19-1596; Rev 0; 3/00 MAX1645 Evaluation System The MAX1645 evaluation system (EV system) consists of a MAX1645 evaluation kit (EV kit) and a companion Maxim System Management Bus (SMBus™) interface board. The EV kit simplifies evaluation of the MAX1645 chemistry-independent Level 2 smart battery charger. The Maxim SMBus interface board (MAXSMBus) allows an IBM-compatible personal computer to use its parallel port to emulate an Intel SMBus 2-wire interface. Windows 95/98® software provides a user-friendly interface to exercise the MAX1645’s features. Order the MAX1645EVSYS for complete IBM PC-based evaluation of the MAX1645. Order the MAX1645EVKIT if you already have an SMBus interface. Features ♦ Charges Any Battery Chemistry: Li-Ion, NiCd, NiMH, Lead Acid, etc. ♦ SMBus-Compatible 2-Wire Serial Interface ♦ 3A max Battery Charge Current ♦ Up to 18.4V Battery Voltage ♦ Up to +28V Input Voltage ♦ Easy-to-Use Software Included ♦ Proven PC Board Layout ♦ Fully Assembled and Tested Surface-Mount Board EV System Component List Ordering Information PART TEMP. RANGE None 1 MAX1645 EV kit MAX1645EVKIT 0°C to +70°C 28 QSOP None 1 MAXSMBus interface MAX1645EVSYS 0°C to +70°C 28 QSOP DESIGNATION QTY DESCRIPTION IC PACKAGE EV Kit Component List DESIGNATION QTY DESCRIPTION DESIGNATION QTY DESCRIPTION 22µF, 35V low-ESR tantalum caps AVX TPSE226M035R0300 H1 1 2x10 right-angle female header H2 1 5-element terminal block 2 22µF, 25V low-ESR tantalum caps AVX TPSD226M025R0200 JU1, JU2, JU3 3 2-pin headers L1 1 3 1µF, 50V ceramic capacitors (1210) Murata GRM42-2X7R105K050 22µH, 3.6A inductor Sumida CDRH127-220 LED1 1 Red LED C6, C7, C12 3 1µF, 10V ceramic capacitors (0805) Taiyo Yuden LMK212BJ105MG N1 1 30V, 11.5A N-channel MOSFET Fairchild FDS6680 C8, C14, C15, C16 4 0.1µF, 16V ceramic capacitors (0603) Taiyo Yuden EMK107BJ104MA N2 1 30V, 8.4A N-channel MOSFET Fairchild FDS6612A C9, C10, C11 3 0.01µF ceramic capacitors (0603) C13 1 1500pF ceramic capacitor (0603) P1, P2 2 30V, 11A P-channel MOSFETs Fairchild FDS6675 C18, C23, C24 3 0.1µF, 50V ceramic capacitors (0805) Taiyo Yuden UMK212BJ104MG R1 1 0.040Ω ±1%, 0.5W resistor Dale WSL-2010/0.040Ω/1% D1, D2 2 40V, 2A Schottky diodes Central Semiconductor CMSH2-40 R2 1 0.050Ω ±1%, 0.5W resistor Dale WSL-2010/0.050Ω/1% D3, D4 2 Schottky diodes (SOT23) Central Semiconductor CMPSH-3 C1, C2 C3, C4 C5, C19, C20 2 R3, R4 2 100kΩ ±1% resistors (0603) R5, R7, R9, R10, R17 5 10kΩ ±5% resistors (0603) R6 1 10kΩ ±1% resistor (0603) SMBus is a registered trademark of Intel Corp. Windows 95/98 are registered trademarks of Microsoft Corp. ________________________________________________________________ Maxim Integrated Products 1 For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800. For small orders, phone 1-800-835-8769. Evaluates: MAX1645 General Description Evaluates: MAX1645 MAX1645 Evaluation System EV Kit Component List (cont.) DESIGNATION QTY DESCRIPTION R8, R13 2 1kΩ ±5% resistors (0603) R11, R16 2 1Ω ±5% resistors (0603) R12 1 33Ω ±5% resistor (0603) R14, R15 2 4.7Ω ±5% resistors (0603) Table 1. Jumper Functions JUMPER Closed* SCL pulled up to VDD through a 10kΩ resistor. U1 1 MAX1645EEI (28-pin QSOP) 3 Shunts (JU1, JU2, JU3) None 1 MAX1645 PC board None 1 MAX1645 data sheet None 1 MAX1645 EV kit data sheet None 1 MAX1645 EV kit software disk Open Closed* JU2 Open Closed* Component Suppliers PHONE FAX AVX 803-946-0690 803-626-3123 Central Semiconductor 516-435-1110 516-435-1824 Dale 402-564-3131 402-563-6418 Fairchild 408-822-2000 408-822-2102 Murata 814-237-1431 814-238-0490 Sumida 847-956-0666 847-956-0702 Taiyo Yuden 408-573-4150 408-573-4159 JU3 Open SCL not pulled up to VDD; SCL must be pulled up to external supply. SDA pulled up to VDD through a 10kΩ resistor. SDA not pulled up to VDD; SDA must be pulled up to external supply. 10kΩ resistor connected between thermistor and ground nodes, simulating the attachment of a smart battery. 