Circuit Note CN-0352 Devices Connected/Referenced Circuits from the Lab® reference designs are engineered and tested for quick and easy system integration to help solve today’s analog, mixed-signal, and RF design challenges. For more information and/or support, visit www.analog.com/CN0352. ADP5065 Fast Charge Battery Manager with Power Path and USB Compatibility ADG715 CMOS, Low Voltage Serially Controlled, Octal SPST Switch AD8601 Precision CMOS, Single-Supply, Rail-to-Rail, Input/Output Wideband Operational Amplifier AD8237 Micropower, Zero Drift, True Rail-to-Rail Instrumentation Amplifier AD8275 G = 0.2, Level Translation,16-Bit ADC Driver AD8276 Low Power, Wide Supply Range, Low Cost, Unity-Gain Difference Amplifier ADuCM360 Low Power, Precision Analog Microcontroller with Dual Sigma-Delta ADCs, ARM Cortex-M3 Cost Effective, Multichannel Lithium Ion Battery Testing System EVALUATION AND DESIGN SUPPORT Circuit Evaluation Boards CN-0352 Evaluation System (EVAL-CN0352-EB1Z) Evaluation system includes EVAL-CN0352-EB1Z_IO (Input/Output Board, 8 Each) EVAL-CN0352-EB1Z_MCU (MCU Board, 1 Each) EVAL-CN0352-EB1Z_BAS (Base Board, 1 Each) Design and Integration Files Schematics, Source Code, Layout Files, Bill of Materials CIRCUIT FUNCTION AND BENEFITS The test system shown in Figure 1 is an accurate, cost effective, 8-channel battery testing system for single-cell, lithium ion (Li-ion) batteries with open circuit voltage (OCV) between 3.5 V and 4.4 V. The demand for Lithium ion (Li-ion) batteries is high for use in both low power and high power applications, such as laptop computers, mobile phones, portable wireless terminals, as well as hybrid electric vehicles/all-electric vehicles (HEV/EV). Li-ion batteries therefore require accurate and reliable test systems. The battery test system in Figure 1 is composed of multiple input/output boards (EVAL-CN0352-EB1Z_IO) for handling the charging and discharging process, an MCU board (EVALCN0352-EB1Z_MCU) for battery data acquisition, testing, monitoring, and temperature management, and a backplane base board (EVAL-CN0352-EB1Z_BAS) that provides the signal interconnections between the MCU board and the multiple input/output boards. The circuit uses the ADP5065 fast charging battery manager for flexible, efficient, high stability charging control with low cost, small printed circuit board (PCB) area, and ease of use compared to traditional discrete solutions. Highly integrated precision data acquisition and processing is provided by the ADuCM360 precision analog microcontroller. The ADuCM360 acquires the battery voltage, current, and temperature. A high precision analog-to-digital converter (ADC), digital-to-analog converter (DAC), and an on-chip microcontroller allows completely self-contained control of the charging and discharging process. The analog front end is fully differential with high CMRR and excellent immunity to both common-mode and ground noise caused by large currents generated during the charge and discharge cycles. The number of channels can easily be expanded to further reduce testing time and cost per battery. Rev. A Circuits from the Lab® reference designs from Analog Devices have been designed and built by Analog Devices engineers. Standard engineering practices have been employed in the design and construction of each circuit, and their function and performance have been tested and verified in a lab environment at room temperature. However, you are solely responsible for testing the circuit and determining its suitability and applicability for your use and application. Accordingly, in no event shall Analog Devices be liable for direct, indirect, special, incidental, consequential or punitive damages due toanycausewhatsoeverconnectedtotheuseofanyCircuitsfromtheLabcircuits. (Continuedonlastpage) One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©2016 Analog Devices, Inc. All rights reserved. Circuit