19-2380; Rev 0; 4/02 MAX5040 Evaluation Kit Features ♦ On-Board Power Supplies Set at 3.3V and 1.8V ♦ Voltage Tracking of Dual Power Supplies During Power-Up and Power-Down ♦ Core Voltage Range Configurable from 0.8V to 4V ♦ I/O Voltage Range Configurable from VCORE to 4V ♦ Detects Short Circuit on VCORE and VI/O ♦ Disables Both Power Supplies During ShortCircuit Condition ♦ Output Undervoltage Monitoring and Power-OK (POK) Status ♦ Surface-Mount Construction ♦ Fully Assembled and Tested Ordering Information PART TEMP RANGE MAX5040EVKIT 0°C to +70°C IC PACKAGE 10 µMAX Component List DESIGNATION QTY DESCRIPTION 1 1.0µF ±10%, 25V X7R ceramic capacitor (1206) TDK C3216X7R1E105KT or Taiyo Yuden TMK316BJ105KL C2, C3, C6 3 0.1µF ±10%, 50V X7R ceramic capacitors (0805) TDK C2012X7R1H104KT or Taiyo Yuden UMK212BJ104KG C4, C5 0 Not installed capacitor (HC) C7 1 1500pF ±10%, 50V X7R ceramic capacitor (0603) Taiyo Yuden UMK107BJ152KZ 2 10µF ±20%, 10V X5R ceramic capacitors (1206) TDK C3216X5R1A106M 2 2.2µF ±10%, 10V X5R ceramic capacitors (0805) TDK C2012X5R1A225KT or Taiyo Yuden LMK212BJ225KG C1 C8, C9 C10, C11 C12 1 0.01µF ±10%, 50V X7R ceramic capacitor (0603) TDK C1608X7R1H103KT or Taiyo Yuden UMK107B103KZ DESIGNATION QTY C13 1 0.022µF ±10%, 50V X7R ceramic capacitor (0603) TDK C1608X7R1H223KT C14, C15 2 470pF ±10%, 50V, X7R ceramic capacitors (0603) TDK C1608X7R1H471KT C16, C17 2 1.0µF ±10%, 10V X5R ceramic capacitors (0603) TDK C1608X5R1A105K C18 0 Not installed capacitor (0603) C19, C20 2 100µF, 6.3V low-ESR capacitors (C) Sanyo 6TPC100M (POSCAP) C21, C22 0 Not installed capacitor (A) D1 1 1A 30V Schottky diode (SOD123) Nihon EP10QY03 or Toshiba CRS02 JU1, JU2, JU3 3 2-pin headers JU4, JU5 2 3-pin headers 2 2.2µH, 3.8A inductors Sumida CDRH6D28 4762-TO54 L1, L2 DESCRIPTION ________________________________________________________________ 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: MAX5040 General Description The MAX5040 evaluation kit (EV kit) is a complete, fully assembled and tested voltage-tracking controller circuit that demonstrates the capability of the MAX5040. The MAX5040 controls the output voltage of two power supplies, VI/O and VCORE, during power-up and powerdown. The device ensures that the two supplies rise or fall at the same rate, limiting the voltage difference between them to under 200mV. The EV kit board comes with two step-down switching power supplies programmed to 3.3V and 1.8V output voltages that allow for an easy evaluation of the featured voltage-tracking controller. The EV kit board operates from a 5V supply capable of supplying up to 4A. MAX5040 Evaluation Kit Evaluates: MAX5040 Component List (continued) QTY DESCRIPTION QTY N1 1 6A, 20V N-channel MOSFET (8-pin SO) Vishay Si9428DY R13 1 39.2kΩ ±1% resistor (0603) R14 1 75kΩ ±1% resistor (0603) N2 0 Not installed N-channel MOSFET (DPAK) R15 1 100kΩ ±1% resistor (0603) R16 1 49.9kΩ ±1% resistor (0603) 0 Not installed N-channel MOSFET (D2PAK) R17, R18, R19 3 10kΩ ±5% resistors (0603) R20 1 10kΩ ±5% resistor (0805) R21 1 51Ω ±5% resistor (1206) N3 N4 1 DESCRIPTION DESIGNATION DESIGNATION 1.8A, 30V N-channel MOSFET (3-pin SOT23) Fairchild FDN361AN U1 1 MAX5040EUB (10-pin µMax) U2, U3 2 MAX1842EEE (16-pin QSOP) R1 1 261kΩ ±1% resistor (0805) R2, R6 2 100kΩ ±1% resistors (0805) VI/O, VCORE, GND 3 Noninsulated banana jack connectors