general description the max8561 evaluation kit (ev kit) demonstrates the max8561/max8562s?up to 4mhz pulse-width modulat- ed (pwm) step-down dc-dc converters. the two circuits are optimized for powering the dsp/microprocessor or the power amplifiers (pas) in wireless applications. the max8561 circuit provides two adjustable output voltages in the 0.6v to 2.5v range from a 2.7v to 5.5v input, and can deliver 500ma of load current. in comparison, the max8562 circuit provides an adjustable voltage in the 0.6v to 2.5v range and a bypass mode where the output voltage is shorted to the input by an external mosfet. features 2.7v to 5.5v input voltage range 0.6v to 2.5v adjustable output voltage range vout1 = 1.8v/1.5v at 500ma (max8561) vout2 = 1.2v at 400ma or bypass mode (max8562) 2mhz pwm switching frequency (max8561) 4mhz pwm switching frequency (max8562) 0.1a (typ) shutdown current surface-mount construction fully assembled and tested evaluates: max8561/max8562 max8561 evaluation kit ________________________________________________________________ maxim integrated products 1 designation qty description c1, c4 2 4.7f 10%, 6.3v x5r ceramic capacitors (0603) tdk c1608x5r0j475k c2, c5 2 2.2f 10%, 6.3v x5r ceramic capacitors (0603) taiyo yuden jmk107bj225ka or tdk c1608x5r0j225k c3 1 150pf 5%, 50v c0g ceramic capacitor (0603) tdk c1608c0g1h151jt or equivalent c6 1 100pf 5%, 50v c0g ceramic capacitor (0603) tdk c1608c0g1h101jt or equivalent ju1 ju4 4 3-pin headers l1 1 2.2h inductor murata lqh32cn2r2m51 ordering information 19-2982; rev 0; 9/03 for pricing, delivery, and ordering information, please contact maxim/dallas direct! at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com. part temp range ic package MAX8561EVKIT 0 c to +70 c 8 thin dfn (3mm x 3mm) supplier phone fax website murata 770-436-1300 770-436-3030 www.murata.com taiyo yuden 800-348-2496 847-925-0899 www.t-yuden.com tdk 847-803-6100 847-390-4405 www.component.tdk.com vishay 203-268-6261 203-452-5670 www.vishay.com component suppliers designation qty description l2 1 1.0h inductor (0806) taiyo yuden lb2016b1r0m p1 1 p-channel mosfet (sc70) vishay si1417edh (top mark bb) r1 1 150k ? 1% resistor (0603) r2 1 301k ? 1% resistor (0603) r3, r4, r5 3 100k ? 1% resistors (0603) u1 1 max8561eta (8-pin thin dfn 3mm x 3mm) top mark ahd u2 1 max8562eta (8-pin thin dfn 3mm x 3mm) top mark ahe u3 0 not installed none 4 shunts none 1 max8561/max8562 pc board component list note: please indicate that you are using the max8561/max8562 when contacting these component suppliers.
evaluates: max8561/max8562 quick start the max8561 ev kit is a fully assembled and tested surface-mount board. follow the steps below for board operation. do not turn on the power supply until all connections are completed: 1) verify that a shunt is connected across pins 1 and 2 of jumper ju1/ju3 (output enabled). 2) verify that a shunt is connected across pins 2 and 3 of jumper ju2/ju4. 3) connect a voltmeter across the vout1/vout2 and the gnd1/gnd2 pads to monitor the output voltage(s). 4) connect a 2.7v to 5.5v power supply to the batt1/batt2 pad. connect the power-supply ground terminal to the gnd1/gnd2 pad. 5) turn on the power supply and verify that vout1 = 1.5v/vout2 = 1.2v. detailed description the max8561 ev kit circuit board demonstrates both the max8561 (upper circuit) and the max8562 (lower cir- cuit). the max8561 circuit is optimized for dsp or micro- processor application, and its switching frequency is set at approximately 2mhz. the max8562 circuit is opti- mized to power the pa in wireless applications, and its switching frequency is set to 4mhz. the ev kit requires a power supply in the 2.7v to 5.5v range. the ev kit board features jumpers that enable the user to configure the shutdown mode and open-drain output control. shutdown mode the ev kit contains jumpers ju1 and ju3 to allow the user to switch the max8561 and max8562 converters from enable to shutdown