Note 12842-001 CN-0352 Figure 1. Cost Effective, Multichannel Li-ion Battery Testing System TO BASE BOARD CNP-12 CNP-11 CNP-10 CNP-9 U1 +5VPWR +5VPWR 1.0µH VOUT SW1 SW2 2.2µF 4.7µF SW ADP5065 VIN1 C3 22µF VIN2 CFILT 4.7µF +3.3VD CNP-4 CNP-8 3MHz BUCK PGND1 A 4-WIRE KEVIN CONNECTION IS RECOMMENDED SHORT JP2 AND JP3 FOR 2-WIRE CONNECTION ISO_S1 10k IIN_EXT CNP-1 CNP-2 CNP-7 SDA SCL SCL NRST SDA CHARGE CONTROL BLOCK SCL SDA AGND V+ 100pF THR V_WEAK_SET JP2 1kΩ BAT_SNS 0.1µF I+ 22µF ISO_B2 SYS_ON_OK 1µF 0.02Ω 1% ISO_B1 +5VA CNS-9 CNS-10 BATTERY CONNECTOR ISO_S2 TRK_EXT t° 10kΩ ERT-JZEG103JA PGND2 V– JP3 U2 D1 D2 D3 D4 D5 D6 D7 D8 S1 S2 S3 S4 S5 S6 S7 S8 CNS-7 CNS-5 CNS-3 CNS-1 CNS-2 CNS-4 CNS-6 CNS-8 +5VA 0.1µF RESET A0 VDD A1 GND SERIAL PORT SCL VSS SDA HSINK 1 1kΩ I_SENSE+ ADG715 100pF V_DAC THR_N IEXT THR_P V_SENSE– V_SENSE+ I_SENSE– I_SENSE+ 100pF AUX CONNECTOR 1kΩ V_SENSE– 1kΩ IEXT 1kΩ THR_P 100pF t° 10kΩ 1kΩ THR_N 10kΩ SCL SDA E-LOAD CIRCUIT V4330K HEAT SINK 1kΩ V_SENSE+ NRST I– 1kΩ I_SENSE– 1kΩ V_DAC 1 1W 1 1W 1 1W 1 1W 10kΩ THERMISTOR NEEDS TO FIT TOGETHER WITH THE BATTERY UNDER TEST +5VA AD8601 10Ω 10MΩ 0.1µF U3 AGND PGND 12842-002 2 × SIR464 FOR COOLING THE E-LOAD CIRCUIT DURING DISCHARGING PROCESS Figure 2. EVAL-CN0352-EB1Z_IO, Li-ion Battery Charging and Discharging Controlling Circuit (Simplified Schematic: All Connections and Decoupling Not Shown) Rev. A | Page 2 of 10 Circuit Note CN-0352 CIRCUIT DESCRIPTION The 8-channel battery testing system (EVAL-CN0352-EB1Z) contains eight input/output boards (EVAL-CN0352-EB1Z_IO) and one MCU board (EVAL-CN0352-EB1Z_MCU) that plug into one base board (EVAL-CN0352-EB1Z_BAS). The circuit shown in Figure 2 is the input/output board. The sample-and-hold circuits shown in Figure 3 control the discharging voltage on each channel. The ADuCM360 refreshes the discharging voltages of the input/output board sequentially by outputting the preconfigured discharging control voltage for each channel and then turning on the corresponding ADG715 switch. MCU BOARD INPUT/OUTPUT BOARDS CH1 Input/Output Board (EVAL-CN0352-EB1Z_IO) Description Battery Charging Control Using the ADP5065 + 1kΩ E-LOAD 10MΩ BAT1 0.1µF ADG715 The ADP5065 handles all the necessary charging control for single cell Li-ion or lithium polymer batteries, including the constant current (CC), constant voltage (CV), and trickle charge (TC) modes. The TC mode allows testing a deeply discharged battery and ensures safety. The ADP5065 uses a dc-to-dc switching converter architecture for high efficiency during the charging process, compared to more traditional linear regulators. ADuCM360 CH2 + 1kΩ 12-BIT DAC E-LOAD 10MΩ BAT2 0.1µF CH8 The ADP5065 integrates a number of significant features to guarantee the high reliability including thermal management, battery fault detection, and fault recovery. The charging parameters of ADP5065, such as fast charging current, charging termination current, and charging termination voltage, are all programmable through an I2C interface. This programmability allows the ADP5065 to operate with many different types of Li-ion batteries as well as to operate as a complete battery charging and test controller. Battery Discharging Control and Electronic Load (E-Load) Circuit The electronic load (E-load) circuit within the dashed rectangular block in Figure 2 provides a programmable constant-current load that uses the AD8601 precision CMOS op amp, four 1 W, 1% power resistors, and two power SIR464 MOSFETs. The E-load current is accurately controlled by the control voltage on the noninverting input of AD8601. The control voltage (V_DAC from MCU board) can range from 0 V to 1 V, which produces a load current of 0 A to 2 A. The typical discharging termination voltage for Li-ion battery is 3.0 V. The minimum allowable output voltage required by this E-load is 2A×1Ω=2V The power MOSFETs and the power resistors consume all the energy from