MAX1567 Step-Up Main Evaluation Kit

Transcription

1 9-3236; Rev 0; 3/04 MAX567 Step-Up Main Evaluation Kit General Description The MAX567 step-up main evaluation kit (EV kit) is a fully assembled and tested circuit that accepts input voltages of.5v to 3.2V and provides all the output voltages required for a typical digital still camera. The outputs consist of the main step-up output (3.3V), a stepdown output (.8V), a general-purpose 5V output, outputs for driving white LED backlighting, and outputs for charge-coupled device (CCD) and LCD bias. The EV kit comes with the MAX567 installed, but can also be used to evaluate the MAX566. For applications with a higher battery voltage, such as Li+ battery applications, another version of the EV kit is available with the main output configured as a step-down converter (MAX567EVKIT). DESIGNATION QTY DESCRIPTION C, C8 2 C2 µf ±0%, 25V X7R ceramic capacitors (206) TDK C326X7RE05K or 0.µF ±0%, 6V X7R ceramic capacitor (0603) TDK C608X7RC04K or Features Up to 95% Efficient.5V to 3.2V Input Voltage Range Main Step-Up Output, 3.3V Step-Down Output,.8V 5V General-Purpose Output CCD and LCD Bias Outputs (+5V/-7.5V) Current-Regulated Output with Overvoltage Protection for White LED Backlighting µa Shutdown Mode Fully Assembled and Tested Ordering Information PART TEMP RANGE IC PACKAGE MAX567SUMEVKIT 0 C to +70 C 40 Thin QFN 6mm x 6mm Component List DESIGNATION QTY DESCRIPTION C7 C8 3300pF ±0%, 50V X7R ceramic capacitor (0402) Taiyo Yuden UMK05BJ332KW or 2200pF ±0%, 50V X7R ceramic capacitor (0402) Taiyo Yuden UMK05BJ222KW or C3 00pF ±5%, 50V C0G ceramic capacitor (0603) TDK C608C0GH0J or C0, C4, C2 3 47µF ±20%, 6.3V X5R ceramic capacitors (82) Taiyo Yuden JMK432BJ476MM or C4 C5, C9 2 C6 0.0µF ±0%, 6V X7R ceramic capacitor (0402) TDK C005X7RE03K or 4700pF ±0%, 25V X7R ceramic capacitors (0402) Taiyo Yuden TMK05B472KW or 6800pF ±0%, 25V X7R ceramic capacitor (0402) Taiyo Yuden TMK05B682KW or C, C3 0 Not installed (0805) C2, C5, C6 3 C7 0µF ±20%, 6.3V X5R ceramic capacitors (0805) Taiyo Yuden JMK22BJ06MG or µf ±0%, 25V X7R ceramic capacitor (0805) TDK C202X7RE05K or C9 0 Not installed (0805) C20 0 Not installed (206) Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at , or visit Maxim s website at

2 DESIGNATION QTY DESCRIPTION D, D7, D0 3 D2 D5 4 D6 Schottky diodes 20V, 500mA (SOD-23) Central CMHSH5-2L White LEDs Nichia NSCW25T Schottky diode 40V, 500mA (SOD-23) Central CMHSH5-4 D8, D9 0 Not installed (SOD-23) D Schottky diode A, 30V (SMA) Nihon EC0QS03 JU JU6 6 3-pin headers JU8, JU9, JU, JU3 JU7, JU0, JU2 0 0 L L2 L3 L4 L5 Not installed Cut here short Not installed Cut here open.5µh inductor Sumida CDRH3D6-R5.5µH inductor TOKO A92CY-R5M 22µH inductor TOKO A92CY-220M 0µH inductor Sumida CDRH8D µH inductor Sumida CDRH5D28-3R0 L6 0µH inductor Sumida CDRH5D28-00 L7 0 Not installed N, N2 2 N-channel MOSFETs (SOT23) Fairchild FDN337N N3 0 Not installed (SOT23) P P-channel MOSFET (SOT23) Fairchild FDN360P R MΩ ±5% resistor (0603) R2, R2, R4, R6, R8, R kΩ ±% resistors (0603) Component List (continued) DESIGNATION QTY DESCRIPTION R3 0Ω ±5% resistor (0603) R4 5kΩ ±5% resistor (0603) R5 68kΩ ±5% resistor (0603) R6 47kΩ ±5% resistor (0603) R7 33kΩ ±5% resistor (0603) R8, R9 2 00kΩ ±5% resistors (0603) R0 8.2kΩ ±5% resistor (0603) R MΩ ±% resistor (0603) R3 549kΩ ±% resistor (0603) R5 274kΩ ±% resistor (0603) R7 50kΩ ±% resistor (0603) R9 40.2kΩ ±% resistor (0603) R2, R22, R kΩ ±5% resistors (0603) R24 R29 0 Not installed (206) R30, R3 0 Not installed (0603) T 0 Transformer (not installed) U MAX567ETL (40-lead thin QFN) None 6 Shunts None MAX567 EV kit PC board Component Suppliers SUPPLIER PHONE WEBSITE Central Semiconductor Fairchild Semiconductor International Rectifier Kamaya Murata Panasonic Sumida Taiyo Yuden TDK TOKO Vishay Note: Please indicate you are using the MAX566/MAX567 when contacting these component suppliers. 2

