general description the max98502 evaluation kit (ev kit) is a fully assembled and tested circuit board that uses the max98502 boost - ed class d amplifier to drive a mono bridge-tied-load (btl) speaker in portable audio applications. designed to operate from a 2.5v to 5.5v dc power supply, the ev kit is capable of delivering 2.2w into an 8 i load or 4w into a 4 i load. the ev kit accepts differential or single- ended input signals, features selectable gain, and sepa - rate speaker and boost shutdown inputs. features s 2.5v to 5.5v single-supply operation s 4w mono class d output s sele ctab le gain: +6db, +15.5db, and +20db s boosted class d output s differential or single-ended input s boost converter shutdown s speaker output shutdown s proven pcb layout s fully assembled and tested designation qty description c1 1 10 f f q 10%, 6.3v x7r ceramic capacitor (0805) murata grm21br70j106k tdk c2012x7r0j106k c2 1 22 f f q 20%, 16v x5r ceramic capacitor (1206) murata grm31cr61c226m taiyo yuden emk316bj226m c3, c4 2 1 f f q 10%, 25v x7r ceramic capacitors (0603) murata grm188r71e105k murata grm188r71e105m c5 1 22 f f q 10%, 6.3v x5r ceramic capacitor (0805) murata grm21br60j226m tdk c2012x5r0j226k c8 1 0.1 f f q 10%, 16v x7r ceramic capacitor (0402) murata grm155r71c104k tdk c1005x7r1c104k c12, c13 0 not installed, ceramic capacitors (0603) c14Cc18 5 0.22 f f q 10%, 25v x7r ceramic capacitors (0603) murata grm188r71e224k tdk c1608x7r1e224k designation qty description fb2, fb3 0 not installed, ferrite beads (0603) j1 1 phono jack, black (side-entry pcb mount) ju1, ju2, ju3 3 3-pin headers ju4 1 2-pin header l1 1 2.2 f h, 91m i , 1.5a inductor (3.2mm x 2.5mm) murata lqh32pn2r2nn0 l2, l3 0 not installed, inductors out-, out+, rknee, pgnd 4 test points r1 1 27.4k i q 1% resistor (0603) r2, r3 2 22 i q 5% resistors (0603) u1 1 boosted class d audio amplifier (16 wlp) maxim max98502ewe+ vccout 0 not installed, test point 4 shunts 1 pcb: max98502 evaluation kit optional components l2, l3 2 22 f h q 20%, 2a inductors (d75lc) toko b1047as-220m _________________________________________________________________ maxim integrated products 1 component list 19-6275; rev 0; 4/12 ordering information appears at end of data sheet. max98502 evaluation kit evaluates: max98502 for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxims website at www.maxim-ic.com.
supplier phone website murata electronics north america, inc. 770-436-1300 www.murata-northamerica.com taiyo yuden 800-348-2496 www.t-yuden.com tdk corp. 847-803-6100 www.component.tdk.com toko america, inc. 847-297-0070 www.tokoam.com shunt position gain pin gain setting (db) 2-3 connected to agnd +6 not installed* unconnected +15.5 1-2 connected to vbat +20 _________________________________________________________________ maxim integrated products 2 quick start recommended equipment ? max98502 ev kit ? 2.5v to 5.5v, 4a dc supply ? 8 i or 4 i speaker ? mono audio signal source procedure the ev kit is fully assembled and tested. follow the steps below to verify board operation. caution: do not turn on the power supply until all connections are completed. 1) verify that shunts are installed as follows: ju1: open (+15.5db gain) ju2: pins 1-2 (speaker enabled) ju3: pins 1-2 (boost enabled) ju4: short (single-ended/unbalanced input) 2) set the power-supply output to 3.6v. 3) disable the power-supply output. 4) connect the power-supply ground to the pgnd pcb pad and the power-supply positive output to the vbat pcb pad on the ev kit. keep vbat lengths < 8in (and twisted to minimize inductance) to ensure proper device operation. 5) verify that the audio source output is disabled. 6) connect the mono audio source between the in+ and in- pcb pads or j1 on the ev kit. 7) connect the speaker across the out+ and out- test points. 8) enable the power-supply output. 9) enable the audio source. 