9-44; Rev ; 0/0 MAX890A Evaluation Kit General Description The MAX890A evaluation kit (EV kit) is a fully assembled and tested circuit board for evaluating the A, -cell Li+ DC-DC battery charger. The EV kit charges a single-cell lithium-ion (Li+) battery from a DC input (AC adaptor) or a USB 00mA/500mA source and provides system power from the DC input, USB input, or battery. Battery charge current and SYS current limit are independently set. Charge current and DC converter output current limit can be set up to A, respectively. The USB input current can be set to 00mA or 500mA and USB suspend mode is also supported. Power not used by the system is available to charge the battery. The EV kit comes standard with the MAX890A installed. However, the EV kit can also be used to evaluate the MAX890B MAX890E and MAX890Y by replacing the MAX890A (U) with the preferred IC. Figure. MAX890A EV Kit Photo Features DC-DC Converter Output Current-Limit Adjustment Range of 0.5A to A (EV Kit Standard Configuration: A) Battery Charger Current-Limit Adjustment Range of 0.5A to A (EV Kit Standard Configuration: A) USB Current Limit of 00mA or 500mA Efficient 4MHz Switching DC-DC Converter Powers System Load and Charger Instant On Works with No Battery or Low Battery 8-Pin, 4mm x 4mm Thin QFN Package with Exposed Pad Fully Assembled and Tested Ordering Information PART MAX890AEVKIT+ +Denotes lead(pb)-free and RoHS compliant Component List DESIGNATION QTY DESCRIPTION C C CA, C4 C5, C7 C6 TYPE EV Kit.μF ±0%, 6V X5R ceramic capacitor (0805) TDK C0X7RC5K or equivalent 4.7μF ±0%, 5V X5R ceramic capacitor (0805) Murata GRMBR6E475KAL or equivalent 0μF ±0%, 0V X5R ceramic capacitors (0805) Taiyo Yuden LMKBJ06KG or equivalent 0.μF ±0%, 0V X7R ceramic capacitors (040) TDK C005X5RA04K or equivalent.μf ±0%, 6.V X5R ceramic capacitor (060) Taiyo Yuden LMK07BJ5MA or equivalent Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at -888-69-464, or visit Maxim s website at www.maxim-ic.com.
DESIGNATION QTY DESCRIPTION C8, C9, C 0 Not installed, capacitors (040) C0 D, D, D4 D J, J J J4 JU, JU, JU, JU8, JU9 JU4 JU7, JU0, JU 5 6 4.7μF ±0%, 6V X5R ceramic capacitor (0805) Taiyo Yuden EMKBJ475K or equivalent Small green LEDs Panasonic LNJ08G8PRA Small red LED Panasonic LNJ08R8ARA USB type-ab right-angle mini jacks Molex 56579-0576.mm male power connector CUI Inc. PJ-00A-SMT.5mm (0.049in) surface-mount, right-angle pitch header, lead-free, 0 circuits Molex 56-07 -pin headers Sullins PEC6SAAN Digi-Key S0E-6-ND -pin headers Sullins PEC6SAAN Digi-Key S0E-6-ND Component List (continued) DESIGNATION QTY DESCRIPTION L μh,.8a, 54mΩ inductor (4.mm x 4.mm x.mm) TOKO A0AS-R0 (DEA40CK series) NTC 0 00kΩ NTC thermistor (040) Murata NCP5WF04J0RC R R4 4.kΩ ±5% resistors (040) R5 00kΩ ± resistor (040) R6, R0, R4, R7, R8 0 Not installed, resistors (040) R7, R8.0kΩ ± resistors (040) R9 6.04kΩ ± resistor (040) R, R 604Ω ± resistors (040) R.kΩ ± resistor (040) R5 U 0.56Ω ± resistor (060) Panasonic ERJ-RQJR56V -cell Li+ charger (8 TQFN-EP*) Maxim MAX890AETI+ 0 Shunts (see Table ) Digi-Key S900-ND or equivalent P C B: M AX 890A E V ALU ATION KIT+ *EP = Exposed pad. Component Suppliers SUPPLIER PHONE WEBSITE CUI Inc. 50-6-00 www.cui.com Digi-Key Corp. 800-44-459 www.digikey.com Molex 800-768-659 www.molex.com Murata Electronics North America, Inc. 770-46-00 www.murata-northamerica.com Panasonic Corp. 800-44- www.panasonic.com Sullins Electronics Corp. 760-744-05 www.sullinselectronics.com Taiyo Yuden 800-48-496 www.t-yuden.com TDK Corp. 847-80-600 www.component.tdk.com TOKO America, Inc. 847-97-0070 www.tokoam.com Note: Indicate that you are using the MAX890 when contacting these component suppliers.
