Monolithic Power Systems Inc. MP6420GJ-Z

Overview

MP6420GJ-Z 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 fixed 3.8s delay, and supports external control via CTL pin for safe production testing.

For engineers reviewing the MP6420GJ-Z datasheet, MP6420GJ-Z pinout, MP6420GJ-Z application, or MP6420GJ-Z equivalent, key selection factors include its integrated MOSFET R_DS(ON), programmable over-charge threshold (4.45V ±25mV for GJ-Z variant), PTC-based thermal protection interface, and low 3µA quiescent current in normal operation.

Technical Context

The MP6420GJ-Z implements a precision analog over-voltage detection architecture with independent voltage comparators per cell pair (VB1–VB2, VB2–VB3, VB3–VSS), each referenced to an internal ±25mV accurate bandgap-derived threshold. Its internal filter provides anti-noise performance equivalent to a 1kΩ/0.1µF external RC network.

OVP response is deterministic: upon any cell exceeding V_OV = 4.45V, the device asserts FLAG high after a fixed 3.8s delay (typical) and turns on the integrated open-drain CO MOSFET. Recovery requires all cells to fall below V_OV – V_{OV_H} (4.29V typical) for ≥60ms before CO deactivates.

Key Specifications

Pinout & Package

MP6420GJ-Z is housed in a thermally enhanced TSOT23-8 package with exposed pad (not electrically connected), optimized for space-constrained battery pack modules. Pin 1 is bottom-left when top marking is read left-to-right.

Key Features

Applications

Equivalent & Alternatives

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

Compared with R5602T001A-TR and BQ77PL900DR, MP6420GJ-Z delivers lower system cost and smaller footprint through its integrated 100mΩ MOSFET and PTC interface, while offering tighter over-charge accuracy (±25mV vs. ±50mV) and guaranteed 3.8s delay timing - critical for safety-certified portable equipment.

Availability

MP6420GJ-Z is available at Aetrix Electronics and suitable for battery pack manufacturing, medical device OEM integration, and industrial UPS module development requiring stable component supply and long-term lifecycle support.

Supply support for MP6420GJ-Z 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 design centers in the US, China, and Taiwan.

The MP6420 belongs to MPS's battery protection IC product line, engineered specifically for space-constrained, cost-sensitive 2S/3S Li-ion applications where integration, accuracy, and reliability outweigh programmability requirements.

FAQ

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

The MP6420GJ-Z has a factory-trimmed over-charge threshold of 4.45V ±25mV at 25°C, with temperature drift bounded to ±45mV from -40°C to +85°C. This value is fixed and non-adjustable, defined by the "GJ" ordering code per MPS documentation.

Can MP6420GJ-Z be used for 4-series Li-ion battery packs?

No - MP6420GJ-Z supports only 2- or 3-series configurations. For 4S packs, two MP6420 devices must be cascaded using the OR logic circuit shown in Figure 9 of the datasheet, with external MOSFETs (Q1–Q3) and resistors (R1–R3) to combine FLAG outputs and control a shared protection path.

How does the PTC interface function without external components?

The PTC pin includes an internal ~1µA sink current source. With a 10kΩ thermistor connected between VB1 and PTC, room-temperature voltage at PTC ≈ VB1. When temperature rises, thermistor resistance increases sharply, pulling PTC voltage down; protection triggers when PTC falls below VB1 − 1.2V, with 400mV hysteresis to prevent oscillation.

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

The CTL pin is used to disable the internal protective MOSFET during board assembly. By pulling CTL to VSS (ground) before applying battery voltage, CO remains off regardless of cell voltage - preventing accidental fuse blow or load disconnect during handling and test, as confirmed in Figure 10 of the datasheet.

Does MP6420GJ-Z provide over-discharge protection?

Yes - it monitors over-discharge with a 3.5V to 4.1V threshold (typical 3.8V) per cell and 60mV hysteresis. When all cells fall below this threshold, the device enters low-quiescent-current mode (2µA), and recovery occurs automatically once all cell voltages rise above the release threshold for ≥1ms.

Is the TSOT23-8 package RoHS-compliant and lead-free?

Yes - MP6420GJ-Z is fully RoHS-compliant, lead-free, and halogen-free per MPS corporate policy and EU Directive 2011/65/EU. The TSOT23-8 package uses matte tin plating on leads and meets JEDEC MO-193BA mechanical specifications.