19-2984; Rev 0; 9/03 MAX1553 Evaluation Kit Features ♦ Constant Current Regulation for Even LED Illumination ♦ Up to 88% Efficiency Driving Six LEDs ♦ Analog or PWM Dimming Control of LED Intensity ♦ Small, Low-Profile Components ♦ 2.7V to 5.5V Input Range ♦ Tiny TDFN 3mm x 3mm IC Package ♦ Fully Assembled and Tested Ordering Information PART TEMP RANGE MAX1553EVKIT 0°C to +70°C IC PACKAGE 8 TDFN 3mm x 3mm Component List MAX1553 Circuit DESIGNATION C1 C2, C7 C3, C6 C4, C5 C8 C9 C10 QTY 1 2 2 DESCRIPTION 4.7µF ±10%, 6.3V X5R capacitor (0603) Panasonic ECJ1VB0J475K or equivalent 0.47µF ±20%, 50V X7R capacitors (1206) TDK C3216X7R1H474M or equivalent 0.1µF ±10%, 50V X7R capacitors (0603) TDK C1608X7R1H104KT or equivalent 0 Not installed 1 10µF ±20%, 6.3V X5R capacitor (0805) Panasonic ECJ2FB0J106M or Taiyo Yuden JMK212BJ106MG 1 1 4700pF ±10%, 50V X7R ceramic capacitor (0603) TDK C1608X7R1H472K or equivalent 3300pF ±10%, 50V X7R ceramic capacitor (0603) TDK C1608X7R1H332K or equivalent DESIGNATION QTY DESCRIPTION D1 1 30V Schottky diode (SOD-123) Toshiba CRS02 D2–D17 16 White LEDs Nichia NSCW215T D18 1 60V, 1A Schottky diode (SMA) Central CMSH1-60M JU1, JU9 2 2-pin headers JU2, JU8 2 3-pin headers JU3 0 Not installed, PC board open JU4–JU7 0 Not installed, PC board short L1 1 33µH inductor TOKO A920CY-330M (D62CB) L2 1 15µH inductor TOKO A920CY-150M (D62CB) R1, R6 2 10.0Ω ±1% resistors (0603) R2 1 200kΩ ±5% resistor (0603) R3, R4 2 10kΩ ±5% resistors (0603) R5 1 330kΩ ±5% resistor (0603) U1 1 MAX1553ETA (8-pin TDFN) U2 1 MAX1554ETA (8-pin TDFN) None 4 Shunts, 2-position None 1 MAX1553EVKIT PC board ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 Evaluates: MAX1553/MAX1554 General Description The MAX1553 evaluation kit (EV kit) is a fully assembled and tested circuit board with two complete circuits for evaluating the MAX1553 and MAX1554 white LED step-up converters. The MAX1553 circuit operates from 2.7V to 5.5V and delivers an adjustable 0 to 20mA to drive up to six white LEDs connected in series. The MAX1554 circuit operates from 3.15V to 5.5V and delivers an adjustable 0 to 20mA for driving up to 10 white LEDs in series. Evaluates: MAX1553/MAX1554 MAX1553 Evaluation Kit Component Suppliers SUPPLIER PHONE WEBSITE Central Semiconductor 631-435-1110 www.centralsemi.com Kamaya 260-489-1533 www.kamaya.com Murata 814-237-1431 www.murata.com Nichia 248-352-6575 www.nichia.com Panasonic 714-373-7939 www.panasonic.com Sumida 847-956-0666 www.sumida.com Taiyo Yuden 408-573-4150 www.t-yuden.com TDK 847-803-6100 www.component.tdk.com TOKO 847-297-0070 www.toko.com Note: Please indicate that you are using the MAX1553/MAX1554 when contacting these component suppliers. Recommended Equipment Power supply capable of providing 2.7V to 5.5V at up to 1A. Quick Start MAX1553 Circuit Follow the steps below to verify operation of the MAX1553 circuit. Do not turn on the power supply until all connections are completed: 1) Verify that the pins of JU1 are shorted. 2) Verify that the pins of JU2 are shorted across pins 2-3. 3) Preset the power supply to between 2.7V and 5.5V. 4) Turn off the power supply. 5) Connect positive power-supply terminal to the pad on the EV kit labeled IN1. 6) Connect power-supply ground terminal to the pad on the EV kit labeled GND1. 7) Turn on the power supply and verify that the LEDs are lit. MAX1554 Circuit Follow the steps below to verify operation of the MAX1554 circuit. Do not turn on the power supply until all connections are completed: 1) Verify that the pins of JU9 are shorted. 2) Verify that the pins of JU8 are shorted across pins 2-3. 3) Preset the power supply to between 3.15V and 5.5V. 4) Turn off the power supply. 5) Connect the positive power-supply terminal to the pad on the EV kit labeled IN2. 2 6) Connect the power-supply ground terminal to the pad on the EV kit labeled GND2. 7) Turn on the power supply and verify that the LEDs are lit. Detailed Description Evaluating the MAX1553 Shutdown To place the part in low-power shutdown mode, short pins 1 and 2 of JU2. For normal operation, short pins 2 and 3 of JU2. Controlling LED Intensity LED intensity can be controlled using the BRT1 input. BRT1 can be used either as an analog or digital input. When using BRT1, remove the shunt from JU1. Connect a 0 to 1.72V voltage source to BRT1, where 0V corresponds to the dimmest setting and 1.72V is full brightness. Ground the voltage source to AGND1. A digital PWM signal (100Hz to 10kHz) can also be connected directly to BRT1. In this case, 0% duty cycle corresponds to the dimmest setting and 100% corresponds to the brightest. Changing the Number of LEDs The MAX1553 can be used to drive two to six LEDs, and the MAX1553 EV kit comes configured for driving six LEDs. To evaluate the MAX1553 driving fewer than six LEDs, short the pads of the unused LEDs. For convenience, JU3 can