MAX1645E

MAX1645 Evaluation System

General Description

Features

The MAX1645 evaluation system (EV system) consists ofa MAX1645 evaluation kit (EV kit) and a companionoCharges Any Battery Chemistry: Li-Ion, NiCd,Maxim System Management Bus (SMBus™) interfaceNiMH, Lead Acid, etc.board. The EV kit simplifies evaluation of the MAX1645oSMBus-Compatible 2-Wire Serial Interfacechemistry-independent Level 2 smart battery charger.The Maxim SMBus interface board (MAXSMBus) allowso3A max Battery Charge Currentan IBM-compatible personal computer to use its paral-oUp to 18.4V Battery Voltagelel port to emulate an Intel SMBus 2-wire interface.Windows 95/98®software provides a user-friendly inter-oUp to +28V Input Voltageface to exercise the MAX1645’s features.

oEasy-to-Use Software IncludedOrder the MAX1645EVSYS for complete IBM PC-basedoProven PC Board Layout

evaluation of the MAX1645. Order the MAX1645EVKIT ifyou already have an SMBus interface.

oFully Assembled and Tested Surface-Mount Board

EV System Component List

Ordering Information

DESIGNATIONQTY

DESCRIPTION

PARTTEMP. RANGEIC PACKAGENone1MAX1645 EV kitMAX1645EVKIT0°C to +70°C28 QSOPNone

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MAXSMBus interface

MAX1645EVSYS0°C to +70°C28 QSOPEV Kit Component List

DESIGNATIONQTYDESCRIPTIONDESIGNATIONQTYDESCRIPTIONC1, C2222µF, 35V low-ESR tantalum capsH112x10 right-angle female headerAVX TPSE226M035R0300H215-element terminal blockC3, C4222µF, 25V low-ESR tantalum capsJU1, JU2, JU332-pin headersAVX TPSD226M025R020022µH, 3.6A inductorC5, C19, C2031µF, 50V ceramic capacitors (1210)L11Sumida CDRH127-220Murata GRM42-2X7R105K050LED11Red LEDC6, C7, C1231µF, 10V ceramic capacitors (0805)Taiyo Yuden LMK212BJ105MGN1130V, 11.5A N-channel MOSFETFairchild FDS6680C8, C14, C15,0.1µF, 16V ceramic capacitors (0603)C164Taiyo Yuden EMK107BJ104MAN2130V, 8.4A N-channel MOSFETFairchild FDS6612AC9, C10, C1130.01µF ceramic capacitors (0603)C1311500pF ceramic capacitor (0603)P1, P2230V, 11A P-channel MOSFETsFairchild FDS6675C18, C23, C2430.1µF, 50V ceramic capacitors (0805)Taiyo Yuden UMK212BJ104MGR110.040Ω±1%, 0.5W resistorDale WSL-2010/0.040Ω/1%D1, D2240V, 2A Schottky diodesCentral Semiconductor CMSH2-40R210.050Ω±1%, 0.5W resistorDale WSL-2010/0.050Ω/1%D3, D42Schottky diodes (SOT23)R3, R42100kΩ±1% resistors (0603)Central Semiconductor CMPSH-3R5, R7, R9,R10, R17510kΩ±5% resistors (0603)R6110kΩ±1% resistor (0603)SMBus is a registered trademark of Intel Corp.

Windows 95/98 are registered trademarks of Microsoft Corp.

________________________________________________________________Maxim Integrated Products

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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: MAX1645MAX1645 Evaluation System Evaluates: MAX1645EV Kit Component List (cont.)DESIGNATIONQTYR8, R13R11, R16R12R14, R15U1NoneNoneNoneNoneNone2212131111DESCRIPTION1kΩ±5% resistors (0603)1Ω±5% resistors (0603)33Ω±5% resistor (0603)4.7Ω±5% resistors (0603)MAX1645EEI (28-pin QSOP)Shunts (JU1, JU2, JU3)MAX1645 PC boardMAX1645 data sheetMAX1645 EV kit data sheetMAX1645 EV kit software diskJU2OpenClosed*JU1OpenTable 1. Jumper Functions

