PixArt Imaging Inc. PAH8002EP Product Brief Low Power Optical Heart Rate Detection Sensor PAH8002EP: Low Power Optical Heart Rate Detection Sensor General Description Parameter Operating Temperature, Tj (°C) Array Size Pixel Size (µm) Max Frame Rate (fps) Dynamic Range (dB) Supply Voltage (V) Key Features Value -20 to +60 1 pixel 780 x 780 50K 70 VDDM: 3.3 – 3.6 VDD_LEDx: 3.3 – 3.6 VDDIO: 1.62 – 3.6 Analog: 2.8 Digital: 1.8 Active: 4.95 with one LED 8.25 with two LEDs 0.825 with IR Touch Detection Sleep: 0.08 P Pi re xA li m rt i n C a on ry fid en tia l The PAH8002EP is a low power and high-performance CMOS-processed optical sensor with three LEDs: two Green and one Infrared (IR), and integrated DSP, targeted as a Heart Rate Detection (HRD) sensor. It is based on optical sensing technology that captures higher resolution image than the traditional photodiode. The images are then processed through our integrated DSP to attain processed PPG (Photoplethysmogram) data for use in deducing heart rate. Key Parameters Heart rate detection function (HRD) SRAM buffer support Integrated ultra-low power mode, while in Sleep mode Adjustable sleep rate control Communication interface options I2C Four-Wire SPI I2C interface up to 1 Mbit/s SPI interface up to 2 Mbit/s Hardware reset support Integrated chip-on-board LEDs with wavelength of 525nm and 940nm Applications Power Consumption (mW) Note: Including LED current, without I/O toggling, package only Heart Rate Measurement 30 - 240 Range (bpm) Package Size (mm) 3.6 x 6.36 x 1.0 Ordering Information Part Number PAH8002EP-IP Package Type 22-Pin LGA Heart Rate Monitor Accessories Wearables: Smartwatch, Wrist Band For any additional inquiries, please contact us at http://www.pixart.com/contact.asp Preliminary: This product is still under product development where the product specifications are subjected to change upon product release Version 1.0 | 13 Sep 2015 | 30001EN 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 PAH8002EP Product Brief Low Power Optical Heart Rate Detection Sensor PixArt Imaging Inc. System Overview The PAH8002 is a low power and high-performance CMOS-process optical sensor, targeted as a Heart Rate Detection (HRD) sensor. It is built-in with 2 Green LEDs, 1 Infrared LED and integrated DSP It comes with two communication interfaces, which are I2C supporting up to 1 Mbit/s and Four-Wire SPI supporting up to 2 Mbit/s. SRAM buffer of 832 bytes is supported for the power saving at the host. The PAH8002 is based on CMOS image sensor technology. It is designed to meet the requirements as heart rate monitor accessories and wearables like smart watch or wrist band device. As shown in block diagram, the processor is accessing PPG data from PAH8002 sensor, heart rate is then calculated using PixArt algorithm library in either the processor or App level before sending heart rate result to the display or end device. Block Diagram P Pi re xA li m rt i n C a on ry fid en tia l 1.1 PAH8002EP VDDM VDDAY P O W E R VDD_LED1 Power Regulator VDD_LED2 Output VDDD: 1.8V VDDA: 2.8V VBGP: 1.2V VDDD VDDA28 VBGP G N D VSSA VSSD VSSLED Timing Generator PGA + ADC LED Driver Signal Process Hi speed RC 32Mhz Lo speed RC 32Khz SRAM FIFO Buffer I/O Interfaces Reset SPI_I2C INT SPI_SDI_ I2C_SDA SPI_SDO LED Channel CH0: IR 940nm Clock Generator RESET_N INT Sensor Array Input VDDM: 3.3 - 3.6V VDD_LED: 3.3 - 3.6V I2C SPI_CSN SPI LED0 CH1: Green 525nm LED1 LED2 T E S T CH2: Green 525nm SPI_SDI_ I2C_SCL SERIAL INTERFACE Figure 1. PAH8002 Functional Block Diagram Preliminary: This product is still under product development where the product specifications are subjected to change upon product release Version 1.0 | 13 Sep 2015 | 30001EN 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 PAH8002EP Product Brief Low Power Optical Heart Rate Detection Sensor P Pi re xA li m rt i n C a on ry fid en tia l PixArt Imaging Inc. Figure 2. System Design Block Diagram 1.2 Signal Description Figure 3. Pin Configuration Preliminary: This product is still under product development where the product specifications are subjected to change upon product release Version 1.0 | 13 Sep 2015 | 30001EN 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. 