, low 3µA quiescent current, and dual OVP/PTC fault indication via FLAG output.

Technical Context

The MP6420GJ-P implements independent voltage comparators per cell pair (VB1–VB2, VB2–VB3, VB3–VSS) with a precision ±25mV over-charge threshold referenced to internal bandgap. Its internal filter emulates a 1kΩ/0.1μF RC network to suppress noise-induced false triggers.

OVP detection activates the open-drain CO output after a fixed 3.8s delay (range 3–4.6s); release occurs only when all cells fall below VOV – VOV_H (e.g., 4.45V – 0.4V = 4.05V) and remain there for 60ms. The PTC interface senses temperature via a 10kΩ resistor pulled to VB1, triggering protection when PTC voltage drops below VB1 – 1.2V.

Key Specifications

Pinout & Package

MP6420GJ-P is housed in a space-saving TSOT23-8 package (2.9mm × 1.6mm × 0.85mm), optimized for compact battery pack PCB layouts and automated assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar battery protection IC applications.

Compared with R5602L001AA-TR and BD14000EFV-C, MP6420GJ-P uniquely combines 3S support, ±25mV OVP accuracy, integrated 100mΩ MOSFET, and PTC interface in a single TSOT23-8 package-reducing component count, improving thermal safety, and extending battery shelf life.

Availability

MP6420GJ-P is available at Aetrix Electronics and suitable for power tools, medical portable devices, uninterruptible power supplies (UPS), and consumer electronics battery packs requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP6420GJ-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 analog and power ICs, with over two decades of expertise in battery management, DC/DC conversion, and motor control solutions.

The MP6420 product line targets compact, high-reliability battery protection for multi-cell Li-ion systems, emphasizing integration, accuracy, and ultra-low power consumption to replace discrete protection circuits in space-constrained applications.

FAQ

What is the exact over-charge threshold voltage for MP6420GJ-P?

The MP6420GJ-P has a factory-trimmed over-charge threshold of 4.45V with ±25mV accuracy across –40°C to +125°C. This value is fixed and not user-adjustable; it corresponds to the "-445" suffix in the ordering code and is verified per Monolithic Power Systems' MP6420 Rev. 1.0 datasheet, page 3.

Can MP6420GJ-P be used in a 2-cell Li-ion configuration?

Yes - MP6420GJ-P natively supports both 2- and 3-series Li-ion configurations. For 2-cell use, VB1 must be shorted to VB2 per Figure 8 in the datasheet, and VB3 serves as the top-cell sense point. All protection functions (OVP, PTC, FLAG, CO) remain fully operational.

How does the PTC interface function without an external power supply?

The PTC pin includes an internal 1µA current sink that pulls the PTC node toward VSS. With a 10kΩ PTC resistor tied to VB1, room-temperature voltage at PTC is ~VB1; rising temperature increases PTC resistance, dropping PTC voltage until it falls below VB1 – 1.2V, triggering protection - no external bias required.

What is the purpose of the CTL pin during PCB assembly?

The CTL pin is pulled low (to VSS) during assembly to force the internal protective MOSFET into the OFF state, preventing accidental activation before battery connection. Its 1.5V/2V hysteresis ensures reliable control even with noisy supply rails, enabling safe functional testing prior to field deployment.

Does MP6420GJ-P provide over-discharge protection?

No - MP6420GJ-P is specifically an over-charge and over-temperature (via PTC) protection IC. It does not monitor or respond to low cell voltage conditions. Over-discharge protection must be implemented separately, typically using a dedicated protection IC or fuel gauge with discharge cutoff logic.

Is the FLAG output compatible with 3.3V microcontrollers?

Yes - FLAG is an open-drain output with active-high assertion (pulled to ≥4V by internal 5V rail). When interfaced with a 3.3V MCU, a pull-down resistor to GND and optional 3.3V-tolerant GPIO suffice; no level shifter is needed since FLAG only sources current when asserted and floats otherwise.

What is the maximum continuous current the integrated MOSFET can handle?

The integrated MOSFET is rated for 4.5A continuous current, validated by Monolithic Power Systems' design specifications (datasheet page 4, "Current capability"). This assumes proper PCB copper area for thermal dissipation and operation within the 125°C junction limit; derating applies above 85°C ambient.