Precision Integrated Analog Front End, Controller, and PWM for Battery Test and Formation Systems Data Sheet AD8452 FEATURES GENERAL DESCRIPTION CC and CV battery test and formation modes with The AD8452 combines a precision analog front-end controller transparent and automatic switchover, for systems of and switch mode power supply (SMPS), pulse-width modulator 20 Ah or less (PWM) driver into a single silicon platform for high volume Precise measurement of voltage and current battery testing and formation manufacturing. A precision Independent feedback control blocks instrumentation amplifier (in-amp) measures the battery charge/ Highly accurate, factory trimmed instrumentation and discharge current, while an equally accurate difference amplifier differential amplifiers measures the battery voltage. Internal laser trimmed resistor In-amp for current sense gain: 66 V/V networks establish the in-amp and difference amplifier gains Difference amplifier for voltage sense gain: 0.4 V/V (66 V/V and 0.4 V/V, respectively), and stabilize the AD8452 Stable over temperature: offset voltage drift <0.6 V/C performance across the rated operating temperature range. (maximum) Desired battery cycling current and voltage levels are established Gain drift: <3 ppm/C (maximum) by applying precise control voltages to the ISET and VSET Current sense CMRR: 120 dB minimum inputs. Actual charge and discharge current levels are sensed Popular SMPS control for charge/discharge (usually by a high power, highly accurate shunt resistor) whose High PWM linearity with internal ramp voltage value is carefully selected according to system parameters. 50 kHz to 300 kHz user controlled switching frequency Switching between constant current (CC) and constant voltage Synchronization output or input with adjustable phase shift (CV) loop integration is instantaneous, automatic, and completely Programmable soft start transparent to the observer. A logic high at the MODE input APPLICATIONS selects the charge or discharge mode (high for charge, low for discharge). Battery formation and testing High efficiency battery test systems with recycle capability The AD8452 simplifies designs by providing excellent Battery conditioning (charging and discharging) systems 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 40C to +85C. FUNCTIONAL BLOCK DIAGRAM LOOP SYSTEM CONTROL COMP (4) VCL +DCBUS VIN SYNC CC FILTER AMPLIFIER SCFG VCL DH MODE VBAT IBAT MOSFET DL SELECT DRIVER DIFF IN-AMP AMP SS PWM 1 CV FILTER CLVT ISREFH/ AMPLIFIER ISREFL DT BVREFH/ FREQ VREF BVREFL 0.4 66 DMAX AD8452 FAULT DGND BV ISV Figure 1. Rev. A Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. Tel: 781.329.4700 20172018 Analog Devices, Inc. All rights reserved. No license is granted by implication or otherwise under any patent or patent rights of Analog Technical Support www.analog.com Devices. Trademarks and registered trademarks are the property of their respective owners. BVN BVMEA BVP ISVP ISMEA ISVN VVE0/VVE1 IVE0/IVE1 VSET MODE ISET VINT VREF EN CLP CLN BV ISV 16187-001AD8452 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Shutdown ..................................................................................... 24 Applications ....................................................................................... 1 Undervoltage Lockout (UVLO) ............................................... 24 General Description ......................................................................... 1 Soft Start ...................................................................................... 24 Functional Block Diagram .............................................................. 1 PWM Drive Signals .................................................................... 25 Revision History ............................................................................... 2 Peak Current Protection and Diode Emulation (Synchronous) ............................................................................. 25 Specifications ..................................................................................... 3 Frequency and Phase Control .................................................. 26 Analog Front-End and Controller Specifications .................... 3 Maximum Duty Cycle ............................................................... 26 Pulse-Width Modulator Specifications ..................................... 5 Fault Input ................................................................................... 27 Digital Interface Specifications ................................................... 6 Thermal Shutdown (TSD) ........................................................ 27 Power Supply ................................................................................. 7 Applications Information .............................................................. 28 Temperature Range Specifications ............................................. 7 Analog Controller ...................................................................... 28 Absolute Maximum Ratings ............................................................ 8 Functional Description .............................................................. 28 Thermal Resistance ...................................................................... 8 Power Supply Connections ....................................................... 29 ESD Caution .................................................................................. 8 Current Sense In-Amp Connections ....................................... 29 Pin Configuration and Function Descriptions ............................. 9 Voltage Sense Differential Amplifier Connections ................ 29 Typical Performance Characteristics ........................................... 11 Battery Current and Voltage Control Inputs In-Amp Characteristics ............................................................. 11 (ISET and VSET) ........................................................................ 29 Difference Amplifier Characteristics ....................................... 12 Loop Filter Amplifiers ............................................................... 30 CC and CV Loop Filter Amplifiers and VSET Buffer (except Selecting Charge or Discharge Options .................................. 30 where Noted) ............................................................................... 13 Select RCL and R for the Peak Current Limit .................. 30 CLVT Reference Characteristics .......................................................... 15 Setting the Operating Frequency and Programming the Pulse-Width Modulator ............................................................. 16 Synchonization Pin .................................................................... 31 Theory of Operation ...................................................................... 18 Programming the Maximum Duty Cycle ............................... 32 Introduction ................................................................................ 18 Selecting CSS ................................................................................ 33 Instrumentation Amplifier (In-Amp) ..................................... 19 Additional Information ............................................................. 33 Difference Amplifier .................................................................. 20 Outline Dimensions ....................................................................... 34 CC and CV Loop Filter Amplifiers .......................................... 20 Ordering Guide .......................................................................... 34 Charge and Discharge Control ................................................. 23 Input and Output Supply Pins .................................................. 23 REVISION HISTORY 10/2018Rev. 0 to Rev. A Changes to Figure 34 and Figure 35 ............................................. 19 Changes to Figure 38 ...................................................................... 21 Changes to Figure 47 ...................................................................... 26 Changes to Figure 49 ...................................................................... 28 Changes to Figure 50 ...................................................................... 29 Updated Outline Dimensions ....................................................... 34 10/2017Revision 0: Initial Version Rev. A Page 2 of 34