analog products division 561 e. elliot road #175 chandler, az 85225 tel: (480) 539-2900. fax: (602) 431-2288 www.protekanalog.com 69 PA4101 punk with p supervisor 95000 rev. 0. 01/08 not for use in life support systems features ? precision supply voltage monitoring ? reset timeout delay ? 36db mute attenuation ? 2.7v to 5.5v single-supply operation ? esd protected outputs ? low supply current ? soft mute out for driving additional channels ? soic 14 applications ? set-top boxes ? cell phones ? pda?s ? portable dvd players ? portable mp3 players ? notebook audio ? critical p power monitoring pin layout functional diagram typical application general description the PA4101 is a low power monolithic cmos mixed signal device. its function is to control power supply transition noise in audio circuits and systems. it requires very few external components for its operation and works from low to medium power supply voltages of 2.7v to 5.5v. as the power supply ramps on or off, the PA4101 ensures that audio inputs to succeeding amplifiers are switched to a convenient low impedance voltage rail. this causes the amplifiers to remain silent as the power supply changes state (from on to off and vice versa). also included in the device is a digital control pin which can be used by a control device such as a micro controller or a micro- processor or any other digital controller to enable the audio mute function. this supervisory circuit provides maximum flexibility for monitoring power supplies and battery controlled functions in systems without backup batteries. a reset is asserted during power up, power down and brownout conditions. reset is guaranteed down to vcc of 1.0v. low line output. the early warning indicator goes low when the supply voltage drops to a value 2% higher than the reset threshold voltage the PA4101 consumes less than 50 a of supply current while providing more than 36db of mute attenuation at the audio lines. esd (human body model) protection circuitry on the outputs protects the PA4101 and dev ices further up the signal chain. the PA4101 is available as a 14l soic package and is specified for operation over t he -40c to +85c temperature range. 95000 1 2 3 4 5 6 7 14 13 12 11 10 9 8 reset reset v cc mcuv cc r cs mute cont gnd mute 1 mute 2 smute out chip op c ext nc nc p mute control 6 5 14 8 3 12 9 10 c1 0.1f c3 0.5f c4 47f c5 47f r2 220 ? r4 220 ? r3 10k ? r5 10k ? PA4101 mute1 mute2 right input left input left output right output vcc vcc smuteout rset rst p v cc chip op 13 1 2 4 c2 10f r1 500k ? c ext rcs
analog products division 561 e. elliot road #175 chandler, az 85225 tel: (480) 539-2900. fax: (602) 431-2288 www.protekanalog.com 70 PA4101 punk with p supervisor 95000 rev. 0. 01/08 not for use in life support systems absolute maximum ratings sustained operation at or above the following ratings is not reco mmended. catastrophic and irreversible damage will occur to th e device at or above these ratings. symbol description rating v x voltage at any pin -0.3 to 7.0+0.3 v i x current at any pin 500ma t a ambient temperature 150 c t s storage temperature 200 c t sol soldering temperature 270 c recommended operating conditions: unless otherwise specified, vdd=2.710%, ta = ambient temperature = 25 deg c. dc operating conditions limit symbol parameter condition min typ max unit v dd positive power supply operating 2.7 5.5 v i dd vdd current operating 1 ma t a ambient temperature operating -30 85 c v oh logic high o/p voltage ioh=100 a vdd-0.1 v v ol logic low o/p voltage iol=-100 a 0.2 v v ih logic high i/p voltage iih=1 a vdd-0.3 v v il logic low i/p voltage iil=1 a 0.3 v r on fet on resistance vdd=2.7v, vdfet=0.4v 1.5 ? supervisor operating conditions limit symbol parameter condition min typ max unit v rst reset voltage operating 2.5 v v rsth reset threshold vdd falling -40 to 85 degc -2.5 2.5 % v hys reset threshold hysteresis vdd=2.7v 17 29 mv v hys reset threshold hysteresis vdd=5.5v 36 60 mv t rd vdd ? reset delay vdd falling at 1mv/ s 20 s t rp reset time out period 44 75 ms
analog products division 561 e. elliot road #175 chandler, az 85225 tel: (480) 539-2900. fax: (602) 431-2288 www.protekanalog.com 71 PA4101 punk with p supervisor 95000 rev. 0. 01/08 not for use in life support systems mute operating conditions limit symbol parameter condition min typ max unit m offd mute release delay mute control=vil set by ext. capacitor cm 10 300 ms m std soft mute fall/rise time mute control transitions to vih. set by ext. capacitor cext 1 300 ms m pdel mute on delay power drops by 10% 5 s nfetv nfet open drain volt 12 v pin out pin name function 1 reset inverted reset output from the voltage supervisor 2 reset reset output from the voltage supervisory circuit. 3 vcc positive power supply. 2.7v to 5.5v 10% 4 mcuvcc microprocessor power supply 5 rcs power on mute delay resistor-capacitor connection. 6 mutecont mute control signal from microprocessor. 8 gnd ground. 9 mute1 open drain output of nfet 1 10 mute2 open drain output of nfet 2 12 smuteout soft mute out for multiple channels. 