?2010-2015 by murata electronics n.a., inc. RX5501 (r) 4/15/15 page 1 of 10 www.murata.com rfm products are now murata products. ? designed for short-range wireless control applications ? 3 v, low current operation plus sleep mode ? characterized for automotive applications ? high emi rejection capability ? complies with directive 2002/95/ec (rohs) the RX5501 hybrid receiver is ideal for short-range wi reless control applications where robust operation, small size, low power consumption and low cost ar e required. the RX5501 employs murata?s amplifier- sequenced hybrid (ash) architecture to achieve this unique blend of characteri stics. all critical rf functions are contained in the hybrid, simplifying and speeding des ign-in. the RX5501 is sensitive and stable. a wide dynamic range log detector pr ovides robust performance in the pres ence of on-channel interference or noise. two stages of saw filtering provide excellent rece iver out-of-band rejection. the RX5501 generates virtually no rf emissions, facilitati ng compliance with fcc part 15 and similar regulations. absolute maximum ratings rating value units power supply and all input/output pins -0.3 to +4.0 v non-operating case temperature -50 to +100 c soldering temperature (10 seconds / 5 cycles max.) 260 c 315.00 mhz hybrid receiver RX5501 sm-20l case electrical characteristics characteristic sym notes minimum typical maximum units operating frequency f o 314.80 315.20 mhz modulation types ook & ask data rate 19.2 kbps receiver performance, high sensitivity mode sensitivity, 1.2 kbps, 10-3 ber, am test method 1 -110.5 dbm sensitivity, 1.2 kbps, 10-3 ber, pulse test method 1 -104.5 dbm current, 1.2 kbps (r pr = 330 k) 2 2.9 ma sensitivity, 2.4 kbps, 10-3 ber, am test method 1 -109 dbm sensitivity, 2.4 kbps, 10-3 ber, pulse test method 1 -103 dbm current, 2.4 kbps (r pr = 330 k) 2 3.0 ma sensitivity, 19.2 kbps, 10-3 ber, am test method 1 -105 dbm sensitivity, 19.2 kbps, 10-3 ber, pulse test method 1 -99 dbm current, 19.2 kbps 3.1 ma receiver performance, low current mode sensitivity, 1.2 kbps, 10-3 ber, am test method 1 -104 dbm sensitivity, 1.2 kbps, 10-3 ber, pulse test method 1 -98 dbm current, 1.2 kbps (r pr = 2000 k) 2 1.65 ma
?2010-2015 by murata electronics n.a., inc. RX5501 (r) 4/15/15 page 2 of 10 www.murata.com electrical characteristics (typical values given for 3.0 vdc power supply, 25 c) characteristic sym notes minimum typical maximum units receiver out-of-band rejection, 5% fo r 5% 380db receiver ultimate rejection r ult 3 100 db sleep mode current i s 0.7 a power supply voltage range v cc 2.2 3.7 vdc power supply voltage ripple 10 mv p-p ambient operating temperature t a -40 85 c 1. typical sensitivity data is based on a 10 -3 bit error rate (ber), using dc-balanced data. there are two test methods commonly used to measure ook/ask receiver sensitivity, the ?100% am? test method and the ?pulse? test method. sensitivity data is given for both test methods. s ee appendix 3.8 in the ash transceiver designer?s guide for the details of each test method, and for sensitivity curves for a 2.2 to 3.7 v supply voltage range at five operating temperatures. the application/test circuit and component values are shown on the next page and in the designer?s guide . 2. at low data rates it is possible to adjust the ash pulse generator to trade-off some receiver sensitivity for lower operating current. sensitivity data and receiver current are given at 1.2 kbps for both high sensitivity operation (r pr = 330 k) and low current operation (r pr = 2000 k). 3. data is given with the ash radio matched to a 50 ohm load. matching component values are given on the next page. 4. see table 1 on page 8 for additional information on ash radio event timing. dimension mm inches min nom max min nom max a 10.795 10.922 11.049 .425 .430 .435 b 9.525 9.652 9.779 .375 .380 .385 c 1.778 1.905 2.032 .070 .075 .080 d 3.048 3.175 3.302 .120 .125 .130 e 0.381 0.508 0.635 .015 .020 .025 f 0.889 1.016 1.143 .035 .040 .045 g 3.175 3.302 3.429 .125 .130 .135 h 1.778 1.905 2.032 .070 .075 0.80 3 4 5 6 7 9 11 12 13 14 15 16 17 19 ash transceiver pin out rfio 8 2 10 20 1 18 lpfadj rref thld2 agccap pkdet bbout cmpin rxdata txmod thld1 prate pwidth gnd1 vcc1 gnd2 vcc2 gnd3 cntrl0 cntrl1 sm-20l package drawing cd e f g a b h caution: electrostatic sensitive device . observe precautions for handling. notes:
