Evaluates: MAX16819/MAX16820 19-0769 Rev 0 3/07 MAX16820 Evaluation Kit General Description Features The MAX16820 evaluation kit (EV kit) demonstrates a Operates from a 5V to 28V, 1.5A Supply step-down, constant-current, hysteretic controlled Constant LED Current Control switching regulator for driving high-brightness LEDs (HB LEDs) using the MAX16820 controller IC. This EV 1A Average LED Current kit is configured to supply an average output LED cur- PWM Dimming Control Up to 20kHz rent of 1A, and operates from a 5V to 28V supply. Fully Assembled and Tested The EV kit eases evaluation of the MAX16820 dedicat- ed pulse-width-modulation (PWM) dimming control and undervoltage lockout (UVLO) features. The MAX16820 EV kit comes with the MAX16820 Ordering Information installed. The MAX16820 EV kit can also be used to evaluate the MAX16819. Contact the factory for free PART TEMP RANGE IC PACKAGE samples of the pin-compatible MAX16819 to evaluate MAX16820EVKIT+ 0C to +70C* 6 TDFN-EP** this part. + Denotes a lead-free and RoHS-compliant EV kit. *This limited temperature range applies to the EV kit PCB only. The MAX16820 IC temperature range is -40C to +125C. **EP = Exposed paddle. Component List DESIGNATION QTY DESCRIPTION DESIGNATION QTY DESCRIPTION C1 0 Not installed, capacitor (2220) 30V, 2.7A n-channel MOSFET (SOT23) 1F 10%, 50V X7R ceramic N1 1 Fairchild Semiconductor capacitor (1210) C2 1 FDN359BN Murata GRM32RR71H105K or TDK C3225X7R1H105K 0.2 1%, 0.5W sense resistor R1 1 (1206) C3 0 Not installed, capacitor (1206) IRC LRC-LR1206LF-01-R200-F 1F 10%, 16V X7R ceramic R2 1 100k 5% resistor (0603) capacitor (0603) C4 1 Murata GRM188R71C105K or MAX16820ATT+ (6-pin TDFN-EP, U1 1 TDK C1608X7R1C105K 3mm x 3mm x 0.8mm) 30V , 1A Sch ottky d i od e (S OD - 123) 1 Shunt (JU1) D1 1 Fairchild Semiconductor FBR130 1 PCB: MAX16820 Evaluation Kit+ JU1 1 2-pin header 56H, 940mA inductor (7.3mm x L1 1 8.1mm) Sumida CR75NP-560KC Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.MAX16820 Evaluation Kit Component Suppliers SUPPLIER PHONE WEBSITE Fairchild Semiconductor 888-522-5372 www.fairchildsemi.com IRC 361-992-7900 www.irctt.com Murata Mfg. Co., Ltd. 770-436-1300 www.murata.com Sumida Corp. 847-545-6700 www.sumida.com TDK Corp. 847-803-6100 www.component.tdk.com Note: Indicate that you are using the MAX16820 when contacting these component suppliers. Quick Start Detailed Description The MAX16820 EV kit features the MAX16820 controller Recommended Equipment and demonstrates a step-down, constant-current, hys- 24V, 1.5A DC power supply teretic controlled regulator for driving HB LEDs. The Voltmeter MAX16820 EV kit output is current-controlled by moni- toring the voltage across external high-side sense LED load rated for at least 1A and a total LED for- resistor R1 in series with the LED output. In hysteretic ward voltage drop V 20V FLED mode, the MAX16820 EV kit is configured to output an Procedure LED current of 1A 6% (I ). The MAX16820 VIN ris- LED The MAX16820 EV kit is fully assembled and tested. ing and falling UVLO threshold points are 5V (max) and Follow the steps below to verify board operation. 4.5V (min), respectively. The EV kit can operate from a Caution: Do not turn on the power supply until all 5V to 28V supply capable of 1.5A. connections are completed. Typically, capacitor C1 is not required if the power sup- 1) Verify that a shunt is installed on JU1 (MAX16820 ply is relatively close to the EV kit. If long wires are used disabled). to connect the power supply to the EV kit, install up to 10F of bulk capacitance at the surface-mount 2220 2) Set the DC power-supply output to 24V. pads provided for C1. 3) Disable the power-supply output. Jumper Selection 4) Connect the power-supply ground to the GND pad on the EV kit. Enable 5) Connect the power-supply output to the VIN pad on EV kit jumper JU1 enables the MAX16820. See Table 1 the EV kit. for JU1 configuration. 6) Connect the LED loads anode to the LED+ output Table 1. MAX16820 Enable (Jumper JU1) pad and the cathode to the LED- output pad. SHUNT 7) Enable the power supply. DIM PIN EV KIT FUNCTION POSITION 8) Remove the shunt on JU1 (MAX16820 enabled). 9) Measure the voltage across the LED+ and LED- Installed Connected to GND MAX16820 disabled pads and verify that the voltmeter reads approxi- mately V . FLED MAX16820 enabled Pulled to VCC Not installed (DIM pin can be used through resistor R2 for PWM dimming) 2 Evaluates: MAX16819/MAX16820