The AD7284 contains all the functions required for the general-purpose monitoring of stacked Li-Ion batteries, as used in hybrid electric vehicles and battery backup applications.The AD7284 has multiplexed cell voltage and auxiliary, analog-to-digital converter (ADC) measurement channels supporting four to eight cells of battery management. The device provides a maximum total unadjusted error, TUE, (cell voltage accuracy) of ±3 mV that includes all the internal errors from input to output. The primary ADC resolution is 14 bits.The AD7284 also includes an integrated secondary measurement path that validates the data on the primary ADC. Other diagnostic features include the detection of open inputs, communication, and power supply related faults.The AD7284 cell balancing interface outputs control the external field effect transistors (FETs) to allow discharging of individual cells.There are two on-chip 2.5 V voltage references: one reference for the primary measurement path, and one for the secondary measurement path.The AD7284 operates from one VDD supply, ranging from 10 V to 40 V. The device provides eight differential analog input channels to accommodate large common-mode signals across the full VDD range. Each channel allows an input signal range, VPINx − VPIN(x − 1) and VSINx – VSIN(x − 1), of 0 V to 5 V, where x = 0 to 8. The input pins assume a series stack of eight cells. The AD7284 includes four auxiliary ADC input channels that can be used for temperature measurement or system diagnostics.The AD7284 has a differential daisy-chain interface that allows multiple devices to be stacked without the need for individual device isolation. By design, this interface allows both device to device communication within the same module and communication between devices on different modules.Applications Li-Ion battery monitoring Electric and hybrid electric vehicles Stationary power applications

Charger IC Multi-Chemistry 7-DDPAK

8 Ch Li-ion Monitor ISO26262/Auto

The AD8451 is a precision analog front end and controller for testing and monitoring battery cells. A precision fixed gain instrumentation amplifier (IA) measures the battery charge/discharge current, and a fixed gain difference amplifier (DA) measures the battery voltage. Internal laser trimmed resistor networks set the gains for the IA and the DA, optimizing the performance of the AD8451 over the rated temperature range. The IA gain is 26 and the DA gain is 0.8 V/V.Voltages at the ISET and VSET inputs set the desired constant current (CC) and constant voltage (CV) values. CC to CV switching is automatic and transparent to the system.A TTL logic level input, MODE, selects the charge or discharge mode (high for charge, low for discharge). An analog output, VCTRL, interfaces directly with the Analog Devices, Inc., ADP1972 PWM controller.The AD8451 simplifies designs by providing excellent accuracy, performance over temperature, flexibility with functionality, and overall reliability in a space-saving package. The AD8451 is available in an 80-lead, 14 mm × 14 mm × 1 mm LQFP package and is rated for an operating temperature of −40°C to +85°C.APPLICATIONS Battery cell formation and testing Battery module testing

Battery Management PowerCap

Battery Management Powercap w/Crystal

Battery Management PowerCap

SM POSITIVE BATTERY CONTACT / BULK

PICCR-2012/BN

Lithium Manganese Dioxide Coin 3V 0.017Ah Secondary