IS31AP4912 integrated silicon solution, inc. ? www.issi.com 1 rev.a, 11/17/2011 stereo headphone driver december 2011 general description the IS31AP4912 is stereo headphone drivers designed to allow the removal of the output dc-blocking capacitors for reduced component count and cost. the IS31AP4912 is ideal for small portable electronics where size and cost are critical design parameters. the IS31AP4912 integrates click-and-pop suppression circuitry and thermal protect circuit. the gain of the amplifier is adjusted via external resistors. IS31AP4912 is available in ut qfn-12 (2mm 2mm) packages . it operates from 2.7v to 5.5v over the temperature range of -40c to +85c. features ? no output dc-blocking capacitors ? supply voltage from 2.7v ~ 5.5v ? low output noise (7v) ? high snr (103db) ? -95db psrr ? thermal protect circuit ? integrated click-and-pop suppression circuitry ? utqfn-12 (2mm 2mm) package applications ? cellular handsets and pdas ? notebook pc ? mp3 ? portable gaming typical application circuit figure 1 typical application circuit note: the sgnd and pgnd pins of the IS31AP4912 must be routed separately back to the decoupling capacitor in order to provide proper device operation. if the sgnd and pgnd pins are connected directly to each other, the part functions without risk of failure, b ut the noise and thd performance do not meet the specifications.
IS31AP4912 integrated silicon solution, inc. ? www.issi.com 2 rev.a, 11/17/2011 pin configuration package pin configuration (top view) utqfn-12 1 2 3 9 8 7 cn inr inl outr vref vcc pin description no. pin description 1 cn charge pump flying capacitor negative terminal. 2 inr right channel audio input. 3 inl left channel audio input. 4 outl left channel audio output. 5 sdb shutdown control terminal, active low. 6 sgnd signal ground. 7 vcc supply voltage. 8 vref internal produced supply voltage for charge pump and audio power amplifier. 9 outr right channel audio output. 10 cp charge pump flying capacitor positive terminal. 11 pgnd power ground. 12 vss output from charge pump. copyright ? ? ? 2011 ? integrated ? silicon ? solution, ? inc. ? all ? rights ? reserved. ? issi ? reserves ? the right ? to ? make ? changes ? to ? this ? specification ? and ? its ? products ? at ? any ? time ? without ? notice. ? issi ? assumes ? no ? liability ? arising ? out ? of ? the ? application ? or ? use ? of ? any ? information, ? products ? or ? services ? described ? herein. ? customers ? are ? advised ? to ? obtain ? the ? latest ? version ? of ? this ? device ? specification ? before ? relying ? on ? any ? published ? information ? and ? before ? placing ? orders ? for ? products. ? integrated ? silicon ? solution, ? inc. ? does ? not ? recommend ? the ? use ? of ? any ? of ? its ? products ? in ? life ? support ? applications ? where ? the ? failure ? or ? malfunction ? of ? the ? product ? can ? reasonably ? be ? expected ? to ? cause ? failure ? of ? the ? life ? support ? system ? or ? to ? significantly ? affect ? its ? safety ? or ? effectiveness. ? products ? are ? not ? authorized ? for ? use ? in ? such ? applications ? unless ? integrated ? silicon ? solution, ? inc. ? receives ? written ? assurance ? to ? its ? satisfaction, ? that: ? a.) ? the ? risk ? of ? injury ? or ? damage ? has ? been ? minimized; ? b.) ? the ? user ? assume ? all ? such ? risks; ? and ? c.) ? potential ? liability ? of ? integrated ? silicon ? solution, ? inc ? is ? adequately ? protected ? under ? the ? circumstances
IS31AP4912 integrated silicon solution, inc. ? www.issi.com 3 rev.a, 11/17/2011 ordering information industrial range: -40c to +85c order part no. package qty/reel IS31AP4912-utls2-tr utqfn-12, lead-free 3000
IS31AP4912 integrated silicon solution, inc. ? www.issi.com 4 rev.a, 11/17/2011 absolute maximum ratings supply voltage, v dd - 0.3v ~ +6.0v voltage at any input pin - 0.3v ~ v dd +0.3v maximum junction temperature, t jmax 150c storage temperature range, t stg - 65c ~ +150c operating temperature range, t a ? 40c ~ +85c note: stresses beyond those listed under ?absolute maximum ratings? may cause permanent damage to the device. these are stress rating s only and functional operation of the device at these or any other condition beyond those indicated in the operational sections of the sp ecifications is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. electrical characteristics v cc = 2.7v ~ 5.5v, t a = 25c, unless otherwise noted. typical value is t a = 25c, v cc = 3.6v. symbol parameter condition min. typ. max. unit v cc supply voltage 2.7 5.5 v i cc quiescent current no load 3 5 ma i sd shutdown current v sdb = 0v 1 a f osc operating frequency 250 khz |v os | output offset voltage v (in) = 0v 1 mv v ih high-level input voltage 1.4 v v il low-level input voltage 0.4 v electrical characteristics (note 1) t a = 25c, v cc = 3.6v, unless otherwise noted. symbol parameter condition min. typ. max. unit p o output power thd+n = 1% r l = 32 ? f = 1khz 30 mw thd+n total harmonic distortion plus noise p o = 20mw r l = 32 ? f = 1khz 0.024 % t wu wake-up time from shutdown 39 ms psrr power supply rejection ratio v p-p = 200mv r l = 32 ? f = 217hz -95 db v p-p = 200mv r l = 32 ? f = 1khz -93 db v no output voltage noise 7 v snr signal-to-noise ratio p o = 30mw thd+n = 0.1% 103 db note 1: guaranteed by design.
