19-1985; Rev 1; 1/02 MAX1800 Evaluation Kit Features The MAX1800 evaluation kit (EV kit) accepts 1.8V to 5.5V battery voltages and provides all of the output voltages required in digital still cameras (DSC). The EV kit consists of the MAX1800 multi-output master converter and the MAX1801 slave step-up converter. The EV kit provides 10 separate output voltages. The MAX1800 provides one main-system step-up converter (3.3V/400mA), one linear regulator for the DSP core (1.8V/200mA), one step-up converter for the backlight (7V/100mA), three flyback outputs for the CCD (14.3V/10mA, 5V/50mA, -8.15V/10mA), and three flyback outputs for the LCD (13.85V/10mA, 5V/50mA, -16.23V/10mA). In addition, the MAX1801 provides one step-up converter for the motor (5V/500mA). ♦ 10 Outputs One Synchronous Rectified Step-Up Converter Two Step-Up Converters One Low-Dropout Linear Regulator Output Six Flyback Outputs The EV kit’s outputs are adjustable and are suitable for applications running from 2- or 3-cell alkaline, NiCd, or NiMH batteries or from a single lithium-on (Li+) battery. ♦ Soft-Start on Each Output ♦ 1.8V to 5.5V Input Voltage Range ♦ All Converters Synchronized to Single Oscillator ♦ 100kHz to 1MHz Switching Frequency ♦ Main Power-OK Output ♦ Independent Shutdown of Each Converter ♦ Short-Circuit-Protected Flyback Outputs ♦ Fully Assembled and Tested Ordering Information PART TEMP RANGE MAX1800EVKIT 0°C to +70°C IC PACKAGE 32 TQFP, 8 SOT23 Component List DESIGNATION QTY C1, C22 2 10µF, 10V ceramic capacitors (1210) TDK C3225X5R1A106M C2 1 100pF, ceramic capacitor (0603) C3, C15, C21 3 0.1µF ceramic capacitors (0603) C4, C18 2 4.7µF, 10V ceramic capacitors (1206) TDK C3216X5R1A475M or Taiyo Yuden LMK316BJ475ML C5−C8, C20 5 1000pF ceramic capacitors (0603) C9−C14 6 1µF, 25V ceramic capacitors (1206) TDK C3216X7R1E105KT C16 1 DESCRIPTION 4.7µF, 6.3V ceramic capacitor (0805) TDK C2012X5R0J475K DESIGNATION QTY DESCRIPTION C17 1 220µF, 10V, 100mΩ low-ESR (E case) AVX TPSE227M010R0100 C19 1 47µF, 6.3V, 100mΩ low-ESR (C case) Sanyo 6TPA47M C24 1 0.01µF ceramic capacitor (0603) D1, D4, D6 3 PN junction diodes (SOT323) Central Semiconductor CMSD-4448 D2, D3, D5, D9 4 Schottky diodes (SOT323) Central Semiconductor CMSSH-3 D7, D8 2 Schottky diodes (SOD-123) Motorola MBR0520L or Fairchild Semiconductor MBR0520L D10 1 Schottky diode (CASE 403A03 SMB) Motorola MBRS130LT3 ________________________________________________________________ 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: MAX1800/MAX1801 General Description MAX1800 Evaluation Kit Evaluates: MAX1800/MAX1801 Component List (continued) DESIGNATION QTY DESCRIPTION DESIGNATION QTY 4 10kΩ ±5% resistors (0402) DESCRIPTION JU1−JU6 6 3-pin headers R7, R8, R9, R27 JU7− JU12 6 2-pin headers R11, R16, R24 3 301kΩ ±1% resistors (0603) 1 44.2kΩ ±1% resistor (0603) R20 1 4.7Ω ±5% resistor (0402) L1 1 1.4µH inductor Sumida CR43-1R4 R18 L2 1 10µH inductor Sumida CDRH6D38-100 R21 1 165kΩ ±1% resistor (0603) R23 1 1MΩ ±5% resistor (0402) L3 1 0.5µH inductor Sumida CR43 Type Sample 4757-T019 R35, R36, R40, R41, R44, R45 6 3kΩ ±5% resistors (1206) Q1, Q2, Q3, Q5 Q4 4 1 N-channel MOSFETs Fairchild Semiconductor FDN337N P-channel MOSFET Fairchild Semiconductor NDS336P R37, R38, R42, R43 4 200Ω ±5% resistors (1206) R1 1 40.2kΩ ±1% resistor (0603) R2, R29, R31, R33 4 Shorted in the PC board layout (0402) (not installed) R39 1 750Ω ±5% resistor (1206) R46 1 100kΩ ±5% resistor (0402) T1 1 Transformer Sumida “Sample Number”: 6333-T330 