?2010-2015 by murata electronics n.a., inc. RX5501 (r) 4/15/15 page 3 of 10 www.murata.com data output top view gnd 3 cnt rl0 cnt rl1 p width p rate thld 1 nc rref gnd2 nc rx data lpf adj cmp in bb out pk det rf a1 vcc 1 vcc 2 rfio gnd1 + 3 vdc ash receiver application circuit ook configuration 1 20 23456789 10 11 12 13 14 15 16 17 18 19 + 3 vdc r pw r pr r th1 r ref r lpf c bbo c dcb l at l esd c rfb1 + r/s c lpf r bbo receiver set-up, 3.0 vdc, -40 to +85 c item symbol ook ook ask units notes nominal nrz data rate dr nom 1.2 2.4 19.2 kbps see page 1& 2 minimum signal pulse sp min 833.33 416.67 52.08 s single bit maximum signal pulse sp max 3333.33 1666.68 208.32 s 4 bits of same value bbout capacitor c bbo 0.2 0.1 0.015 f 10% ceramic bbout resistor r bbo 12 12 0 k 5% lpfaux capacitor c lpf 0.01 0.0047 - f 5% lpfadj resistor r lpf 330 300 100 k 5% rref resistor r ref 100 100 100 k 1% thld1 resistor r th1 0 0 0 k 1%, typical values prate resistor r pr 330 330 330 k 5% pwidth resistor r pw 270 to gnd 270 to gnd 270 to gnd k 5% dc bypass capacitor c dcb 4.7 4.7 4.7 f tantalum rf bypass capacitor 1 c rfb1 100 100 100 pf 5% npo antenna tuning inductor l at 82 82 82 nh 50 ohm antenna shunt tuning/esd inductor l esd 33 33 33 nh 50 ohm antenna
?2010-2015 by murata electronics n.a., inc. RX5501 (r) 4/15/15 page 4 of 10 www.murata.com ash receiver block di agram & timing cycle antenna pulse generator saw delay line saw filter rfa1 rfa2 data out detector & low-pass filter rf data pulse p1 p2 rfa1 out rf input p1 delay line out p2 t pw2 t pw1 t pri t prc figure 1 ash receiver theory of operation introduction murata?s rx5500 series amplifier-sequenced hybrid (ash) receivers are specifically designed for short-range wireless control and data communication applic ations. the receivers provide robust operation, very small size, low power consumption and low implementation cost. all critical rf functions are contained in the hybrid, simplifying and speeding design-in. the ash receiver can be readily configured to support a wide range of data rates and protocol requirements. the receiv er features virtually no rf emissions, making it easy to certify to short-range (unlicensed) radio regulations. amplifier-sequenced receiver operation the ash receiver?s unique feature set is made possible by its system architecture. the heart of the receiver is the amplifier- sequenced receiver section, whic h provides more than 100 db of stable rf and detector gain without any special shielding or decoupling provisions. stability is achieved by distributing the total rf gain over time . this is in contrast to a superheterodyne receiver, which achieves stability by distributing total rf gain over multiple frequencies. figure 1 shows the basic block diagram and timing cycle for an amplifier-sequenced receiver. note t hat the bias to rf amplifiers rfa1 and rfa2 are independently controlled by a pulse generator, and that the two amplif iers are coupled by a surface acoustic wave (saw) delay line, which has a typical delay of 0.5 s. an incoming rf signal is first f iltered by a narrow-band saw filter, and is then applied to rfa1. the pulse generator turns rfa1 on for 0.5 s. the amplified signal from rfa1 emerges from the saw delay line at the input to rfa2. rfa1 is now switched off and rfa2 is switched on for 0.55 s, amplifying the rf signal further. the on time for rfa2 is usually set at 1.1 times the on time for rfa1, as the filtering effect of the saw delay line stretches the signal pulse from rfa1 somewhat. as shown in the timing diagram, rfa1 and rfa2 are never on at the same time, assuring excellent receiver stability. note that the narrow-band saw filter eliminates sampling sideband responses outside of the receiver passband, and the saw filter and delay line act together to provide very high receiver ultimate rejection. amplifier-sequenced receiver operation has several interesting characteristics that can be expl oited in system design. the rf amplifiers in an amplifier-sequenced receiver can be turned on and off almost instantly, allowing for very quick power-down (sleep) and wake-up times. also, both rf amplifiers can be off between on sequences to trade-off receiver noise figure for lower average current consumption. the effect on noise figure can be modeled as if rfa1 is on continuously, with an attenuator placed in front of it with a loss equivalent to 10*log 10 (rfa1 duty fact or), where the duty factor is the average amount of time rfa1 is on (up to 50%).