A. Li+\Li-POLY BATTERY B. SIMULATED BATTERY (PRELOADED POWER SUPPLY) BAT MAX890A EV KIT Quick Start Recommended Equipment MAX890A EV kit Adjustable DC power supply capable of greater than 6V at A Battery or simulated battery -cell Li+ or Li-poly battery (Figure A) Simulated battery preloaded power supply (Figure B) Two digital multimeters (DMM) Up to A adjustable load Three 0A ammeters Procedure The EV kit is fully assembled and tested. Follow the steps below to verify board operation. Use twisted wires of appropriate gauge that are as short as possible to connect the battery and power sources. ) Preset the DC power supply to 6V. Turn off the power supply. Caution: Do not turn on the power supply until all connections are completed. ) Preset the adjustable load to 0A. ) Connect the EV kit to the power supply, battery or preloaded power supply, adjustable load, and meters, as shown in Figure. 4) Ensure that the EV kit has the jumper settings shown in Figure and Table. 5) Turn on the power supply. 6) Verify that the voltage at SYS is approximately 4.4V and that the current from BATT into the battery is 0A. 0 TO 4.V.5A 7) Remove the shunt from pins - of jumper JU8 and place the shunt on pins - of jumper JU8. 8) If V V BAT 4.V for MAX890A/MAX890B/ MAX890C, or V V BAT 4.0V for MAX890D/ MAX890E/MAX890Y, verify that the current from BATT into the battery is approximately A. 9) Increase the load current on SYS to A. 0) Verify that the voltage on SYS remains approximately equal to V BATT. ) Verify that the charge current into the battery remains near A. ) Increase the load current on SYS to.5a. ) Verify that the voltage on SYS remains approximately equal to V BATT. 4) Verify that the charge current into the battery decreased to approximately 0.5A. 5) Increase the load current on SYS to.5a. 6) Verify that current out of the battery (from the battery to SYS) is near 0.5A. Detailed Description of Hardware Adjusting the EV Kit for In-Circuit Evaluation Verify that the AC adapter source current limit is higher than the SYS and BAT current requirements. Note that if SYS current demand exceeds the DC-DC converter output current limit, then the battery will help supply the extra current. The DC-DC converter output current limit can also be adjusted on the MAX890A EV kit by replacing R7 or adjusting JU4 and JU5. Verify that the USB source supplies at least 500mA. Verify the maximum charge current rating or desired charge current Ω 0W BAT MAX890A EV KIT Figure. Battery Options for Evaluating the MAX890A EV Kit
POWER SUPPLY A DC JU/DCM JU/IUSB MAX890A EVALUATION KIT JU JU5 JU4 JU6 JU7 *ALL AMMETERS NEED TO BE SET FOR 0A READINGS. THIS MINIMIZES THE SERIES IMPEDANCE OF THE AMMETER. JU JU8/CEN JU9/USUS Figure. Connection Diagram and Default Jumper Connections Table. Jumper Settings (JU JU) JUMPER LABEL JU0/THM SYS BAT A A SYS VOLTMETER BAT VOLTMETER ADJUSTABLE LOAD BATTERY OR SIMULATED BATTERY DEFAULT DESCRIPTION POSITION PINS - PINS - JU Pins - shunted Use the DC pad or J as the DC input Use the DC pad or J as the DC input JU DCM Pins - shunted JU IUSB Pins - shunted Configures DC input as adapter source (see Table ) With DCM pins - shunted, IUSB sets 500mA USB charge current JU4 Shunted Shorts out R8 (see Table ) JU5 Shunted Shorts out R9 (see Table ) JU6 Open Shunting JU6 shorts out R (see Table 4) JU7 Shunted Shorts out R (see Table 4) JU8 CEN Pins - shunted Disables the battery charger (when the charger is off, SYS remains on) Configures DC input for USB power (see Table ) With DCM pins - shunted, IUSB sets 00mA USB charge current Enables the battery charger (when the charger is on, SYS remains on) JU9 USUS Pins - USB suspend mode USB not suspended JU0 THM Shunted Connects THM to to bypass thermistor function JU Shunted Indicator LED anodes connected to SYS 4