T2 1 Transformer Sumida “Sample Number”: 6333-T329 U1 1 MAX1800EHJ (32-pin TQFP) U2 1 MAX1801EKA (8-pin SOT23) None 12 Shunts graph in the Typical Operating Characteristics in the MAX1800 data sheet before loading MAIN. R3, R12−R15, R26, R28, R30, R32, R34 10 Open, not installed (0402) R4 1 464kΩ ±1% resistor (0603) R5, R10, R17, R19, R22, R25 6 100kΩ ±1% resistors (0603) R6 1 200kΩ ±5% resistor (0402) 3) Make sure jumpers JU7–JU12 are connected if no external loads are attached to the OUT1A, OUT1B, OUT1C, OUT2A, OUT2B, and OUT2C outputs. 4) Attach a 1.8V to 5.5V battery or power supply to IN. 5) Using the DVM, measure the voltage at MAIN, LDO, OUT1_, OUT2_, OUT3 and OUT4. Detailed Description Quick Start Recommended Equipment • 1.8V to 5.5V battery or power supply • Digital voltmeter (DVM) Connections and Setup 1) Make sure jumpers JU1–JU6 are connected in the 12 (ON) position. This ensures that all converters will turn-on at power-up. 2) Before loading any output, check the output voltage and output current capability shown in Table 1. See the Startup Input Voltage vs. MAIN Output Current 2 The main output (MAIN) powers the MAX1800’s internal circuitry. MAIN must be regulated before any of the other outputs function. To enable MAIN, place jumper JU2 in the 1-2 position. Apply 1.8V to 5.5V between IN and GND. The voltage between MAIN and GND should be approximately 3.3V if IN is <3.3V. Because the IC is powered from MAIN, the IC does not work at maximum efficiency until MAIN is in regulation. Thus, at low battery voltages and heavy loads, MAIN may not have sufficient power to start. The output current capability shown in Table 1 is valid for input voltages down to 1.8V. The circuit operates for _______________________________________________________________________________________ MAX1800 Evaluation Kit LABEL VOLTAGE/CURRENT MAIN 3.3V at 400mA LDO 1.8V at 200mA OUT1A 14.3V at 10mA OUT1B 5V at 50mA OUT1C -8.15V at 10mA OUT2A 13.85V at 10mA OUT2B 5V at 50mA OUT2C -16.23V at 10mA OUT3 7V at 100mA OUT4 5V at 500mA input voltages below 1.8V but with reduced output current capability. Refer to the MAX1800 data sheet for the minimum allowable input voltage for the part to start at a given load. When the MAIN output is in regulation, the MAIN_OK output will be pulled up to the MAIN output voltage. If the MAIN_OK output is low (near ground), MAIN is not in regulation. LDO Output The LDO output is linearly regulated from MAIN to 1.8V. Note that the load current on LDO is produced from MAIN. Drawing more than 200mA out of LDO reduces the current capability at MAIN. To enable LDO, place jumper JU3 in the 1-2 (ON) position. OUT1_ (Flyback Outputs) The voltages at OUT1_ are typical of CCD bias voltages. The output voltages are 14.3V/10mA, 5V/50mA, and -8.15V/10mA. These voltages are generated through a custom flyback transformer. OUT1B (5V) is used to regulate the flyback circuit. The other output voltages (14.3V and -8.15V) are controlled by the turnsratio of the flyback transformer. If the 14.3V and -8.15V outputs are not loaded at the fixed 10mA load, then the output voltage will change from the nominal loaded output voltage. Loads are included on the MAX1800 EV kit by shorting jumpers JU7 through JU12. If external loads are used, disable the built-in loads by removing these jumpers. 