Evaluates: MAX8902A/MAX8902B 19-4051 Rev 1 9/08 MAX8902 Evaluation Kit General Description Features 1.7V to 5.5V Input-Voltage Range The MAX8902 evaluation kit (EV kit) is a fully assembled and tested PCB for evaluating the MAX8902A low- Guaranteed 500mA Output Current dropout linear regulator (LDO). The EV kit operates 1.5% Output Accuracy over from a 1.7V to 5.5V supply and provides a jumper- Load/Line/Temperature selectable output voltage of 1.5V, 1.8V, 2.0V, 2.5V, 100mV (max) Drop Out at 500mA Load 3.0V, 3.1V, 3.3V, 4.6V, or 4.7V, with loads up to 500mA. < 1A Shutdown Supply Current The MAX8902 EV kit comes with the MAX8902A 700mA Short-Circuit Protection installed, but can also be used to evaluate the MAX8902B with an adjustable output voltage from 0.6V Reverse-Current Protection to 5.3V. Thermal-Overload Protection 2mm x 2mm x 0.8mm TDFN IC Package Lead-Free and RoHS Compliant Fully Assembled and Tested Component List Ordering Information DESIGNATION QTY DESCRIPTION PART TYPE 10F 10%, 6.3V X5R ceramic MAX8902EVKIT+ EV Kit capacitors (0805) +Denotes lead-free and RoHS compliant. C1*, C3 2 TDK C2012X5R0J106K Murata GRM21BR60J106K Quick Start 0.01F 10%, 25V X7R ceramic Recommended Equipment C2 1 capacitor (0402) Before beginning, the following equipment is needed: TDK C1005X7R1E103K 1.7V to 5.5V power supply or battery able to deliver 1A C4 0 Not installed, capacitor (0805) Voltmeter C5 0 Not installed, capacitor (0402) Load (up to 500mA) JU1, JU2, JU3 3 3-pin headers, 0.1in R1 1 0 resistor (0402) Procedure R2, R3 0 Not installed, resistors (0402) The MAX8902 EV kit is fully assembled and tested. Follow the steps below to verify board operation: Low dropout linear regulator U1 1 (8 TDFN-EP**) 1) Preset the power supply to between 1.7V and 5.5V. Maxim MAX8902AATA+ 2) Turn off the power supply. Caution: Do not turn 3 Shunts, 2 position on the power supply until all connections are 1 PCB: MAX8902 Evaluation Kit+ completed. 3) Place the shunt of JU1 across pins 2-3 to enable *Due to the poor voltage coefficient of small case sizes, if the device is operating in dropout, a 1206 size capacitor is recom- the MAX8902A. mended for C1. 4) Select the output voltage using jumpers JU2 and **EP = Exposed pad. JU3 (see Table 2). Component Suppliers 5) Connect the positive power-supply lead to the IN pad of the EV kit. SUPPLIER PHONE WEBSITE 6) Connect the power-supply ground to the GND pad Murata Electronics www.murata- next to IN. 770-436-1300 North America, Inc. northamerica.com 7) Connect the voltmeter and load from the EV kit TDK Corp. 847-803-6100 w w w .comp onent.tdk .com OUT pad to the GND pad next to OUT. Note: Indicate that you are using the MAX8902A or MAX8902B 8) Turn on the power supply. when contacting these component suppliers. 9) Verify that the output voltage matches the values as shown in Table 2. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.MAX8902 Evaluation Kit where V is the feedback regulation voltage of 0.6V. FB Detailed Description of Hardware When setting the output to 0.6V, short R1 and leave The MAX8902 evaluation kit (EV kit) is a fully assembled R2 open. and tested PCB for evaluating the MAX8902A low-dropout linear regulator (LDO). The EV kit operates from a 1.7V to POK Output (MAX8902B) 5.5V supply and provides a jumper-selectable output volt- The MAX8902B has an open-drain power-OK output age of 1.5V, 1.8V, 2.0V, 2.5V, 3.0V, 3.1V, 3.3V, 4.6V, or (POK). POK pulls low to indicate that the output voltage 4.7V, with loads up to 500mA. The output-voltage setting is in regulation. During startup, POK is high impedance set by jumpers JU2 and JU3 is fixed at startup. Changing until the output voltage rises to 90% of its regulation these jumpers while the IC is operating has no effect. The level. If an overload occurs at the output, or the output MAX8902 EV kit comes with the MAX8902A installed, is shut down, POK is high impedance. To use POK as a but can also be used to evaluate the MAX8902B. logic-level output, install pullup resistor R3. Evaluating the MAX8902B Enable To evaluate the MAX8902B, carefully remove the IC Jumper JU1 is provided to enable or disable the IC by (U1) and replace it with the MAX8902B. Remove the connecting EN to IN or GND. If an external enable sig- shunt from jumper JU3. Install a shunt on JU2 in 1-2 nal is used, remove the shunt from JU1 and connect position. Remove the 0 resistor from R1 and install R1 the external signal to pin 2 of JU1. Ensure that the sig- and R2 to set the desired output voltage. nal does not exceed 5.5V. Setting the MAX8902B Output Voltage The MAX8902B uses external feedback resistors to set the Table 2. JU2 and JU3 Settings output regulation voltage. The output can be set from 0.6V (MAX8902A Only) to 5.3V. Set the lower feedback resistor (R2) to 120k to minimize FB input bias current error. Then calculate OUTPUT VOLTAGE (V) JU2 JU3 the value of the upper feedback resistor (R1) as follows: 1.5 2-3 Open 1.8 Open 1-2 V OUT RR12 = x 1 2.0 Open 2-3 V FB 2.5 Open Open 3.0 1-2 1-2 Table 1. JU1 Settings 3.1 1-2 2-3 (MAX8902A and MAX8902B) 3.3 1-2 Open 1-2 2-3 4.6 2-3 1-2 Shutdown Enable 4.7 2-3 2-3 IN IN 1.7V TO 5.5V OUT C1 500mA MAX 1 8 R3 OUT 10F IN C3 C4 C2 OPEN GND POK 10F OPEN 0.01F 5 7 U1 BP SELB R1 4 0 MAX8902A SELA IN IN IN GND 3 6 EN OUTS 3 3 3 JU3 JU2 JU1 EP GND C5 2 2 2 R2 OPEN 2 OPEN 1 1 1 Figure 1. MAX8902 EV Kit Schematic 2 Evaluates: MAX8902A/MAX8902B