3 Quick Start Recommended Equipment Power supply capable of supplying.5v to 3.2V at 5A Voltmeter Load resistors or electronic loads Procedure Follow the steps below to verify operation of the MAX567 EV kit: ) Preset the power supply to.5v to 3.2V. 2) Turn off the power supply. Do not turn on the power supply until all connections are completed. 3) Connect the power-supply positive lead to the pad on the EV kit board labeled. 4) Connect the power-supply ground lead to the pad on the EV kit board labeled GND. 5) Connect loads from outputs VM, VSD, OUTA, and OUT2 to GND. See Table for maximum load currents. 6) Verify that the EV kit jumper JU has pins 2-3 shorted (to enable 5V step up). 7) Verify that jumpers JU2 JU6 have pins -2 shorted (to disable all other outputs). 8) Turn on the power supply. 9) Verify the voltage is 5V using a voltmeter. 0) If desired, connect a load from to GND. ) To verify other outputs, move jumpers JU2 JU6 to short pins 2 and 3 to enable corresponding output, and verify the voltages with a voltmeter (see Table ). Detailed Description Step-Up Output () The main step-up output () powers the internal circuitry of the MAX567 and must reach its regulation voltage (5V) before any other output can turn on. To enable, short pins 2-3 of jumper JU. When jumper JU is on pins -2, all outputs shut down and the IC is in low-current shutdown mode. Short-Circuit Flag (SCF) SCF is an open-drain output that is high impedance when overload protection occurs. Under normal operation SCF pulls low. In the default configuration there is a 00kΩ pullup resistor (R23) from SCF to VM. Table. Output Voltages and Maximum Currents OUTPUT VOLTAGE (V) MAXIMUM CURRENT (ma) (Note ) VM VSD OUTA OUT LEDOUT+ to LEDOUT- 5.0 max (Note 2) 20 Note : If both and VSD are operating, subtract half the VSD load current from the maximum load capability of. Note 2: The LED outputs are current regulated to 20mA with overvoltage protection set to 5V. Main Step-Up Output (VM) The main step-up output is set to 3.3V. To enable VM, short pins 2-3 of jumper JU2. To shut down VM, short pins -2 of JU2. Step-Down Output (VSD) The step-down output (VSD) is set to.8v. To enable VSD, short pins 2-3 of jumper JU3. To shut down OUTSD, short pins -2 of JU3. Step-Down OK (SDOK) The step-down OK output (SDOK) is an open-drain output that is pulled low until the step-down converter has completed soft-start. For more details on SDOK, refer to the MAX567 data sheet. Auxiliary Output OK (AUXOK) AUXOK is an open-drain output that goes low when OUT has successfully completed soft-start. AUXOK goes high impedance in shutdown, overload, and thermal limit. CCD/LCD Bias Outputs (OUTA, OUTB) Output OUTA provides a regulated +5V output. To enable OUTA, short pins 2-3 of JU5. To turn OUTA off, short pins -2 of JU5. In the standard configuration, OUTA and OUT2 provide the +5V and -7.5V bias voltages for CCD and LCD. OUTB is not used in the standard configuration of the EV kit. 3

