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19-1974; Rev 0; 03/01
MAX1522 Evaluation Kit
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 0.5s or 3s. o Input Voltage +1.5V to +5.5V (Left Side, BOOTSTRAPPED) +2.5V to +5.5V (Right Side, NONBOOTSTRAPPED) o Output Voltage +5V Output Up to 1A (Left Side) +12V Output Up to 200mA (Right Side) o No Current-Sense Resistor o Fault-Detection o Soft-Start Limits Inrush Current o Selectable Maximum Duty Cycle (45% or 80%) o Adjustable Output Voltages o 1A (max) Shutdown Current o Switching Frequency Up to 1MHz o Fully Assembled and Tested
Features
Evaluates: MAX1522/MAX1523/MAX1524
Component Suppliers
SUPPLIER Fairchild Murata Nihon USA Sanyo Sumida Taiyo Yuden TDK Toshiba PHONE 408-822-2000 814-237-1431 661-867-2555 619-661-6835 847-956-0666 408-573-4150 847-803-6100 949-455-2000 FAX 408-822-2102 814-238-0490 661-867-2698 619-661-1055 847-956-0702 408-573-4159 847-803-6296 949-859-3963
Ordering Information
PART MAX1522EVKIT TEMP. RANGE 0C to +70C IC PACKAGE 6 SOT23
Note: Please indicate that you are using the MAX1522, MAX1523, or MAX1524 when contacting these component suppliers.
DESIGNATION QTY DESCRIPTION 100pF, 50V COG ceramic capacitors (0603) TDK C1608COG1H101JT or Murata GRM39COG101J050AD 47pF, 50V COG ceramic capacitor (0603) TDK C1608COG1H470JT 330pF, 50V COG ceramic capacitor (0603) TDK C1608X7R1H331KT or Murata GRM39COG331J050AD 1F, 16V X7R ceramic capacitor (1206) Taiyo Yuden EMK316BJ105KF or TDK C3216X7R1C105KT
Component List
DESIGNATION QTY DESCRIPTION 10F, 6.3V X5R ceramic capacitors (1206) TDK C3216X5R0J106KT or Taiyo Yuden JMK316BJ106KL 47F 20%, 20V aluminum electrolytic capacitor Sanyo 25CV47AX 33F, 10V Poscap capacitor (C) Sanyo 10TPA33M 301k 1% resistor (0805) 100k 1% resistors (0805) 866k 1% resistor (0805) 10 5% resistor (0805) 30V, 5.2A N-channel MOSFET Fairchild FDC633N (6-pin SuperSOT)
C1, C2
2
C6, C7
2
C3
1
C8
1
C9 R1 R2, R4 R3 R5 N1, N2
1 1 2 1 1 2
C4
1
C5
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.
MAX1522 Evaluation Kit Evaluates: MAX1522/MAX1523/MAX1524
Component List (continued)
DESIGNATION D1 QTY 1 DESCRIPTION 2.2A, 30V Schottky diode (SMD) Nihon EC31QS03L 1A, 30V Schottky diode (SOT123) Toshiba CRS02 or Nihon EP10QY03 3.3H, 1.44A inductor Sumida CR43-3R3 33H, 0.88A Inductor Sumida CDR74B-330 MAX1524EUT (6-pin SOT23) (Top mark - AAOZ) MAX1522EUT (6-pin SOT23) (Top mark - AAOX) 3-pin headers Shunts (JU1-JU4) MAX1522 PC board MAX1522 data sheet MAX1522 EV kit data sheet
+12.0V Output Circuit (NONBOOTSTRAPPED)
1) Verify that shunts are across pins 1 and 2 of jumpers JU3 (SET, 3s) 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.
D2
1
L1 L2 U1 U2 JU1-JU4 None None None None
1 1 1 1 4 4 1 1 1
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.
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, 0.5s) 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.
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.
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MAX1522 Evaluation Kit Evaluates: MAX1522/MAX1523/MAX1524
Table 1. Jumper JU2 and JU4 Functions
SHUNT LOCATION 1 and 2 2 and 3 JUMPER JU2 JU4 JU2 JU4 SHDN PIN Connected to VIN Connected to GND FUNCTION MAX1524 Enable MAX1522* Enable MAX1524 Disable 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 3s ensures an 80% maximum duty factor and a maximum switching frequency of 285kHz. Setting the on-time to 0.5s 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 0.5s on-time. Before switching the shunt on jumper JU1 from pins 2 and 3 (0.5s on-time) to pins 1 and 2 (3.0s 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 3.0s on-time. Switching the shunt on jumper JU3 from pins 1 and 2 (3.0s ontime) to pins 2 and 3 (0.5s 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.
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.
Table 2. Jumper JU1 and JU3 Functions
SHUNT LOCATION 1 and 2 2 and 3 SET PIN Connected to VCC Connected to GND FUNCTION 3.0s On-Time 0.5s On-Time
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
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MAX1522 Evaluation Kit Evaluates: MAX1522/MAX1523/MAX1524
VIN1 C6 10F C5 1F D1 VOUT1 (+5V) 6 6 1 2 3 JU1 3 SET VCC U1 MAX1524 1 2 3 JU2 4 SHDN GND 1 FB 2 R2 100k 1% C2 100pF EXT 5 3 4 N1 5 2 1 C9 33F 10V R1 301k 1% C1 100pF GND1
VOUT1
GND1 L1 3.3H
R5 10
VIN2 C7 10F
GND2
L2 33H D2 VOUT2 (+12V) 6 6 1 C8 47F 20V
5
2
1 2 3
JU3
3
SET
VCC U2
EXT
5
3 4
N2 R3 866k 1%
C3 47pF
GND2
GND2 MAX1522 1 2 3 JU4 4 SHDN GND 1 FB 2
R4 100k 1%
C4 330pF
Figure 1. MAX1522 EV Kit Schematic
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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 (c) 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

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