AD8450 Precision Analog Front End and Controller for Battery Test/Formation Systems

The AD8450 is a precision analog front end for testing and monitoring battery cells. Referring to figure one, a precision programmable gain instrumentation amplifier (PGIA) measures the battery’s charge/discharge current and a programmable gain difference amplifier (PGDA) measures the battery’s voltage. Internal laser trimmed resistor networks set the gains for the PGIA and the PGDA, optimizing the AD8450’s performance over the rated temperature range. PGIA gains are 26×, 66×, 133×, and 200×. PGDA gains are 0.2×, 0.27×,0.4×, and 0.8×.

Voltages at the ISET and VSET inputs set the desired constant voltage (CV) and constant current (CC) values. CC to CV switching is automatic and transparent to the system.

A TTL level logic input, MODE, selects between charge and discharge modes (high for charge, low for discharge). An analog output, VCTRL, interfaces directly with ADI’s ADP1972 & ADP1974 PWM controllers.

The AD8450 includes resistor programmable overvoltage and overcurrent detection and current sharing circuitry. Current sharing is used to balance charge among multiple batteries. The AD8450 simplifies designs by providing excellent accuracy, performance over temperature, flexibility with functionality, and overall reliability in a space-saving package. The AD8450 is available in an 80 lead 14 mm ×14 mm × 1 mm LQFP package and is rated at −40 °C to +85 °C operating temperature.

APPLICATIONS
  • Battery cell testing & formation
  • Battery module testing
Features and Benefits
  • Integrated constant current and voltage modes with automatic switchover
  • Charge and Discharge modes
  • Precision voltage and current measurement
  • Integrated precision control feedback blocks
  • Precision interface to PWM or linear power converters
  • Programmable gain settings
  • Current sense gains:
    26, 66, 133, 200
  • Voltage sense gains:
    0.2, 0.27, 0.4, 0.8
  • Programmable OVP, OCP fault detection
  • Current sharing & balancing
  • Excellent ac & dc performance
  • See datasheet for additional features
Application Specific
Instrumentation and Measurement
  • Battery Testing and Formation
SPICE Models
Data Sheets
Documentnote
AD8450: Precision Analog Front End and Controller for Battery Test/Formation Systems Data Sheet (Rev. B)PDF 983 kB
Application Notes
Documentnote
AN-1319: Compensator Design for a Battery Charge/Discharge Unit Using the AD8450 or the AD8451 (Rev. 0)PDF 344.36 K
User Guides
Documentnote
UG-845: AD8450/ADP1972 Battery Testing and Formation Evaluation Board (Rev. 0)PDF 1.45 M
Order Information
Part NumberPackagePacking QtyTemp RangePrice 100-499Price 1000+RoHS
AD8450ASTZ Production80 ld LQFP (14x14mm)OTH 90-40 to 85C8.346.95Y
AD8450ASTZ-RL Production80 ld LQFP (14x14mm)REEL 1000-40 to 85C8.346.95Y
Evaluation Boards
Part NumberDescriptionPriceRoHS
AD8450-EVALZEvaluation Board for 80-Lead LQFP package260Y
Reference Materials
AD8450: Precision Analog Front End and Controller for Battery Test/Formation Systems Data Sheet (Rev. B) ad8450
AD8450:用于电池测试/化成系统的精密模拟前端和控制器 (Rev. 0) ad8450
AD8450 SPICE Macro Model ad8450
AN-1319: Compensator Design for a Battery Charge/Discharge Unit Using the AD8450 or the AD8451 (Rev. 0) ad8450
UG-845: AD8450/ADP1972 Battery Testing and Formation Evaluation Board (Rev. 0) adp1972
Accurate Analog Controller Optimizes High-Efficiency Li-Ion Battery... ad7656