Evaluates: MAX889 19-1861 Rev 0 11/00 MAX889S Evaluation Kit General Description Features +2.7V to +5.5V Input Range The MAX889 IC is an inverting charge pump that deliv- ers a regulated negative output voltage at loads up to Uses One 2.2F and Two 10F Ceramic 200mA. The device operates from an input of +2.7V to Capacitors +5.5V to produce a user-adjustable, regulated output of Output Adjustable from -2.5V to -V -2.5V to -V . IN IN The MAX889S evaluation kit (EV kit) is a fully assem- 200mA Output Current bled and tested surface-mount board. The board is set 1MHz Switching Frequency up to provide a -3.3V output from a +5.0V input supply. The EV kit is shipped with a MAX889S (1MHz switching Fully Assembled and Tested Surface-Mount frequency) installed. The board may also be used to Board evaluate the MAX889R (500kHz) or the MAX889T (2MHz). To do so, request a free sample of the MAX889RESA or MAX889TESA, and refer to the MAX889 data sheet for the appropriate capacitor val- ues. Component List Ordering Information PART TEMP. RANGE IC PACKAGE DESIGNATION QTY DESCRIPTION MAX889SEVKIT 0C to +70C 8 SO 10F, 6.3V X5R ceramic capacitors C1, C3 2 Taiyo Yuden JMK316BJ106ML Murata GRM42-6X5R106K6.3 Quick Start 2.2F, 10V X5R ceramic The MAX889S EV kit is fully assembled and tested. C2 1 capacitor Follow the steps below to verify board operation. Do Taiyo Yuden LMK212BJ225MG not turn on the power supply until all connections JU1 1 3-pin jumper are completed: JU2, JU3 2 2-pin jumpers 1) Connect a voltmeter and the load to the VOUT pad. R1 1 49.9k 1% resistor 2) Place the shunts in the following positions: JU1 1-2, R2 1 33.2k 1% resistor JU2 closed, JU3 closed. U1 1 MAX889SESA 3) Connect a +5.0V supply to the pad labeled VIN. Con- None 1 MAX889S EV kit data sheet nect the ground lead to the pad labeled GND. None 1 MAX889 IC data sheet 4) Turn on the power and verify that the output is 3.3V. None 3 Shunts Component Suppliers SUPPLIER PHONE FAX Murata 814-237-1431 814-238-0490 Taiyo Yuden 408-573-4150 408-573-4159 Note: Please indicate that you are using the MAX889S when contacting these suppliers. Maxim Integrated Products 1 For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.MAX889S Evaluation Kit Capacitor Selection Detailed Description Use capacitors with a low effective series resistance Jumper Selection (ESR), such as ceramic or surface-mount chip tantalum The MAX889 can be placed in shutdown mode, using types. Refer to the MAX889 data sheet for more infor- jumper JU1. See Table 1 for jumper settings. mation. Jumper JU2 connects VIN to the voltage-divider that Table 1. Jumper Functions sets the output voltage. To use a voltage source other JUMPER than VIN as the reference, open JU2, and connect the JUMPER FUNCTION POSITION reference source to the pad labeled VREF. SHDN = High, MAX889 The MAX889 can be placed into free-run mode (unreg- 1-2* enabled ulated, VOUT = -VIN) by removing the shunt on JU3 and installing a shunt on JU2. SHDN = Low, MAX889 2-3 JU1 disabled Output Voltage Adjustment Drive SHDN pad with an Open The MAX889S EV kit is shipped with the resistor-divider external signal selected for an output of -3.3V and an input of +5.0V. Drive VREF pad with an Output voltages other than -3.3V can be set one of two Open external voltage to set the ways: output voltage 1) Change the resistor-divider formed by R1 and R2. JU2 Use the following equation to determine the resistor VIN is used to set the output Closed* values: voltage R2 = -(VOUT / VREF) R1 Used to place the MAX889 Open into free-run mode (JU2 must (The current through R1 and R2 should be at least be closed) 30A.) JU3 Output voltage is set by 2) Remove the shunt from JU2 and apply a voltage to Closed* resistor-divider and VIN or the VREF pad. Use the following equation to deter- VREF mine the voltage for VREF: VREF = -(R1 / R2) VOUT *Default position JU2 VREF VIN + C1 R1 GND 10 F 49.9k 1 1% 1 IN JU1 6 7 2 SHDN SHDN FB 3 U1 R2 33.2k MAX889S 2 1% CAP+ + C2 JU3 2.2 F 4 5 CAP- OUT VOUT AGND GND C3 8 3 + 10 F GND Figure 1. MAX889S EV Kit Schematic Diagram 2 Evaluates: MAX889