JUMPER STATEClosed*FUNCTIONSCL pulled up to VDDthrougha 10kΩresistor.SCL not pulled up to VDD;SCL must be pulled up toexternal supply.SDA pulled up to VDDthrougha 10kΩresistor.SDA not pulled up to VDD;SDA must be pulled up toexternal supply.10kΩresistor connectedbetween thermistor and groundnodes, simulating the attach-ment of a smart battery.10kΩresistor disconnected;for use when an actual smartbattery will be connected tothe EV kit.Component Suppliers

SUPPLIERAVXCentralSemiconductorDaleFairchildMurataSumidaTaiyo YudenPHONE803-946-0690516-435-1110402-564-3131408-822-2000814-237-1431847-956-0666408-573-4150FAX803-626-3123516-435-1824402-563-6418408-822-2102814-238-0490847-956-0702408-573-4159JU3Closed*Open*Indicates default jumper settingProcedure

See Figure 1 as you follow these steps:

1)Carefully connect the boards by aligning the 20-pinconnector of the MAX1645 EV kit with the 20-pinheader of the MAXSMBus interface board. Gentlypress them together. The two boards should be flushagainst each other.

2)Verify that jumpers JU1, JU2, and JU3 are allshunted. JU1 and JU2 pull up the SMBus clock anddata lines to the VDDsupply. JU3 connects a 10kΩresistor between the ground and thermistor nodes,making it appear to the MAX1645 as if a smart batterywere connected. Table 1 describes the jumper func-tions.Caution: Do not turn on the power until all connec-tionsare made.

3)Connect a +20VDC to +28VDC power supplybetween the VIN pad and the adjacent GND pad onthe MAX1645 EV kit board.

4)Connect a cable from the computer’s parallel port tothe SMBus interface board. Use a straight-through,25-pin, female-to-male cable. To avoid damaging theEV kit or your computer, do not use a 25-pin SCSIport or any other connector that is physically similarto the 25-pin parallel printer port.

Note:Do not connect a power supply to the MAXSMBus board. Power is supplied through theMAX1645 EV kit board.

Note:Please indicate that you are using the MAX1645 whencontacting the above component suppliers.Quick Start

Required Equipment

Before you begin, you will need the following equip-ment:

•IBM PC-compatible computer capable of runningWindows 95/98

•Parallel printer port (this is a 25-pin socket on theback of the computer)•Standard 25-pin, straight-through, male-to-femalecable to connect the computer’s parallel port to theMaxim SMBus interface board•DC power supply capable of supplying +20V to+28V at 3A

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MAX1645 Evaluation System

TO PCPARALLEL PORTDC POWER SUPPLY-+MAXSMBusGNDVINMAX1645 EVALUATION KITLOADVLDB-25MREFJU1JU2BATTJU3GNDLED1(+)CDT(-)(+)CDS(-)SMART BATTERYFigure 1. Block Diagram of MAX1645 EV System

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Evaluates: MAX1645MAX1645 Evaluation System Evaluates: MAX16455)Install the MAX1645 EV kit software on your comput-er by running the INSTALL.EXEprogram on the flop-py disk. This program copies the MAX1645 programfile 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 inthe START MENU. The EV kit software automaticallydetects the correct port by testing for the pin 5 to pin13 loopback. Verify that LED1 turns off, signifyingthat communication between the PC and theMAX1645 has been established.

8)The software should appear as shown in Figure 2.Verify that Charging Voltage = 65535mV, ChargingCurrent = 128mA; HOT_STOP is checked; VoltagePolling, Current Polling, and Status Polling arechecked; and the following checkboxes are checkedin the Charger Status panel: VOLTAGE_NOTREG,VOLTAGE_OR, BATTERY_PRESENT, and AC_PRE-SENT.

device. The software enables the command panel(Figure 2), after which the user may issue any of theallowed SMBus commands to the MAX1645. Refer tothe MAX1645 data sheet for more information regardingthe allowed SMBus commands.

Command Panel

ChargingVoltage()

To issue the ChargingVoltage() command to theMAX1645, enter the desired voltage, in millivolts, into theCharging Voltage text edit box and select the adjacent[Send] button. By default, the software issues theChargingVoltage() command three times a second. Toenable/disable this feature, check/uncheck the VoltagePolling checkbox. If a smart battery is connected to thecharger, the Charging Voltage value displayed will beidentical to the value being broadcast by the smart bat-tery.