?2010-2015 by murata electronics n.a., inc. RX5501 (r) 4/15/15 page 5 of 10 www.murata.com figure 2 since an amplifier-sequenced receiver is inherently a sampling receiver, the overall cycle time be tween the start of one rfa1 on sequence and the start of the next rfa1 on sequence should be set to sample the narrowest rf data pulse at least 10 times. otherwise, significant edge jitter will be added to the detected data pulse. rx5500 series ash receiver block diagram figure 2 is the general block diagram of the rx5500 series ash receiver. please refer to figure 2 for the following discussions. antenna port the only external rf components needed for the receiver are the antenna and its matching components. antennas presenting an impedance in the range of 35 to 72 ohms resistive can be satisfactorily matched to the rfio pin with a series matching coil and a shunt matching/esd pr otection coil. other antenna impedances can be matched using two or three components. for some impedances, two inductors and a capacitor will be required. a dc path from rfio to ground is required for esd protection. receiver chain the output of the saw f ilter drives amplifier rfa1. the output of rfa1 drives the saw delay line, which has a nominal delay of 0.5 s. the second amplifier, rfa2, provides 51 db of gain below saturation. the output of rfa2 driv es a full-wave detector with 19 db of threshold gain. the onset of saturation in each section of rfa2 is detected and summed to provide a logarithmic response. this is added to the output of the full-wave detector to produce an overall detector response that is square law for low signal levels, and transitions into a log response for high signal levels. this combination provides excellent th reshold sensitivity and more than 70 db of detector dynamic range. in combination with the 30 db of agc range in rfa1, more than 100 db of receiver dynamic range is achieved. the detector output drives a gyrato r filter. the filter provides a three-pole, 0.05 degree equiripple low-pass response with excellent group delay flatness and minimal pulse ringing. the 3 db bandwidth of the filter can be set from 4.5 khz to 1.8 mhz with an external resistor. the filter is followed by a ba se-band amplifier which boosts the detected signal to the bbout pin. when the receiver rf amplifiers are operating at a 50%-50% duty cycle, the bbout signal changes about 10 mv/db, with a peak-t o-peak signal level of up to 685 mv. for lower duty cycles, the mv/db slope and peak-to-peak signal level are proportionately less. the detected signal is riding on a 1.1 vdc level that varies somewhat with supply voltage, temperature, etc. bbout is coupled to the cmpin pin or to an external data recovery process (dsp, etc.) by a series capacitor. the correct value of the series capacitor depends on data rate, data run length, and other factors as discussed in the ash transceiver designer?s guide . when the receiver is placed in the power-down (sleep) mode, the output impedance of bbout becomes very high. this feature helps preserve the charge on the coupling capacitor to minimize data slicer stabilization time when the receiver switches out of the sleep mode. data slicers the cmpin pin drives data slicer ds1, which convert the analog signal from bbout back into a digital stream. data slicer ds1 is a capacitively-coupled comparator with provisions for an adjustable threshold. the threshold, or squelch, offsets the comparator?s rx5500 series ash receiver block diagram rfa1 rfa2 saw delay line saw cr filter log antenna rfio esd choke detector low-pass filter bb pulse generator & rf amp bias lpfadj prate pwidth rxdata cntrl1 cntrl0 r ref thld1 bias control power down control threshold control bbout ds1 ref thld c bbo r lpf r pr r pw r th1 20 17 18 14 15 9 56 13 vcc1: pin 2 vcc2: pin 16 gnd1: pin 1 gnd2: pin 10 gnd3: pin 19 nc: pin 8 rref: pin 11 cmpin: pin 6 nc: pin 4 nc: pin 12 rfa1 3 7 11 rref