10) verify that the speaker is playing the audio source signal. detailed description of hardware the max98502 ev kit features the max98502 boosted class d amplifier ic, designed to drive a btl mono speaker in portable audio applications. the ev kit accepts a differential or single-ended audio input, features three selectable gain settings, and provides two active-low shutdown inputs for flexibility. the audio input source is amplified to drive 2.2w into an 8 i speaker or 4w into an 4 i speaker. the ev kit operates from a single dc power supply that can provide 2.5v to 5.5v. the ev kit provides two sets of differential outputs. the device outputs (out+/out-) can be connected directly to a speaker load, without any filtering, with up to 24in of cable. however, a filter can be added to ease evaluation. selectable gain setting the ic features three internal gain settings that are selectable with the gain input. jumper ju1 controls the amplifiers gain select input. see table 1 for ju1 con - figuration. shutdown inputs the ic features two active-low shutdown inputs ( sdspk and sdbst ). jumper ju2 enables or disables the speaker amplifier ( sdspk ) and jumper ju3 controls the boost converter ( sdbst ). see table 2 for ju2 and ju3 configuration. the boost must be enabled for the speaker amplifier to enable. component suppliers note: indicate that ou are using the m hen contacting these component suppiers. table 1. gain input (ju1) default position. max98502 evaluation kit evaluates: max98502
sdbst pin (ju3) sdspk pin (ju2) boost status speaker status 2-3 (low) 2-3 (low) off off 2-3 (low) 1-2 (high) off off 1-2 (high) 2-3 (low) on off 1-2* (high) 1-2* (high) on on shunt position in- pin input mode installed* connected to agnd single-ended/ unbalanced input not installed connected to user- supplied negative differential output differential input designation qty description l2, l3 2 22 f h q 20%, 2a inductors (d75lc) toko b1047as-220m designation qty description c5 1 22 f f, 6.3v ceramic capacitor (0805) c8 1 0.1 f f, 6.3v ceramic capacitor (0402) designation qty description c5 1 22 f f, 6.3v ceramic capacitor (0603) c8 1 not installed, ceramic capacitor _________________________________________________________________ maxim integrated products 3 input mode jumper ju4 provides the option to select between a dif - ferential or single-ended input mode for the ev kit. see table 3 for ju4 configuration. optional output filtering the ic is designed to pass fcc emissions standards without any filtering when using up to 24in of cable to connect the speaker. when evaluating the ic without any filtering, connect the speaker to the output test points (out+/out-). the ev kit also features pcb pads for a lowpass filter that can be added to ease evaluation. audio analyzers typi - cally cannot accept the class d amplifiers pulse-width- modulated (pwm) waveform at their inputs. the lowpass filter extracts the audio content from the pwm output signal and allows the device to be connected directly to an audio analyzer. the pwm output signal can be lowpass-filtered by simply installing l2 and l3; all other components are populated. the filtered outputs should then be monitored at the fout+/fout- pads. see table 4 for suggested filtering components for an 8 i load. contact the factory for suggested filtering components for a 4 i load. optional output loading the ev kit can be used to drive a 4 i or 8 i load. see tables 5 and 6 below for required components for each load. table 3. input mode (ju4) table 4. suggested filtering components for 8 i load table 5. components required for 4 i speaker drive table 6. minimum components required for 8 i speaker drive default position. default position. table 2. shutdown configuration (ju2, ju3) max98502 evaluation kit evaluates: max98502
_________________________________________________________________ maxim integrated products 4 figure 1. max98502 ev kit schematic max98502 evaluation kit evaluates: max98502
1.0? 1.0? 1.0? _________________________________________________________________ maxim integrated products 5 figure 2. max98502 ev kit component placement guide component side figure 3. max98502 ev kit pcb layoutcomponent side figure 4. max98502 ev kit pcb layoutsolder side max98502 evaluation kit evaluates: max98502
part type MAX98502EVKIT# ev kit _________________________________________________________________ maxim integrated products 6 ordering information # denotes rohs compliant. max98502 evaluation kit evaluates: max98502
revision number revision date description pages changed 0 4/12 initial release 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 ? 2012 maxim integrated products maxim is a registered trademark of maxim integrated products, inc. revision history max98502 evaluation kit evaluates: max98502
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