* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Evaluates: MAX8725 MAX8725 Evaluation Kit General Description Features
Survey
Document related concepts
History of electric power transmission wikipedia , lookup
Schmitt trigger wikipedia , lookup
Electrical ballast wikipedia , lookup
Power electronics wikipedia , lookup
Electric battery wikipedia , lookup
Voltage regulator wikipedia , lookup
Resistive opto-isolator wikipedia , lookup
Voltage optimisation wikipedia , lookup
Switched-mode power supply wikipedia , lookup
Stray voltage wikipedia , lookup
Surge protector wikipedia , lookup
Rechargeable battery wikipedia , lookup
Power MOSFET wikipedia , lookup
Mains electricity wikipedia , lookup
Current source wikipedia , lookup
Alternating current wikipedia , lookup
Buck converter wikipedia , lookup
Transcript
19-0292; Rev 0; 5/05 MAX8725 Evaluation Kit Features The MAX8725 evaluation kit (EV kit) is an accurate and efficient multichemistry battery charger. The EV kit can charge three or four series Li+ cells with a current up to 3A. Charge current and input-source current are adjustable using on-board potentiometers. The output voltage is set to 4.2V ✕ the number of series cells in the battery pack. The number of series cells is jumper selectable. The output voltage is adjustable between 4V to 4.4V (✕ the number of series cells) by installing two resistors. The EV kit provides outputs to monitor the ACadapter current and the presence of an AC adapter. The MAX8725 automatically selects the power path for supplying power to the system by controlling two external p-channel MOSFETs. This decision is made based on the presence of an AC adapter. ♦ Input Current Limiting ♦ ±0.5% Output Voltage Accuracy Using Internal Reference ♦ Automatic Selection of System Power Source ♦ Analog Inputs Control Charge Current and Charge Voltage ♦ Monitor Outputs for AC Adapter Current AC Adapter Presence ♦ Up to 17.6V Battery Voltage ♦ +8V to +25V Input Voltage ♦ Up to 3A Battery-Charge Current ♦ Charges Li+, NiCd, and NiMH Battery Chemistries ♦ Surface-Mount Construction ♦ Fully Assembled and Tested Ordering Information PART TEMP RANGE MAX8725EVKIT 0°C to +70°C IC PACKAGE 28 Thin QFN Component List DESIGNATION QTY DESCRIPTION C1, C2 2 10µF ±20%, 25V X5R ceramic capacitors (1812) Taiyo Yuden TMK432BJ106KM, TDK C4532X5R1E106M C3 0 Not installed (2220) C4 1 22µF ±20%, 25V ceramic capacitor (2220) TDK C5750X5R1E226M C5, C6 0 Not installed, E-size capacitors C7, C8, C9 C13, C14, C15 0 Not installed, capacitors (0603) 3 1µF ±10%, 6.3V X5R ceramic capacitors (0603) Murata GRM188R60J105K, Taiyo Yuden JMK107BJ105KA, TDK C1608X5R1A105K 3 0.1µF ±10%, 25V X7R ceramic capacitors (0603) Murata GRM188R71E104K, TDK C1608X7R1E104K C10, C11, C21 C12, C17, C18 DESIGNATION QTY DESCRIPTION 1 1µF ±10%, 25V X7R ceramic capacitor (1206) Murata GRM31MR71E105K, Taiyo Yuden TMK316BJ105KL, TDK C3216X7R1E105K 2 0.01µF ±10%, 50V X7R ceramic capacitors (0603) Murata GRM188R71H103K, Taiyo Yuden UMK107B103KZ, TDK C1608X7R1H103K 1 2.2µF ±20%, 35V tantalum capacitor (B-size) AVX TAJB225M035 Kemet T491B225M035AS D1 1 Schottky diode, 0.5A, 30V SOD-123 Diodes Inc. B0530W, General Semiconductor MBR0530, ON Semiconductor MBR0530 D2 0 Not installed C16 C19, C20 C22 ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 Evaluates: MAX8725 General Description Evaluates: MAX8725 MAX8725 Evaluation Kit Component List (continued) DESIGNATION QTY DESCRIPTION J1 1 Smart battery header assembly, right angle, keyless, five position Tyco Electronics (AMP) 787441-1 JU1, JU2 2 2-pin headers JU3 0 Not installed 1 10µH, 4.4A inductor Sumida CDRH104R-100NC, TOKO 919AS-100M 1 Single, n-channel, 8.4A, 30V, 8-pin SO MOSFET Fairchild FDS6612A L1 N1 P1 1 P2, P3, P4 3 Single, p-channel, -5.3A, -30V, 8-pin SO MOSFET Fairchild FDS9435A Single, p-channel, -11A, -30V, 8-pin SO MOSFETs Fairchild FDS6675 DESIGNATION QTY DESCRIPTION 1 0.01Ω ±1%, 0.5W sense resistor (2010) Vishay Dale WSL2010 0.010 