?2010-2015 by murata electronics n.a., inc. RX5501 (r) 4/15/15 page 6 of 10 www.murata.com slicing level from 0 to 90 mv, a nd is set with a resistor between the rref and thld1 pins. this threshold allows a trade-off between receiver sensitivity and output noise density in the no-signal condition. for best sensit ivity, the threshold is set to 0. in this case, noise is output continuously when no signal is present. this, in turn, requires the circuit being driven by the rxdata pin to be able to process noise (and signals) continuously. this can be a problem if rxdata is driving a circuit that must ?sleep? when data is not present to conserve power, or when it its necessary to minimize false interr upts to a multitasking processor. in this case, noise can be greatly reduced by increasing the threshold level, but at the expens e of sensitivity. the best 3 db bandwidth for the low-pass filter is also affected by the threshold level setting of ds1. the bandwidth must be increased as the threshold is increased to minimize data pulse-width variations with signal amplitude. receiver pulse generato r and rf amplifier bias the receiver amplifier-sequence op eration is controlled by the pulse generator & rf amplifier bi as module, which in turn is controlled by the prate and pwidth input pins, and the power down (sleep) control signal from the bias control function. in the low data rate mode, the interval between the falling edge of one rfa1 on pulse to the rising edge of the next rfa1 on pulse tpri is set by a resistor between the prate pin and ground. the interval can be adjusted between 0.1 and 5 s. in the high data rate mode (selected at the pwidth pi n) the receiver rf amplifiers operate at a nominal 50 %-50% duty cycle. in this case, the start- to-start period tprc for on pulses to rfa1 are controlled by the prate resistor over a range of 0.1 to 1.1 s. in the low data rate mode, the pw idth pin sets the width of the on pulse t pw1 to rfa1 with a resistor to ground (the on pulse width t pw2 to rfa2 is set at 1.1 time s the pulse width to rfa1 in the low data rate mode). the on pulse width t pw1 can be adjusted between 0.55 and 1 s. however, when the pwidth pin is connected to vcc through a 1 m resi stor, the rf amplifiers operate at a nominal 50%-50% duty cycle, facilitating high data rate operation. in this case, the rf amplifiers are controlled by the prate resistor as described above. both receiver rf amplifiers are turned off by the power down control signal, which is invoked in the sleep mode. receiver mode control the receiver operating modes ? receive and power-down (sleep), are controlled by the bias control function, and are selected with the cntrl1 and cntrl0 control pins. setting cntrl1 and cntrl0 both high place the unit in the receive mode. setting cntrl1 and cntrl0 both low place the unit in the power-down (sleep) mode. cntrl1 and cntrl0 are cmos compatible inputs. these inputs must be held at a logic level; they cannot be left unconnected. receiver event timing receiver event timing is summarized in table 1. please refer to this table for the following discussions. turn-on timing the maximum time t pr required for the receive function to become operational at turn on is influenc ed by two factors. all receiver circuitry will be operational 5 ms after the supply voltage reaches 2.2 vdc. the bbout-cmpin coupling-capacitor is then dc stabilized in 3 time constants (3* tbbc ). the total tu rn-on time to stable receiver operation for a 10 ms power supply rise time is: t pr = 15 ms + 3*t bbc sleep and wake-up timing the maximum transition time from the receive mode to the power- down (sleep) mode t rs is 10 s after cntrl1 and cntrl0 are both low (1 s fall time). the maximum transition time t sr from the sleep mode to the receive mode is 3*t bbc , where t bbc is the bbout-cmpin coupling-capacitor time constant . when the operating temperature is limited to 60 c, the time required to switch from sleep to receive is dramatically less for short sleep times, as less charge leaks away from the bbout- cmpin coupling capacitor. pulse generator timing in the low data rate mode, the interval