ChargingCurrent()

To issue the ChargingCurrent() command to theMAX1645, enter the desired current, in milliamps, intothe Charging Current text edit box and select the adja-cent [Send] button. By default, the software issues theChargingCurrent() command three times a second. To

Detailed Description

of SoftwareUpon execution of the MAX1645 program, the softwareautomatically resolves the SMBus address of the

Figure 2. MAX1645 EV Kit Software Command Panel4

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MAX1645 Evaluation System

enable/disable this feature, check/uncheck the CurrentThe Alert Response operation works as follows: thePolling checkbox. If a smart battery is connected to theSMBus specification revision 1.0 describes an optionalcharger, the Charging Current value displayed will bewired-or signal called SMBALERT that, in a typical sys-identical to the value being broadcast by the smart bat-tem, is connected to all the devices and then pulled uptery.

to VNote that when either Voltage Polling or Currentbus MASTER that it wants to communicate. It does thisDD. A SLAVE device can use this signal to notify thePolling are checked, the action of issuing theby pulling the SMBALERT line LOW. When the MASTERChargingVoltage() or ChargingCurrent() commandssees the SMBALERT line go LOW, it knows that one ofautomatically services the watchdog timer. If both ofthe SLAVE devices wants attention, but not which one.these checkboxes are unchecked, the watchdog timerTo determine which SLAVE pulled the SMBALERT linewill eventually time out and charging will stop. For moreLOW, the MASTER broadcasts the Alert Responseinformation about the watchdog timer, refer to theAddress (0x18) to all of the SLAVE devices on the busMAX1645 data sheet. If the watchdog timer period ofusing a modified RECEIVE BYTE operation. The SLAVE175s is exceeded, reset the watchdog timer by issuingdevice wanting to communicate with the MASTERboththe ChargingVoltage() and ChargingCurrent()responds with its SMBus address (0x13) during thecommands.

second byte of the modified RECEIVE BYTE operation.ChargerMode()

AlarmWarning()

To issue the ChargerMode() command to the MAX1645,To issue the AlarmWarning() command to theselect a combination of checkboxes in the ChargerMAX1645, select the [Alarm Warning] button. ThisMode panel of commands. Check the checkboxes nextoperation sends the AlarmWarning() command byteto commands for which the software should write a 1,with a data word of 0x8000.

uncheck the checkboxes next to commands for whichthe software should write a 0, and then select the [Send]ChargerSpecInfo()

button.

To issue the ChargerSpecInfo() command to theMAX1645, select the [Spec Info] button. The responseChargerStatus()

of the MAX1645 is displayed to the right of the [SpecOn the right-hand side of the command panel, locateInfo] button.

the Status Polling checkbox and the Charger Statuspanel. If the Status Polling checkbox is checked (theCommunication with a Smart Battery

default setting), the software automatically issues theIf a smart battery is connected to the MAX1645 EV kit,ChargerStatus() command three times a second, inthe user may observe the status of the smart battery bywhich case the checkboxes in the Charger Statusselecting the [Battery] button. At this point, the smartpanel are automatically updated and always representbattery window appears (Figure 3). If software pollingthe charger’s current status. Unchecking the Statusof the charger’s status is enabled, the software also

Polling checkbox disables automatic software polling.If polling is disabled, the user can issue theChargerStatus() command to the MAX1645 by select-ing the [Charger Status] button, which is adjacent tothe Status Polling checkbox.

AlertResponse()

The MAX1645 has an external interrupt pin that ispolled by the software if the Status Polling checkbox ischecked. When an interrupt occurs, LED1 on the EV kitboard illuminates. If polling is enabled, the softwaredetermines which event triggered the interrupt, clearsthe interrupt, and prints a diagnostic message in theInterrupts box. If polling is disabled and an interruptoccurs, the user can manually service the interrupt byFigure 3. MAX1645 EV Kit Smart Battery Window

selecting the [Alert Response] button.

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Evaluates: MAX1645MAX1645 Evaluation System Evaluates: MAX1645automatically polls the status of the smart battery, andthe parameters displayed in the smart battery windowalways represent the current status of the smart battery.If polling is disabled, manually query the smart batteryby selecting the [Update] button. When finished, selectthe [Done] button to return to the main MAX1645 userinterface window.

