general description the max1577z evaluation kit (ev kit) is a fully assem- bled and tested circuit for evaluating the max1577z white led 1x/2x charge pump. the max1577z ev kit strobes a white led at up to 1.1a using an on-board pulse generator. in movie mode, it drives the led at a constant 220ma. the current levels are adjusted by changing a resistor. the ev kit can also be used to evaluate the max1577y. features ? selectable flash/movie modes ? up to 92% efficiency (p led / p batt ) ? 3% led current regulation ? adaptive 1x/2x mode switchover ? 2.7v to 5.5v supply voltage range ? 8-pin tdfn 3mm x 3mm ic package ? fully assembled and tested evaluates: max1577y/max1577z max1577z evaluation kit ________________________________________________________________ maxim integrated products 1 19-3602; rev 0; 3/05 component list 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. ordering information designation qty description c1 1 2.2? ?0%, 6.3v x5r ceramiccapacitor (0603) panasonic ecj1vb0j225k tdk c1608x5r0j225k c2 1 4.7? ?0%, 6.3v x5r ceramiccapacitor (0603) panasonic ecj1vb0j475k tdk c1608x5r0j475k c3 1 10? ?0%, 6.3v x5r ceramiccapacitor (0805) taiyo yuden jmk212bj106mg panasonic ecj2fb0j106m tdk c2012x5r0j106m c4 1 0.047? ?0%, 10v x7r ceramiccapacitor (0402) taiyo yuden lmk105bj473kv tdk c1005x7r1c473k c5 1 0.01? ?0%, x7r ceramiccapacitor (0402) tdk c1005x7r1e103k or equivalent part temp range ic package MAX1577ZEVKIT 0? to +70? 8 tdfn (3mm x 3mm) designation qty description d1 1 white led flash emitterlumileds lxcl-pwf1 d2 1 diode (sod-323)central cmdd4448 ju1, ju3 2 2-pin headers ju2 1 3-pin header r1 1 0.27 ?%, 0.25w resistor (0805) panasonic erj-6rqfr27v r2, r4, r5 3 100k ?% resistors (0402) r3 1 10k ?% resistor (0402) sw1 1 momentary pushbutton switchpanasonic evq-php03t u1 1 max1577zeta (8-pin tdfn, 3mm x 3mm) top mark: amq u2 1 max6422xs23-t (4-pin sc70) none 3 shunts, 2-position none 1 MAX1577ZEVKIT pc board downloaded from: http:///
evaluates: max1577y/max1577z quick start recommended equipment 2.7v to 5.5v power supply or battery capable ofdelivering 2.5a procedure follow the steps below to verify board operation: 1) verify that shunts are connected across pins 1-2 of jumpers ju1, ju2, and ju3. 2) preset the power supply to 4.2v. 3) turn off the power supply. do not turn on the power supply until all connections are com- pleted. 4) connect the positive power-supply terminal to the pad on the ev kit labeled in. 5) connect the power-supply ground terminal to the pad on the ev kit labeled gnd. 6) turn on the power supply. the led will flash once due to the on-board pulse generator circuit power-ing up. 7) press the button to flash the led at 1.1a. the pulse generator limits the flash duration to approximately125ms. 8) move jumper ju2 to short pins 2-3 (selects movie mode). 9) verify that the led is lit. detailed description adjusting the 100% brightness level the led current is adjusted by changing the resistorr1. calculate the value of r1 with the following equa- tion, where i out is the output current in amps for 100% brightness:for more information on setting the brightness, refer to the max1577y/max1577z data sheet. control inputs the max1577z has two inputs for selecting 100%,33%, and 20% output current, or shutdown. using ju1 and ju2 (see table 1), these inputs can be connected to the output of the on-board pulse generator for a strobed output, while en2 can be connected to in for movie mode, pulled low, or driven from an external pulse generator. with the default 100% current setting (r1 = 0.27 ), the selectable output currents are described in table 2. r v i out 1 03 . = max1577z evaluation kit 2 _______________________________________________________________________________________ table 1. jumper descriptions jumper short 1-2 short 2-3 open ju1 en1 connects to the output ofthe on-board pulse generator. n/a en1 is pulled low by a 100k resistor. en1 can be driven from an external pulse generator connectedto the en1 pad on the left side of the ev kit. ju2 en2 connects to the output ofthe on-board pulse generator. en2 connects to in for moviemode. en2 is pulled low by a 100k resistor. en2 can be driven from an external pulse generator connectedto the en2 pad on the left side of the ev kit. ju3 connects power to the on-board pulse generator. n/a power to the on-board pulse generator isdisconnected. leave ju3 open when measuring the quiescent current of the max1577z. ju4 ju4 is shorted on the pc board and connects the white led tothe output of the max1577z. cut the trace shorting ju4 to use an external led,or when operating in voltage regulation mode. table 2. default output currents ju1 ju2 function 1-2 1100ma flash 2-3 220ma movie mode/1100ma flash 1-2 open 367ma flash 1-2 220ma flash 2-3 220ma movie mode open open shutdown downloaded from: http:///