R3, R4 2 10kΩ ±1% resistors (0805) None 5 Shunts (JU1–JU5) R5 1 143kΩ ±1% resistor (0805) None 1 MAX5040 PC board R7, R8 2 20kΩ ±5% resistors (0603) None 1 MAX5040 data sheet R9, R10 0 Not installed resistor (0603) None 1 MAX5040 EV kit data sheet R11, R12 2 10Ω ±5% resistors (0603) Component Suppliers PHONE FAX Fairchild SUPPLIER 888-522-5372 408-522-5372 WEBSITE Nihon 81-33343-3411 81-33342-5407 www.niec.co.jp Sanyo 619-661-6322 619-661-1055 www.sanyo.com Sumida 847-545-6700 847-545-6720 www.sumida.com Taiyo Yuden 800-348-2496 847-925-0899 www.t-yuden.com TDK 847-803-6100 847-390-4498 www.component.tdk.com Toshiba 949-455-2000 949-859-3963 www.toshiba.com/taec/ Vishay 203-268-6261 203-452-5670 www.vishay.com www.fairchildsemi.com Note: Please indicate that you are using the MAX5040 when contacting these component suppliers. Quick Start The MAX5040 EV kit is a fully assembled and tested surface-mount board. Follow the steps below for simple board operation. Do not turn on the power supply until all connections are completed. 1) Verify that a shunt is connected across jumpers JU1, JU2, and JU3. 2) Verify that a shunt is connected across pins 1 and 2 of jumpers JU4 and JU5. 3) Connect the positive terminal of the 5V power supply to the VIN pad. Connect the ground terminal of the 5V power supply to the GND pad. Leave the VCC pad open circuit; it is connected to VIN through jumper JU3. 2 4) Connect voltmeters or an oscilloscope to pads SDO and POK to analyze the functionality of the MAX5040 voltage-tracking controller during power-up. 5) Connect an oscilloscope at VIN, VI/O, and VCORE to observe voltage tracking during power-up and power-down. Set the oscilloscope to trigger on the rising edge of VIN. 6) Turn on the 5.0VDC power supply. 7) Verify that VI/O is 3.3V and VCORE is 1.8V. Note: Connect the ground terminals of the voltmeters connected to SDO and POK to the AGND pad. _______________________________________________________________________________________ MAX5040 Evaluation Kit The MAX5040 EV kit is a complete, fully assembled and tested circuit that demonstrates the capability of the MAX5040 voltage-tracking controller. The MAX5040 provides intelligent control to power systems where two supply voltages need to be tracked. The device limits the voltage difference between the two supply voltages during power-up and power-down. The controller generates logic signals that can be used to shut down the power sources or other devices when a fault is detected. The EV kit board comes with two MAX1842 step-down switching power supplies preset to 3.3V (VI/O), 1.8V (VCORE), and operates from a 5V supply voltage capable of supplying up to 4A. The MAX5040 controller turns on the N-channel MOSFET (N1) when VI/O is below VCORE or when VCORE is below 1.6V. The undervoltage lockout threshold for the MAX5040 controller is set to 4.5V. Input Voltage The MAX5040 EV kit requires an input voltage of 4.5V to 5.5V for normal operation. The MAX5040 controller starts to function at an input voltage of 2.5V but it holds the VI/O and VCORE power supplies in shutdown mode until the 4.5V undervoltage lockout threshold has been exceeded. Once the input voltage exceeds this threshold, the controller enables the VI/O and VCORE supplies. The EV kit has a maximum input voltage limit of 5.5V. See the Monitoring External Power Sources section