Features and Benefits
- 8 analog input channels, integrated secondary monitor
- ±3 mV maximum cell voltage accuracy, TUE, 14-bit ADC
- Very low measurement latency across 96 cells
- Stack voltage measurement
- ±16 mV typical battery stack voltage (TUE) accuracy
- Cell balancing interface, with individually programmable on time
- 4 auxiliary analog input channels, 14-bit ADC
- Suitable for thermistor inputs and external diagnostics
- Buffered reference output for ratiometric measurements
- Internal temperature sensor
- VDD operating range: 10 V to 40 V
- On-chip 5 V regulator
- Watchdog timer
- IDD matching current: 100 μA
- Robust, proprietary daisy-chain interface
- SPI to host controller
- CRC protection on read and write commands
- 2 general-purpose outputs
- 64-lead low profile quad flat package, exposed pad (LQFP_EP)
- Junction temperature range: −30°C to +120°C
- Qualified for automotive applications
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.
- Li-Ion battery monitoring
- Electric and hybrid electric vehicles
- Stationary power applications
Product Lifecycle Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
The AD7284 is a complete, 14-bit resolution, lithium ion battery monitoring system, integrating multiple voltage and auxiliary analog-to-digital converter (ADC) input channels. Full details about the device are available in the AD7284 data sheet from Analog Devices, which should be consulted in conjunction with this user guide when using the evaluation kit.
On-board components on the master board include isolated power and interface using the ADuM1201 and the ADuM5401 digital isolators, and power using the ADP3303 and the ADP7104 regulators.
The AD7284 master board is used in conjunction with the EVAL-SDP-CB1Z SDP board available from Analog Devices, which must be purchased separately from the evaluation board.
Features & Benefits
- Full featured evaluation board for the AD7284
- Separate master and slave evaluation kits
- Direct current daisy chain or isolated daisy-chain options
- Master configuration kit
- EVAL-SDP-CB1Z compatible
- Standalone capability
- Isolated power and interface
- Slave configuration kit
- To be used in conjunction with an AD7284 master evaluation kit
- Direct interface to the AD7284 master board
- Daisy-chain capability for chains of up to 20 devices
- PC software for control and data analysis when used with the Analog Devices, Inc., system demonstration platform (SDP), EVAL-SDP-CB1Z
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.