1.0%, IRC LRC-LR2010-01-R010-F R2 1 0.015Ω ±1%, 0.5W sense resistor (2010) Vishay Dale WSL2010 0.015 1.0%, IRC LRC-LR2010-01-R015-F R3, R4, R8, R13, R14, R15, R17–R23 0 Not installed, resistors (0603) R5 1 590kΩ ±1% resistor (0603) R6 1 196kΩ ±1% resistor (0603) R1 R7, R12 2 50kΩ potentiometers (multiturn) R9, R10, R11 3 10kΩ ±5% resistors (0603) R16 1 33Ω ±5% resistor (0603) R24 1 10Ω ±5% resistor (0603) U1 1 MAX8725ETI (28-pin thin QFN-EP) Component Suppliers SUPPLIER PHONE FAX AVX 843-946-0238 843-626-3123 WEBSITE www.avxcorp.com Diodes Inc. 805-446-4800 805-381-3899 www.diodes.com Fairchild Semiconductor 888-522-5372 — www.fairchildsemi.com General Semiconductor International Resistive Co. 760-804-9258 760-804-9259 www.gensemi.com 361-992-7900 361-992-3377 www.irctt.com Kemet 864-963-6300 864-963-6322 www.kemet.com Murata 770-436-1300 770-436-3030 www.murata.com ON Semiconductor 602-244-6600 602-244-4545 www.onsemi.com Sumida 847-545-6700 847-545-6720 www.sumida.com Taiyo Yuden 800-348-2496 847-925-0899 www.t-yuden.com TDK 847-803-6100 847-390-4405 www.component.tdk.com TOKO 847-297-0070 847-699-1194 www.tokoam.com Vishay Dale 402-564-3131 402-563-6296 www.vishay.com Note: Indicate you are using the MAX8725 when contacting these manufacturers. 2 _______________________________________________________________________________________ MAX8725 Evaluation Kit Table 1. Jumper Selection Required Equipment Before beginning, the following equipment is required: • DC source to supply the input current to the charger; this source must be capable of supplying a voltage greater than the battery-voltage set point and have sufficient current rating • Voltmeter • Battery pack or load JUMPER JU1 JU2 JUMPER POSITION Closed* MODE = LDO. Cell count = 4. Open MODE = float. Cell count = 3. Closed* PKPRES = GND. MAX8725 enabled. Open PKPRES connected to LDO through 10kΩ pullup resistor. The MAX8725 is disabled unless the battery thermistor is connected to THRM. Procedure The MAX8725 EV kit is a fully assembled and tested surface-mount board. Follow the steps below to verify board operation. Do not turn on the power supply until all connections are completed. Observe all precautions on the battery manufacturer’s data sheet: 1) Set jumper JU1 to indicate the number of cells in the battery pack (Table 1). Closed* VCTL = LDO. Battery-regulation (shorted by voltage set to 4.2V x the number of PC trace) cells. JU3 Open 2) Remove the shunt on JU2 to disable the MAX8725. 3) The battery-regulation voltage is set to 4.2V per cell. If a different voltage is required, see the Battery Regulation Voltage section. 4) The charge current is set to 3A. If a different current is required, see the Charging Current Limit section. 5) The source current is set to 5A. If a different current is required, see the Source Current Limit section. 6) Connect the input current supply across the ADAPTER_IN and PGND pads. 7) Connect a battery pack or load between the BATT+ and BATT- pads. 8) Turn on the power supply. 9) Enable the MAX8725 by installing the shunt on JU2. 10) Verify current is being delivered to the battery. Detailed Description The MAX8725 includes all the functions necessary to charge Li+ batteries. The EV kit is shipped with a charge current of 3A and a battery-regulation voltage of 4.2V x the number of cells in the battery pack. The MAX8725 includes a battery-conditioning feature, which allows for the relearning of the battery-pack capacity. For more information on the operation of the MAX8725, refer to the Detailed Description section of the MAX1909/MAX8725 data sheet. Jumper JU1 Jumper JU1 selects the number of series cells to be charged. See Table 1 for jumper settings. FUNCTION Battery-regulation voltage can be set between 4V and 4.4V x the number of cells. Resistors R3 and R4 must be installed. *Default position. Jumper JU2 Jumper JU2 controls the pack-presence PKPRES pin. A shunt on JU2 enables the MAX8725. Removing the shunt places the