Evaluates: MAX MAX38888 Evaluation Kit. Quick Start. General Description. Features. MAX38888 EV Kit Files. Required Equipment.

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1 Click here for production status of specific part numbers. MAX8888 Evaluation Kit Evaluates: MAX8888 General Description The MAX8888 evaluation kit (EV kit) evaluates the MAX8888 IC. The MAX8888 is a super cap backup regulator designed to transfer power between a super cap and a system supply rail. When the main battery is present and above the minimum system supply voltage, the regulator charges the super cap at up to a 500mA rate. Once the super cap is charged, the circuit draws only.5µa of current while it maintains the super cap in its ready state. When the main battery is removed, the regulator prevents the system from dropping below the minimum operating voltage, discharging the super cap at up to a.5a rate. The MAX8888 is externally programmable for minimum and maximum super cap voltage, minimum system voltage, and maximum charge and discharge currents. The internal DC/DC converter requires only a µh inductor. Features.99V to.6v System Output Voltage Range.V to.7v Super Cap Voltage Range.5A Peak Discharge Current Resistor Adjustable Voltage and Current Thresholds Proven -Layer oz Copper PCB Layout Demonstrates Compact Solution Size Fully Assemble and Tested MAX8888 EV Kit Files FILE MAX8888 EV BOM MAX8888 EV PCB Layout MAX8888 EV Schematic DECRIPTION EV Kit Bill of Material EV Kit Layout EV Kit Schematic Quick Start Required Equipment MAX8888 EV kit 5V, A DC power supply One digital multimeter (DMM) Procedure The EV kit is fully assembled and tested. Follow the steps below to verify board operation. Caution: Do not turn on power supply until all connections are completed. ) Verify that a shunt is installed onto pins and jumper JU (EV kit enabled). ) Verify that jumper JU is opened (No load is connected across VSYS and ). ) Set the power supply output to.v and disable the power supply. ) Connect the power supply between the VSYS and terminal posts. 5) Connect the DMM between the VSC and terminal posts. 6) Enable the power supply and verify that super cap voltage at VSC is ramping up and stops at about.7v. 7) Disable and disconnect the power supply from the VSYS and terminal posts. 8) Verify that VSYS drops to about V, and VSC drops to about.5v. 9) Install jumper JU (This connects a 5Ω load across VSYS and ). 0) Verify that VSYS remains at V while VSC is ramping down toward.5v. ) Verify that VSYS is 0V when VSC drops below.5v. ) <<Place Holder>>. Ordering Information appears at end of data sheet. 9-00; Rev 0; 8/8

2 MAX8888 Evaluation Kit Evaluates: MAX8888 Detailed Description of Hardware The MAX8888 EV kit provides a flexible circuit to evaluate the super cap backup regulator. External components allow a wide range of system and super cap voltages as well as charging and discharging currents. EN The MAX8888 EV kit provides a jumper (JU) to enable or disable the MAX8888. Refer to Table for JU jumper settings. VSYS Load The MAX8888 EV kit provides a jumper (JU) to connect a 5Ω resistive load across VSYS and to simulate a discharging scenario during test. Refer to Table for JU jumper settings. Charge Mode When the main battery is present and is above the minimum system supply voltage, the regulator charges the super cap at up to a 500mA rate. The MAX8888 EV Kit minimum system supply voltage is set to.6v, by resistors R5 and R6 with V FBS = 0.56V. Table. EN (JU) JU SHUNT POSITION *Default position. Table. VSYS Load (JU) DESCRIPTION -* Enabled. EN = VSYS - Disabled. EN = Not Installed JU SHUNT POSITION Enabled. EN = VSYS (through resistor R9) DESCRIPTION Ready Mode Once the super cap is charged to its maximum voltage,.7v, the circuit draws only.5µa of current while it maintains the super cap in its ready state. The MAX8888 EV Kit maximum super cap voltage is set to.7v, by resistors R, R, and R with V FBCH = 0.5V, Discharge Mode When the main battery is removed, the regulator discharges the super cap at up to a.5a rate to prevent the system from dropping below the minimum operating voltage. The MAX8888 EV kit minimum operating voltage is set to.99v, by resistors R5 and R6 with V FBS = 0.5V. Preserve Mode As the super cap is discharged toward its minimum voltage,.v, the MAX8888 disconnects all circuitry from the super cap and draws only.5µa of current to preserve the remaining capacity for keeping alive the real-time clock, memory, or other low-level function. The MAX8888 EV Kit minimum super cap voltage is set to.v, by resistors R, R, and R with V FBCL = 0.75V. Charge/Discharge Current Configuration The MAX8888 EV Kit provides a resistor R to configure the charge/discharge current rate for the super cap. The peak discharge current is set by resistor R connecting between the ISET and GND pins. I DISCHARGE =.5A x (0kΩ/R) The super cap charging current is internally set to /5 of the discharge current. I CHARGE = 0.5A x (0kΩ/R) Choose a value of R between 0kΩ to 00kΩ to ensure accurate current compliance. Installed Not Installed* *Default position. Test Mode: A 5Ω resistive load is connected across VSYS and Normal Operating Mode Maxim Integrated