when using the on-board pulse generator, the ledflashes when power is first applied to the ev kit. this is due to the pulse generator circuit and not the max1577z.to use external pulse generators, remove the shunts from both ju1 and ju2, and connect the pulse genera- tors to the pads labeled en1 and en2. for a simple flash at 100% brightness, connect en1 to en2 and drive with a single pulse generator. shutdown to place the max1577z in low-power shutdown mode,remove the shunt from both jumpers ju1 and ju2. for measuring quiescent current while in shutdown mode, also remove the shunt from ju3 to disconnect the on- board pulse generator from the supply. connecting external led(s) to connect external led(s) to the max1577z ev kit, cutthe trace shorting ju4. connect the anode(s) of the external led(s) to the pad labeled led+. connect the cathode(s) to the pad labeled gnd. evaluating the max1577y to evaluate the max1577y, carefully remove themax1577z from the ev kit and replace with the max1577y. free samples of the max1577y are available from maxim. to evaluate the voltage regulation settings of the max1577y, follow the procedure in the voltage regulation section. voltage regulation the max1577y/max1577z can provide a constant volt-age output. in voltage-regulation mode, the max1577z has a fixed 5.1v output. the output voltage of the max1577y is selected using ju1 and ju2. refer to the max1577y/max1577z data sheet for more information. to configure the max1577z ev kit for voltage regula- tion, cut the trace shorting ju4. connect the load from the pad labeled out to the pad labeled gnd. evaluates: max1577y/max1577z max1577z evaluation kit _______________________________________________________________________________________ 3 component suppliers supplier phone web components central semiconductor 631-435-1110 www.centralsemi.com diodes kamaya 260-489-1533 www.kamaya.com resistors lumileds 408-435-6044 www.lumileds.com leds panasonic 714-373-7939 www.panasonic.com capacitors, resistors, switches taiyo yuden 408-573-4150 www.t-yuden.com capacitors tdk 847-803-6100 www.component.tdk.com capacitors vishay 402-563-6866 www.vishay.com resistors note: indicate that you are using the max1577y/max1577z when contacting these component suppliers. downloaded from: http:///
evaluates: max1577y/max1577z max1577z evaluation kit 4 _______________________________________________________________________________________ r10.27 c3 10 f d1 ju4 out gnd led+ c2 4.7 f in in r4 100k en1 ju1 21 pulse gnd en2 r5 100k max1577z u1 c1 2.2 f 65 1 4 ingnd en1 en2 87 out cs cp cn 23 ju2 2 31 in max6422 u2 v cc reset gnd srt 12 43 pulse c4 0.047 f sw1 23 in 12 ju3 r2 100k r3 10k d2 c5 0.01 f pulse figure 1. max1577z ev kit schematic downloaded from: http:///
evaluates: max1577y/max1577z max1577z evaluation kit _______________________________________________________________________________________ 5 figure 2. max1577z ev kit component placement guide?omponent side downloaded from: http:///
evaluates: max1577y/max1577z max1577z evaluation kit 6 _______________________________________________________________________________________ figure 3. max1577z ev kit pc board layout?omponent side downloaded from: http:///
maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim product. no circuit patent licenses are implied. maxim reserves the right to change the circuitry and specifications without notice at any time. maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 _____________________ 7 2005 maxim integrated products printed usa is a registered trademark of maxim integrated products, inc. evaluates: max1577y/max1577z max1577z evaluation kit figure 4. max1577z ev kit pc board layout?older side downloaded from: http:///
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