the battery during discharging process. The cooling system implemented in this module is only for demonstration purposes, and additional attention is required to guarantee adequate cooling performance when the discharging current is higher than 750 mA. Because the on-resistance of MOSFETs have a positive temperature coefficient, multiple devices of the same type can be used in parallel and controlled by a single loop shown as the E-circuit in Figure 2. This is a common way to extend the power handling ability of power MOSFET circuits. + BAT8 12842-003 ADG715 Figure 3. Sample-and-Hold Circuit for Multichannel Discharging Current Control Circuit Only one input/output board has its ADG715 switch closed at any given time. The 0.1 μF capacitor is charged by the DAC through a 1 kΩ resistor during the sampling interval and discharged through the 10 MΩ resistor the 1 kΩ to ground during the holding interval. The bandwidths for charging and discharging are approximately 1.6 kHz and 0.16 Hz, respectively. The 10 MΩ resistor is required to discharge the voltage on the 0.1 μF capacitor and pull the discharging voltage close to ground if there is no MCU board connected. Assuming an N-channel system and a sampling and holding time of TS and TH, respectively, the following condition must be met: TH = TS (N − 1). Therefore more channels require a longer holding time, and the leakage current produces a larger droop voltage. For the CN-0352 system, N = 8, TS = 1 ms, and TH = 7 ms, and the droop voltage is negligible. Thermal Management Most Li-ion batteries cannot be charged at temperatures lower than 0°C or above 60°C. Fast charging and discharging can only be performed from 10°C to 45°C. In addition to safety issues, the performance of the Li-ion cell can change dramatically with temperature. Therefore, the temperature of the battery needs to be measured with proper accuracy to ensure the repeatability of the test results and also to guarantee safety. Battery temperature is monitored using 10 kΩ thermistors connected to the temperature connector blocks with a 2-wire connection. The battery under test is usually located near the board, therefore the thermistor lead resistance is negligible. There is another 10 kΩ thermistor on the input/output board connected to the THR pin of ADP5065 as shown in Figure 2. Rev. A | Page 3 of 10 CN-0352 Circuit Note resistance to carry the charging and discharging current. The V+ and V− lines sense the voltage of battery and carry only a small bias current. The charging and discharging current is sensed by measuring the voltage across the 0.02 Ω, 1% current sense resistor. This thermistor is for monitoring the temperature near the heat sink on the input/output board, because the temperature can be relatively high during discharging. The thermistor temperature information is sensed and stored in the ADP5065 Charger Status Register 2 and is monitored by the MCU board through the I2C bus. There are two headers on the input/output board for the external fan connections with configurable pulsewidth modulation (PWM) signals assigned. If the thermistor temperature is less that 45°C, the PWM signal to the fans is set at 50% duty cycle by the MCU. If the temperature is greater than 45°C the duty cycle is increased to 95%. If the temperature is greater than 60°C the ADP5065 automatically stops the charging process. The temperature thresholds can be fine tuned by placing a fixed resistor in parallel or in series with the thermistor. All the battery information is sensed differentially to increase the robustness and reduce the common-mode error, which is very important because of the large ground currents during charging and discharging. MCU Board (EVAL-CN0352-EB1Z_MCU) Description Voltage Conditioning Circuit The circuit shown in Figure 4 shows the signal conditioning circuits for the voltage, current, and temperature channels. All the signals from