MAX1583

19-3246; Rev 0; 4/04 MAX1583 Evaluation Kit General Description The MAX1583 evaluation kit (EV kit) is a fully assembled and tested surface-mount circuit board for evaluating the MAX1583 white LED flash boost converter. The EV kit accepts a 2.6V to 5.5V input voltage and drives up to five series white LEDs with a constant current to provide camera flash/strobe in cell phones, PDAs, DSCs, and other hand-held devices. The MAX1583 switching frequency is 1MHz, allowing tiny external components. Two logic inputs control four modes of operation: shutdown mode (0.5µA max), movie mode for high-efficiency continuous lighting (programmable up to 100mA), precharge mode for charging a reservoir capacitor to 24V while the LEDs are off (POK output indicates a full reservoir capacitor), and strobe mode for firing the flash during an exposure with a regulated current programmable up to 300mA (100mA with installed components). A pushbutton pulse generator is installed to simulate a 30ms flash pulse. The MAX1583 comes with the MAX1583X (1A current limit) installed, but the entire MAX1583 family can be evaluated with this EV kit with minor component changes. Features ♦ Supports Up to 5 LEDs for Strobe/Flash ♦ Four Operational Modes Strobe: Up to 300mA (Preset to 100mA) Precharge: With POK Indicator Movie: Up to 100mA (Preset to 20mA) Shutdown: 0.01µA (typ) Quiescent Current ♦ Input Current Limiting 1A (MAX1583X) 500mA (MAX1583Y) 250mA (MAX1583Z) ♦ 24V Output Overvoltage Protection ♦ 80% Efficient (PLED / PIN) Movie Mode ♦ Thermal-Shutdown Protection ♦ 10-Lead 3mm x 3mm TDFN Package ♦ Surface-Mount Components ♦ Fully Assembled and Tested Evaluates: MAX1583 Ordering Information PART MAX1583EVKIT TEMP RANGE 0°C to +70°C IC PACKAGE 10 TDFN 3mm x 3mm Note: To evaluate the MAX1583Y or MAX1583Z, request a MAX1583YETB or MAX1583ZETB free sample with the MAX1583 EV kit. Component List DESIGNATION QTY C1 1 DESCRIPTION 22µF, 6.3V X5R ceramic capacitor (0805) TDK C2012X5R0J226M 10µF ±10%, 25V X5S ceramic capacitor (1206) Taiyo Yuden TMK316C106KL 0.01µF ±10%, 16V X7R ceramic capacitors (0402) TDK C1005X7R1E103K 0.1µF ±10%, 25V X7R ceramic capacitor (0603) TDK C1608X7R1E104K 30V, 500mA, VF = 0.4V Schottky diode (SOD-323) Diodes, Inc. B0530WS DESIGNATION QTY D2 1 DESCRIPTION White LED module Nichia NBCW011T 30V, 100mA Schottky diode (SOD 523) Central Semiconductor CMOSH-3 3-pin headers 2-pin header 4.7µH, 1.06A, 450mΩ TOKO 984FB-4R7M 6.04kΩ ±1% resistor (0402) 3.01kΩ ±1% resistor (0402) 100kΩ ±5% resistors (0402) Momentary pushbutton switch Panasonic EVQ-PHP03T D5 JU1, JU2 JU3 L1 R1 R2 R3, R4, R5 SW1 1 2 1 1 1 1 3 1 C2 1 C3, C4 2 C5 1 D1 1 ________________________________________________________________ Maxim Integrated Products 1 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. MAX1583 Evaluation Kit Evaluates: MAX1583 Component List (continued) DESIGNATION QTY U1 U2 None None 1 1 2 1 DESCRIPTION MAX1583XETB (10-pin TDFN) MAX6422XS23 (SOT23) Shunts MAX1583 EV kit PC board 13) Remove the shunt on JU2 and place it between pins 1 and 2 of JU3. Remove the shunt on JU1 and place it between pins 1 and 2 of JU1. This places the MAX1583 into precharge mode. 14) Verify that the white LED module is off. Verify that VOUT is approximately 23.5V and VPOK is approximately 2.7V. 15) Sweep the power supply to 5.5V. Verify that the LED module remains off, VOUT is approximately 23.5V, and VPOK tracks VVIN. 16) Set the power supply to 3.3V. 17) Push the button on the bottom of the EV kit. This enables a strobe/flash. 18) Verify that the LED module flashes. Recommended Equipment • 0 to +6V at 1A, variable-output power supply • Two digital multimeters (DMMs) Quick Start The MAX1583 EV kit is fully assembled and tested. Perform the following steps to verify board operation: 1) Verify that shunts are across pins 2 and 3 of jumpers JU1 (EN2) and JU2 (EN1). This places the MAX1583 into shutdown mode. 2) Verify that JU3 is open. 3) Preset the power supply to 2.7V and turn off. Do not turn on the power supply until all connections are completed. 4) Connect the positive lead of the power supply to the VIN pad on the EV kit PC board. Connect the ground lead of the power supply to the GND pad on the EV kit PC board. 5) Connect the positive lead of one DMM to the OUT pad on the EV kit PC board and connect the negative lead of the DMM to the GND pad. This DMM measures the voltage at OUT (VOUT). 