Connecting an Electronic Load

If a smart battery is unavailable, an electronic load canbe connected across the BATT and GND pads on theMAX1645 EV kit board. Make sure that the EV kit poweris turned off before connecting a load. Make sure thatJU3 is shunted, making it appear to the MAX1645 as ifa smart battery were connected. After the load is con-nected, program the load in voltage mode and set theelectronic load to clamp at 5V. Turn on the power to theEV kit, and program the MAX1645 with a charging voltageof 12V at the maximum charging current. Verify that theMAX1645 is supplying the maximum current to theload. Increase the electronic load clamp voltage in 1Vincrements, and verify that as the electronic load voltagecrosses 12V, the MAX1645 transitions from current regu-lation to voltage regulation; as the electronic load voltageincreases beyond 12V, the BATT voltage should remainfixed at 12V.

Serial Communications Interface

When the user issues a command, the MAX1645 soft-ware first determines the command byte, then, if thecommand is a Write-Word type, the data word corre-sponding to the selected function. The software andMAX1645 device communicate serially through theMAXSMBus board. Refer to the MAX1645 data sheetfor more information regarding the serial communica-tions protocol.

Detailed Description

of HardwareInput Current Limiting

The MAX1645 EV kit is configured to regulate the batterycurrent so that the total VINinput current does notexceed 2.5A. If a load is connected across the LOADand GND pads (another system power supply, forexample) that would cause the total current from VINtoexceed 2.5A, the MAX1645 will automatically decreaseits charging current to regulate the input current to2.5A. Refer to the MAX1645 data sheet for more infor-mation regarding input current limiting.

Layout Considerations

The MAX1645 EV kit layout is optimized for fast switchingand high currents. The traces connecting the powercomponents must be able to carry at least 3A. Takecare 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 acommon point, and to isolate the power GND from thequiet analog GND.

Connecting a Smart Battery

The MAX1645 EV kit includes a five-element terminalblock to facilitate connecting the EV kit to a smart battery.Refer to the smart battery specification to identify thetype of smart battery connector suited to your application.Make sure that the EV kit power is turned off, and connectthe (+), C, D, T, and (-) terminals from the EV kit boardto the smart battery connector using no more than 2inches of wire. Remove the JU3 shunt, attach a smartbattery to the smart battery connector, and turn the EVkit power back on. See Figure 1 if necessary.

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MAX1645 Evaluation System

C5D41µFVIN= 3A TRACES50VR131kLDOC23P1D10.1µFR14150V284.7ΩLDO2LDODCINCVSPDS27C20R1C61µFR150.040Ω1µF8GNDCSSP2650V4.7Ω1%CSSN25C191/2WREF41µF 50VC7REF24C1C21µFR3U1BSTC14100kDHI230.1µF22µF22µFN135V35V1%MAX1645C153LX22R120.1µFR410CLSDACD333Ω100kC8DLOV21LDO1%0.1µFC1670.1µFL1CCVDLO20N2D222µHR510k6C10CCIPGND19R11C90.01µF1Ω0.01µF518C18R2C11CCSCSIP0.1µFR160.050ΩLOAD0.01µF50V1Ω1%CSIN171/2WLOADH1-111C24C12R6C13VDD0.1µFH1-21µF10k1500pF50V1%12PDL16P2H1-4THMBATT9R7C4BATTH1-510kINTSCLSDAC315131422µF22µF25V25VH1-6H1-3H1-7R8GNDJU31kLED1H2GNDLOADH1-20R17R9(+)CDT(-)10kJU110kR10JU210kFigure 4. MAX1645 EV Kit Schematic

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Evaluates: MAX1645MAX1645 Evaluation System Evaluates: MAX16451.0\"1.0\"Figure 5. MAX1645 EV Kit Component Placement Guide—Component SideFigure 6. MAX1645 EV Kit Component Placement Guide—Solder Side

1.0\"1.0\"Figure 7. MAX1645 EV Kit PC Board Layout—Component SideFigure 8. MAX1645 EV Kit PC Board Layout—Solder Side

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