input/output boards are routed into the analog input channels of ADuCM360 and digitized by the two, on-chip, 24-bit, Σ-Δ integrated ADCs. Battery Connection and Sensing The battery under test is connected to the input/output board by a 4-wire Kelvin connection to eliminate errors caused by lead resistance. The I+ and I− connecting wires must have low lead AD8275 –IN 100pF 1kΩ V_SENSE– VBAT: 0V TO 5V 10kΩ SENSE 200Ω 40kΩ –IN 20kΩ REF2 50kΩ +IN 20kΩ REF1 100pF 40kΩ R11 5.6kΩ R12 5.6kΩ C16 1nF C17 100pF D4 SDM40E20LS 1kΩ R55 R18 5.6kΩ VOUT 8 2 +IN FB 7 3 –IN REF 6 4 –VS +VS 5 THR_NIN +5VA RF2 90.9kΩ THR_OUT+ THRPIN THRNIN THR_OUT– THR_OUT+ THR_OUT– C39 1nF V_OUT+ V_OUT– R56 1kΩ RF1 90.9kΩ R21 5.6kΩ RG1 10kΩ R22 5.6kΩ C45 1nF THRNIN I_OUT+ I_OUT– VDAC +I_OUT C29 1nF –I_OUT C31 100pF AVDD_REG AVDD_REG AVDD IOVDD AVDD_REG AVDD IOVDD AIN6/IEXC AIN7 AIN8 AIN10 AIN11 AIN3 AIN2 THRPIN R105 1kΩ –V_OUT C36 100pF OUT RG2 10kΩ I_EXT C34 1nF +V_OUT C30 1nF C32 100pF 1 BW C40 100pF THR_PIN R20 5.6kΩ 40kΩ REF I_EXT R17 5.6kΩ I_EXT U3 10.µF C41 100pF 2.2kΩ 0.1% 25ppm R19 5.6kΩ U5 AD8237 C18 100pF I_SENSE– 40kΩ 200Ω SENSE I_SENSE+ C37 100pF AVDD_REG 1kΩ V_SENSE+ +IN OUT U2 1nF AD8276 AIN5 AIN4 U1 ADuCM360 DAC AGND EPAD P0.6 P0.7 P0.4/ RX TX DIR P1.2 P1.3/ FAN_PWM1 FAN_PWM2 P1.0 P1.3 FAN1_SPD FAN2_SPD P2.0 P2.1 SCL SDA P0.0 P0.1 P0.2 A0 A1 A2 P0.3 P0.5 I2C_EN SW_RST 12842-004 50kΩ Figure 4. EVAL-CN0352-EB1Z_MCU, Signal Conditioning, Data Acquisition by ADuCM360 (Simplified Schematic: All Connections and Decoupling Not Shown) Rev. A | Page 4 of 10 Circuit Note CN-0352 The charging termination voltage is generated by the ADP5065 and is adjustable from 3.5 V to 4.42 V for compatibility with different types of Li-ion batteries. Discharge termination voltage is usually set to 3.0 V. In special circumstances, the battery maybe deeply discharged to a voltage much lower than 3.0 V. The discharge termination voltage can be set from 0 V to 5 V, and that range covers almost conditions for Li-ion battery cells. Current Conditioning Circuit The sensed battery voltage is processed by the AD8275 (G = 0.2 difference amplifier) and the AD8276 (unity-gain difference amplifier). The two amplifiers are connected in a balanced circuit to provide a differential output with an overall gain of 0.2 and an output common-mode voltage of 1.8 V. The AD8237 is a micropower, zero drift, rail-to-rail instrumentation amplifier. A simplified block diagram is shown in Figure 5. The AD8237 utilizes the indirect current feedback architecture, and achieves true rail-to-rail capability. The common-mode input voltage can be equal to or slightly beyond the power supply rails. The battery current is sensed on the input/output boards by a 0.02 Ω resistor placed in series with the high side of the battery. Assuming that the maximum current during testing is 2 A, the maximum differential voltage across the resistor is ±40 mV with the common-mode voltage equal to the battery voltage that can be higher than 4.2 V. The two 1 kΩ resistors placed in series with the AD8275 inputs shown in Figure 4 act as current limiting protection resistors. The 200 Ω resistors compensate for the reduction in gain due to the 1 kΩ series resistors and restore the gain of the circuit to 0.2. The gain of the AD8237 circuit is set to 10.09 by the ratio of RF1 to RG1 (G = 1 + RF1/RG1). The RF2 and RG2 resistors cancel the error from the input bias current. With the equations set as shown, The ±40 mV current sensed signal is converted to ±400 mV with a reference voltage of AVDD_REG = 1.8 V. VOUT VOUT 0 .2 (VSENSE V SENSE ) VOUT VOUT 2 V AVDD _ REG The amplified and level-shifted current sense signal drives the AIN5 and AIN4 differential inputs of the ADuCM360 which is configured for a bipolar input, gain = 2, buffer enabled, and internal reference enabled. The differential voltage at the input of the ADuCM360 internal ADC is ±800 mV. The absolute voltage on the input pins are both 1.0 V to 2.6 V. The final voltage of VOUT+ and VOUT− is VOUT V AVDD _ REG 0 . 