3 MAX8888 Evaluation Kit Evaluates: MAX8888 MAX8888 EV Kit Bill of Materials ITEM REF_DES /DNP QTY MFG PART # MANUFACTURER VALUE DESCRIPTION BKUPB, RDY 500 KEYSTONE N/A C GRMCR7A6ME5 MURATA UF C SCCS0B6SRBA AVX F TEST POINT; PIN DIA = 0.IN; TOTAL LENGTH = 0.IN; BOARD HOLE = 0.0IN; WHITE; PHOSPHOR BRONZE WIRE SILVER; CAPACITOR; SMT (06); CERAMIC CHIP; UF; 0V; TOL = 0%; TG = -55 C TO +5 C; TC = X7R CAP; THROUGH HOLE-RADIAL LEAD; F; +0%/-0%;.7V; ALUMINUM-ELECTROLYTIC ; C C0805C6M9PAC; GRMBR60J6ME9; JMKBJ6MG; CLA6MQCLQN KEMET;MURATA; TAIYO YUDEN; SAMSUNG ELECTRO-MECHANICS UF CAPACITOR; SMT (0805); CERAMIC CHIP; UF; 6.V; TOL = 0%; TG = -55 C TO +5 C; TC = X5R 5 GND 500 KEYSTONE N/A TEST POINT; PIN DIA = 0.IN; TOTAL LENGTH = 0.IN; BOARD HOLE = 0.0IN; BLACK; PHOSPHOR BRONZE WIRE SILVER PLATE FINISH; 6 JU PEC0SAAN SULLINS PEC0SAAN CONNECTOR; MALE; THROUGH HOLE; BREAKAWAY; STRAIGHT; PINS 7 JU PEC0SAAN SULLINS PEC0SAAN CONNECTOR; MALE; THROUGH HOLE; BREAKAWAY; STRAIGHT; PINS 8 L 7700 WURTH ELECTRONICS INC UH INDUCTOR; SMT; SHIELDED; UH; 0%; 5.00A 9 LX, VSC, VSYS TEKTRONICS CONNECTOR; WIREMOUNT; CIRCUIT BOARD TEST POINT MINIATURE PROBE; STRAIGHT; PINS 0, TP-TP EMERSON NETWORK POWER CONNECTOR; MALE; PANELMOUNT; BANANA JACK; STRAIGHT; PIN R, R5 CRCW06099KFK VISHAY DALE 99K RESISTOR; 060; 99KΩ; %; 00PPM; 0.W; THICK FILM R CRCW0600FK VISHAY DALE 0K RESISTOR; 060; 0K; %; 00PPM; 0.0W; THICK FILM R CRCW060M80FK VISHAY DALE.8M RESISTOR, 060,.8MΩ, %, 00PPM, 0.0W, THICK FILM R MCR0EZPFX00; ERJ-EKF00; CR060-FX-00ELF ROHM;PANASONIC;BOURNS 0K RESISTOR; 060; 0KΩ; %; 00PPM; 0.0W; THICK FILM 5 R6 RMCF060FTM9 STACKPOLE ELECTRONICS INC..9M RES; SMT (060);.9M; %; ±00PPM/DEGC; 0.0W 6 R7, R8 CHPHT060K00FGT VISHAY SFERNICE 0K RESISTOR; 060; 0KΩ; %; 00PPM; 0.05W; THICK FILM 7 R9 CRCW060M00FK; MCR0EZPFX00 VISHAY DALE;ROHM M RESISTOR, 060, MΩ, %, 00PPM, 0.0W, THICK FILM 8 R0-R CRCW Z0 VISHAY DALE 0 RESISTOR; 060; 0Ω; 0%; JUMPER; 0.W; THICK FILM 9 R ERJ-NF9R9U PANASONIC 9.9 RESISTOR; 0; 9.9Ω; %; 00PPM; 0.5W; THICK FILM 0 SU, SU S00-B;SX00-B KYCON;KYCON SX00-B U MAX8888ATD+ MAXIM MAX8888ATD+ TEST POINT; JUMPER; STR; TOTAL LENGTH = 0.IN; BLACK; INSULATION = PBT;PHOSPHOR BRONZE CONTACT = GOLD PLATED EVKIT PART - IC; REG; SUPER CAP REGULATOR; PACKAGE OUTLINE: -07; PACKAGE CODE: T+; LAND PATTERN: ; TDFN-EP PCB MAX8888 MAXIM PCB PCB:MAX8888 J-J5 DNP 0 N/A EVK KIT PARTS; MAXIM PAD; NO WIRE TO BE SOLDERED ON THE C DNP 0 N/A N/A OPEN CAPACITOR; SMT (0); OPEN; IPC MAXIMUM LAND PATTERN TOTAL Component Suppliers Ordering Information SUPPLIER WEBSITE PART TYPE AVX MAX8888EVKIT# EVKIT Kemet #Denotes RoHS Murata/TOKO Wurth Electronics Note: Indicate that you are using the MAX8888 when contacting these component suppliers. Maxim Integrated

4 Maxim Integrated Evaluates: MAX8888 MAX8888 Evaluation Kit MAX8888 EV Kit Schematic R JU R VSYS R LX R0 VSC C C C R9 C U GND L RDY BKUPB JU R8 R7 R6 R R R R5 R PEC0SAAN UF OPEN EN 0K.8M VSYS VSC VSYS VSC UF 0 UH 0K.9M F 0K 0K M 0 MAX8888ATD+ PEC0SAAN 99K 99K + SYS BKUPB ISET FBCH EN CAP LX NC EP G NC RDY FBS FBCL

5 MAX8888 Evaluation Kit Evaluates: MAX8888 MAX8888 EV Kit PCB Layout Diagrams.0.0 MAX8888 EV Kit Component Placement Guide Top Silkscreen MAX8888 EV Kit PCB Layout Top Layer.0 MAX8888 EV Kit PCB Layout Bottom Layer Maxim Integrated 5

6 MAX8888 Evaluation Kit Evaluates: MAX8888 Revision History REVISION NUMBER REVISION DATE DESCRIPTION PAGES CHANGED 0 8/8 Initial release For pricing, delivery, and ordering information, please visit Maxim Integrated s online storefront at Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. 08 Maxim Integrated Products, Inc. 6