13 chipop supply voltage selector. conne ct to gnd for 2.7v, vcc for 5.5v. 14 cext soft mute delay capacitor. operation of supervisor circuit. the reset input of a p initializes the device into a known state. the PA4101 supervisor circuitry asserts a forced reset output to prevent code execution errors during power-up, power-down and brownout conditions. reset is valid for v cc >1volt. once v cc exceeds the threshold, an internal timer maintains the output for the reset period timeout. after this interval, reset goes high. any time v cc drops below the reset threshold, the reset activates. when v cc again rises above the threshold, the internal timer starts. reset holds until v cc exceeds the reset threshold for longer than the re set timeout period. after this time the reset release supervisor application v cc reset gnd r c v in v out v rsth reset v in v out t rp
analog products division 561 e. elliot road #175 chandler, az 85225 tel: (480) 539-2900. fax: (602) 431-2288 www.protekanalog.com 72 PA4101 punk with p supervisor 95000 rev. 0. 01/08 not for use in life support systems timing diagram supervisor theory of operation audio muting startup during startup, the power supply ramps from 0v to vcc. this time is usually in excess of 20ms. as soon as this change in voltage is sensed, punk latches the mute controller outputs to h igh, thus ?muting? the lines. this is the startup operati on (figure 1). the duration for which the controller outputs are latched high can be controlled by an external rc circuit. when the voltage at this rc pin reaches a certain threshold, the mute controller releases the lines (gate voltage is low) and normal operation starts. shutdown during shutdown, the reverse process happens. as the power supply reaches the threshold on its way down, the mute controller again latches the outputs to high, thus ?muting? the lines (figure 2). this muting prevents unwanted signal spikes from getting to the power amplifiers. however, for optimal performance, it is suggested to mute the lines using the mutecont signal before power down. this process will ensure that the pop noise involved during shutdown is diminished softmute during normal operation, punk is in off state. but if there arises a situation when the audio lines need to be muted, the designer can do this by asserting the mutecont signal to high. this will initiate a softmute sequence (figure 3). when the mutecont signal is asserted, the mute controller gradually ramps the control voltages in a ?soft? fashion so as to provide a soft mute operation. the mute delay is fully controllable by the designer by using an external capacitor at cext. typical values of cext are between 0.1 f and 0.5 f. the reverse happens when the mutecont signal is released. this operation is explained in detail in the application circuit section. figure 1: startup pop-noise reduction figure 2: shutdown pop-noise reduction figure 3: soft mute operation v cc v rst v rsth t rp t rd t rp reset
analog products division 561 e. elliot road #175 chandler, az 85225 tel: (480) 539-2900. fax: (602) 431-2288 www.protekanalog.com 73 PA4101 punk with p supervisor 95000 rev. 0. 01/08 not for use in life support systems v cc r cs gnd mutecont mute 1 mute 2 c16 10f c12 1f c14 10f r15 10k r16 10k r14 22k r13 240k c13 10f c15 10f r17 100 ? r19 100 ? r21 10k d1 u2 74ls04 smuteout cext r18 10k r20 10k line out left line out right v cc 3.3v function. generator 1v ptp 1khz sine wave v.s. 1 s1 3 5 6 9 10 12 8 14 typical application audio muting. notes: 1. a set top box audio output is ?sim ulated? using c14, r15, r16 and vs 1. 2. vs 1 is a signal generator having an output impedance of 50ohm. 3. u2 is the ic 74ls04. 4. u2 runs off of punk vcc (output of d1, c16 and r14). 5. input to u2 is the set top box vcc 6. switch s1 serves as a manual ?audio mute? to enable the muting function. 7. scope probes were attached to set top box power supply and line out. 8. waveform shown in figure 4 to figure 9
analog products division 561 e. elliot road #175 chandler, az 85225 tel: (480) 539-2900. fax: (602) 431-2288 www.protekanalog.com 74 PA4101 punk with p supervisor 95000 rev. 0. 01/08 not for use in life support systems figure 4: startup pop-noise without punk figure 5: shutdown pop-noise without punk figure 6: startup pop-noise with punk figure 7: shutdown pop-noise with punk figure8: audio mute enable figure 9: audio mute disable
analog products division 561 e. elliot road #175 chandler, az 85225 tel: (480) 539-2900. fax: (602) 431-2288 www.protekanalog.com 75 PA4101 punk with p supervisor 95000 rev. 0. 01/08 not for use in life support systems package layout and dimensions life support policy protek analog's products are not authorized for use as critical components in life support devices or systems without the express written approval of the president of protek devices inches dim min typ min p1 0.337 0.341 0.346 p2 0.230 0.238 0.244 p3 0.060 0.065 0.070 p4 0.150 0.155 0.157 l1 0.014 0.016 0.019 l2 0.007 0.009 0.010 l3 0.023 0.026 0.029 p 0.050 0.050 0.050 g 0.004 0.006 0.008 l1 p1 p2 p3 g p l2 top view side view p4 l3 end view 0.245? min 0.030? 0.005? 0.160? 0.005? 0.045? 0.005? 0.050? typ recommended pattern layout
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