rating of the battery. Ensure that the charge current setting of the EV kit does not exceed the battery rating, or replace resistor R (or adjust JU6 and JU7) as required. See the Adjusting the DC-DC Converter Output Current Limit and BAT Fast-Charge Current Limit section for more details. Adjusting the DC-DC Converter Output Current Limit and BAT Fast-Charge Current Limit Input and charger current limits are set, as shown in Table. It is often preferable to change the input current limit as the input power source is changed. The MAX890A facilitates this by allowing different input current limits for the DC and USB inputs. The SYS voltage regulates to three different regulation points depending on the state of the MAX890: ) If CEN is high to disable the charger, or charging is done, the SYS voltage regulates to 4.4V. ) When charging the battery with V BAT < V SYSMIN, the SYS voltage regulates to V SYSMIN + 0.V and stays above V SYSMIN during transient loads. Table. Input Limiter Control Logic POWER SOURCE DOK UOK DCM IUSB USUS ) When charging the battery with V BAT > V SYSMIN, the SYS voltage is regulated at the battery voltage for lowest power dissipation. When the input current limit is reached, the first action taken by the MAX890 is to reduce battery charge current. This allows the charging current to be programmed for the fastest charge time, without dropping the SYS load at load currents that would cause the input supply regulation current to be exceeded. If, after the charge current is reduced to 0mA, the load at SYS still exceeds the input current limit, the battery helps supply power to support the system load. The MAX890 features flexible input connections (at the DC and USB inputs) and current-limit settings (set by DCM and IUSB) to accommodate nearly any input power configuration. However, it is expected that most systems use one of two external power schemes: separate connections for USB and an AC adapter, or a single connector that accepts either USB or the AC adapter output. Input and charger current limits are shown in Table. DC STEP-DOWN OUTPUT CURRENT LIMIT USB INPUT CURRENT LIMIT MAXIMUM CHARGE CURRENT*** AC Adapter at DC Input L X H X X 6000/R IDC 00/R ISET and Lesser of 6000/R IDC USB Power at DC Input USB Power at USB Input, DC Unconnected L X L L L 00mA L X L H L 500mA L X L X H USB suspend USB input off. DC input has priority. H L X L L 00mA No DC input H L X H L 500mA Lesser of 00/R ISET and 00mA Lesser of 00/R ISET and 500mA ***Charge current cannot exceed the input current limit. Charge may be less than the maximum charge current if the total SYS load exceeds the input current limit. X = Don t care. 0 Lesser of 00/R ISET and 00mA Lesser of 00/R ISET and 500mA H L X X H USB suspend 0 DC and USB Unconnected H H X X X No USB input 0 5
EV Kit On-Board Current-Limit Adjustment The MAX890 s DC-DC converter output current limit can be adjusted on the EV kit by shunting JU4, JU5, or both. See Table for jumper and resistor combinations and corresponding current limits. The BAT fast-charge current limit can be adjusted by shunting JU6, JU7, or both. See Table 4 for jumper and resistor combinations and corresponding fast-charge current limits. Thermistor (THM) The EV kit comes with a thermistor preinstalled on the NTC footprint. To evaluate the MAX890A with a battery-pack thermistor, remove the thermistor and connect to the EV kit using the THM