1 (V SENSE V SENSE ) VOUT V AVDD _ REG 0 . 1 (V SENSE V SENSE ) For a 0 V to 5 V battery voltage range, VOUT+ and VOUT− vary from 1.8 V to 2.3V and 2.3 V to 1.8 V, respectively. The differential output voltage (VOUT+ − VOUT−) is 0 V to 1 V. These ranges are compatible with the common-mode and differential input voltage requirements of ADuCM360. The current and voltage information is sampled simultaneously using the two internal ADCs in ADuCM360. Differential and common-mode RFI and noise filters are placed in front of the AD8275, AD8237, and ADuCM360 accordingly. The configuration of ADuCM360 for voltage acquisition is as follows: differential input on AIN3 and AIN2, unipolar, unitygain with buffer disabled, and internal reference. INTERNAL IN-AMP AD8237 + VOUT TIA – RFI FILTER +IN –VS +VS –VS + ALS RFI FILTER –IN +VS – V VCM = S 2 FB TO gm2 + gm1 – – I2 gm2 + V VCM = S 2 + –VS +VS ALS Rev. A | Page 5 of 10 FB R1 + RFI FILTER –VS Figure 5. AD8237 Simplified Schematic R2 – RFI FILTER TO gm1 – I1 –IN REF 12842-005 I1 – I2 +VS CN-0352 Circuit Note Battery Temperature Conditioning Circuit The battery temperature is measured with a 10 kΩ thermistor placed near or inside the battery casing. The value of the thermistor resistor is determined by measuring the voltage across the thermistor when driven with a known current. As shown in Figure 6, the integrated current source in the ADuCM360 (I_EXT) drives the 10 kΩ thermistor through a series network that includes a 2.2 kΩ precision current sense resistor, a Schottky diode for reverse voltage protection, two 1 kΩ current limit resistors, and a 10 kΩ bias voltage generator resistor. The maximum voltage drop through the series connected circuit is VMAX = IEXT × (1 kΩ + 2.2 kΩ + 1 kΩ + 50 kΩ +10 kΩ) + VF = IEXT × 64.2 kΩ + 0.31 V The total voltage drop must be less than (AVDD − 0.85 V). The exciting current is limited by IEXT << (AVDD − 0.85 V − 0.31 V)/64.2 kΩ Therefore, the maximum allowable exciting for this circuit is 33.3 μA. The exciting current is set to 10 μA so that the voltage across the 10 kΩ resistor is less than 0.5 V. The internal ADuCM360 PGA is set for a gain of 2, and the internal buffer of ADuCM360 is enabled. The bias voltage on the temperature input is 10 μA × 10 kΩ = 0.1 V in order to meet the common-mode input voltage requirement of the ADuCM360 when the internal buffer is enabled. The excitation current reference channel and thermistor voltage channels are sampled simultaneously to cancel any commonmode error sources, such as drift in the exciting current source or the power supply. The configuration for temperature acquisition for the reference channel is: differential input, unipolar, gain = 32, buffer enabled, and internal reference. The configuration for thermistor channel is: differential input, unipolar, gain = 2, buffer enabled. and internal reference. EVAL-CN0352-EB1Z-MCU 100pF THR_OUT+ 1nF THR_OUT– REVERSE PROTECTION SDM40E20LS 5.6kΩ 5.6kΩ 0.1% 2.2kΩ 25ppm ADG715 100pF 1nF THR_PIN 1kΩ 1kΩ 100pF 1kΩ THR_NIN CURRENT LIMITATION 1kΩ 2.5kΩ TO 50kΩ FOR –10° TO +60°C 1kΩ t° 1nF 10kΩ 0.1V V_BIAS GENERATED BY 10kΩ × 10µA FOR ADuCM360 Figure 6. Battery Temperature Conditioning Circuit Rev. A | Page 6 of 10 12842-006 I_EXT CURRENT LIMITATION 1kΩ EVAL-CN0352-EB1Z-IO Circuit Note CN-0352 Base Board (EVAL-CN0352-EB1Z_BAS) Description I2C Interface Extension 3.3VD 1kΩ SCL SDA 3.3VD 1kΩ 3.3VD VCC Y0 Y1 Y2 74LVC138 Y3 Y4 E1 Y5 E2 Y6 E3 GND Y7 I2C_EN DGND SCL_CS1 SCL_CS2 SCL_CS3 SCL_CS4 SCL_CS5 SCL_CS6 SCL_CS7 SCL_CS8 SCL_CH1 0Ω SDA_CH1 SCL_CH2 0Ω SDA_CH2 SCL_CH8 0Ω DGND SDA_CH8 12842-007 A0 A1 A2 A0 A1 A2 Figure 7. I2C interface Extension Circuit –0.95 –1.00 –1.05 12842-008 –1.10 2201 2001 1801 1601 1401 1201 1001 801 401 601 201 –1.15 1 The number of battery channels can be expanded by adding additional