10kΩ resistor disconnected; for use when an actual smart battery will be connected to the EV kit. *Indicates default jumper setting Note: Please indicate that you are using the MAX1645 when contacting the above component suppliers. Quick Start Required Equipment Before you begin, you will need the following equipment: • IBM PC-compatible computer capable of running Windows 95/98 • Parallel printer port (this is a 25-pin socket on the back of the computer) • Standard 25-pin, straight-through, male-to-female cable to connect the computer’s parallel port to the Maxim SMBus interface board • DC power supply capable of supplying +20V to +28V at 3A 2 FUNCTION JU1 None SUPPLIER STATE Procedure See Figure 1 as you follow these steps: 1) Carefully connect the boards by aligning the 20-pin connector of the MAX1645 EV kit with the 20-pin header of the MAXSMBus interface board. Gently press them together. The two boards should be flush against each other. 2) Verify that jumpers JU1, JU2, and JU3 are all shunted. JU1 and JU2 pull up the SMBus clock and data lines to the VDD supply. JU3 connects a 10kΩ resistor between the ground and thermistor nodes, making it appear to the MAX1645 as if a smart battery were connected. Table 1 describes the jumper functions. Caution: Do not turn on the power until all connections are made. 3) Connect a +20VDC to +28VDC power supply between the VIN pad and the adjacent GND pad on the MAX1645 EV kit board. 4) Connect a cable from the computer’s parallel port to the SMBus interface board. Use a straight-through, 25-pin, female-to-male cable. To avoid damaging the EV kit or your computer, do not use a 25-pin SCSI port or any other connector that is physically similar to the 25-pin parallel printer port. Note: Do not connect a power supply to the MAXSMBus board. Power is supplied through the MAX1645 EV kit board. _______________________________________________________________________________________ MAX1645 Evaluation System Evaluates: MAX1645 TO PC PARALLEL PORT DC POWER SUPPLY MAXSMBus - + GND VIN MAX1645 EVALUATION KIT LOAD VL DB-25M REF JU1 BATT JU2 JU3 GND LED1 (+) C D T (-) (+) C D S (-) SMART BATTERY Figure 1. Block Diagram of MAX1645 EV System _______________________________________________________________________________________ 3 Evaluates: MAX1645 MAX1645 Evaluation System 5) Install the MAX1645 EV kit software on your computer by running the INSTALL.EXE program on the floppy disk. This program copies the MAX1645 program file and creates an icon for it. 6) Turn on the power supply. Verify that LED1 turns on. 7) Start the MAX1645 program by opening its icon in the START MENU. The EV kit software automatically detects the correct port by testing for the pin 5 to pin 13 loopback. Verify that LED1 turns off, signifying that communication between the PC and the MAX1645 has been established. 8) The software should appear as shown in Figure 2. Verify that Charging Voltage = 65535mV, Charging Current = 128mA; HOT_STOP is checked; Voltage Polling, Current Polling, and Status Polling are checked; and the following checkboxes are checked in the Charger Status panel: VOLTAGE_NOTREG, VOLTAGE_OR, BATTERY_PRESENT, and AC_PRESENT. Detailed Description of Software Upon execution of the MAX1645 program, the software automatically resolves the SMBus address of the device. The software enables the command panel (Figure 2), after which the user may issue any of the allowed SMBus commands to the MAX1645. Refer to the MAX1645 data sheet for more information regarding the allowed SMBus commands. Command Panel ChargingVoltage() To issue the ChargingVoltage() command to the MAX1645, enter the desired voltage, in millivolts, into the Charging Voltage text edit box and select the adjacent [Send] button. By default, the software issues the ChargingVoltage() command three times a second. To enable/disable this feature, check/uncheck the Voltage Polling checkbox. If a smart battery is connected to the charger, the Charging Voltage value displayed will be identical to the value being broadcast by the smart battery. ChargingCurrent() To issue the ChargingCurrent() command to the MAX1645, enter the desired current, in milliamps, into the Charging Current text edit box and select the adjacent [Send] button. By default, the software issues the ChargingCurrent() command three times a second. To Figure 2. MAX1645 EV Kit Software Command Panel 4 _______________________________________________________________________________________ MAX1645 Evaluation System The Alert Response operation works as