6) Connect the positive lead of the other DMM to POK on the EV kit PC board and connect the negative lead of the DMM to the GND pad. This DMM measures the voltage at POK (VPOK). 7) Turn on the power supply. 8) Verify that the white LED module is off. 9) Remove the shunt on JU2 and place it between pins 1 and 2 of JU2. This places the MAX1583 into movie mode. 10) Verify that the white LED module lights up. VOUT should read approximately 7V. 11) Sweep the input voltage from 2.7V to 5.5V, verifying that the LED module remains on with constant brightness and VOUT does not change. 12) Set the power supply to 2.7V. Detailed Description Jumper Selection EN1 and EN2 on the MAX1583 provide control for shutdown mode, movie mode, precharge mode, and strobe mode. Jumpers JU1 and JU2 connect EN2 and EN1 to either VIN or GND (see Table 1). An external signal can be used to drive EN1 or EN2 by removing the corresponding shunt completely from the jumper and connecting the external signal to the appropriate connecting pad. JU3 enables the pulse generator for the strobe mode. JU3 must be open if a jumper is installed on JU2 or if EN1 is externally driven. Setting LED Current The preset LED current in movie mode is 20mA. To set a different movie-mode LED current, change R2, where R2 = 60 / I LED(MOVIE). The MAX1583 is capable of movie-mode currents up to 100mA. The preset LED current in strobe mode is 100mA. To set a different strobe-mode LED current, change R1, where R1 = 600 / ILED(STROBE). The MAX1583 can regulate strobe-mode LED currents up to 300mA; however, the LED installed on the MAX1583 EV kit has a maximum pulse-current rating of 100mA. If larger currents are desired, a new LED with a higher pulsed current rating must be installed on the EV kit. Evaluating Off-Board LEDs The MAX1583 EV kit allows for easy evaluation of offboard LEDs. To evaluate off-board LEDs, first remove the installed LED module, D2. Next, connect the pad labeled OUT on the EV kit to the anode of the series LED string under evaluation and connect the cathode of the external series LED string to the EV kit pad labeled LED. 2 _______________________________________________________________________________________ MAX1583 Evaluation Kit Changing the Strobe Pulse Width The MAX1583 EV kit includes a pulse generator for convenience in evaluating the strobe function of the MAX1583. The strobe pulse width is determined by C4. To change the pulse width of the strobe, replace C4 with a capacitor corresponding to the following equation: t − 275µs C4 = PULSE 2.73 × 106 The minimum pulse width of the pulse generator is 1ms. Using a strobe pulse longer than 30ms may require a larger output reservoir capacitance (C2). Refer to the Reservoir Capacitance vs. Current Limit section in the MAX1583 data sheet for details on calculating the required capacitance. Evaluates: MAX1583 Table 1. JU1 and JU2 Functions (Dimming Control) JU2 POSITION 1 and 2 1 and 2 2 and 3 2 and 3 EN1 Connected to VIN Connected to VIN Connected to GND Connected to GND JU1 POSITION 1 and 2 2 and 3 1 and 2 2 and 3 EN2 Connected to VIN Connected to GND Connected to VIN Connected to GND MAX1583 OUTPUT Strobe Mode Movie Mode Precharge Mode Shutdown Mode Component Suppliers SUPPLIER Diodes, Inc. Nichia Panasonic Taiyo Yuden TDK COMPONENT Schottky Diode LEDs Resistors Capacitors Capacitors PHONE 805-440-4800 717-285-2323 714-373-7366 408-573-4150 888-835-6646 www.diodes.com www.nichia.com www.maco.panasonic.co.jp www.t-yuden.com www.component.tdk.com WEBSITE Note: Indicate that you are using the MAX1583 when contacting these suppliers. _______________________________________________________________________________________ 3 MAX1583 Evaluation Kit Evaluates: MAX1583 VIN VIN L1 4.7µH 2 R3 100kΩ POK C1 22µF IN GND POK U1 LX 10 D1 OUT C2 10µF 1 5 OUT 8 C5 0.1µF D2 WHITE LED MODULE 1 EN2 2 3 4 GND R1 6.04kΩ 1% R2 3.01kΩ 1% 1 EN1 2 3 JU2 STB JU1 7 EN2 MAX1583XETB LED 9 LED 3 MOV EN1 6 VIN VIN JU3 R5 100kΩ SW1 R4 100kΩ D5 VCC RESET U2 C3 0.01µF MAX6422XS23 SRT GND C4 0.01µF Figure 1. MAX1583 EV Kit Schematic 4 _______________________________________________________________________________________ MAX1583 Evaluation Kit Evaluates: MAX1583 Figure 2. MAX1583 EV Kit Component Placement Guide—Top Silkscreen Figure 3. MAX1583 EV Kit PC Board Layout—Component Side Figure 4. MAX1583 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 © 2004 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.