New Content (1)
Technical ArticlesPower Efficient Battery Formation
Features and Benefits
- CC and CV battery test and formation modes with transparent and automatic switchover, for systems of 20 Ah or less
- Precise measurement of voltage and current
- Independent feedback control blocks
- Highly accurate, factory trimmed instrumentation and differential amplifiers
- In-amp for current sense gain: 66 V/V
- Difference amplifier for voltage sense gain: 0.4V/V
- Stable over temperature: offset voltage drift <0.6 µV/°C (maximum)
- Gain drift: <3 ppm/°C (maximum)
- Current sense CMRR: 120 dB minimum
- Popular SMPS control for charge/discharge
- High PWM linearity with internal ramp voltage
- 50 kHz to 300 kHz user controlled switching frequency
- Synchronization output or input with adjustable phase shift
- Programmable soft start
The AD8452 combines a precision analog front-end controller and switch mode power supply (SMPS), pulse-width modulator (PWM) driver into a single silicon platform for high volume battery testing and formation manufacturing. A precision instrumentation amplifier (in-amp) measures the battery charge/discharge current, while an equally accurate difference amplifier measures the battery voltage. Internal laser trimmed resistor networks establish the in-amp and difference amplifier gains (66 V/V and 0.4 V/V, respectively), and stabilize the AD8452 performance across the rated operating temperature range.
Desired battery cycling current and voltage levels are established by applying precise control voltages to the ISET and VSET inputs. Actual charge and discharge current levels are sensed (usually by a high power, highly accurate shunt resistor) whose value is carefully selected according to system parameters. Switching between constant current (CC) and constant voltage (CV) loop integration is instantaneous, automatic, and completely transparent to the observer. A logic high at the MODE input selects the charge or discharge mode (high for charge, low for discharge).
The AD8452 simplifies designs by providing excellent performance, functionality, and overall reliability in a space saving 48-lead, 7 mm × 7 mm × 1.4 mm LQFP package rated for operation at temperatures from −40°C to +85°C.
- Battery formation and testing
- High efficiency battery test systems with recycle capability
- Battery conditioning (charging and discharging) systems
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 AD8452-EVALZ is a platform for the AD8452, designed for investigation of the AD8452 analog and pulse-width modulation (PWM) features and performance without the added complications of a driver and/or switch mode power supply (SMPS) design. For convenience, a precision 5 V reference IC and four trim pots are built in to the evaluation board, for driving the battery current and voltage ISET and VSET inputs. All device pins are accessible with test loops or probe landings.
At the same time, the AD8452-EVALZ has the flexibility to interface and drive a typical half bridge inductor input SMPS with output levels in the 1 A to 15 A range. SMPS and associated components are specified and sourced by the user.
The AD8452 is intended for use as the core controller for commercial battery test and formation systems. Its advanced miniaturization and extraordinarily high level of analog precision meet the challenge of mass production of high energy density storage lithium ion packs for transportation and energy storage in homes.
When working with the evaluation board, consult the AD8452 data sheet for a detailed device Theory of Operation and for additional information in conjunction with user guide UG-1180.
Features & Benefits
- Pin accessible, standalone AD8452
- Simplified operation: connect a power supply and scope and start looking at waveforms
- On-board precision 5 V reference included for accurate gain measurements
- Factory tested
- Four optional control loops available but not necessary for operation; may be bypassed as desired
- Safe: only low power circuitry is present; no accidental power discharges
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.
Models for the following parts are available in LTspice:
Press Releases (1)
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.