Key Specs
| Spec | Value | Condition | Source |
|---|---|---|---|
| Battery Chemistry | Lithium Ion/Polymer | Digi-Key | |
| Fault Protection | Over Current, Over Temperature, Over/Under Voltage, Short Circuit | Digi-Key | |
| Function | Fuel Gauge | Digi-Key | |
| Interface | I2C | Digi-Key | |
| Mounting Type | Surface Mount | Digi-Key | |
| Number Of Cells | 1 ~ 4 | Digi-Key | |
| Operating Temperature Range | -40°C ~ 85°C (TA) | Digi-Key | |
| Package Case | 30-WFBGA, WLBGA | Digi-Key | |
| Supplier Device Package | 30-WLP (2.37x2.55) | Digi-Key |
When To Use
Use the MAX17320X20+T in single to quad-cell Lithium Ion/Polymer battery packs where accurate fuel gauging and comprehensive fault protection (over current, over temperature, over/under voltage, short circuit) are critical. Its surface-mount 30-WFBGA package and small footprint (30-WLP, 2.37x2.55 mm) make it ideal for compact portable devices operating over a wide temperature range (-40°C to 85°C).
Do not use this device in battery chemistries other than Lithium Ion/Polymer or in applications requiring more than four cells in series. For higher cell counts or different chemistries, consider alternative fuel gauge ICs specifically designed for those conditions.
When Not To Use
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Systems demanding output current beyond integrated gauge limits: If the load current exceeds this part’s internal current measurement and protection range, use a high-current synchronous buck with external FETs to handle elevated current while maintaining accurate load regulation and fault protection.
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Battery-powered devices with ultra-low standby current (μA range): The MAX17320X20+T’s quiescent current is not optimized for deep-sleep battery life in coin cell or small-cell applications. Instead, choose a low-IQ PFM buck to minimize battery drain during extended idle periods.
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Applications requiring galvanic isolation between battery and system: Since MAX17320X20+T lacks isolation features, use an isolated flyback converter or controller to prevent ground loops and ensure safety compliance in medical or industrial environments.
Application Notes
The MAX17320X20+T integrates all necessary sensing and protection internally, so no external sense components are required. The device communicates via the I2C interface, which is noise-sensitive; therefore, minimize I2C bus trace lengths and route away from high-current switching nodes to reduce interference.
The internal switching node related to fault protection should have the smallest possible loop area on the PCB to minimize EMI and ensure accurate current sensing.
Due to the device’s low power dissipation and integration in a compact 30-WFBGA package, no external heatsink is required across the full operating temperature range (-40°C to 85°C). Proper PCB thermal design is sufficient for heat dissipation under typical operating conditions.
Gotchas
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Mistake: Connecting the device to battery chemistries other than Lithium Ion/Polymer.
Failure Mode: Incorrect fuel gauging and fault detection, leading to inaccurate state-of-charge readings and potential battery damage.
Fix: Ensure the battery pack chemistry matches Lithium Ion/Polymer specifications before integrating the MAX17320X20+T. -
Mistake: Operating the device outside the specified temperature range (-40°C to 85°C).
Failure Mode: Device performance degradation or failure, including unreliable fault protection and inaccurate measurements.
Fix: Design the system to maintain operating temperatures within the specified range or select a device rated for extended temperature ranges. -
Mistake: Using a non-surface mount package or incompatible PCB layout that does not accommodate the 30-WFBGA package.
Failure Mode: Mechanical stress or poor thermal dissipation causing device failure or reduced reliability.
Fix: Use proper PCB footprint and assembly processes for the 30-WFBGA package and ensure mounting is compatible with surface mount technology.