follows: the SMBus specification revision 1.0 describes an optional wired-or signal called SMBALERT that, in a typical system, is connected to all the devices and then pulled up to VDD. A SLAVE device can use this signal to notify the bus MASTER that it wants to communicate. It does this by pulling the SMBALERT line LOW. When the MASTER sees the SMBALERT line go LOW, it knows that one of the SLAVE devices wants attention, but not which one. To determine which SLAVE pulled the SMBALERT line LOW, the MASTER broadcasts the Alert Response Address (0x18) to all of the SLAVE devices on the bus using a modified RECEIVE BYTE operation. The SLAVE device wanting to communicate with the MASTER responds with its SMBus address (0x13) during the second byte of the modified RECEIVE BYTE operation. ChargerMode() To issue the ChargerMode() command to the MAX1645, select a combination of checkboxes in the Charger Mode panel of commands. Check the checkboxes next to commands for which the software should write a 1, uncheck the checkboxes next to commands for which the software should write a 0, and then select the [Send] button. AlarmWarning() To issue the AlarmWarning() command to the MAX1645, select the [Alarm Warning] button. This operation sends the AlarmWarning() command byte with a data word of 0x8000. ChargerStatus() On the right-hand side of the command panel, locate the Status Polling checkbox and the Charger Status panel. If the Status Polling checkbox is checked (the default setting), the software automatically issues the ChargerStatus() command three times a second, in which case the checkboxes in the Charger Status panel are automatically updated and always represent the charger’s current status. Unchecking the Status Polling checkbox disables automatic software polling. If polling is disabled, the user can issue the ChargerStatus() command to the MAX1645 by selecting the [Charger Status] button, which is adjacent to the Status Polling checkbox. AlertResponse() The MAX1645 has an external interrupt pin that is polled by the software if the Status Polling checkbox is checked. When an interrupt occurs, LED1 on the EV kit board illuminates. If polling is enabled, the software determines which event triggered the interrupt, clears the interrupt, and prints a diagnostic message in the Interrupts box. If polling is disabled and an interrupt occurs, the user can manually service the interrupt by selecting the [Alert Response] button. ChargerSpecInfo() To issue the ChargerSpecInfo() command to the MAX1645, select the [Spec Info] button. The response of the MAX1645 is displayed to the right of the [Spec Info] button. Communication with a Smart Battery If a smart battery is connected to the MAX1645 EV kit, the user may observe the status of the smart battery by selecting the [Battery] button. At this point, the smart battery window appears (Figure 3). If software polling of the charger’s status is enabled, the software also Figure 3. MAX1645 EV Kit Smart Battery Window _______________________________________________________________________________________ 5 Evaluates: MAX1645 enable/disable this feature, check/uncheck the Current Polling checkbox. If a smart battery is connected to the charger, the Charging Current value displayed will be identical to the value being broadcast by the smart battery. Note that when either Voltage Polling or Current Polling are checked, the action of issuing the ChargingVoltage() or ChargingCurrent() commands automatically services the watchdog timer. If both of these checkboxes are unchecked, the watchdog timer will eventually time out and charging will stop. For more information about the watchdog timer, refer to the MAX1645 data sheet. If the watchdog timer period of 175s is exceeded, reset the watchdog timer by issuing both the ChargingVoltage() and ChargingCurrent() commands. Evaluates: MAX1645 MAX1645 Evaluation System automatically polls the status of the smart battery, and the parameters displayed in the smart battery window always represent the current status of the smart battery. If polling is disabled, manually query the smart battery by selecting the [Update] button. When finished, select the [Done] button to return to the main MAX1645 user interface