mode. shutdown mode reduces the supply current to 0.1a (typ) and sets the output volt- age to 0v. see table 1 for ju1 and ju3 configurations. open-drain control jumper ju2 allows the user to set vout1 at either 1.8v or 1.5v. jumper ju4 allows the user to enable the con- verter to regulate at 1.2v or set the output voltage vout2 to equal the input voltage batt2 under the bypass mode. see table 2 for ju2 and ju4 configurations. evaluating other voltage outputs the max8561 ev kit circuit board comes with two inde- pendent circuits, the max8561 (upper circuit) and the max8562 (lower circuit). the max8561 circuit can pro- vide two adjustable output voltages, and the ev kit default voltages of vout1 are set at 1.8v and 1.5v. to evaluate other voltages at vout1, use 150k ? at r1, and calculate r2 and r3 using the following two equations: where v fb = 0.6v and vout1 (high) and vout1 (low) are the two desired output voltages. the ev kit default output voltage of vout2 is set at 1.2v. to evaluate other voltage outputs on the max8562 circuit, keep r4 as 100k ? . then r5 is given by: where v fb = 0.6v and vout2 is the desired output voltage. r rv vout v fb fb 5 4 2 = ? r rv vout v and r r vout v r r fb low fb high fb 3 1 2 1 1 3 1 = ? = ?? () () max8561 evaluation kit 2 _______________________________________________________________________________________
evaluates: max8561/max8562 max8561 evaluation kit _______________________________________________________________________________________ 3 ju1/ju3 shunt location shdn pin max8561/max8562 output pins 1 and 2 connected to batt_ output enabled pins 2 and 3 connected to gnd output disabled none connected to shdn pad output controlled by the user (user-supplied control signal must be connected to shdn pad) table 1. jumpers ju1 and ju3 functions ( shdn ) ju2/ju4 shunt location odi1/odi2 pin max8561 output max8562 output pins 1 and 2 connected to vin vout1 = 1.8v vout2 = batt2 pins 2 and 3 connected to gnd vout1 = 1.5v vout2 = 1.2v none connected to odi1/odi2 pad output controlled by the user (user- supplied control signal must be connected to odi1 pad) output controlled by the user (user- supplied control signal must be connected to odi2 pad) table 2. jumpers ju2 and ju4 functions (odi1/odi2) max8561 outputs vout1 low (v) vout1 high (v) r2 value (k ? ) r3 value (k ? ) 0.9 1.3 226 301 1.1 1.3 432 182 0.9 1.5 150 301 1.1 1.5 221 182 1.2 1.5 301 150 table 3. recommended r2 and r3 values for typical dynamic output voltages note: r1 = 150k ? , l1 = 2.2?, and c3 = 150pf.
evaluates: max8561/max8562 max8561 evaluation kit max8561 batt1 gnd1 odi1 1 2 3 batt1 ju1 shdn1 c1 4.7 f 6.3v 1 7 8 4 in agnd odi shdn 3 6 5 l1 2.2 h r1 150k ? 1% r2 301k ? 1% r3 100k ? 1% c3 150pf c2 2.2 f 6.3v vout1 1.8v/1.5v at 500ma lx fb odo u1 max8562 batt2 gnd2 odi2 shdn2 c4 4.7 f 6.3v 1 7 8 4 in agnd odi shdn 3 6 l2 1 h r4 100k ? 1% r5 100k ? 1% c6 100pf c5 2.2 f 6.3v vout2 1.2v at 400ma/batt2 lx 5 odo fb u2 pgnd 2 pgnd 2 3 4 5 2 1 6 p1 1 2 3 batt1 ju2 1 2 3 batt2 ju3 1 2 3 batt2 ju4 figure 1. max8561 ev kit schematic 4 _______________________________________________________________________________________
evaluates: max8561/max8562 max8561 evaluation kit _______________________________________________________________________________________ 5 figure 2. max8561 ev kit component placement guide component side figure 3. max8561 ev kit pc board layout?omponent side
evaluates: max8561/max8562 max8561 evaluation kit maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim product. no circu it patent licenses are implied. maxim reserves the right to change the circuitry and specifications without notice at any time. 6 _____________________maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 ? 2003 maxim integrated products printed usa is a registered trademark of maxim integrated products. figure 4. max8561 ev kit pc board layout?older side
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