19-1974; Rev 0; 03/01 MAX1522 Evaluation Kit Component Suppliers SUPPLIER Features ♦ Input Voltage +1.5V to +5.5V (Left Side, BOOTSTRAPPED) +2.5V to +5.5V (Right Side, NONBOOTSTRAPPED) ♦ Output Voltage +5V Output Up to 1A (Left Side) +12V Output Up to 200mA (Right Side) ♦ No Current-Sense Resistor ♦ Fault-Detection ♦ Soft-Start Limits Inrush Current ♦ Selectable Maximum Duty Cycle (45% or 80%) ♦ Adjustable Output Voltages PHONE FAX Fairchild 408-822-2000 408-822-2102 ♦ 1µA (max) Shutdown Current Murata 814-237-1431 814-238-0490 Nihon USA 661-867-2555 661-867-2698 ♦ Switching Frequency Up to 1MHz Sanyo 619-661-6835 619-661-1055 Sumida 847-956-0666 847-956-0702 Taiyo Yuden 408-573-4150 408-573-4159 TDK 847-803-6100 847-803-6296 Toshiba 949-455-2000 949-859-3963 Note: Please indicate that you are using the MAX1522, MAX1523, or MAX1524 when contacting these component suppliers. DESIGNATION QTY DESCRIPTION C1, C2 2 100pF, 50V COG ceramic capacitors (0603) TDK C1608COG1H101JT or Murata GRM39COG101J050AD C3 1 47pF, 50V COG ceramic capacitor (0603) TDK C1608COG1H470JT 1 330pF, 50V COG ceramic capacitor (0603) TDK C1608X7R1H331KT or Murata GRM39COG331J050AD C4 C5 1 1µF, 16V X7R ceramic capacitor (1206) Taiyo Yuden EMK316BJ105KF or TDK C3216X7R1C105KT ♦ Fully Assembled and Tested Ordering Information PART TEMP. RANGE MAX1522EVKIT 0°C to +70°C IC PACKAGE 6 SOT23 Component List DESIGNATION QTY DESCRIPTION C6, C7 2 10µF, 6.3V X5R ceramic capacitors (1206) TDK C3216X5R0J106KT or Taiyo Yuden JMK316BJ106KL C8 1 47µF ±20%, 20V aluminum electrolytic capacitor Sanyo 25CV47AX C9 1 33µF, 10V Poscap capacitor (C) Sanyo 10TPA33M 301kΩ ±1% resistor (0805) R1 1 R2, R4 2 100kΩ ±1% resistors (0805) R3 1 866kΩ ±1% resistor (0805) R5 1 10Ω ±5% resistor (0805) N1, N2 2 30V, 5.2A N-channel MOSFET Fairchild FDC633N (6-pin SuperSOT) ________________________________________________________________ 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: MAX1522/MAX1523/MAX1524 General Description The MAX1522 evaluation kit (EV kit) is a fully assembled and tested surface-mount circuit board that contains two separate step-up switching controller circuits. The first circuit (left side) utilizes the MAX1524, is configured for +5V output, and can deliver up to 1A of current. The MAX1524 supply pin is bootstrapped to the output. The second circuit (right side) utilizes the MAX1522, is configured for +12V output, and can deliver up to 200mA of current with the input voltage as low as +2.7V. The MAX1522 and MAX1524 feature soft-start and faultdetect. The EV kit allows the user to set the on-time of the N-channel MOSFETs to either 0.5µs or 3µs. Evaluates: MAX1522/MAX1523/MAX1524 MAX1522 Evaluation Kit Component List (continued) DESIGNATION QTY DESCRIPTION D1 1 2.2A, 30V Schottky diode (SMD) Nihon EC31QS03L D2 1 1A, 30V Schottky diode (SOT123) Toshiba CRS02 or Nihon EP10QY03 L1 1 3.3µH, 1.44A inductor Sumida CR43-3R3 L2 1 33µH, 0.88A Inductor Sumida CDR74B-330 U1 1 MAX1524EUT (6-pin SOT23) (Top mark – AAOZ) U2 1 MAX1522EUT (6-pin SOT23) (Top mark – AAOX) JU1–JU4 4 3-pin headers None 4 Shunts (JU1–JU4) None 1 MAX1522 PC board None 1 MAX1522 data sheet None 1 MAX1522 EV kit data sheet Quick Start The MAX1522 EV kit is fully assembled and tested. Follow these steps to verify board operation. Do not turn on the power supply until all connections are completed. +5.0V Output Circuit (BOOTSTRAPPED) 1) Verify that shunts are across pins 2 and 3 of jumper JU1 (SET, 0.5µs) and pins 1 and 2 of jumper JU2 (SHDN). 