t pri between the falling edge of an on pulse to the first rf am plifier and the rising edge of the next on pulse to the first rf amplifier is set by a resistor r pr between the prate pin and ground. the interval can be adjusted between 0.1 and 5 s with a resistor in the range of 51 k to 2000 k. the value of the r pr is given by: r pr = 404* t pri + 10.5, where t pri is in s, and r pr is in kilohms in the high data rate mode (selected at the pwidth pin) the receiver rf amplifiers operate at a nominal 50%-50% duty cycle. in this case, the period t prc from the start of an on pulse to the first rf amplifier to the start of the next on pulse to the first rf amplifier is controlled by the prate resistor over a range of 0.1 to 1.1 s using a resistor of 11 k to 220 k. in this case r pr is given by: r pr = 198* t prc - 8.51, where t prc is in s and r pr is in kilohms in the low data rate mode, the pwidth pin sets the width of the on pulse to the first rf amplifier t pw1 with a resistor r pw to ground (the on pulse width to the second rf amplifier t pw2 is set at 1.1 times the pulse width to the first rf amplifier in the low data rate mode). the on pulse width t pw1 can be adjusted between 0.55 and 1 s with a resistor value in the range of 200 k to 390 k. the value of r pw is given by: r pw = 404* t pw1 - 18.6, where t pw1 is in s and r pw is in kilohms however, when the pwidth pin is connected to vcc through a 1 m resistor, the rf amplifiers operate at a nominal 50%-50% duty cycle, facilitating high data rate ope ration. in this case, the rf amplifiers are controlled by the prate resistor as described above. lpf group delay the low-pass filter group delay is a function of the filter 3 db bandwidth, which is set by a resistor r lpf to ground at the lpfadj pin. the minimum 3 db bandwidth f lpf = 1445/r lpf , where f lpf is in khz, and r lpf is in kilohms. the maximum group delay t fgd = 1750/f lpf = 1.21*r lpf , where t fgd is in s, f lpf in khz, and r lpf in kilohms.
?2010-2015 by murata electronics n.a., inc. RX5501 (r) 4/15/15 page 7 of 10 www.murata.com receiver event timing, 3.0 vdc, -40 to +85 c event symbol time min/ max test conditions notes turn on to receive t pr 3*t bbc + 15 ms max 10 ms supply voltage rise time time until receiver operational sleep to rx t sr 3*t bbc max 1 s cntrl0/cntrol 1 rise times time until receiver operational rx to sleep t rs 10 s max 1 s cntrl0/cntrol 1 fall times t ime until receiver is in power-down mode prate interval t pri 0.1 to 5 s range low data rate mode user selected mode pwidth rfa1 t pw1 0.55 to 1 s range low data rate mode user selected mode pwidth rfa2 t pw2 1.1*t pw1 range low data rate mode user selected mode prate cycle t prc 0.1 to 1.1 s range high data rate mode user selected mode pwidth high (rfa1 & rfa2) t pwh 0.05 to 0.55 s range high data rate mode user selected mode lpf group delay t fgd 1750/f lpf max t fgd in s, f lpf in khz user selected lpf 3 db bandwidth f lpf 1445/r lpf min f lpf in khz, r lpf in kilohms user selected bbout-cmpin time constant t bbc 0.064*c bbo min t bbc in s, c bbo in pf user selected table 1
?2010-2015 by murata electronics n.a., inc. RX5501 (r) 4/15/15 page 8 of 10 www.murata.com pin descriptions pin name description 1 gnd1 gnd1 is the rf ground pin. gnd2 and gnd3 should be connected to gnd1 by s hort, low-inductance traces. 2 vcc1 vcc1 is the positive supply voltage pin for the receiver bas e-band circuitry. vcc1 must be bypassed by an rf capacitor, which may be shared with vcc2. see the descript ion of vcc2 (pin 16) for additional information. 3rfa1 4 nc this pin should be left unconnected. 