IS31AP4912 integrated silicon solution, inc. ? www.issi.com 5 rev.a, 11/17/2011 typical performance characteristic thd+n(%) output power(w) 0.01 20 0.02 0.05 0.1 0.2 0.5 1 2 5 10 1m 2m 5m 10m 20m 50m 100m f = 20hz f = 1khz f = 10khz v cc = 3.0v r l = 32 ? figure 2 thd+n vs. output power thd+n(%) output power(w) 0.01 20 0.02 0.05 0.1 0.2 0.5 1 2 5 10 1m 2m 5m 10m 20m 50m 100m v cc = 4.2v r l = 32 ? f = 1khz f = 20hz f = 10khz figure 4 thd+n vs. output power output voltage(v) 20 20k 50 100 200 500 1k 2k 5k 10k frequency(h z) 1u 20u 2u 3u 5u 7u 10u v cc = 3.0v~4.2v r l = 32 ? figure 6 noise thd+n(%) output power(w) 0.01 20 0.02 0.05 0.1 0.2 0.5 1 2 5 10 1m 2m 5m 10m 20m 50m 100m f = 20hz f = 1khz f = 10khz v cc = 3.6v r l = 32 ? figure 3 thd+n vs. output power thd+n(%) 20 20k 50 100 200 500 1k 2k 5k 10k frequency(hz) 0.001 1 0.002 0.005 0.01 0.02 0.05 0.1 0.2 0.5 v cc = 3.0v~4.2v r l = 32 ? p o = 20mw figure 5 thd+n vs. frequency psrr(db) 20 20k 50 100 200 500 1k 2k 5k 10k frequency(hz) -120 +0 -100 -80 -60 -40 -20 v cc = 3.6v, 4.2v r l = 32 ? input grounded figure 7 psrr vs. frequency
IS31AP4912 integrated silicon solution, inc. ? www.issi.com 6 rev.a, 11/17/2011 application information charge pump converter IS31AP4912 integrate a charge pump converter to change input supply voltage (v cc ) into a negative voltage providing a 0v reference voltage for output. the charge pump converter only needs three external components: supply decoupling capacitor, output bypass capacitor and flying capacitor. choose low esr capacitors to ensure the best operating performance and place the capacitors as close as possible to the IS31AP4912. gain setting the input resistors (r in ) and feedback resistors (r f ) set the gain of the amplifier according to equation (1). in f r r ain ? g ? ? ? ? ? ? v v (1) for example, in figure 1: r f = 20k ? , r in = 20k ? , so, 1 g 20 20 ? ? ain ? ? ? ? ? ? v v resistor matching is very important in the amplifiers. the balance of the output on the reference voltage depends on matched ratios of the resistors. cmrr, psrr, and cancellation of the second harmonic distortion diminish if resistor mismatch occurs. therefore, it is recommended to use 1% tolerance resistors or better to keep the performance optimized. matching is more important than overall tolerance. resistor arrays with 1% matching can be used with a tolerance greater than 1%. place the input resistors very close to the IS31AP4912 to limit noise injection on the high-impedance nodes. input capacitor (c in ) the input capacitors and input resistors form a high pass filter with the corner frequency, f c , determined in equation (2). in in c r c f ? 2 1 ? (2) for example, in figure 1: r in = 20k ? , c in = 0.47f, so, hz c f f k 17 47 . 0 20 2 1 ? ? ? ? ? ? ? the value of the input capacitor is important to consider as it directly affects the bass (low frequency) performance of the circuit. the capacitors should have a tolerance of 10% or better, because any mismatch in capacitance causes an impedance mismatch at the corner frequency and below. design note component selection the value and esr of the output capacitor for charge pump will affect output ripple and transient performance. a x7r or x5r ceramic capacitor in 2.2 f should be recommended. the flying capacitor should use a 2.2f x7r or x5r ceramic capacitor. all the capacitors should support at least 10v. pcb layout the decoupling capacitors should be placed close to the vcc pin and the output capacitors should be placed close to the vss pin. the flying capacitor should be placed close to the cn and cp pins. the input capacitors and input resistors should be placed close to the inr and inl pins and the traces must be parallel to prevent noise. the traces of outr and outl pins connected to the headphone should be as possible as short and wide. the recommended width is 0.5mm. trace width should be at least 0.75mm for the power supply and the ground plane. the sgnd and pgnd pins of the IS31AP4912 must be routed separately back to the decoupling capacitor in order to provide proper device operation. if the sgnd and pgnd pins are connected directly to each other, the part functions without risk of failure, but the noise and thd performance do not meet the specifications.
IS31AP4912 integrated silicon solution, inc. ? www.issi.com 7 rev.a, 11/17/2011 classification reflow profiles profile feature pb-free assembly preheat & soak temperature min (tsmin) temperature max (tsmax) time (tsmin to tsmax) (ts) 150c 200c 60-120 seconds average ramp-up rate (tsmax to tp) 3c/second max. liquidous temperature (tl) time at liquidous (tl) 217c 60-150 seconds peak package body temperature (tp)* max 260c time (tp)** within 5c of the specified classification temperature (tc) max 30 seconds average ramp-down rate (tp to tsmax) 6c/second max. time 25c to peak temperature 8 minutes max. figure 8 classification profile
IS31AP4912 integrated silicon solution, inc. ? www.issi.com 8 rev.a, 11/17/2011 tape and reel information
IS31AP4912 integrated silicon solution, inc. ? www.issi.com 9 rev.a, 11/17/2011 packaging information utqfn-12 note: all dimensions in millimeters unless otherwise stated.
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