for instructions to disconnect the power supplies Note: A 33µF capacitor is recommended to stabilize the VI/O and VCORE inputs if a lab power supply is connected to the EV kit through long wires or if it has a poor transient response. For further information on the MAX1842 power supplies, refer to the MAX1742/ MAX1842 EV kit or data sheets. Output Voltage Delays The VCORE and VI/O power supplies have an external RC signal delay of 2ms at their respective shutdown pins. If the delay is used in one of the power supplies, its startup is delayed by 2ms with respect to the other power supply. VI/O and VCORE power supplies also have different soft-start capacitor values causing VCORE to rise slower than VI/O. The delay can be used to evaluate how the MAX5040 functions when one of the two tracking voltages lags behind the other during system startup. The delay can be bypassed by placing a shunt across pins 1 and 2 of jumpers JU4 and JU5. See Table 1 for jumper JU4, JU5 configurations and functions. Table 1. Power Supplies Shutdown and Signal Delay (Shunt on JU2 Is Installed) JUMPER SHUNT POSITION SHDN PIN FUNCTION 1 and 2 Connected to SDO Bypasses the 2ms signal delay on the shutdown pin of VI/O 2 and 3 Connected to ground VI/O in shutdown mode None Connected to SDO pin through the RC filter VI/O shutdown pin has a 2ms delay 1 and 2 Connected to SDO Bypasses the 2ms signal delay on the shutdown pin of VCORE 2 and 3 Connected to ground VCORE in shutdown mode None Connected to SDO pin through the RC filter VCORE shutdown pin has a 2ms delay On-Board Power Supplies The MAX5040 EV kit includes two MAX1842 step-down switching power supplies that allow the user to evaluate the MAX5040 under conditions similar to a real system application. The first power supply (VI/O) is set to an output voltage of 3.3V and provides 2.5A of current. The VI/O supply is used to simulate a power source to an I/O bus in a system. The second power supply (VCORE) is set to an output voltage of 1.8V and provides 2.5A of current. The VCORE supply is used to simulate a power source to the main core processor in a system. The VI/O and VCORE power supplies require a 3.3V to 5.5V input voltage at VIN. However, VI/O and VCORE do not start up until VIN reaches 4.5V. The MAX5040 controller’s undervoltage lockout threshold is set to 4.5V and the controller holds VI/O and VCORE in shutdown mode until VIN is greater than 4.5V. VI/O and VCORE can be manually shut down by placing a shunt across pins 2 and 3 of jumpers JU4 and JU5. See Table 1 for jumper JU4 and JU5 configurations. JU4 JU5 _______________________________________________________________________________________ 3 Evaluates: MAX5040 Detailed Description Evaluates: MAX5040 MAX5040 Evaluation Kit Voltage Thresholds The MAX5040 EV kit voltage-monitoring thresholds are programmed with external resistors as indicated in Table 2. Refer to the MAX5039/MAX5040 data sheet to select new resistor values. Table 2. Threshold Settings SOURCE THRESHOLD (V) VCC 4.5 EV KIT FUNCTIONS FEEDBACK RESISTORS Voltage below which SDO goes low R1, R2 R3, R4 R5, R6 VCORE 1.6 VCORE threshold/ regulation voltage VI/O (Sense) 3.0 Voltage below which POK goes low Startup Mode The MAX5040 EV kit starts to function when the system voltage VIN reaches the minimum input voltage of 2.5V required by the voltage-tracking controller. The