19-4759; Rev 1; 1/99 MAX1701 Evaluation Kit ____________________________Features The MAX1701 evaluation kit provides a regulated 3.3V output while operating on input voltages as low as 0.7V. The input may be a DC source or a 1 to 2–cell battery. Efficiency is up to 95% with output loads up to 200mA. The kit, which uses surface-mount components, is fully assembled and tested for quick evaluation. Jumpers are provided to select the output voltage, switching mode, and shutdown control. This EV kit can also be used to evaluate the MAX1700. Simply order a free sample of the MAX1700EEE and replace the MAX1701EEE that comes installed on the board. ♦ 3.3V Output ____________________Component List DESIGNATION QTY ♦ 0.7V to 3.5V Input ♦ Up to 95% Efficiency ♦ 3µA Shutdown Current ♦ 300kHz PWM Operation ♦ Optional Low-Power PFM Mode ♦ Small Surface-Mount Components _______________Ordering Information DESCRIPTION C1 1 22µF, 25V, low-ESR tantalum capacitor AVX TPSD226M025R0200 Sprague 593D226X0025D C2, C3 2 0.22µF, 25V ceramic capacitors C4 1 0.10µF, 25V ceramic capacitor 1 100µF, 10V low-ESR tantalum capacitor AVX TPSD107M010R0100 or Sprague 593D107X0010D7 C5 ♦ 200mA Output PART TEMP. RANGE PIN-PACKAGE 0°C to +70°C 16-pin QSOP MAX1701EVKIT ______________Component Suppliers SUPPLIER PHONE FAX AVX (803) 946-0690 (803) 626-3123 Coilcraft (847) 639-6400 (847) 639-1469 (561) 241-7876 (561) 241-9339 C6, C7 0 Not installed. Space for optional user capacitor. Coiltronics Sprague (603) 224-1961 (603) 224-1430 D1 1 0.5A, 20V Schottky diode Motorola MBR0520L Sumida (847) 956-0666 (847) 956-0702 Motorola (303) 675-2140 (303) 675-2150 J1, J2, J3 3 3-pin jumpers J4, J5 2 2-pin jumpers L1 1 10µH, 1.6A power inductor CoilCraft DO3316-103, Coiltronics UP1B-100, Sumida CDR74B-100 R1, R4, R6 3 100kΩ, 1% resistors R2, R3, R5 3 Not installed R7, R8, R9 3 100kΩ, 5% resistors R10, R11, R12 3 1MΩ, 5% resistors R13 1 10Ω, 5% resistor U1 1 MAX1701EEE None 5 Shunts None 1 3.4” x 2.4” printed circuit board None 1 MAX1700/MAX1701 data sheet _________________________Quick Start The MAX1701 EV kit is shipped fully assembled and tested. Follow these steps to verify board operation. Do not turn on the power supply until all connections are completed. 1) Verify that the shunts are connected as listed in Table 2 for a 3.3V output. 2) Connect a +1.1V to +3.3V supply to the pad marked VIN. The ground connects to the GND pad. Note: the input voltage may drop as low as 0.7V after startup. 3) Connect a voltmeter to the VOUT pad. 4) Turn on the power and verify that the output voltage is 3.3V. 5) Connect a load (if any). ________________________________________________________________ Maxim Integrated Products 1 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 1-800-835-8769. Evaluates: MAX1700/MAX1701 ________________General Description Evaluates: MAX1700/MAX1701 MAX1701 Evaluation Kit _______________Detailed Description Jumper Selection Five jumpers on the printed circuit board allow user selection of several configurations. Table 1 lists the jumpers and their functions. Table 2 lists the jumper positions when the board is set for normal 3.3V output operation. Component Selection The final circuit performance is determined by the quality of the components surrounding the MAX1701. The power inductor must not saturate at the 1.6A maximum peak current produced by MAX1701. Inductors in the Component List all have high current ratings and low coil resistance. Table 1. Jumper Functions JUMPER J1 SHUNT LOCATION ONA connected to GND MAX1701 is disabled if ONB is VOUT. 2 and 3 ONA connected to VOUT MAX1701 is enabled. ONA is not controlled by the board ONA must be driven by a signal connected to the ONA pad. 1 and 2 ONB connected to GND MAX1701 is enabled. 