3 (OFF) position. To enable/disable the output voltages using an external signal, see the Logic Control of the Output Voltages section. If a different set of output voltages is required, see the Setting the Flyback Circuit Voltages (OUT1_ and OUT2_) section. OUT2_ (Flyback Outputs) The voltages at OUT2_ are typical of LCD bias voltages. The output voltages are 13.85V/10mA, 5V/50mA, and -16.23V/10mA. These voltages are generated through a custom flyback transformer. OUT2B (5V) is used to regulate the flyback circuit. The other output voltages (13.85V and -16.23V) are controlled by the turns-ratio of the flyback transformer. If the 13.85V and -16.23V outputs are not loaded at the fixed 10mA load, then the output voltage will change from the nominal loaded output voltage. Loads are included on the MAX1800 EV kit by shorting jumpers JU7 through JU12. If external loads are used, disable the built-in loads by removing these jumpers. To enable OUT2_, place jumper JU5 to the 1-2 (ON) position. To disable OUT2_, place jumper JU5 to the 23 (OFF) position. To enable/disable the output voltages using an external signal, see the Logic Control of the Output Voltages section. If a different set of output voltages is required, see the Setting the Flyback Circuit Voltages (OUT1_ and OUT2_) section. OUT3 The voltage at OUT3 is typical of that required by a CCFL backlight inverter. To enable OUT3, place jumper JU6 to the 1-2 (ON) position. Place the external load between OUT3 and GND. To change the output voltage of OUT3, see the Setting the Step-Up Output Voltage (OUT3 and OUT4) section. OUT3 can be configured to drive a white LED backlight instead of a CCFL backlight. OUT4 The voltage at OUT4 is a general-purpose 5V output that can be used for powering a small motor or other peripheral circuitry and can supply up to 500mA. To enable OUT4, place jumper JU1 to the 1-2 (ON) position. Place the external load between OUT4 and GND. To change the output voltage of OUT4, see the Setting the Step-Up Output Voltage (OUT3 and OUT4) section. To enable OUT1_, place jumper JU4 to the 1-2 (ON) position. To disable OUT1_, place jumper JU4 to the 2- _______________________________________________________________________________________ 3 Evaluates: MAX1800/MAX1801 Table 1. Output Voltage and Current Capability Evaluates: MAX1800/MAX1801 MAX1800 Evaluation Kit Customizing the MAX1800 EV Kit Setting the Main Output Voltage MAIN is set by a voltage divider, which drops the output voltage to the 1.25V feedback threshold voltage. To change the 3.3V setting of MAIN, change the resistor divider ratio by changing R21. Use: R21 = 80kΩ / V ✕ ( VMAIN - 1.25V ) The MAIN output voltage may be set to any voltage between 2.7V and 5.5V. For additional information, see the MAX1800 data sheet. Setting the LDO Output Voltage The LDO output voltage is set by a voltage divider, which drops the output voltage to the 1.25V feedback threshold voltage. To change the 1.8V setting of LDO, change the resistor divider ratio by changing R18. Use: R18 = 80kΩ / V ✕ ( VLDO - 1.25V ) The LDO output voltage may be set to any voltage between 1.25V and 5.5V but must remain less than the voltage at MAIN when powered from MAIN. The MAX1800 EV kit is configured so that MAIN powers the LDO input; however, opening up the short across R33 and shorting R34 will allow LDO to be powered from IN. Setting the Flyback Circuit Voltages (OUT1_ and OUT2_) A flyback circuit generates OUT1_ and OUT2_. This allows multiple, positive, or negative voltages to be generated by a single converter and allows the voltages to drop to 0V when the converter is disabled. The transformer must be designed for a given