Evaluates: MAX1722/MAX1723/MAX1724 19-2076 Rev 1 5/05 MAX1724 Evaluation Kit General Description Features The MAX1724 evaluation kit (EV kit) is a fully assembled 0.91V to V Input Voltage Range OUT and tested surface-mount circuit board that contains Two Complete Boost Circuits two separate boost switching-regulator circuits. The 3.3V Fixed (MAX1724) left-side circuit contains a MAX1724 with a preset 3.3V output. Other preset voltages of 2.7V, 3.0V, or 5.0V are 3.6V Adjustable Output (MAX1722) also available. The right-side circuit contains a Up to 50mA Output from a 1-Cell Input MAX1722, which has an adjustable output voltage. This Up to 100mA Output from a 2-Cell Input circuits output is set for 3.6V. All devices regulate with input voltages from 0.91V to V , making them ideal 1.5A Quiescent Current from V OUT OUT for 1- or 2-cell alkaline and NiMH battery applications. Up to 90% Efficiency with Synchronous The right-side circuit may also be used to evaluate the Rectification MAX1723, which features a shutdown (SHDN) mode. Switching Frequency Up to 200kHz The MAX1722/MAX1724 has a BATT pin, which lowers the guaranteed startup voltage from 1.2V to 0.91V. All Surface-Mount Design The MAX1722/MAX1723/MAX1724 feature synchronous Fully Assembled and Tested Board rectification and ultra-low (1.5A typ) quiescent current for maximum efficiency and long battery life. Operation Ordering Information up to 200kHz allows tiny surface-mount components. PART TEMP RANGE IC PACKAGE MAX1724EVKIT 0C to +70C THIN SOT23-5 Component List Quick Start The MAX1724 EV kit is fully assembled and tested. DESIGNATION QTY DESCRIPTION Follow these steps to verify board operation. Do not 10F, 16V X7R ceramic capacitors turn on the power supply until all connections are C1C4 4 TDK C3225X7R1C106MT or completed. Murata GRM32DR71C106MA 3.3V Output (left side): D1 0 Not installed 1) Connect a 0.91V to 3.3V supply to the VBATT pad. Connect the supply ground to the GND pad. 10H inductors L1, L2 2 Sumida CDR43-100MC 2) Connect a voltmeter to the VOUT pad. 2M 1% resistor (0805) 3) Verify there is a shunt across pins 1 and 2 of R1 1 Venkel CR0805-10W-2004FT jumper JU1 (SHDN), thus enabling the MAX1724. 1.02M 1% resistor (0805) 4) Turn on the power supply and verify that the output R2 1 Venkel CR0805-10W-1024FT is at 3.3V. M axim M AX17 24EZ K33 ( 5- p i n THIN 3.6V Output (right side): U1 1 S OT23, top m ark A DQ J) 1) Connect a 0.91V to 3.6V supply to the VBATT pad. Connect the supply ground to the GND pad. Maxim MAX1722EZK (5-pin THIN U2 1 SOT23, top mark ADQF) 2) Connect a voltmeter to the VOUT pad. JU1, JU2 2 3-pin headers 3) Verify there is a shunt across pins 1 and 2 of jumper None 2 Shunts JU1, JU2 JU2 to connect BATT to VBATT for the MAX1722. None 1 MAX1724 PC board 4) Turn on the power supply and verify that the output is at 3.6V. For instructions on selecting feedback resistors for Note: Quantities are for both circuits. other output voltages, see Evaluating Other Output Voltages (Right Side). Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.MAX1724 Evaluation Kit Component Suppliers SUPPLIER PHONE FAX WEBSITE Murata 814-237-1431 814-238-0490 www.murata.com Sumida 847-956-0666 847-956-0702 www.sumida.com TDK 847-803-6100 847-390-4405 www.component.tdk.com Venkel 512-794-0081 512-794-0087 www.venkel.com Note: Please indicate that you are using the MAX1724 when contacting component suppliers. that BATT is connected to the battery input (VBATT). Detailed Description When the right-side circuit is used to evaluate a The MAX1724 EV kit contains two separate boost MAX1723, see Evaluating the MAX1723 section. Table switching-regulator circuits. The left-side circuit 2 lists the MAX1722 jumper options. (MAX1724) supplies a preset 3.3V output. The right- side circuit (MAX1722) supplies an adjustable 3.6V out- Table 2. MAX1722 Jumper JU2 Functions put, but can also be set from 2.0V to 5.5V. Both circuits SHUNT LOCATION BATT PIN regulate with input voltages from 0.91V to V , but OUT 1-2 Connected to VBATT can accept higher input voltages (below 5.5V) if it is 2-3 Not allowed acceptable for the output voltage to rise above the set V . Output current for both circuits is 50mA with a OUT 3.6V Output (right side): 1.2V input, and 100mA for a 2.4V input. 1) Connect a 0.91V to 3.6V supply to the VBATT pad. The 3.6V output voltage (right side) can also be adjust- Connect the supply ground to the GND pad. ed from 2.0V to 5.5V using external resistors R1 and 2) Connect a voltmeter to the VOUT pad. R2. The input voltage ranges from 0.91V to (V ) OUT when operating from a DC source. 3) Verify there is a shunt across pins 1 and 2 of The MAX1724 boost converter (left side) features a jumper JU2 to connect BATT to VBATT for the 0.1A shutdown mode. MAX1722. Jumper Selection 4) Turn on the power supply and verify that the output MAX1724 Circuit (Left Side) is at 3.6V. The MAX1724 EV kits shutdown mode reduces the ICs For instructions on selecting feedback resistors for quiescent current to 0.1A (typ), preserving battery life. other output voltages, see Evaluating Other Output Jumper JU1 selects the shutdown mode for the Voltages (Right Side). MAX1724. Table 1 lists the MAX1724 jumper options. Evaluating Other Output Voltages Table 1. MAX1724 Jumper JU1 Functions (Right Side) The MAX1722 output is set to 3.6V by feedback resis- SHUNT SHDN PIN MAX1724 OUTPUT tors R1 and R2. To generate output voltages other than LOCATION 3.6V (2.0V to 5.5V), select different external voltage- Connected to MAX1724 enabled, 1-2 divider resistors (R1, R2). Refer to the Setting the VBATT V = 3.3V OUT Output Voltage section in the MAX1722/MAX1723/ Shutdown mode, 2-3 Connected to GND MAX1724 data sheet for instructions on selecting R1 V = V - V OUT BATT DIODE and R2 for the MAX1722/MAX1723. Evaluating the MAX1723 MAX1722 Circuit (Right Side) The MAX1723 can be evaluated using the MAX1722 When jumper JU2 on the right-side circuit is used with a circuit (right side). Replace the MAX1722 with a MAX1722, pins 1 and 2 must be connected together so MAX1723EZK. Diode D1 (Motorola MBR0520L or equiv- 2 Evaluates: MAX1722/MAX1723/MAX1724