19-5449; Rev 0; 7/10 MAX17127 Evaluation Kit The MAX17127 evaluation kit (EV kit) is a fully assembled and tested surface-mount PCB that evaluates the highefficiency MAX17127 white LED (WLED) driver. The EV kit utilizes a step-up DC-DC converter to generate the voltage required to drive up to six strings of 10 surfacemount WLEDs. The EV kit uses a 5V to 26V input power supply and can be configured to provide an adjustable 10mA to 30mA full-scale LED current. Features S 5V to 26V Input Range S WLED Drives Up to 30mA/String S Drives Six Strings of 10 WLEDs S Full-Scale LED Current Adjustable from 10mA to 30mA S 1MHz PWM Switching Frequency Adjustable from 250kHz to 1MHz (Component Change Required) S All Components < 1mm Height S Fully Assembled and Tested Ordering Information PART TYPE MAX17127EVKIT+ EV Kit +Denotes lead(Pb)-free and RoHS compliant. Component List DESIGNATION C1 C2-C8, C10-C16, C24 C9 C17 C18, C22, C23 C19, C21 C20 QTY DESCRIPTION DESCRIPTION D1 1 D2-D61 60 White LEDs Nichia NSSW008CT-P1 OPTEK OVSRWACR6 510pF Q5%, 50V C0G ceramic capacitor (0603) Murata GRM1885C1H511J AVX 06035A511JA12A JU1, JU6, JU8-JU12 7 3-pin headers JU2 0 Not installed, 2-pin header-- short PC trace 1FF Q10%, 10V X7R ceramic capacitor (0603) Taiyo Yuden LMK107BJ105KA Murata GRM188R71A105K JU7 0 Not installed, 3-pin header (pins 2-3--short PC trace) JU4, JU13-JU19, JU20, JU21 10 2-pin headers L1 1 10FH, 1.2A power inductor Sumida CR6D09HPNP-100MC TDK VLP6810T-100M1R2 R1, R8, R10 3 100kI Q5% resistors (0603) R2 1 1MI Q5% resistor (0603) R3 1 0I Q5% resistor (0603) R4 1 10kI Q5% resistor (0603) 1 0 Not installed, ceramic capacitors (0603) 1 0 Not installed, ceramic capacitors (1206) 2 2.2FF Q20%, 50V X7R ceramic capacitors (1206) Murata GRM31CR71H225K 1 QTY 0.7A, 60V Schottky diode (US Flat) Toshiba CUS04 0.1FF Q10%, 50V X7R ceramic capacitor (0603) Murata GRM188R71H104K TDK C1608X7R1H104K 1 DESIGNATION 4.7FF Q10%, 25V X5R ceramic capacitor (1206) Murata GRM319R61E475K ________________________________________________________________ Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com. Evaluates: MAX17127 General Description Evaluates: MAX17127 MAX17127 Evaluation Kit Component List (continued) DESIGNATION QTY R5 1 82.5kI Q1% resistor (0603) R6 1 2.21MI Q1% resistor (0603) R7 1 71.5kI Q1% resistor (0603) R11 0 R12 R14 DESIGNATION DESCRIPTION QTY DESCRIPTION U1 1 Six-string WLED driver (20 TQFN-EP*) Maxim MAX17127ETP+ Not installed, resistor (0603) -- 17 Shunts 0 Not installed, multiturn potentiometer -- 1 PCB: MAX17127 EVALUATION KIT+ 2 500kI multiturn potentiometer *EP = Exposed pad. Component Suppliers SUPPLIER PHONE WEBSITE AVX Corporation 843-946-0238 www.avxcorp.com Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com Nichia Corp. 248-352-6575 www.nichia.com OPTEK Technologies 972-323-2200 www.optekinc.com Sumida Corp. 847-545-6700 www.sumida.com Taiyo Yuden 800-348-2496 www.t-yuden.com TDK Corp. 847-803-6100 www.component.tdk.com Toshiba America Electronic Components, Inc. 949-623-2900 www.toshiba.com/taec Note: Indicate that you are using the MAX17127 when contacting these component suppliers. Quick Start Recommended Equipment * MAX17127 EV kit * 5V to 26V power supply (VIN) Procedure The EV kit is fully assembled and tested. Follow the steps below to verify board operation. Caution: Do not turn on the power supply until all connections are completed. 1) On the EV kit, verify that the shunts are installed, as shown in Table 1. 2) Connect the positive terminal of the VIN power supply to the VIN pad. Connect the ground terminal of the VIN power supply to the PGND pad. 3) Set the VIN power supply to 12V and enable its output. 4) Verify that the six strings of WLEDs are on. Table 1. Default Shunt Positions JUMPER SHUNT POSITION JU1, JU6, JU8-JU12 1-2 JU4, JU14, JU15, JU17-JU20, JU21 Not installed JU13, JU16 Installed Detailed Description of Hardware The MAX17127 evaluation kit (EV kit) operates on a 5V to 26V wide-input voltage range and provides adjustable 10mA to 30mA full-scale LED current. The EV kit utilizes a step-up DC-DC converter to generate the voltage required to drive up to six strings of 10 surfacemount WLEDs. 