4 The outputs OUTA and OUTB can be configured to use a flyback transformer to provide both the +5V (OUTA) and -7.5V (OUTB) necessary for CCD and LCD bias. This is useful when using the MAX566 where OUT2 is configured as a boost converter. See the Flyback Transformer Configuration for OUTA/OUTB section. Inverter Output (OUT2) OUT2 is a regulated -7.5V output. To enable OUT2, connect pins 2-3 of jumper JU6. To shut down OUT2, connect pins -2 of JU6. OUT2 can also be configured as a boost output when evaluating the MAX566. See the Evaluating the MAX566 section. LED Outputs (OUT3+, OUT3-) The outputs OUT3+ and OUT3- are for driving a series of white LEDs for display backlighting. The EV kit comes with four surface-mount white LEDs installed and is configured to drive the LEDs at a regulated 20mA. To protect against an open LED string, the overvoltage protection limits the maximum output voltage to 5V. To evaluate with fewer than four LEDs, short the pads of the unused LEDs. To use LEDs other than the ones mounted on the board, break the string by removing one of the LEDs on the board, then connect a series array consisting of two to six white LEDs in series to the OUT3+ and OUT3- outputs. The anode side of the array connects to OUT3+, and the cathode side connects to OUT3-. To enable the LED outputs, short pins 2-3 of JU4. To turn the LED outputs off, short pins -2 of JU4. To adjust the LED brightness or overvoltage protection, see the Adjusting the LED Brightness section. Customizing the MAX567 Evaluation Kit Adjusting the Step-Up Output () The main step-up output () is adjustable from 2.7V to 5.5V using the following procedure: ) Select a value for R6 between 0kΩ and 00kΩ. 2) Solve for R5 using: V R5 = R ) Install resistors R5 and R6. Table 2. Jumper Functions JUMPER JU SHORT PINS -2 All outputs are shut down. Table 3. PC Board Jumper Functions Adjusting the Main Step-Up Output (VM) The main step-up output (VM) is adjustable from 2.7V to using the following procedure: ) Select a value for R8 between 0kΩ and 00kΩ. 2) Solve for R7 using: V R7 = R8 VM ) Install resistors R7 and R8. SHORT PINS 2-3 enabled. JU2 VM shut down. VM enabled. JU3 VSD shut down. VSD enabled. JU4 LEDs (OUT3+/OUT3-) shut down. LEDs (OUT3+/OUT3-) enabled. JU5 OUT shut down. OUT enabled. JU6 OUT2 shut down. OUT2 enabled. JUMPER FUNCTION DEFAULT JU7 JU8 JU9 JU0 JU JU2 JU3 S el ect the i np ut p ow er for the O U T2 conver ter. S hor t onl y one of these j um p er s. S hor t JU 7 to connect the O U T2 i np ut p ow er to, or shor t JU 8 to connect to V S U. Connects the ground planes together. This must remain shorted for proper circuit operation. Select the input power for the stepdown converter. Short only one of these jumpers. Short JU0 to connect the step-down input power to, short JU for, or short JU2 for VM. S el ects top ol og y for OU TA/OU TB. S hor t for OU TA step - up, or op en for OU TA/OU TB tr ansfor m er fl yb ack. Open Short Short Open Short Open Short 4

5 Configuring the Step-Down Output (VSD) The input to the step-down converter (PVSD) on the EV kit comes connected to, but the connection can be changed to either or VM. To use as the input to the step-down converter, cut the trace shorting JU and short the pads of JU0. To use VM as the input to the step-down converter, cut the trace shorting JU, and short the pads of JU2. Make sure one and only one of JU0, JU, and JU2 are shorted. The step-down output voltage (VSD) is adjustable from.25v to V PVSD using the following procedure: ) Select a value for R20 between 0kΩ and 00kΩ. 2) Solve for R9 using: V R9 = R20 VSD ) Install resistors R9 and R20. Adjusting the OUTA Voltage OUTA can be set to a voltage above.25v. The upper limit depends on the ratings of the external components. Note that if the input voltage is greater than what OUTA is set to, then OUTA rises above its regulation voltage. Use the following procedure to set V OUTA : ) Select a value for R2 between 0kΩ and 00kΩ. 2) Solve for R using: V R = R2 OUT A ) Install resistors R and R2. Configuring the Inverting Output (OUT2) The input to the inverter is normally connected to. To change this connection to, cut trace shorting JU8 and short the pads of JU7. Note that the lower limit of inverter operation, when powered from, depends on the external P-channel MOSFET threshold voltage. To adjust the OUT2 voltage, use the following procedure: ) Select a value for R3 between 0kΩ and 00kΩ. 2) Solve for R4 using: V R3 = R4 OUT ) Install resistors R3 and R4. Adjusting the LED Brightness Resistor R3 sets the regulation current of the LEDs as follows: R3 = The overvoltage protection threshold for the LEDs is also adjustable. To ensure the LEDs are current regulated, this threshold (V OVP ) must be set higher than the maximum forward voltage drop of the LED string. V OVP should be set lower than the maximum voltage ratings of the capacitor, diode, and MOSFET (C, D, and N) used in the LED driver circuit. Use the following procedure to set the overvoltage protection: ) Select a value for R between 0kΩ and 00kΩ. 2) Solve for R2 using: V R = R2 OVP ) Install resistors R and R V I LED Changing the Switching Frequency The switching frequency of the MAX567 is adjustable. Typically, frequencies from 400kHz to 500kHz provide a good compromise between efficiency and component size. To change the frequency, replace C3 and R4. Refer to the MAX567 data sheet for information on selecting values for these components. Evaluating the MAX566 To evaluate the MAX566, first carefully remove U and replace it with the MAX566. Free samples of the MAX566 can be obtained from Maxim. The MAX566 requires that OUT2 be configured as a boost converter. 5