5 bbout bbout is the receiver base-band output pin. this pin drives the cmpi n pin through a coupling capacitor c bbo for internal data slicer operation. the time constant t bbc for this connection is: t bbc = 0.064*c bbo , where t bbc is in s and c bbo is in pf a 10% ceramic capacitor should be used between bbout and cmpin. the time constant can vary between t bbc and 1.8*t bbc with variations in supply voltage, temperature, etc. the optimum time constant in a given circumstance will depend on the data rate, data run length, and other factors as discussed in the ash transceiver designer?s guide . a common criteria is to set the time constant for no more than a 20% voltage droop during sp max . for this case: c bbo = 70*sp max , where sp max is the maximum signal pulse width in s and c bbo is in pf the output from this pin can also be used to drive an external data recovery proces s (dsp, etc.). the nominal output imped- ance of this pin is 1 k. when the receiver rf amplifiers are operating at a 50%-50% duty cycle, the bbout signal changes about 10 mv/db, with a peak-to-peak signal level of up to 685 mv. for lower duty cycles, the mv/db slope and peak-to-peak signal level are proportionately less. the signal at bbout is riding on a 1.1 vdc value that varies somewhat with supply volt- age and temperature, so it should be coupled through a capaci tor to an external load. a load impedance of 50 k to 500 k in parallel with no more than 10 pf is recommended. when an exte rnal data recovery process is used with agc, bbout must be coupled to the external data recovery process and cmpin by separate series coupling capacitors. the agc reset function is driven by the signal applied to cmpin. when the receiver is in power-down (sleep) mode, the output impedance of this pin becomes very high, preserving t he charge on the coupling capacitor. 6 cmpin this pin is the input to the inter nal data slicers. it is driven from bbout through a coupling capacitor. the input imped ance of this pin is 70 k to 100 k. 7 rxdata rxdata is the receiver data output pi n. this pin will drive a 10 pf, 500 k parallel load. the peak current available fro m this pin increases with the receiver low-pa ss filter cutoff frequency. in the power-down (sleep) mode, this pin becomes high impedance. if required, a 1000 k pull-up or pull-down resistor can be used to establish a definite logic state when this pin is high impedance. if a pull-up resistor is used, the positive su pply end should be connected to a voltage no greater than vcc + 200 mv. 8 nc this pin may be left unconnected or may be grounded. 9 lpfadj this pin is the receiver low-pass filter bandwid th adjust. the filter bandwidth is set by a resistor r lpf between this pin and ground. the resistor value can range from 330 k to 820 ohms, providing a filter 3 db bandwidth f lpf from 4.5 khz to 1.8 mhz. the resistor value is determined by: r lpf = 1445/ f lpf , where r lpf is in kilohms, and f lpf is in khz a 5% resistor should be used to set the filter bandwidth. this will provide a 3 db filter bandwidth between f lpf and 1.3* f lpf with variations in supply voltage, temperature, etc. the filt er provides a three-pole, 0.05 degree equiripple phase response. the peak drive current available from rxdata increas es in proportion to the filter bandwidth setting. 10 gnd2 gnd2 is an ic ground pin. it should be connec ted to gnd1 by a short, low inductance trace. 11 rref rref is the external reference resistor pin. a 100 k re ference resistor is connected between this pin and ground. a 1% resistor tolerance is recommended. it is important to keep t he total capacitance between ground, vcc and this node to less than 5 pf to maintain current source stability. if thld1 and/or thdl2 are connected to rref through resistor values less that 1.5 k, their node capacitance must be added to the rref node capacitance and the total should not exceed 5 pf. 12 nc this pin should be left unconnected. 13 thld1 the thld1 pin sets the threshold for the standard data slicer (ds1) through a resistor r th1 to rref. the threshold is increased by increasing the resistor value. connecting this pin directly to rref pr ovides zero threshold. the acceptable range for the resistor is 0 to 100 k, providing a thld1 range of 0 to 90 mv. the resistor value is given by: r th1 = 1.11*v, where r th1 is in kilohms and the threshold v is in mv a 1% resistor tolerance is recommended for the thld1 resistor.