2 _______________________________________________________________________________________ MAX17127 Evaluation Kit Off-Board WLED String Configuration The EV kit can also be used to drive off-board WLED strings. To evaluate external WLED strings, reconfigure shunts from jumpers JU1 and JU8-JU12. See Table 2 for jumpers JU1 and JU8-JU12 configuration and Table 3 for jumper JU13 configuration. Removing these jumpers effectively disconnects the on-board WLED strings between the output and feedback pins, allowing the connection of external WLED strings. For each external WLED string, connect the cathode terminal of the string to the corresponding feedback pad (FB1-FB6) and connect the anode terminal of the string to the VOUT pad. Once the external WLED strings are connected between the VOUT pad and the FB1-FB6 pins, the EV kit can be evaluated in the same manner as the on-board WLED strings. Evaluating more than 10 WLEDs per string may require component changes. Refer to the MAX17127 IC data sheet for component selections. Enable (EN) The EV kit features 2-pin jumper JU16 to control the activelow shutdown input. Drive EN high to place the device in normal operation. If the JU16 shunt is removed, an internal 200kI (typ) pulldown resistor places the device in disabled mode. See Table 4 for shunt positions. Table 2. Jumper Function (JU1, JU8-JU12) SHUNT POSITION FB_ PIN STRING_ 1-2* Connected to cathode of WLED string Enabled 2-3 Connected to AGND Disabled Not installed Connect to an external WLED string On-board WLED string not used *Default position. Brightness Control by PWM Signal Input (PWM) The EV kit features 2-pin jumper JU20 to implement brightness control through the PWM signal input. See Table 5 for shunt positions. LED String Capacitance In some LCD panel applications, a 0.1FF (typ) capacitor (CLED) is placed in parallel with each LED string to improve ESD immunity. As such, the EV kit provides a footprint across each LED string for optional CLED. Full-Scale LED Current Adjustment (ISET) The EV kit features 3-pin jumper JU6, along with R8 and R14, to set the full-scale LED current. The resistance from ISET to AGND controls the full-scale current in each LED string according to the following equation: 180k ILED(MAX) = 20 x mA R8 + R14 where R8 is a 100kI resistor and R14 is a 500kI potentiometer. See Table 6 for jumper JU6 settings. Switching-Frequency Selection (FSLCT) The EV kit is configured to operate at 1MHz, but provides the option to set the switching frequency of the step-up DC-DC converter from 250kHz to 1MHz. The switching frequency is set by adjusting the resistance from FSLCT to AGND according to the following equation: 100k fSW = 1 MHz x R10 Changing the switching frequency might require different converter components (refer to the MAX17127 IC data sheet for proper component selections). Table 4. Jumper Function (JU16) SHUNT POSITION EN PIN MAX17127 Installed* Connected to VDDIO Enabled Not installed Internally connected to AGND Disabled *Default position. Table 3. Jumper Function (JU13) SHUNT POSITION VOUT Installed* Connected to anodes of on-board WLED strings Not installed Connect to anodes of off-board WLED strings *Default position. _______________________________________________________________________________________ 3 Evaluates: MAX17127 White LED String Configuration As configured, the EV kit is assembled with six strings of 10 WLEDs. Each string has an associated 3-pin header (JU1, JU8-JU12) and feedback pin (FB1-FB6). The function of the 3-pin jumpers is summarized in Table 2. To evaluate the EV kit with off-board WLED strings, see the Off-Board WLED String Configuration section. Evaluates: MAX17127 MAX17127 Evaluation Kit Table 5. Jumper Function (JU20) SHUNT POSITION PWM PIN PWM DUTY CYCLE OF LED CURRENT Installed Connected to AGND Zero Not installed* Connected to VDDIO through R2 Maximum (100%) Not installed Connect to an external PWM signal (0.1kHz to 25kHz) Follows the signal applied at PWM pad Table 6. Jumper Function (JU6) SHUNT POSITION ISET PIN ILED(MAX) 1-2* Connected to AGND through R8 and R14 Adjustable from 10mA to 30mA 2-3 Connected to AGND 0.3mA (typ) *Default position. *Default position. 4 _______________________________________________________________________________________ MAX17127 Evaluation Kit Evaluates: MAX17127 Figure 1. MAX17127 EV Kit Schematic _______________________________________________________________________________________ 5 Evaluates: MAX17127 MAX17127 Evaluation Kit 1.0'' Figure 2. MAX17127 EV Kit Component Placement Guide--Component Side 6 _______________________________________________________________________________________ MAX17127 Evaluation Kit Evaluates: MAX17127 1.0'' Figure 3. MAX17127 EV Kit PCB Layout--Component Side _______________________________________________________________________________________ 7 Evaluates: MAX17127 MAX17127 Evaluation Kit 1.0'' Figure 4. MAX17127 EV Kit PCB Layout--Solder Side 8 _______________________________________________________________________________________ MAX17127 Evaluation Kit REVISION NUMBER REVISION DATE 0 7/10 DESCRIPTION Initial release PAGES CHANGED -- 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, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2010 Maxim Integrated Products 9 Maxim is a registered trademark of Maxim Integrated Products, Inc. Evaluates: MAX17127 Revision History Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Maxim Integrated: MAX17127EVKIT+