EVAL-CN0352-EB1Z systems that share one RS485 bus connection to the PC. In this situation, each module must have a unique ID from 1 to 255. The ID0 is reserved. The CN-0352 evaluation software scans all the IDs and records the ID and channel number for each available ID. Note that the baud rate of RS485 bus is the limiting factor to channel expansion using this approach. –0.90 VOLTAGE (mV) The base board provides the interconnections between the input/output boards and MCU board. The user can address the ADP5065 and the ADG715 on a particular input/output board by using different I2C DEV_ID. The logic shown in Figure 7 uses the 3-bit general-purpose input/outputs (GPIOs) from the ADuCM360 to route the SCLK signal to the proper input/output board. More channels can be added; however, more channels require higher ADC sampling rates, more MCU ram size, faster refreshing rate for the discharging voltage, and higher communication bandwidth to the upper-level processer. SAMPLING INTERVAL Figure 8. Voltage Noise Measured with Battery Connection Pins Shorted (140 μV p-p Voltage Noise) 1.20 Circuit Performance Measurements CURRENT (mA) 1.15 1.10 1.05 1.00 12842-009 System noise was measured by shorting the battery voltage sense pins, V+ and V−, together on the battery connector (shown in Figure 3) and measuring the peak-to-peak variation in the ADC output codes over a 2000 point sampling interval. Similar measurements were done for the current channel. For the temperature channel, a 10 kΩ fixed resistor was connected instead of a thermistor. The results are shown in Figure 8, Figure 9, and Figure 10, respectively. 2201 2001 1801 1601 1401 1201 1001 801 601 401 201 1 0.95 SAMPLING INTERVAL Figure 9. Current Noise Measured with Battery Connections Shorted (140 μA p-p Current Noise) Rev. A | Page 7 of 10 CN-0352 Circuit Note 25.510 CIRCUIT EVALUATION AND TEST Warning This evaluation system interfaces to lithium ion batteries, which can be damaged, catch on fire, or explode if overcharged, overdischarged, or subjected to source or sink currents that exceed the specifications of the battery manufacturer. Take all necessary steps to protect users during operation. 25.500 25.495 The CN-0352 evaluation software on the PC communicates with the EVAL-CN0352-EB1Z hardware to capture and analyze data from the EVAL-CN0352-EB1Z circuit board. 12842-010 25.490 Equipment Needed 2201 2001 1801 1601 1401 1201 1001 801 601 401 201 1 25.485 The following equipment is needed: SAMPLING INTERVAL Figure 10. Thermistor Noise Measured with 10 kΩ Resistor (0.014°C p-p Noise) A typical lithium ion battery charge and discharge profile is shown in Figure 11. 5.0 4.5 3000 VOLTAGE CAPACITY 2000 3.5 3.0 CURRENT Getting Started CURRENT (mA) CAPACITY (mAh) VOLTAGE (V) 4.0 Detailed operation of the evaluation hardware and software is contained in the CN-0352 User Guide, which can be found at www.analog.com/CN0352-UserGuide. Functional Diagram 1000 A functional block diagram of the test setup is shown in Figure 12 2.5 0 50 100 150 0 200 12842-011 2.0 EVAL-CN0352-EB1Z circuit evaluation board system 5 V, 3 A or higher dc power supply or wall wart PC or laptop with USB Port USB to RS485 adapter supporting baud rate of 115,200 bps CN-0352 evaluation software (see the CN-0352 User Guide) Li-ion battery samples and battery holder (for safety consideration, using the Li-ion battery with protection circuit integrated is highly recommended) TIME (Minutes) PC USB Figure 11. Typical Charging and Discharging Profile COMMON VARIATIONS The ADP5061 and ADP5062 are both linear battery chargers with management functions for charging current up to 2 A. The ADP5062 is available in a 4 mm × 4 mm LFCSP package. The ADG714 is an octal, single-pole/single-throw (SPST) switch with a QSPI™-compatible interface. The SPI clock of ADG714 can be much higher than the 400 kHz upper limit of the I2C bus. The channel switching time