?2010-2015 by murata electronics n.a., inc. RX5501 (r) 4/15/15 page 9 of 10 www.murata.com 14 prate the interval between the falling edge of an on pulse to th e first rf amplifier and the rising edge of the next on pulse to the first rf amplifier t pri is set by a resistor r pr between this pin and ground. the interval t pri can be adjusted between 0.1 and 5 s with a resistor in the range of 51 k to 2000 k. the value of r pr is given by: r pr = 404* t pri + 10.5, where t pri is in s, and r pr is in kilohms a 5% resistor value is recommended. when the pwidth pin is connected to vcc through a 1 m resistor, the rf amplifiers operate at a nominal 50%-50% duty cycle , facilitating high data rate oper ation. in this case, the period t prc from start-to-start of on pulses to the first rf amplifier is controlled by the prat e resistor over a range of 0.1 to 1.1 s using a resistor of 11 k to 220 k. in this case the value of r pr is given by: r pr = 198* t prc - 8.51, where t prc is in s and r pr is in kilohms a 5% resistor value should also be us ed in this case. please refer to the ash transceiver designer?s guide for additional amplifier duty cycle information. it is important to keep the total capacitance between ground, vcc and this pin to less than 5 pf to maintain stability. pin name description 15 pwidth the pwidth pin sets the width of the on pulse to the first rf amplifier t pw1 with a resistor r pw to ground (the on pulse width to the second rf amplifier t pw2 is set at 1.1 times the pulse width to th e first rf amplifier). the on pulse width t pw1 can be adjusted between 0.55 and 1 s with a resistor val ue in the range of 200 k to 390 k. the value of r pw is given by: r pw = 404* t pw1 - 18.6, where t pw1 is in s and r pw is in kilohms a 5% resistor value is recommended. when th is pin is connected to vcc through a 1 m resistor, the rf amplifiers operate at a nominal 50%-50% duty cycle, facilitating high data rate operation. in this case, the rf amplifier on times are controlled by the prate resistor as described above. it is important to keep the total capacitance between ground, vcc and this node to less than 5 pf to maintain stability. when using the high dat a rate operation with the sleep mode, connect the 1 m resistor between this pin and cntrl1 (pin 17), so this pin is low in the sleep mode. 16 vcc2 vcc2 is the positive supply voltage pin for the receiver rf section. this pin must be bypassed with an rf capacitor, whic h may be shared with vcc1. vcc2 must also be bypassed with a 1 to 10 f tantalum or electrolytic capacitor. 17 cntrl1 cntrl1 and cntrl0 select the receiver modes. cntrl1 and cntrl0 both high place the unit in the receive mode. cntrl1 and cntrl0 both low place the unit in the power-down (sleep) mode. cntrl1 is a high-impedance input (cmos compatible). an input voltage of 0 to 300 mv is interpreted as a logic low. an input voltage of vcc - 300 mv or greater is inte r- preted as a logic high. an input voltage greater than vcc + 200 mv should not be applied to this pin. a logic high requires a maximum source current of 40 a. sleep mode requires a maximu m sink current of 1 a. this pin must be held at a logic level; it cannot be left unconnected. 18 cntrl0 cntrl0 is used with cntrl1 to control the receiver modes. cntrl0 is a high-impedance input (cmos compatible). an input voltage of 0 to 300 mv is interpreted as a logic low. an input voltage of vcc - 300 mv or greater is interpreted as a log ic high. an input voltage greater than vcc + 200 mv should not be ap plied to this pin. a logic high requires a maximum source current of 40 a. sleep mode requires a maximum sink current of 1 a. this pin must be held at a logic level; it cannot be left unconnected. 19 gnd3 gnd3 is an ic ground pin. it should be connec ted to gnd1 by a short, low inductance trace. 20 rfio rfio is the receiver rf input pin. this pin is connected directly to the sa w filter transducer. antennas presenting an im ped- ance in the range of 35 to 72 ohms resistive can be satisfactori ly matched to this pin with a series matching coil and a shunt matching/esd protection coil. other antenna impedances can be matched using two or three components. for some imped- ances, two inductors and a capacitor will be required. a dc pa th from rfio to ground is required for esd protection.
?2010-2015 by murata electronics n.a., inc. RX5501 (r) 4/15/15 page 10 of 10 www.murata.com 0.000 0 . 0 0 0 . 1 4 0 . 2 7 0 . 4 1 0 .0775 .1025 .1175 .1575 .1975 .2375 .2775 .3175 .3575 .3825 .4600 . 1 9 7 5 . 1 7 2 5 . 2 1 2 5 . 2 3 7 5 dimensions in inches sm-20l pcb pad layout note: specifications subject to change without notice.
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