1 version 1. 1 | 1 3 s ep 2015 | 30000en pixart imaging inc. http://www.pixart.com all rights reserved. any portion in this paper shall not be reproduced, copied, or transformed to any other forms without permission. pah8001e i - 2g product brief optical heart rate detection sensor pixart imaging inc. pah8001ei- 2g : optical heart rate detection sensor general description the PAH8001EI-2G is a high performance and low power cmos-processed optical sensor with green led and integrated digital signal processor serving as a heart rate detection sensor. it is based on optical technology which measures the variation of human blood movement in the vessel and using this measured data to estimate heart beat rate. key features ? heart rate detection function ? ultra-low power consumption with power saving modes during no touch movement period ? lpt sleep1 ? lpt sleep2 ? flexible sleep rate control ? flexible communication interface ? i 2 c ? 4-wire spi ? 2-wire spi ? i 2 c interface up to 1 mbit/s ? spi interface up to 1 mbit/s ? hardware reset support ? hardware power down support ? integrated chip- on -board led with wavelength of 525nm applications ? healthcare/sports wearable device ? photoplethysmogram waveform ? smart wearable eg . watch, wrist-band key parameters parameter value operating junction temp e rature ( c ) - 20 to +60 interfaces i2c, 2 - wire spi, 4 - wire spi input clock (mhz) 6. 8mhz supply voltage (v) v ddm : 3.3 C 3.6 v ddio : 1.62 C 3.6 average supply current (ma) note: including led current without i/o toggling run: 1.5 sleep1: 0.16 sleep2: 0.04 power down: 0.015 frame rate (fps) up to 3000 heart rate measurement range (bpm) 30 - 210 package size (mm) 3.0 x 4.7 x 1.0 ordering information part number package type pah8001ei - 2g 16 - pin lga package for any additional inquiries, please contact us at http://www.pixart.com/contact.asp pixart confidential
2 pixart imaging inc. pah8001ei - 2g optical heart rate detection sensor version 1. 1 | 1 3 s ep 2015 | 30000en pixart imaging inc. http://www.pixart.com all rights reserved. any portion in this paper shall not be reproduced, copied, or transformed to any other forms without permission. 1.0 system overview the heart rate detection of pah8001 is based on optical measurement technique that uses a light source and a detector to detect cardio-vascular pulse wave that propagates through body. the detected signal (pulse wave) is called photoplethysmography and its acronym in some literatures is ppg or ptg. the ppg signal reflects the blood movement in the vessel, which goes from the heart to the fingertips through the blood vessels in a wave-like motion. therefore, we can use this ppg signal to estimate heart rate. this optical based technology could offer significant benefits to healthcare application as it is noninvasive yet accurate and simple to use. 1.1 block diagram figure 1 . p ah8001 functional block diagram figure 2 . system block diagram cmos image sensor digital signal processor & algorithm power on reset led driver control register sck sdio oscillator voltage regulator and power control vddm 4-wire spi interface vdd 18 v touch/ wake up sci serial interface csn_ id 1 sdi_ id 0 sck sdio 2-wire spi interface vdd 28 v vddio sck sdio i2c interface vss green led pixart confidential
3 pixart imaging inc. pah8001ei - 2g optical heart rate detection sensor version 1. 1 | 1 3 s ep 2015 | 30000en pixart imaging inc. http://www.pixart.com all rights reserved. any portion in this paper shall not be reproduced, copied, or transformed to any other forms without permission. 2.0 signal description figure 3 . pin configuration table 1 . pah8001 signal pins description pin no. signal name type description functional group: power supplies 1 led_p power led anode . provide vddm supply voltage 2 vdd28v output analog circuit power regulator output . must connect a 0.1 f capacitor to gnd 3 vss ground chip g round 4 vdd18v output analog and digital circuit power regulator output . must connect a 0.1 f capacitor to gnd 10 vddm power power supply for internal power regulator . vddm: 3.3 C 3.6 v 12 vddio power i/o power supply. v ddio : 1.62 C 3.6 v 16 led_n led led cathode . must connect to led functional group: control interface 9 sdio bidir 4 - w ire spi: data output pin 2 - w ire spi: data in - out pin i 2 c: data in - out pin 11 csn_id1 input 4 - w ire spi: chip select (active low) i 2 c: address set id1 (tri state io) 13 sdi_id0 input 4 - w ire spi: data input pin i 2 c: address set id0 (tri - s tate io) 15 sck input 2 - w ire spi/ 4 - w ire spi/ i 2 c: serial c lock pin functional group: functional i/o 5 sci output touch o n/ o ff int (active h igh) 6 reset_n input hardware control to enter r eset mode level high: exit r eset mode level low: e nter r eset mode set to high when not us ing pixart confidential
4 pixart imaging inc. pah8001ei - 2g optical heart rate detection sensor version 1. 1 | 1 3 s ep 2015 | 30000en pixart imaging inc. http://www.pixart.com all rights reserved. any portion in this paper shall not be reproduced, copied, or transformed to any other forms without permission. pin no. signal name type description 7 pd input hardware control to enter p ower d own mode with internal 1m ? pull - down resistor level high: enter power down mode level low: leave power down mode set to low when not us ing 8 led output led driver connection. must connect to led_n 14 mdsel input tri state io . for mode select ion of 2 - wire spi, 4 - w i re spi or i 2 c i 2 c: pull down . tie to gnd 4 - w ire spi: floating 2 - w ire spi: pull high . tie to vddio 3.0 mechanical dimensions figure 4 . package outline diagram pixart confidential
5 pixart imaging inc. pah8001ei - 2g optical heart rate detection sensor version 1. 1 | 1 3 s ep 2015 | 30000en pixart imaging inc. http://www.pixart.com all rights reserved. any portion in this paper shall not be reproduced, copied, or transformed to any other forms without permission. 4.0 reference schematics figure 5 . application circuit of pah8001 design notes 1. vddm & vddio = 3.3v~3.6v (for 3.3v system). 2. v ddm = 3.3v~3.6v, vddio: 1.62v~1.98v (for 1.8v system). 3. connect r1 and r2 for i2c only. 4. vdd28v and vdd18v must have 0.1f bypass capacitor connected to gnd. 5. sci can connect to mcu hw int as touch int for power saving (active high). 6. vddm and vddio power noise must be under 100mv. 7. tie mdsel to vddio for 2-wire spi, floating for 4-wire spi, and gnd for i 2 c. 8. id0 and id1 can be directly tied to vddio or gnd based on your i 2 c id selection. 9. led pin must pull high with 100k resistor to vddm for internal circuit voltage reference 10. at power on, vddm and vddio must be power ed on at the same time or vddio to be power ed on first before vddm. 11. at power off, vddm and vddio must be power ed off at the same time or vddio to be power ed off first before vddm. pixart confidential
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