3 PixArt Imaging Inc. PAH8002EP Product Brief Low Power Optical Heart Rate Detection Sensor Table 1. PAH8002 Signal Pins Description Type Description Power Supplies Input IR/Green LED Anode. Provide VDDM supply voltage Input Analog circuit power regulator input. Connect to VDDA28 or provide 2.8V voltage Output Analog circuit power regulator output. Must connect 1µF capacitor to GND Output Digital circuit power regulator output. Must connect 1µF capacitor to GND Output Reference regulator output. Must connect 0.1µF capacitor to GND Input Power supply (3.3 - 3.6V) for internal power regulator GND LED Ground GND Digital Ground I/O Power Supply (1.62 - 3.6V) Input GND Analog Ground Input Green LED Anode. Provide VDDM supply voltage Interface 4-wire SPI: Data input 11 SPI_SDI_I2C_SDA BiDir I2C: Data input-output 12 SPI_SDO Output 4-wire SPI: Data output 13 SPI_CSN Input 4-wire SPI: Chip Select. Active Low 14 SPI_SCLK_I2C_SCL Input 4-wire SPI/ I2C: Clock Functional Group: Functional I/O Data ready interrupt. Default is edge sensitive interrupt, can be changed to level 16 INT Output sensitive interrupt (high active) in INT_Type register Interface Selection 17 SPI_I2C Input I2C: Pull down (Tie to GND) 4-wire SPI: Pull high (Tie to VDDIO) Hardware control to enter Reset Mode. Connect to VDDIO when not used 18 RESET_N Input Level High: Leave Reset Mode Level Low: Enter Reset Mode Functional Group: Reserved 9 LED0 RSV Reserved for LED0 test pin 10 LED1 RSV Reserved for LED1 test pin 10 LED2 RSV Reserved for LED2 test pin 21 NC RSV Reserved. No Connection P Pi re xA li m rt i n C a on ry fid en tia l Pin No. Signal Name Functional Group: VDD_LED01 1 2 VDDAY 3 VDDA28 4 VDDD 5 VBGP 7 VDDM 8 VSSLED 15 VSSD 19 VDDIO 20 VSSA 22 VDD_LED2 Functional Group: Preliminary: This product is still under product development where the product specifications are subjected to change upon product release Version 1.0 | 13 Sep 2015 | 30001EN 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 PixArt Imaging Inc. PAH8002EP Product Brief Low Power Optical Heart Rate Detection Sensor P Pi re xA li m rt i n C a on ry fid en tia l Mechanical Dimensions Figure 4. Package Outline Diagram Preliminary: This product is still under product development where the product specifications are subjected to change upon product release Version 1.0 | 13 Sep 2015 | 30001EN 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. 5 PixArt Imaging Inc. PAH8002EP Product Brief Low Power Optical Heart Rate Detection Sensor P Pi re xA li m rt i n C a on ry fid en tia l Reference Schematics Figure 5. Reference Application Circuit Schematic Design 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. VDDM & VDDIO: 3.3V~3.6V (for 3.3V System) VDDM: 3.3V~3.6V, VDDIO: 1.62V~1.98V (for 1.8V System) It is recommended to separate the power system for VDDM to avoid power interference. SPI_SDI_I2C_SDA and SPI_SCLK_I2C_SCL pull high to VDDIO with resistor for I2C Only VDDD, VDDA28 must have 1µF and VBGP must have 0.1µF capacitor connecting to GND and place closely to 8002. The GND1, GND2 and GND3 must be separated and connected to PCB main GND. INT pin is recommended to be connected to MCU HW INT as data ready INT for power saving. Ensure that the VDDM and VDDIO’s power noise should be under 100mV (with 0.1µF and 10µF capacitor) Tie SPI_I2C pin to VDDIO for SPI or tie to GND for I2C. At power on, VDDM and VDDIO must be powered on at the same time or VDDIO to be powered on first before VDDM. At power off, VDDM and VDDIO must be powered off at the same time or VDDM to be powered off first before VDDIO. Preliminary: This product is still under product development where the product specifications are subjected to change upon product release Version 1.0 | 13 Sep 2015 | 30001EN 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. 6