6 Configuring OUT2 as a Boost Converter To configure OUT2 as a boost converter, remove components C7, R3, R4, D7, and P. Then add components C9, R30, R3, D8, L7, and N3. Refer to the MAX566/MAX567 data sheet for information on component selection. Table 4 shows typical components for generating +5V at up to 20mA. Table 4. Typical Components for OUT2 Boost Circuit DESIGNATION QTY DESCRIPTION C9 D8 L7 µf ±0%, 25V X7R ceramic capacitor (0805) TDK C202X7RE05K Schottky diode 40V, 500mA (SOD-23) Central CMHSH5-4.5µH inductor Sumida CDRH3D6-R5 N3 N-channel MOSFET (SOT23) Fairchild FDN337N R30 MΩ ±% resistor (0603) R3 90.9kΩ ±% resistor (0603) Flyback Transformer Configuration for OUTA/OUTB OUT can be configured to provide two outputs using a transformer. This is usually done to generate CCD/LCD bias when using the MAX566. To use a transformer, remove L2 and cut the trace shorting JU3. Install the transformer on the footprint (T) that overlaps L2 and JU3. Refer to the MAX566/MAX567 data sheet for details on component selection. Table 5 shows typical components for generating +5V and -7.5V. Table 5. Typical Components for OUTA/OUTB Transformer Circuit DESIGNATION QTY DESCRIPTION C8, C20 2 D6 D9 µf ±0%, 25V X7R ceramic capacitors (206) TDK C326X7RE05K Schottky diode 40V, 500mA (SOD-23) Central CMHSH5-4 Schottky diode 20V, 500mA (SOD-23) Central CMHSH5-2L N2 N-channel MOSFET (SOT23) Fairchild FDN337N R MΩ ±% resistor (0603) R2 90.9kΩ ±% resistor (0603) T Transformer TDK T 6

7 LEDOUT+ D5 LEDOUT- GND AUXOK SDOK D2 D3 D4 R3 0Ω C µf R22 00kΩ R2 00kΩ R MΩ R2 90.9kΩ D C4 C5 C6 C7 C8 C9 3 N 2 JU C2 0.µF REF R4 5kΩ JU2 JU3 JU4 JU5 JU6 L.5µH R5 R6 R7 R8 R9 R DL3 U DL 39 FB3L 5 REF 22 OSC C3 00pF C5 0µF ONSU ONM ONSD ON3 ON ON2 SUSD CCSU CCSD CCM CC3 CC CC2 AUXOK SDOK MAX567 3 FB3H FB EP INDL2 DL2 FB GND 33 PV 37 P 25 C6 0µF DL FB L3 22µH FB2 24 D0 LXSU L4 0µH PGSU 23 FBSU 7 PVM 28 SCF 9 LXM 27 PGM 26 FBM 3 PVSD 7 LXSD 6 FBSD 9 PGSD 5 L5 3.0µH C C2 0µF L6 0µH DL2 R4 90.9kΩ JU7 OPEN JU9 SHORT P D7 R3 549kΩ REF R7 50kΩ R8 90.9kΩ JU8 SHORT C7 µf R5 274kΩ R6 90.9kΩ R23 00kΩ R9 40.2kΩ R kΩ JU0 OPEN C4 47µF OUT2 R26 C2 47µF C0 47µF JU SHORT R27 OUT2-7.5V +5V D 2 JU2 OPEN C3 SCF VM +3.3V VSD +.8V Figure. MAX567 EV Kit Schematic (Sheet of 2) 7

8 DL2 N3 OPTIONAL OUT2 BOOST CIRCUIT L7 D8 FB2 JU3 SHORT L2.5µH 7 8 R30 R3 2 3 D6 FB C9 R2 90.9kΩ OUT2 R MΩ C8 µf R24 R25 OUTA +5V DL 3 N2 5 6 T 4 D9 C20 OUTB 2-7.5V R28 R29 OUTA BOOST CIRCUIT AND OPTIONAL OUTA/OUTB TRANSFORMER CIRCUIT Figure. MAX567 EV Kit Schematic (Sheet 2 of 2) 8

9 Figure 2. MAX567 EV Kit Component Placement Guide Component Side 9

10 Figure 3. MAX567 EV Kit Component Placement Guide Solder Side 0

11 Figure 4. MAX567 EV Kit PC Board Layout Component Side

12 Figure 5. MAX567 EV Kit PC Board Layout Inner Layer 2 2

13 Figure 6. MAX567 EV Kit PC Board Layout Inner Layer 3 3

14 Figure 7. MAX567 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. 4 Maxim Integrated Products, 20 San Gabriel Drive, Sunnyvale, CA Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.