? 652 5- 030 71 3- 1 featur es: ? power derived from 3.0v lithiu m battery ? v dd operating range 2.3v to 3.6v ? 25 a maximum quiescent current (LS6525) ? 30 a maximum quiescent current (ls6526) ? direct interface with pir sensor ? analog signa l an d digital interrupt signal outputs f o r interfacing with a mcu ? 2.175v regulated output ? low battery indicator output (ls6526) ? LS6525 (dip), l s 6525-s (soi c) ls6526 (dip), l s 6526-s (soi c) applications: the low operating voltage and low current drain make the ls65 25 / ls6526 ideal for microcontroller based portable application s such as battery operate d motion detectors and photographic equipment, automatic doors, intrusion detecti on, and anywhere electric outlets are not available . descriptio n: the LS6525 / ls6526 is a cmos integrated circuit designe d fo r detecting motion from a pir sen s or and is micro c ontroller interface ready. it uses a 3.0v li battery as a source of energy fo r its operation. the detailed de scrip tion of the functional b l ocks is as follows (refer to figure 2). amplifiers the input pir p r eamplifier, amp1, has a nominal gain set at 2 9v/v using internal resistors. an int e rnal bias is u s ed so that amp1o output has a q u iescent voltag e of 1.1v. the output of the pir amplifier is ac coupled to a second amplifier (amp2) which uses external components to set the gain. this secon d stage is internally biased and applied to a window comparator which has lower and higher trip levels set with respe c t to that bias. external compo nents are used to set a typical gain of 22v/v. amplifie d signals greater in magnitude than the trip levels will cause an in terrupt signal to be generated at the int open drain output, pin 12. the int output can be pulled to a vo ltage higher than v dd (pin 13). the output of th e pir amplifier i s also ac coupled to an additional amplifier (mcu amplifier) which uses external components to set the gain. an internal bias set the mco output a t 0.5v and external resistors set a typical ga in = 10v/v, the mco o utput signal can be applied to a micr ocontroller input for processing. figure 1 input / outp ut des cript ion pin1 ? pyro input ? non-i n verting input of pir amplifier ac coupled to source of pir signal. pin2 ? vreg output ? this output provides power to the pir sensor circuit an d for all the internal amplifier circuitry. pin3 ? amp1o ou tp ut ? output terminal of the pir amplifier pin4 ? mcp ? 0 . 5v internal bias. (internal use only. no external components.) pin5 ? mcn i n put ? inverting input to the mcu amplifier. pin6 ? mco o u tp ut ? output of the mcu amplifier. battery powered low-power pir sensor interface ma r 2013 LS6525 ls6526 pin assign m e nt http://
? 652 5- 030 71 3- 2 pin7 ? v1p1 ? internally biased to 1.1v and applied to non-inverting input of amp2. requires an external bypass capacitor. pin8 ? amp2n ? inverting input of amp2 amplifier. pin9 ? amp2o ? output of the amp2 amplifier. pin10 ? nc ? for LS6525. pin10 ? lobat output ? for l s 6526 only. open drain output re quiring an external pull- up resisto r to a power-supply that can be h i gher than v dd . an active low at the output signifies that a low battery condition exists. pin11 ? test ? this pin is not u s ed and must be tied to ground. pin12 ? int output ? open drai n output requiring an external pull-up resist or to a power supply that can be higher than v dd . a recognized interrupt signal will be an active low at this output. pin13 ? vdd ? power supply voltage pin14 ? vss ? power supply ground
? 652 5- 030 71 3- 3 absolute m a ximum rati ngs: parameter symbol value unit dc supply voltage v dd +7 v input voltage v in v ss - 0.3 to v dd + 0.3 v operating temperature t a -40 to +70 c storage temperature t stg -65 to +150 c electrical characteristics: (all voltages referenced to v ss , t a = 25 c, v dd = 2.3v - 3.6v, unless otherwise specified.) parameter symbol min typ max unit conditions supply current: v dd = 2.3v ? 3.6v i dd - - 25 a LS6525, no load@vreg i dd 30 a ls6526, no load@vreg regu la to r: voltage v r 2.13 2.175 2.22 v source current capability i r - - 25 a amplifie rs: pir amplifier gain g p 28 29.5 32 v/v vi /p 1mv p- p , 10hz r l = no load to 3m input impedance r p 2 m mcu amplifier / amp2 open loop gain g m 70 db mco output qui e scent voltage v q 0.48 0.5 0.52 v amp2 internal reference v ir 1.1 v window -comparator amplifier input sensitivity to int output v s 120 v p amp1 and amp2 cascaded for net gain = 675v/v comparator v lo, thresho l d 1.02 v v hi, threshol d 1.18 v int ou tp ut v ol , int 0.1 v r pull-u p = 2m , v pull -up = 3.6v v pull -up 5.5 v lo bat trip voltage v trip 2.45 v hysteresis hys 0.1 v v ol, lobat 0.1 v r pull-u p = 2m , v pull -up = 3.6v v pull -up 5.5 v
? 652 5- 030 71 3- 4 fi gure 2 block diag ram
? 652 5- 030 71 3- 5 l1 68 nh c1 1 f c 2 1 f r1 2 m c3 1 f r2 10 k c4 4 7 pf r3 4. 7m c5 4 7 pf r4 44 2k c6 3.3 f r5 1 m c7 1 f r6 10m c8 3. 3nf r7 10 0k c9 0. 16 f r8 2 m c10 1 0 f r9 10 m r10 10 0k b1 typical battery used: 3v cr1 23a li thium pir exceli t as lhi96 8 pyr o ( t ypical ) fig u re 3 applica t i on schema t ic f o r ls6 526. for the ls65 2 5 , pin 10 has n o co nnec tion. the gain of a m p2 i s se t u s i ng r6 a nd r4 to a no minal g a in o f 22 v/v. t h e mcu am plif ier gain is set to 1 0 v/v usin g r9 and r5. r1 0-c 9 and r7- c 8 ar e addi tional filt er stages for the mco and int outputs whe n applied t o th e microc ont rolle r.
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