set of output voltages. On the flyback circuits, only a single output voltage is used to regulate all the voltages. All other voltages are controlled by the turns-ratio of the transformer. If another set of output voltages is required, a transformer with a different secondary turns-ratio must be used. Consult the transformer manufacturer for details. Typically the highest power, positive voltage output of the flyback transformer is fed back to the controller. To change the regulated output voltage, use a different resistor in the voltage divider. Table 2 lists the resistors used for each output. Leave the resistors off (open) for unregulated outputs. For a given output voltage, the resistor value (Table 2) is: R = 80kΩ / V ✕ ( VOUT - 1.25V ) Setting the Step-Up Output Voltage (OUT3 and OUT4) The output voltage of the step-up circuit voltages (OUT3 and OUT4) may be set to any voltage above 1.25V. Note that if the battery voltage is greater than the step-up regulation voltage, the output voltage will rise above the regulation voltage. To set the output voltage, choose the voltage divider resistors. For OUT3, choose: R4 = 80kΩ / V ✕ ( VOUT3 - 1.25V ) For OUT4, choose: R24 = 80kΩ / V ✕ ( VOUT4 - 1.25V ) Setting the Maximum Duty Cycle DCON1, DCON2, and DCON3 set the maximum duty cycle for controllers 1, 2, and 3, respectively. A resistor divider from REF to DCON_ sets the corresponding maximum duty cycle up to 90%. The EV kit has DCON_ shorted to REF, producing a default duty cycle of 84%. See the MAX1800 data sheet for additional information. Setting the Switching Frequency All of the switching regulators are synchronized to a single oscillator frequency. The oscillator capacitor (C2) is charged through R1 and discharged internally by the MAX1800. The EV kit is designed to operate at 440kHz with MAIN set to 3.3V. If a different MAIN voltage is used, or if a different oscillator frequency is desired, change resistor R1 or capacitor C2. Consult the MAX1800 data sheet for the correct values to use for R1 and C2. Logic Control of the Output Voltages Table 2. Flyback Converter Feedback Resistors 4 OUTPUT OUT1_ OUT2_ OUT_A R13 R14 OUT_B R11 R16 OUT_C R12 R15 Each controller may be independently turned off or on using jumpers (JU1–JU6) or with logic voltages. To control an output using an external logic signal, remove the ON/OFF jumper for that output, and place the control signal on the corresponding ON_ pad. To enable the output, make sure that the voltage of the control signal at the corresponding ON_ pad is >1.6V. To disable it, make sure the voltage at the corresponding ON_ pad is <0.3V. _______________________________________________________________________________________ MAX1800 Evaluation Kit High Input Voltage Operation The MAIN output is designed to operate with an input voltage above or below the output regulation voltage. Since MAIN is a step-up converter, when the input voltage is above the regulation voltage, the output will be nearly that of the input voltage. If the input battery voltage ranges above and below the regulation voltage, follow the MAIN output with the LDO output to form a step-up/step-down regulator. In this case, when the battery voltage is low, the step-up converter raises the battery voltage to the regulation voltage. When the battery voltage is above the regulation voltage, the LDO regulator controls the output voltage. Component Suppliers PHONE FAX AVX SUPPLIER 803-946-0690 803-626-3123 Central Semiconductor 631-435-1110 