MAX8725 in shutdown mode. If the battery pack used with the MAX8725 EV kit has a thermistor, remove the shunt on JU2 and connect the thermistor to the THRM pad. Jumper JU3 Jumper JU3 connects VCTL to LDO. This sets the battery-regulation voltage to 4.2V x the number of cells. The battery-regulation voltage can be set between 4.0V and 4.4V (x the number of cells) by cutting the short across JU3 and installing resistors at R3 and R4. See the Battery-Regulation Voltage section for more information. Battery-Regulation Voltage The default battery-regulation voltage on the MAX8725 EV kit is 4.2V x the number of cells. To set it to a value between 4.0V and 4.4V (x the number of cells), remove the shunt on JU1 and install resistors at R3 and R4. Use the following equation to calculate the resistor values: 5 . 4 R3 = R4 − 1 VBATT − 4.223 + 1.8 9.523 CELLS _______________________________________________________________________________________ 3 Evaluates: MAX8725 Quick Start Evaluates: MAX8725 MAX8725 Evaluation Kit V BATT is the desired battery-regulation voltage and CELLS is the number of cells selected by jumper JU1. Choose 1% resistors with a total resistance less than 250kΩ to minimize error caused by bias current. For VBATT / CELLS = 4, use 100kΩ for R4 and leave R3 uninstalled. Source Current Limit (Potentiometer R12) Potentiometer R12 is connected to CLS, the source current-limit input. Adjusting R12 allows the input current limit to be set between 3.75A and 7.5A. Refer to the Setting the Input Current Limit section of the MAX1909/MAX8725 data sheet for more information. For VBATT / CELLS = 4.4, use 100kΩ for R4 and 49.9kΩ for R3. Charging Current Limit (Potentiometer R7) The default charging current limit on the MAX8725 EV kit is 3A. To set it to a value between 0.156A and 5A, adjust potentiometer R7. Refer to the Setting the Charging Current Limit section of the MAX1909/ MAX8725 data sheet for more information. Note: 5A charging current requires a different inductor. 4 _______________________________________________________________________________________ _______________________________________________________________________________________ BATT+ SCL SDA THM THM BATT- GND C6 OPEN J1-10 J1-5 J1-4 J1-9 J1-3 J1-8 J1-2 J1-7 J1-1 J1-6 SMART BATTERY CONNECTOR PGND C5 OPEN ADAPTER_IN IINP THRM ACOK MODE R4 OPEN R3 OPEN C22 2.2µF R10 10kΩ THM R8 OPEN 2 4 JU1 7 8 PKPRES ACOK MODE ICTL VCTL ACIN R11 10kΩ 13 CSSN C19 0.01µF R23 SHORT PC TRACE 14 CCS C21 1µF REF 4 C9 OPEN C20 0.01µF MAX8725 U1 25 CSSP C8 OPEN R15 SHORT PC TRACE 26 CCI 12 R22 SHORT PC TRACE CCV 8 IINP 5 6 7 10 11 3 C18 0.1µF LDO C17 0.1µF C7 OPEN R14 SHORT PC TRACE 27 24 SRC PDS 1 DCIN C16 1µF 5 6 P4 R13 SHORT PC TRACE JU2 R9 10kΩ LDO D1 SRC 1 2 3 LDO R6 196kΩ 1% REF R24 10Ω 1 4 P3 2 3 3 R7 50kΩ 1 JU3 SHORT R5 590kΩ 1% LDO D2 OPEN 7 8 5 6 1 R12 50kΩ 2 REF 9 3 CSIN CSIP PGND DLO DHI DLOV LDO PDL C12 0.1µF 15 BATT CLS GND DHIV 22 SRC 16 17 18 19 20 23 21 2 28 CLS C15 OPEN C13 OPEN R18 SHORT PC TRACE R17 SHORT PC TRACE C10 1µF R21 SHORT PC TRACE 4 3 6 78 5 4 1 C11 1µF R16 33Ω 3 P1 8 7 65 N1 1 2 2 C3 OPEN R20 SHORT PC TRACE C14 R19 OPEN SHORT PC TRACE LDO R2 0.015Ω 1% L1 10µH C2 10µF 5 6 C4 22µF P2 4 1 C1 10µF 7 8 2 3 BATT- BATT+ LOAD Evaluates: MAX8725 R1 0.01Ω 1% MAX8725 Evaluation Kit Figure 1. MAX8725 EV Kit Schematic 5 Evaluates: MAX8725 MAX8725 Evaluation Kit Figure 2. MAX8725 EV Kit Component Placement Guide— Component Side Figure 3. MAX8725 EV Kit PC Board Layout—Component Side Figure 4. MAX8725 EV Kit PC Board Layout—Signal and Ground Layer 2 Figure 5. MAX8725 EV Kit PC Board Layout—Ground Layer 3 6 _______________________________________________________________________________________ MAX8725 Evaluation Kit Evaluates: MAX8725 Figure 6. MAX8725 EV Kit PC Board Layout—Solder Side Figure 7. MAX8725 EV Kit Component Placement Guide— Solder Side Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 7 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.