2) Connect a +2.5V to +5.5V DC power supply to the VIN1 pad. Connect the supply ground to the GND1 pad. 3) Turn on the power supply. 4) With a voltmeter, verify that the output voltage VOUT1 is +5.0V. For instructions on selecting the feedback resistors for other output voltages, refer to Evaluating Other Output Voltages in this document. 2 +12.0V Output Circuit (NONBOOTSTRAPPED) 1) Verify that shunts are across pins 1 and 2 of jumpers JU3 (SET, 3µs) and JU4 (SHDN). 2) Connect a +2.5V to +5.5V DC power supply to the VIN2 pad. Connect the supply ground to the GND2 pad. 3) Turn on the power supply. 4) With a voltmeter, verify that the output voltage VOUT2 is +12V. For instructions on selecting the feedback resistors for other output voltages, refer to Evaluating Other Output Voltages in this document. Detailed Description The MAX1522 EV kit is a fully assembled and tested surface-mount circuit board that contains two separate step-up switching controller circuits. The first circuit (left side), labeled BOOTSTRAPPED, utilizes the MAX1524, is configured for +5.0V output, and can deliver up to 1A of current with 3.3V input voltage. The circuit requires a +1.5V to +5.5V input DC source. The MAX1524 VCC supply is bootstrapped to the output to provide +5V gate drive with low input voltages. The device features a fault-detect that reinitiates soft-start whenever the output drops to half of its nominal voltage regulation level. The second circuit (right side), labeled NON-BOOTSTRAPPED, utilizes the MAX1522, is configured for +12V output, and can deliver up to 200mA of current with 2.7V input voltage. The circuit requires a +2.5V to +5.5V input DC source. The MAX1522 is not bootstrapped to the output because during regulation the +12.0V exceeds the maximum supply voltage rating of the controller. The MAX1522 features a latched faultdetect that can be reset by toggling the SHDN pin with the jumper provided on the EV kit. Each circuit requires an input DC source that can supply 2A of current. Both ICs implement soft-start to prevent excessive input currents during startup. The MAX1522 EV kit also provides jumpers to set the fixed on-time of the N-channel MOSFETs. See Setting the On-Time section. Jumper Selection Shutdown Mode The MAX1522 EV kit features 3-pin jumpers (JU2 and JU4) to shut down or power up the BOOTSTRAPPED or NON-BOOTSTRAPPED circuits. Table 1 lists the selectable jumper options for jumpers JU2 and JU4. _______________________________________________________________________________________ MAX1522 Evaluation Kit SHUNT LOCATION JUMPER JU2 1 and 2 JU4 JU2 2 and 3 JU4 SHDN PIN FUNCTION MAX1524 Enable Connected to VIN MAX1522* Enable MAX1524 Disable Connected to GND MAX1522* Disable *To reset a latched fault-detect condition, the respective IC must be disabled first and then enabled. Setting the On-Time The MAX1522 EV kit features 3-pin jumpers (JU1 and JU3) to set the fixed on-time of the N-channel power MOSFET in each circuit. Table 2 lists the selectable jumper options for jumpers JU1 and JU3. Setting the on-time to 3µs ensures an 80% maximum duty factor and a maximum switching frequency of 285kHz. Setting the on-time to 0.5µs ensures a 45% maximum duty factor and a maximum switching frequency of 1MHz. On the left circuit (BOOTSTRAPPED) of the