controller pulls the SDO pin low at an input voltage of 0.9V, which keeps the VI/O and VCORE supplies in shutdown. The SDO pin is connected to the active-low shutdown pin of VI/O and VCORE regulators through jumper JU2. When VIN exceeds 4.5V, the SDO pin is pulled HIGH (to VIN) to enable VI/O and VCORE. If the VI/O and VCORE output voltages are not above their thresholds within 15ms, the controller pulls SDO and POK low, shutting the voltage regulators and signaling a fault in the system. If VI/O and VCORE are above their thresholds within 15ms, the controller enters normal operation mode. See Table 3 for the complete startup sequence of the EV kit that also includes voltage conditions and EV kit outputs. Note: SDO is the inverted signal of SDO that can be used for active-high shutdown pins. SDO and SDO high state is VIN. POK high state is VI/O. Normal Mode In normal operation, the controller attempts to keep VCORE from falling below 1.6V. If VIN falls below 4.5V, the controller shuts down the power supplies by pulling SDO low. If VCORE falls below 1.6V, the controller drives the NDRV pin high, which turns on the MOSFET connected across VCORE and VI/O, sourcing current from the VI/O rail to raise VCORE to 1.6V. The controller also drives the NDRV pin high if VI/O voltage falls below VCORE to source current in the opposite direction. POK is always pulled low when any fault is detected. See Table 4 for fault conditions. Shutdown The MAX5040 controller can be forced into shutdown mode by connecting an external device to the UV_CC pad and driving it low. When the controller is in shutdown mode, the controller pulls the SDO pin low, forcing VI/O and VCORE into shutdown. Table 3. Startup Sequence STEP CONDITIONS EV KIT OUTPUTS EV KIT FUNCTIONS VCC VI/O VCORE SDO SDO POK 1 <0.9V X X X X X Not operating 2 0.9V ≤ VCC < 4.5V 0V 0V L H L Power supplies in shutdown mode 3 ≥4.5V S S H L L Power supplies are turned ON H L L VI/O low forces POK low L H L Startup fault H L H Normal operation 15ms later 4 5 ≥4.5V VCORE < VI/O < 3.0V ≥1.6V X <1.6V <VCORE ≥1.6V ≥3.0V ≥1.6V X = Don’t care. S = VI/O and VCORE power supplies in startup mode. 4 _______________________________________________________________________________________ MAX5040 Evaluation Kit CONDITIONS EV KIT OUTPUTS EV KIT FUNCTIONS VCC VI/O VCORE SDO SDO POK <4.5V ≥3.0V ≥1.6V L H L Power supplies are turned OFF ≥4.5V VCORE ≤ VI/O < 3.0V ≥1.6V H L L VI/O low forces POK low VI/O < VCORE ≥1.6V H L L NDRV pin is driven HIGH L H L Power supplies are turned OFF ≥4.5V After 15ms X ≥4.5V <1.6V After 15ms H L L NDRV pin is driven HIGH L H L Power supplies are turned OFF X = Don’t care. Monitoring External Power Sources Jumper JU1 The MAX5040 voltage-tracking controller monitors two MAX1842 step-down switching power supplies that are set for 3.3V and 1.8V, and can deliver up to 2.5A. The input voltage range for the EV kit is 2.5V to 5.5V. The EV kit circuit can be modified to operate with external power sources set at different output voltages and/or current capabilities. The two on-board power supplies must be disabled from the controller circuit when using external supplies. To monitor external power supplies: The MAX5040 EV kit circuit features D1 between the input power connection and the VCC pin of the voltagetracking controller. D1 and C1 can be used to hold the supply in the event of a rapid voltage drop by the power source. Install a 10µF capacitor at C1 to use this feature. This protection can be bypassed or implemented by reconfiguring jumper JU1. See Table 5 for jumper JU1 configuration. 