2 and 3 ONB connected to VOUT MAX1701 is disabled if ONA = GND. ONB is not controlled by the board ONB must be driven by a signal connected to the ONB pad. 1 and 2 CLK/SEL connected to GND Low-power mode, MAX1701 operates in the PFM mode. 2 and 3 CLK/SEL connected to VOUT High-power mode, MAX1701 operates in the PWM mode. CLK/SEL connected to CLK/SEL pad CLK/SEL pin can be driven by an external source to select power mode, or a 200kHz to 400kHz signal to control switching frequency. FB connected to GND VOUT is preset to 3.3V. FB connected to the resistor divider Resistors must be installed in R3 and R4 for proper circuit operation. Shorted for normal operation VOUT connected to pull-up resistors. Pull-ups disconnected R7–R9 are disconnected so that MAX1701 shutdown current may be verified. Open J3 Open Shorted J4 Open Shorted J5 MAX1701 OPERATION 1 and 2 Open J2 PIN CONNECTION Open Table 2. Jumper Position for Normal 3.3V Operation 2 JUMPER SHUNT LOCATION PIN CONNECTION J1 2 and 3 ONA connected to VOUT MAX1701 is enabled. J2 1 and 2 ONB connected to GND MAX1701 is enabled. J3 2 and 3 CLK/SEL connected to VOUT High-power mode, MAX1701 operates in the PWM mode. J4 Shorted FB connected to GND VOUT is preset to 3.3V. This jumper must be shorted or resistors installed in R3 and R4 for proper circuit operation. J5 Shorted VOUT connected to pull-up resistors MAX1701 OPERATION _______________________________________________________________________________________ MAX1701 Evaluation Kit nected between LX and P OUT as close to the IC as possible. A Schottky diode is specified for the lower forward voltage drop as well as the fast switching characteristic. Most Schottky diodes with a sufficient current rating will work. The diode for the evaluation board was selected for its small size. A separate low-noise ground plane connects pin 5 to the reference and signal grounds. This low-noise ground plane is then connected to the power-ground plane at the PGND pin (Figure 4). A low-ESR input capacitor must be located physically close to the inductor. The Schottky diode must be con- VIN 0.7V TO 3.5V C1 22µF 25V GND R2 OPEN L1 10µH 1 R1 100k 1% 2 3 LX LBN POUT OUT FB C7 OPEN 8 2 AO 3 J2 7 2 R3 OPEN J4 R4 100k 1% R7 100k R8 100k R9 100k AO ONA 1 ONB J5 C4 0.1µF 11 R11 1M 3 C6 OPEN R13 10 14 C3 0.22µF MAX1701 J1 15 U1 VOUT ONA C5 100µF 10V REF C2 0.22µF VOUT D1 13 LBP LBO 9 LO BATT 16 ONB 1 POK PWR 0K 6 3 CLK/SEL J3 4 2 1 R10 1M R12 1M CLK/SEL AIN GND PGND 5 12 AIN 10 R6 100k 1% R5 OPEN Figure 1. MAX1701 EV Kit Schematic _______________________________________________________________________________________ 3 Evaluates: MAX1700/MAX1701 The input and output capacitors must have low equivalent series resistance (ESR) to handle the high peak currents found in switching regulators. Low ESR is especially critical in low-voltage circuits to reduce the AC voltage across the capacitors. A higher ESR on the output capacitor will increase the output ripple. Consider using parallel capacitors to reduce the total ESR if the application requires lower output ripple. An additional output capacitor (C6) may be required for output current greater than 200mA or output voltages less than 3.3V. Evaluates: MAX1700/MAX1701 MAX1701 Evaluation Kit 1.0" 1.0" Figure 2. MAX1701 EV Kit Component Placement Guide Figure 3. MAX1701 EV Kit PC Board Layout—Component Side 1.0" Figure 4. MAX1701 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, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 1999 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.