High-Accuracy 12-/16-Cell Measurement AFEs
Industry's Most Accurate and Flexible Battery Management System Building Block
DescriptionThe MAX14920/MAX14921 battery measurement analog front-end devices accurately sample cell voltages and provide level shifting for primary/secondary battery packs up to 16 cells/+65V (max). The MAX14920 monitors up to 12 cells, while the MAX14921 monitors up to 16 cells. Both devices simultaneously sample all cell voltages, allowing accurate state-of-charge and source-resistance determination. All cell voltages are level shifted to ground reference with unity gain, simplifying external ADC data conversion.
The devices have a low-noise, low-offset amplifier that buffers differential voltages of up to +5V, allowing monitoring of all common lithium-ion (Li+) cell technologies. The resulting cell voltage error is ±0.5mV.
The devices’ high accuracy make them ideal for monitoring cell chemistries with very flat discharge curves, such as lithium-metal phosphate.
Passive-cell balancing is supported by external FET drivers. Integrated diagnostics in the devices allow open-wire detection and undervoltage/overvoltage alarms. The devices are controlled by a daisy-chainable SPI interface.
The MAX14920 is available in a 64-pin (10mm x 10mm) TQFP package with an exposed pad. The MAX14921 is available in an 80-pin (12mm x 12mm) TQFP package. Both devices are specified over the -40°C to +85°C extended temperature range.
- High Accuracy
- ±0.5mV (max) Cell Voltage Error
- Simultaneous Cell Voltage Sampling
- Integrated Diagnostics
- Open-Wire and Short Fault Detection
- Undervoltage/Overvoltage Warning
- Thermal Shutdown
- High Flexibility
- SPI Interface
- 12-Cell and 16-Cell Versions
- +6V Minimum (3 Cells) Operation
- +0.5V to +4.5V Cell Voltage Range
- Integrated Cell-Balancing FET Drivers
- Integrated 5V LDO
- Low Power
- 1µA Shutdown Mode
- 1µA/10µA Cell Current Draw
- e-Transportation Energy Packs
- Energy Storage Packs
- Industrial Battery Backup Systems
- Telecom Battery Backup Systems
|Part Number||Functions||Battery Type||Interface||Parameters Measured||Applications||Battery Protection||VSUPPLY|
|MAX14920||Status Monitor||3-12 Cell Li-Ion||SPI|
|-40 to +85||$5.24 @1k|
|MAX14921||3-16 Cell Li-Ion|
|See All Battery Fuel Gauges, Protectors, and Monitors (51)|
| Pricing Notes: |
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.
MAX14921EVKIT: Evaluation Kit for the MAX14921
Technical DocumentsApp Note 5760 Getting the Most Out of the MAX14920/MAX14921 High-Accuracy Battery-Measurement AFEs
App Note 5620 Optimize Battery Measurement and Cell-Stack Monitoring with Highly Accurate AFE
App Note 5495 PCB Layout Guidelines for the MAX14921 High-Accuracy 12-/16-Cell Measurement AFE
Quality and Environmental DataProduct Reliability Reports: MAX14920.pdf
Lead-Free Package Tin (Sn) Whisker Reports
|Device||Fab Process||Technology||Sample size||Rejects||FIT at 25°C||FIT at 55°C|
- -40°C to +105°C
- Standby Mode: 2mA
- Shutdown Mode: 2μA
|App Note||5760||Getting the Most Out of the MAX14920/MAX14921 High-Accuracy Battery-Measurement AFEs|
|App Note||5620||Optimize Battery Measurement and Cell-Stack Monitoring with Highly Accurate AFE|
|App Note||5495||PCB Layout Guidelines for the MAX14921 High-Accuracy 12-/16-Cell Measurement AFE|