Evaluates: MAX8556/MAX8557 19-3393 Rev 0 8/04 MAX8556 Evaluation Kit General Description Features The MAX8556 evaluation kit (EV kit) is a fully assembled 1.425V to 3.6V Input Voltage Range and tested surface-mount circuit board demonstrating 1.2V Output Voltage the MAX8556 low-dropout (LDO) regulator. The EV kit comes assembled with a MAX8556ETE circuit that Up to 4A Output Current steps down a 1.425V to 3.6V input voltage range to a Low Dropout Voltage (200mV max at 4A) 1.2V output capable of sourcing up to 4A (limited by power dissipation). The MAX8556 features a POK out- Internal p-Channel MOSFET Pass Transistor put that goes high impedance once the output is within Power-OK (POK) Output 10% of its regulation value. The device utilizes an internal p-channel MOSFET for reduced dropout and Fully Assembled and Tested quiescent current. In addition, the p-channel MOSFET eliminates the need for an external bias or noisy charge pump. The MAX8556 EV kit can also be used to evalu- ate the MAX8557 with no component changes. Ordering Information Component List DESIGNATION QTY DESCRIPTION PART TEMP RANGE IC PACKAGE 10F 20%, 6.3V X5R ceramic MAX8556EVKIT 0C to +70C 16 Thin QFN 5mm x 5mm C1C4 4 capacitors (0805) Note: To evaluate the MAX8557, request a MAX8557ETE free Taiyo Yuden JMK212BJ106MG sample with the MAX8556 EV kit. 3-pin header JU1 1 Sullins PTC36SAAN R1 1 100k 5% resistor (0603) 1.40k 0.1% resistor (0603) R2 1 Vishay TNPW06031401BT9RT1 1k 0.1% resistor (0603) R3 1 Panasonic ERA3YEB102V U1 1 MAX8556ETE (16-pin Thin QFN) None 1 Shunt None 1 MAX8556EVKIT PC board Component Suppliers SUPPLIER COMPONENT PHONE WEBSITE Panasonic Resistors 714-373-7366 www.maco.panasonic.co.jp Taiyo Yuden Capacitors 408-573-4150 www.t-yuden.com Vishay Resistors 402-563-6866 www.vishay.com Note: Indicate that you are using the MAX8556/MAX8557 when contacting these component suppliers. 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.MAX8556 Evaluation Kit Recommended Equipment Detailed Description One 4V, 5A variable-output power supply Adjusting the Output Voltage R2 and R3 are used to adjust the output voltage for the Dummy load capable of sinking 4A MAX8556. To adjust the output voltage, replace R2 with Digital multimeter (DMM) a 0.1% resistor that is calculated as: 3 R2 = 1 x 10 x ((V / V ) - 1) OUT FB Quick Start where V is 0.5V and V is the desired output voltage. FB OUT The MAX8556 EV kit is fully assembled and tested. Follow these steps to verify board operation: POK Output 1) Preset the power supply to 1.425V and turn off the The MAX8556 has an open-drain POK output that goes power supply. Do not turn on the power supply high impedance after the output is within 10% of the until all connections are made. regulation voltage. On the EV kit, R1 pulls up POK to V . The MAX8556 EV kit can also be used to evaluate IN 2) Verify that the shunt is across pins 2 and 3 of JU1 to the MAX8557. In this case, the POK output becomes enable the device. the POR output. 3) Connect the positive lead of the power supply to the VIN pad on the EV kit, and the negative lead of the Shutdown power supply to the GND pad on the EV kit. The MAX8556 features a shutdown mode to power down the output and reduce input current. To shut 4) Connect the positive input of the DMM to the VOUT down the device, place the shunt between positions 1 pad on the EV kit, and the negative input of the and 2 of JU1. To operate normally, place the shunt DMM to the GND pad on the EV kit to measure the between positions 2 and 3 of JU1. output voltage. 5) Turn on the power supply and verify that the output Jumper Settings voltage is 1.2V 1%. 6) Sweep the input voltage from +1.425V to +3.6V. Verify that the output voltage is 1.2V 1% over the Table 1. Jumper JU1 Functions (EN) entire input range. 7) Set the power supply to 2V. SHUNT EN CONNECTION OPERATION LOCATION 8) Connect the 4A load between the VOUT and GND pads on the EV kit. 1 and 2 Connected to GND Output disabled 9) Verify that the output voltage is 1.2V 1%. 2 and 3 Connected to VIN Output enabled 2 Evaluates: MAX8556/MAX8557