Click here for production status of specific part numbers. Evaluates: MAX17701 in MAX17701EVKITA Evaluation Kit 5V Output-Voltage Application General Description Quick Start The MAX17701EVKITA (EV kit) provides a proven Recommended Equipment design to evaluate the MAX17701 high-efficiency, high- MAX17701EVKITA voltage, Himalaya synchronous step-down DC-DC super- 60V, 20A DC input power supply capacitor charger controller. The EV kit provides constant current (CC) mode and constant voltage (CV) modes to 10A electronic load charge supercapacitors. The EV kit is designed to deliver Four digital voltmeters (DVM) 20A CC mode current (I ) and 5V CV mode volt- CHGMAX Digital ammeter (DAM) age (V ) from a 9V to 60V input supply. The EV kit OUT supports up to continuous 10A load connected in parallel Equipment Setup and Test Procedure to supercapacitors at the output. The EV kit is optimized The EV kit is fully assembled and tested. Use the follow- for 24V nominal input voltage application. The switching ing steps to verify board operation: frequency of the EV kit is set at 350kHz (f ) for optimum SW Caution: Do not turn on power supply until all con- efficiency and component size. The EV kit features a safe- nections are completed. ty timer (TMR) to set the maximum allowed constant cur- rent (CC) mode charging time. For more details about the 1) Set electronic load with 10A and disable the IC benefits and features, refer MAX17701 IC data sheet. electronic load. 2) Connect the positive terminal of the electronic load Features to the VOUT connector and negative terminal of Operates from a 9V to 60V Input Supply electronic load to the nearest PGND connector. 20A CC Mode Charging Current 3) Turn on electronic load and discharge supercapaci- tors till the voltage across the output goes to 0V. 5V CV Mode Output Voltage Disconnect the electronic load. 350kHz Switching Frequency 4) Set the power supply at a voltage between 9V and Resistor-Programmable UVLO Threshold 60V. Disable the power supply. Input Short Protection 5) Verify that shunts are installed across pins 1-2 on CC Mode Safety Timer (TMR) EN/UVLO jumper (J1), pins 1-2 on ILIM jumper (J2), pins 2-3 on TMR jumper (J3). See Table 1, Table 2, Cycle-by-Cycle Overcurrent Limit and Table 3 for details. External Clock Synchronization (RT/SYNC) 6) Connect the positive terminal of the input power sup- Charger Status Flags (FLG1, FLG2) ply to the DCIN connector and the negative terminal Charging Current Monitoring (ISMON) to the nearest PGND connector. 7) Connect the positive terminal of the electronic load Output Overvoltage Protection (OVI) to the VOUT connector in series with DAM and the IC Overtemperature Protection negative terminal to the nearest PGND connector. Proven PCB Layout 8) Connect first DVM (DVM1) between the VOUT Fully Assembled and Tested connector and nearest PGND connector. Connect second DVM (DVM2) between the ISMON PCB pad and nearest SGND PCB pad. 9) Connect third DVM (DVM3) between the FLG1 PCB Ordering Information appears at end of data sheet. pad and nearest SGND PCB pad. Connect fourth DVM (DVM4) between the FLG2 PCB pad and near- est SGND PCB pad. 319-100560 Rev 3 4/21MAX17701EVKITA Evaluation Kit Evaluates: MAX17701 in 5V Output-Voltage Application 10) Turn on DC power supply. Figure 1, the input at which the charger controller of the IC turns on, can be set with a resistor-divider connected 11) The charger starts in CC mode. Observe that the to EN/UVLO from DCIN to PGND. The V is DCIN(MIN) DVM2 displays 1.5V, translates to 20A charging selected as 8.7V for this EV kit. current. Choose R1 as follows: 12) Verify that the FLG1 voltage displays 0V on DVM3 and FLG2 voltage displays 5V on DVM4, in CC R1(10000 V ) mode. DCIN(MIN) 13) The charger enters CV mode when V reaches CV where V is the voltage at which the device is FB DCIN(MIN) threshold (1.219V) and the charging current starts required to turn on. to fall from 20A. Observe that the voltage reading in Calculate the value of R2 using the following equation: DVM2 falls from 1.5V to 0.75V in CV mode. 14) Verify that both DVM3 and DVM4 displays 0V, in CV V R1 EN TH R R2 = mode. V V +(I R1) DCIN(MIN) EN TH R EN-BIAS 15) Verify that the current reading in DAM is 10A in both CC and CV modes. where: 16) The charger continues to regulate the output voltage I = Internal bias pullup current on the EN/ULVO EN-BIAS in CV mode and supercapacitors are fully charged. pin (3A) Verify that the DVM1 displays close to 5V. V = EN/UVLO pin rising threshold voltage EN TH R 17) During charging process, verify that the FLG1 (1.25V) voltage displays 0V on DVM3, which shows that For more details about setting the undervoltage lockout there is no fault. level, refer to the MAX17701 data sheet. 18) After testing is completed, switch off the power sup - ply. Remove the electronic load after supercapacitor voltage is discharged to 0V. VDCIN(MIN) TO VDCIN(MAX) Detailed Description DCIN MAX17701 The MAX17701EVKITA (EV kit) provides charging solu- R1 3A tion for supercapacitor with CC mode charging current of 20A and CV mode voltage of 5V from a 9V to 60V input EN/UVLO supply. The EV kit supports a continuous load current up R2 D1 to 10A at the output. The EV kit features a 350kHz switch- 4.7V ing frequency for optimum efficiency and component SGND/EP size. The RT/SYNC PCB pad allows an external clock to synchronize the device. The EV kit includes jumper J1 to enable/disable the controller. The FLG1 and FLG2 PCB pads allows to monitor the charger status. The ISMON Figure 1. Setting the Input Under Voltage Lockout PCB pad allows to monitor charging current. Table 1. EN/UVLO Jumper (J1) Settings Enable/Undervoltage-Lockout (EN/UVLO) Programming SHUNT EN/UVLO MAX17701 JUMPER POSITION PIN OUTPUT The EV kit offers an adjustable input undervoltage lockout feature. The EN/UVLO pin can be used to set a desired Connected to Enabled, UVLO input voltage at which the charger is enabled or disable the input level is set by the 1-2* the charger by pulling down EN/UVLO to SGND/EP. UVLO divider resistor divider from Figure 1 shows the input under voltage lockout setting J1 midpoint DCIN to SGND/EP on the EV kit. The EN/UVLO pin can be used as input Connected to undervoltage lockout detector with a typical hysteresis of 2-3 Disabled SGND/EP 160mV. To disable the MAX17701, install a shunt across pins 23 on J1. See Table 1 for J1 settings. As shown in *Default position Maxim Integrated 2 www.maximintegrated.com