be used to short LEDs D2 and D3 for four LED operation. Connecting External LEDs to the EV Kit Surface-mount white LEDs come installed on the EV kit, but it can also be connected to an external LED string. To connect external LEDs, cut the trace shorting JU4. Then, connect the anode of the series string to OUT1+ and connect the cathode of the series string to OUT1-. Using Separate Supplies to Power the IC and Boost In some applications, the MAX1553 IC and the boost inductor are powered from different supplies. For example, the IC can be powered with a 3.3V logic supply and the boost inductor can be connected to a battery. This is useful if the battery voltage is lower than the operating range of the MAX1553. To use different supplies for the IC and boost, cut the trace shorting JU5 on the solder side of the EV kit, then install a 0.1µF ceramic capacitor in C4. Connect a 2.7V to 5.5V power supply to VCC1 to power the IC. Connect another power supply to IN1 (the voltage range is not limited to the IC supply range). Ground both power supplies at GND1. _______________________________________________________________________________________ MAX1553 Evaluation Kit Shutdown To place the part in low-power shutdown mode, short pins 1 and 2 of JU8. For normal operation, short pins 2 and 3 of JU8. Controlling LED Intensity LED intensity can be controlled using the BRT2 input. BRT2 can be used either as an analog or digital input. When using BRT2, remove the shunt from JU9. Connect a 0 to 1.72V voltage source to BRT2, where 0V corresponds to the dimmest setting and 1.72V is full brightness. Ground the voltage source to AGND2. A digital PWM signal (100Hz to 10kHz) can also be connected directly to BRT2. In this case, 0% duty cycle corresponds to the dimmest setting and 100% corresponds to the brightest. Changing the Number of LEDs The MAX1554 can be used to drive up to 10 LEDs. If fewer than 10 LEDs are used, short the pads of the unused LEDs. Connecting External LEDs to the EV Kit To connect external LEDs, cut the trace shorting JU7, then connect the anode of the series string to OUT2+ and connect the cathode of the series string to OUT2-. Using Separate Supplies to Power the IC and Boost To use different supplies for the IC and boost, cut the trace shorting JU6 on the solder side of the EV kit; then, install a 0.1µF ceramic capacitor in C5. Connect a 2.7V to 5.5V power supply to VCC2 to power the IC. Connect another power supply to IN2 (voltage range is not limited to the IC supply range). Ground both power supplies at GND2. Table 1. MAX1553 Circuit Jumper Functions JUMPER FUNCTION DEFAULT SETTING JU1 Connects VCC to BRT when no separate BRT control signal is used. Shorted. JU2 EN Control. Jumper pin 1 to pin 2 for shutdown. Jumper pin 2 to pin 3 for enable. Jumper 2 to 3. Enabled. JU3 Bypasses two of the six LEDs for four LED testing. Open. Six LED operation. JU4 Connects on-board LEDs. Cut the PC board trace to power other LEDs. Shorted for on-board LEDs. JU5 The PC board trace connects VCC to IN for single-supply operation. Cut the trace to separately power VCC and IN. Shorted for single-supply operation. Table 2. MAX1554 Circuit Jumper Functions JUMPER FUNCTION DEFAULT SETTING JU6 PC board trace connects VCC to IN for single-supply operation. Cut the trace to separately power VCC and IN. Shorted for single-supply operation. JU7 Connects on-board LEDs. Cut the PC board trace to power other LEDs. Shorted for on-board LEDs. JU8 EN Control. Jumper pin 1 to pin 2 for shutdown. Jumper pin 2 to pin 3 for enable. Jumper 2 to 3. Enabled. JU9 Connects VCC to BRT when no separate BRT control signal is used. Shorted. _______________________________________________________________________________________ 3 Evaluates: MAX1553/MAX1554 Evaluating the MAX1554 Evaluates: MAX1553/MAX1554 MAX1553 Evaluation Kit D3 L1 33µH IN1 VCC VCC1 JU5 SHORT OUT1+ D5 VCC LX 8 D1 C4 BRT1 R2 200kΩ 4 BRT U1 OV 6 VCC 3 2 1 SS GND C2 0.47µF 7 MAX1553 AGND1 GND1 JU3 OPEN D2 C1 4.7µF 2 JU1 D4 1 D6 C9 4700pF R3 10kΩ C3 0.1µF JU2 D7 3 EN EP FB 5 OUT1R1 10Ω JU4 SHORT D11 D10 L2 15µH IN2 D12 D9 OUT2+ D13 D8 VCC2 VCC2 JU6 SHORT C8 10µF 2 LX 8 BRT2 R5 330kΩ 4 BRT U2 OV 6 VCC2 3 2 1 SS GND C7 0.47µF D15 7 MAX1554 AGND2 D14 D18 C5 JU9 GND2 VCC 1 R4 10kΩ C10 3300pF D16 C6 0.1µF JU8 3 EN EP FB D17 5 OUT2R6 10Ω JU7 SHORT Figure 1. MAX1553 EV Kit Schematic 4 _______________________________________________________________________________________ MAX1553 Evaluation Kit Figure 3. MAX1553 EV Kit Component Placement—Solder Side Figure 4. MAX1553 EV Kit PC Board Layout—Component Side Figure 5. MAX1553 EV Kit PC Board Layout—Solder Side 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 _____________________ 5 © 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. Evaluates: MAX1553/MAX1554 Figure 2. MAX1553 EV Kit Component Placement—Component Side