window. Serial Communications Interface When the user issues a command, the MAX1645 software first determines the command byte, then, if the command is a Write-Word type, the data word corresponding to the selected function. The software and MAX1645 device communicate serially through the MAXSMBus board. Refer to the MAX1645 data sheet for more information regarding the serial communications protocol. Detailed Description of Hardware Input Current Limiting The MAX1645 EV kit is configured to regulate the battery current so that the total V IN input current does not exceed 2.5A. If a load is connected across the LOAD and GND pads (another system power supply, for example) that would cause the total current from VIN to exceed 2.5A, the MAX1645 will automatically decrease its charging current to regulate the input current to 2.5A. Refer to the MAX1645 data sheet for more information regarding input current limiting. Connecting an Electronic Load If a smart battery is unavailable, an electronic load can be connected across the BATT and GND pads on the MAX1645 EV kit board. Make sure that the EV kit power is turned off before connecting a load. Make sure that JU3 is shunted, making it appear to the MAX1645 as if a smart battery were connected. After the load is connected, program the load in voltage mode and set the electronic load to clamp at 5V. Turn on the power to the EV kit, and program the MAX1645 with a charging voltage of 12V at the maximum charging current. Verify that the MAX1645 is supplying the maximum current to the load. Increase the electronic load clamp voltage in 1V increments, and verify that as the electronic load voltage crosses 12V, the MAX1645 transitions from current regulation to voltage regulation; as the electronic load voltage increases beyond 12V, the BATT voltage should remain fixed at 12V. Layout Considerations The MAX1645 EV kit layout is optimized for fast switching and high currents. The traces connecting the power components must be able to carry at least 3A. Take care to ensure that C1 and C2 (the input capacitors), D2 and N2 (the synchronous rectifier), and C3 and C4 (the output capacitors) are all connected to GND at a common point, and to isolate the power GND from the quiet analog GND. Connecting a Smart Battery The MAX1645 EV kit includes a five-element terminal block to facilitate connecting the EV kit to a smart battery. Refer to the smart battery specification to identify the type of smart battery connector suited to your application. Make sure that the EV kit power is turned off, and connect the (+), C, D, T, and (-) terminals from the EV kit board to the smart battery connector using no more than 2 inches of wire. Remove the JU3 shunt, attach a smart battery to the smart battery connector, and turn the EV kit power back on. See Figure 1 if necessary. 6 _______________________________________________________________________________________ MAX1645 Evaluation System LDO 2 LDO C6 1µF 8 1 DCIN LDO C23 0.1µF 50V GND C7 1µF U1 R3 100k 1% C15 0.1µF 3 CLS 10 DAC R4 C8 100k 1% 0.1µF R5 10k C9 0.01µF 7 6 C10 0.01µF 5 C11 0.01µF H1-1 H1-2 11 C12 R6 1µF 10k 1% C13 1500pF H1-4 12 R7 10k H1-5 REF MAX1645 P1 R14 4.7Ω 28 CVS 27 PDS 26 CSSP CSSN 4 REF = 3A TRACES VIN R13 1k BST C20 1µF 50V 25 DLOV C14 0.1µF N1 CSIP CCS CSIN SCL 13 R12 33Ω LDO C16 0.1µF N2 D2 L1 22µH R11 1Ω 18 C18 0.1µF 50V 17 R16 1Ω C24 0.1µF 50V VDD THM INT 15 C2 22µF 35V D3 21 PGND 19 CCI C1 22µF 35V 22 DLO 20 CCV R1 0.040Ω 1% 1/2W R15 4.7Ω C19 1µF 50V 24 DHI 23 LX D1 PDL 16 9 BATT SDA 14 R2 0.050Ω 1% 1/2W LOAD LOAD P2 C3 22µF 25V BATT C4 22µF 25V H1-6 H1-3 H1-7 JU3 LOAD H1-20 R17 10k R8 1k JU1 JU2 GND LED1 H2 R9 10k GND (+) C D T (-) R10 10k Figure 4. MAX1645 EV Kit Schematic _______________________________________________________________________________________ 7 Evaluates: MAX1645 D4 C5 1µF 50V Evaluates: MAX1645 MAX1645 Evaluation System 1.0" Figure 5. MAX1645 EV Kit Component Placement Guide— Component Side 1.0" Figure 7. MAX1645 EV Kit PC Board Layout—Component Side 8 1.0" Figure 6. MAX1645 EV Kit Component Placement Guide— Solder Side 1.0" Figure 8. MAX1645 EV Kit PC Board Layout—Solder Side _______________________________________________________________________________________