MAX1522EVKIT, the inductor has been selected for 0.5µs on-time. Before switching the shunt on jumper JU1 from pins 2 and 3 (0.5µs on-time) to pins 1 and 2 (3.0µs on-time), it is necessary to change inductor L1 to a higher value and a higher saturation current rating to prevent inductor saturation. Refer to the Design Procedure section of the MAX1522 data sheet for details. On the right circuit (NON-BOOTSTRAPPED) of the MAX1522EVKIT, the inductor and the output voltage setting have been selected for 3.0µs on-time. Switching the shunt on jumper JU3 from pins 1 and 2 (3.0µs ontime) to pins 2 and 3 (0.5µs on-time) will prevent the output voltage from reaching 12V under load. Refer to the Design Procedure section of the MAX1522 data sheet for details. Table 2. Jumper JU1 and JU3 Functions SHUNT LOCATION SET PIN FUNCTION 1 and 2 Connected to VCC 3.0µs On-Time 2 and 3 Connected to GND 0.5µs On-Time generate output voltages other than +5V (+2.5V to +5.5V), replace resistors R1 and R2. Refer to the Component List to verify that the circuit’s components will function properly if the output voltage is reconfigured. The output voltages are determined by the following equation: VOUT1 = VFB((R1 / R2) + 1) where VFB = 1.25V. Right Circuit (+12V) The MAX1522 EV kit contains a MAX1522 step-up controller on the right side of the board (NONBOOTSTRAPPED) that is set for +12V (VOUT2) output by two feedback resistors. To generate output voltages other than +12.0V, replace resistors R3 and R4. Refer to the Component List to verify that the circuit’s components will function properly if the output voltage is reconfigured. The output voltages are determined by the following equation: VOUT2 = VFB((R3 / R4) + 1) where VFB = 1.25V. Evaluating the MAX1523 The MAX1522 EV kit can also evaluate the MAX1523 step-up controller. The MAX1523 is different from the MAX1522 in that it doesn’t latch a fault-detect. To evaluate the MAX1523, replace the MAX1522, located on the right circuit (NON-BOOTSTRAPPED), with the MAX1523. To request MAX1523 samples, call the phone number listed at the bottom of page 1 of this data sheet and ask for MAX1523EUT samples. Evaluating Other Output Voltages Left Circuit (+5V) The EV kit contains a MAX1524 step-up controller on the left side of the board (BOOTSTRAPPED) that is set for +5V (VOUT1) output by two feedback resistors. To _______________________________________________________________________________________ 3 Evaluates: MAX1522/MAX1523/MAX1524 Table 1. Jumper JU2 and JU4 Functions Evaluates: MAX1522/MAX1523/MAX1524 MAX1522 Evaluation Kit VIN1 C6 10µF VOUT1 GND1 L1 3.3µH C5 1µF R5 10Ω D1 VOUT1 (+5V) 6 5 2 1 C9 33µF 10V 6 1 2 3 JU1 3 VCC SET EXT 5 N1 3 4 C1 100pF GND1 R1 301kΩ 1% U1 MAX1524 1 2 3 JU2 4 SHDN FB 2 GND 1 R2 100kΩ 1% C2 100pF VIN2 C7 10µF GND2 L2 33µH D2 VOUT2 (+12V) 6 5 2 1 6 1 2 3 JU3 3 VCC SET EXT 5 3 GND2 C3 47pF N2 4 U2 C8 47µF 20V R3 866kΩ 1% MAX1522 1 2 3 JU4 4 SHDN FB GND 1 2 R4 100kΩ 1% C4 330pF Figure 1. MAX1522 EV Kit Schematic 4 _______________________________________________________________________________________ GND2 MAX1522 Evaluation Kit Evaluates: MAX1522/MAX1523/MAX1524 1.0" Figure 2. MAX1522 EV Kit Component Placement Guide—Component Side 1.0" Figure 3. MAX1522 EV Kit PC Board Layout—Component Side 1.0" Figure 4. MAX1522 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. 5 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.