631-435-1824 Fairchild Semiconductor 408-721-2181 408-721-1635 Motorola 602-303-5454 602-994-6430 Sumida 847-956-0666 847-956-0702 Taiyo Yuden 408-573-4150 408-573-4159 TDK 847-803-6100 847-803-6296 Note: Please indicate that you are using the MAX1800/ MAX1801 when contacting these suppliers. For high input voltages, if the power is applied abruptly, the MAIN output capacitor charges quickly, causing the L2 inductor current to rise above the 2A current limit. To prevent damage to the MAX1800, diode D10 is used to charge main output capacitor C17, preventing excessive current in the inductor. Components R46, C24, and D9 delay turn-on of the MAIN converter when power is applied. This prevents damage to the switches caused by switching with excessive inductor current at turn-on. If the MAX1800 is used exclusively with low input voltage, components R46, C24, D9, and D10 may be omitted. _______________________________________________________________________________________ 5 Evaluates: MAX1800/MAX1801 Also, note that the voltages at MAIN, OUT3, and OUT4 will drop slightly below the battery voltage when OFF, due to the DC current path through the inductor and output rectifier. For the step-up outputs, a switch may be added between the output voltage and the load to disconnect them while the output is disabled. 6 MAIN GND D8 2 3 Q5 4 OUT3 R28 OPEN FB DL OCON 5 COMP 6 8 L3 0.5µH R27 10kΩ IN C20 1000pF C19 47µF 6.3V ON4 JU1 1 R25 100kΩ 1% R24 301kΩ 1% OUT4 GND IN MAIN D9 IN R5 100kΩ 1% R46 100kΩ C4 4.7µF R26 OPEN ON1 LDO_ON JU2 R7 10kΩ ON2 JU3 3 1 2 Figure 1. MAX1800 EV Kit Schematic _______________________________________________________________________________________ GND ON3 JU5 3 1 JU4 2 JU6 3 1 2 MAIN 3 MAIN 1 2 C8 1000pF 3 1 2 MAIN DL3 DCON3 DCON2 DCON1 REF OSC 29 11 ON2 ON1 ONA ONM 15 GND 31 ON3 9 3 27 24 COMP3 COMP2 30 FB3 18 COMPM 5 COMP1 32 25 12 5 14 16 R9 10kΩ R3 OPEN R2 SHORT R1 40.2kΩ 1% MAIN R8 10kΩ R30 OPEN R29 SHORT C7 1000pF R32 OPEN C5 R6 1000pF 200kΩ C6 1000pF Q1 L1 1.4µH C1 10µF C3 R31 0.1µF SHORT C2 100pF C21 0.1µF D7 R4 464kΩ 1% 2 3 1 7 MAIN_ON C24 0.01µF GND REF MAX1801 OSC U2 IN MAIN PGND 1 MAX1800 U1 25 28 10 8 4 19 PGND ROYM FBM OUT 23 17 13 POUT 7 22 POUT A1 A0 FB2 DL2 FB1 20 LX LX 21 DL1 2 Q2 4 C18 4.7µF R20 4.7Ω R19 100kΩ 1% R18 44.2kΩ 1% Q3 Q4 4 1 5 6 7 8 5 R22 100kΩ 1% R21 165kΩ 1% C16 4.7µF C15 0.1µF D6 R15 OPEN C14 1µF R12 OPEN GND LDO C13 1µF D5 D4 D3 C11 1µF T1 XFMR-CLQ72 D1 8 1 7 D2 C22 10µF 6 C10 1µF T2 XFMR-CLQ72 L2 10µH IN C9 1µF JU11 C12 1µF R39 750Ω R23 1MΩ MAIN R33 SHORT R34 OPEN IN MAIN_OK R42 200Ω R37 200Ω MAIN D10 C17 220µF 10V IN R44 3kΩ OUT2C R45 3kΩ JU12 JU9 JU8 R36 3kΩ OUT1C JU7 R35 3k R43 200Ω JU10 R10 100kΩ 1% R38 200Ω R17 100kΩ 1% R16 301kΩ 1% OUT2B R11 301kΩ 1% OUT1B R40 3kΩ R41 3kΩ R13 OPEN OUT1A R14 OPEN OUT2A GND Evaluates: MAX1800/MAX1801 MAX1800 Evaluation Kit MAX1800 Evaluation Kit Figure 2. MAX1800 EV Kit Component Placement Guide— Component Side Figure 3. MAX1800 EV Kit PC Board Layout—Component Side 1.0" 1.0" Figure 4. MAX1800 EV Kit PC Board Layout—Inner Layer 2 (AGND) Figure 5. MAX1800 EV Kit PC Board Layout—Inner Layer 3 (VCC) _______________________________________________________________________________________ 7 Evaluates: MAX1800/MAX1801 1.0" 1.0" Evaluates: MAX1800/MAX1801 MAX1800 Evaluation Kit 1.0" Figure 6. MAX1800 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. 8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2002 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.