is therefore much shorter than that of the ADG715, and the ADG714 is a better choice for systems with 16 or 32 battery channels. A complete set of documentation for the EVAL-CN0352-EB1Z board, including complete schematic, MCU source code, layout drawings, Gerber files, and bill of materials are available in the CN-0352 Design Support Package at www.analog.com/CN0352-DesignSupport. Rev. A | Page 8 of 10 RESET USB TO RS-485 ADAPTER PWM FAN2 PWM FAN1 FAN2 FAN1 5V DC POWER RS-485 COM PWR EVAL-CN0352-EB1Z BAT1 BAT2 BAT3 BAT4 BAT5 BAT6 BAT7 Figure 12. Test Setup Functional Diagram BAT8 12842-012 TEMPERATURE (°C) 25.505 Circuit Note CN-0352 FPWR Setup FAN1 AND FAN2 VFAN PGND FAN SPEED FEEDBACK PWM CONTROL Figure 13. Fan Connections Plug the USB port of USB to RS485 adapter to the USB port on the PC and connect the RS485 side to the terminal block of the MCU board marked COM. Turn on the 5 V dc power supply and the fan power supply, then connect the Li-ion battery to the input/output board. The CN-0352 Software User Guide provides information and details regarding the test setup and how to use the evaluation software for gathering the test data and analyzing the result. 12842-014 The header marked FAN1, FAN2, and FPWR are for connecting to the fans. The pin definitions are shown in Figure 13. Carefully verify the pin connections of the fans. Typical power for a PWM controlled fan is 12 V. The acceptable range of VFAN is 0 V to 15 V. Connect the VFAN to the external dc fan power supply. VFAN PGND 12842-013 Plug the MCU board (EVAL-CN0352-EB1Z_MCU) and the input/output boards (EVAL-CN0352-EB1Z_I/O) into the connector on the base board (EVAL-CN0352-EB1Z_BAS), as shown in Figure 12. With the 5 V power supply off, connect the 5 V dc power supply to the terminal block marked PWR. The fans for cooling the heat sink on the input/output board are necessary but not included into the packaging box. Figure 14. Complete Battery Testing System Connected to Eight Batteries Rev. A | Page 9 of 10 CN-0352 Circuit Note LEARN MORE Data Sheets and Evaluation Boards CN-0352 Design Support Package: www.analog.com/CN0352-DesignSupport. CN-0352 Evaluation System (EVAL-CN0352-EB1Z) “Battery Chargers,” Chapter 5 in Power and Thermal Management, Analog Devices, 1998. ADG715 Data Sheet MT-031 Tutorial. Grounding Data Converters and Solving the Mystery of AGND and DGND. Analog Devices. AD8237 Data Sheet MT-101 Tutorial. Decoupling Techniques. Analog Devices. ADP5065 Data Sheet AD8601 Data Sheet AD8275 Data Sheet AD8276 Data Sheet ADuCM360 Data Sheet REVISION HISTORY 3/16—Rev. 0 to Rev. A Changes to Circuit Evaluation and Test Section ...........................8 1/16—Revision 0: Initial Version (Continued from first page) Circuits from the Lab reference designs are intended only for use with Analog Devices products and are the intellectual property of Analog Devices or its licensors. While you may use the Circuits from the Lab reference designs in the design of your product, no other license is granted by implication or otherwise under any patents or other intellectual property by application or use of the Circuits from the Lab reference designs. Information furnished by Analog Devices is believed to be accurate and reliable. However, Circuits from the Lab reference designs are supplied "as is" and without warranties of any kind, express, implied, or statutory including, but not limited to, any implied warranty of merchantability, noninfringement or fitness for a particular purpose and no responsibility is assumed by Analog Devices for their use, nor for any infringements of patents or other rights of third parties that may result from their use. Analog Devices reserves the right to change any Circuits from the Lab reference designs at any time without notice but is under no obligation to do so. ©2016 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. CN12842-0-3/16(A) Rev. A | Page 10 of 10