MAX14920

High-Accuracy 12-/16-Cell Measurement AFEs

Industry's Most Accurate and Flexible Battery Management System Building Block


Description

The 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.
MAX14920, MAX14921: Functional Diagram MAX14920, MAX14921: Functional Diagram Enlarge+

Key Features

  • High Accuracy
    • ±0.5mV (max) Cell Voltage Error
    • Simultaneous Cell Voltage Sampling
    • Self-Calibration
  • 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

Applications/Uses

  • 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
(V)
VSUPPLY
(V)
Package/Pins Oper. Temp.
(°C)
Budgetary
Price
min max See Notes
MAX14920  Status Monitor 3-12 Cell Li-Ion SPI
Temperature
Voltage
Pack
Over-Temperature
Over/Under Voltage
6 65
TQFP-EP/64
-40 to +85 $4.99 @1k
MAX14921  3-16 Cell Li-Ion
TQFP/80
$6.16 @1k
See All Battery Monitors, Protectors, and Selectors (39)
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

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