1) Place a shunt across pins 2 and 3 of jumper JU4 and JU5 to disable the on-board power supplies. Table 5. Jumper JU1 Functions SHUNT LOCATION EV KIT FUNCTIONS None EV kit operates normally when there is a momentary loss of input power (requires a 10µF capacitor at C1). Installed Full operation may be disrupted if there is a momentary loss of input power. 2) Remove the shunt across jumper JU2. 3) Connect the external voltage source to the VI/O banana jack and the external core source to the VCORE banana jack. Connect the grounds from the external voltage sources to the GND banana jack. 4) Connect the shutdown pin of the external supplies to SDO (active-low shutdown) or SDO (active-high shutdown) pads. 5) Replace the feedback resistor pairs listed in Table 2 if the voltage thresholds or the output voltages are different from 3.3V and 1.8V. For higher current capabilities, remove MOSFET N1 on the EV kit and install a DPAK N-channel MOSFET (N2) or a D2PAK N-channel MOSFET (N3). _______________________________________________________________________________________ 5 Evaluates: MAX5040 Table 4. Fault Conditions Evaluates: MAX5040 MAX5040 Evaluation Kit SYSTEM POWER-UP/POWER-DOWN (VI/O RISING BEFORE VCORE) VCC 5V/div VCC NRDV 5V/div NDRV SDO SDO AND POK 5V/div POK I/O I/O AND CORE 1V/div CORE 5ms/div Figure 1. System Power-Up/Power-Down (VI/O Rising Before VCORE) SHDN1 R7 20kΩ 5% 1 2 C3 0.1µF NOTE: ALL RESISTORS ARE 1%, UNLESS OTHERWISE SPECIFIED. JU4 3 VI/O VI/O VI/O SHDN2 R8 20kΩ 5% 1 2 C2 0.1µF 3 UV_CC 1 N3 OPEN 1 3 2 3 C5 OPEN VCORE NDRV 8 CORE SDO U1 COREFB R3 10kΩ 7 2 1 C1 1µF VCC UV_CC IO GND 4 GND R20 10kΩ 5% VI/O IOSEN 3 C7 1500pF VCORE C6 0.1µF R4 10kΩ MAX5040 JU1 R2 100kΩ 4 VCORE VCC R1 261kΩ N2 OPEN 1 VCORE R19 10kΩ 5% D1 C4 3.3V OPEN SDO 1 VIN 2 3 1 10 3 N4 2 AGND 6 2 R18 JU2 10kΩ 5% JU3 8 7 N1 4 JU5 VCC SDO VCC 5V 5 SD_IN POK VI/O R5 143kΩ 9 5 6 R9 SHORT (PC TRACE) POK R6 100kΩ R17 10kΩ 5% VLOGIC Figure 2. MAX5040 EV Kit Schematic—Voltage-Tracker Controller 6 _______________________________________________________________________________________ R21 51Ω 5% 1.8V MAX5040 Evaluation Kit Evaluates: MAX5040 VIN C21 OPEN C8 10µF R11 10Ω 5% 2 12 VCC C10 2.2µF 1 SHDN1 IN IN SHDN U2 5 SS C12 0.01µF 16 LX 14 LX 3 LX 15 PGND 13 PGND C14 470pF C19 100µF 6.3V 8 10 REF R16 49.9kΩ C16 1µF COMP 7 TOFF R13 39.2kΩ 9 GND FBSEL GND R15 100kΩ C18 OPEN MAX1842 FB 6 VI/O LI 2.2µH 4 11 Figure 3. MAX5040 EV Kit Schematic—VI/O Step-Down Power Supply VIN VIN 5V C22 OPEN C9 10µF R12 10Ω 5% GND 2 12 C11 2.2µF VCC 4 IN IN LX LX LX 1 SHDN2 PGND SHDN U3 5 C13 0.022µF R14 75kΩ 7 REF VCORE 14 C20 100µF 6.3V 3 15 GND VCORE 13 MAX1842 FB 6 C15 470pF SS PGND 16 L2 2.2µH 8 R10 SHORT (PC TRACE) 10 COMP TOFF FBSEL GND 9 11 C17 1µF Figure 4. MAX5040 EV Kit Schematic—VCORE Step-Down Power Supply _______________________________________________________________________________________ 7 Evaluates: MAX5040 MAX5040 Evaluation Kit Figure 5. MAX5040 EV Kit Component Placement Guide— Component Side Figure 6. MAX5040 EV Kit PC Board Layout—Component Side Figure 7. MAX5040 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.