pad. Details of thermistors are covered in the MAX890 IC data sheet. To disable the thermistor function, shunt jumper JU0. Charge Timers A fault timer prevents the battery from charging indefinitely. The fault prequalification and fast-charge timers are controlled by the capacitance at CT (C5). C tprequal = 5 min 05. μf (t PREQUAL is when V BATT < V). C5 tfst- CHG = 660min 05. μf ttop-off = 5s( MAX890A/ C/ D/ Y) C t TOP-OFF = min CT ( / ). μf MAX 890 05 B E Table. DC-DC Converter Output Current Limit (JU4, JU5) JU4 JUMPER JU5 RESISTORS FROM IDC TO While in fast-charge mode, a large system load or device self-heating could cause the MAX890 to reduce charge current. Under these circumstances, the fast-charge timer is slowed by x if the charge current drops below 50% of the programmed fast-charge level, and suspended if the charge current drops below 0% of the programmed level. The fast-charge timer is not affected at any current if the charger is regulating the BAT voltage at 4.V (i.e., the charger is in voltage mode). Indicator LEDs Indicator LEDs are provided for CHG, FLT, DOK, and UOK. The CHG LED (D) is on when the battery charger is in its prequalification and fast-charge states. The FLT LED (D) is on when the battery charger has entered a fault state after the charge timer expires. The DOK LED (D) is on when 4.5V < V DC < 6V. The UOK LED (D4) is on when the source at USB is 4.V < V USB < 6.6V. Refer to the MAX890 IC data sheet for more details regarding CHG, FLT, DOK, and UOK. Charge Enable (CEN) When CEN is low, the charger is on. When CEN is high, the charger turns off. CEN does not affect the SYS output, which remains on. In many systems, there is no need for the system controller (typically a microprocessor) to disable the charger, because the MAX890 Smart Power Selector circuitry independently manages charging and adapter/battery power hand-off. In these situations, CEN may be connected to ground. RESISTANCE FROM IDC TO ( ) SYS CURRENT LIMIT (A) Open Open R7 + R8 + R9 k 0.5 Open Shunt R7 + R8 6k Shunt Open R7 + R9 9k 0.66 Shunt Shunt R7 k Table 4. BAT Fast-Charge Current Limit (JU6, JU7) JUMPER RESISTORS FROM IDC TO RESISTANCE FROM IDC TO BAT FAST-CHARGE CURRENT JU6 JU7 ( ) LIMIT (A) Open Open R + R + R.4k 0.5 Open Shunt R + R.k Shunt Open R + R.8k 0.66 Shunt Shunt R 604 Smart Power Selector is a trademark of Maxim Integrated Products, Inc. 6
J J DC 4 5 DOK TP C6.μF JU5 JU VL JU R9 6.04kΩ C9 JU7 C8 R.kΩ C0 4.7μF R5 0.56Ω DC LED VL JU R7 VL JU4 JU9 LX R.kΩ R8.0kΩ R4 R8 JU6 R 604Ω R0 DC C.μF VL C7 0.μF D JU8 C5 0.μF R7.0kΩ R 604Ω TP TP DC 4 DC PG PG 5 DCM 6 BST 7 IUSB 8 DOK 9 VL 0 CT IDC ISET 4 CEN 5 USUS U MAX890A EP LX LX CHG USB THM 8 7 CS 6 CS 5 SYS SYS 4 BAT BAT 0 UOK FLT 7 6 C 4.7μF L μh C4 0μF 9 8 NTC D CA 0μF D4 D LED JU0 JU R.kΩ R4.kΩ R.kΩ LED LED LED VL R6 SYS CHG BATT UOK FLT USB R5 00kΩ THM THM C J4 J4-0 J4-9 J4-8 J4-7 J4-6 J4-5 J4-4 J4- J4- J4- J 4 THM Figure 4. MAX890A EV Kit Schematic 7
Figure 5. MAX890A EV Kit Component Placement Guide Top Layer 8
Figure 6. MAX890A EV Kit PCB Layout Top Layer 9
Figure 7. MAX890A EV Kit PCB Layout Inner Layer 0
Figure 8. MAX890A EV Kit PCB Layout Inner Layer
Figure 9. MAX890A EV Kit PCB Layout Bottom Layer
REVISION NUMBER REVISION DATE DESCRIPTION Revision History PAGES CHANGED 0 /09 Initial release 8/09 Added MAX890C and MAX890D to parts evaluated 0/0 Added MAX890B, MAX890E, and MAX890Y to parts evaluated 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. Maxim Integrated Products, 0 San Gabriel Drive, Sunnyvale, CA 94086 408-77-7600 00 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.