MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications General Description The MAX30105 is an integrated particle-sensing module. It includes internal LEDs, photodetectors, optical elements, and low-noise electronics with ambient light rejection. The MAX30105 provides a complete system solution to ease the design-in process of smoke detection applications including fire alarms.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Absolute Maximum Ratings VDD to GND..........................................................-0.3V to +2.2V GND to PGND.......................................................-0.3V to +0.3V X_DRV, VLED+ to PGND.......................................-0.3V to +6.0V All Other Pins to GND...........................................-0.3V to +6.0V Output Short-Circuit Current Duration........................
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Electrical Characteristics (continued) (VDD = 1.8V, VLED+ = 5.0V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = 25°C.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Electrical Characteristics (continued) (VDD = 1.8V, VLED+ = 5.0V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = 25°C.) (Note 2) Radiant Power PARAMETER PO ILED = 20mA, TA = +25°C SYMBOL CONDITIONS 9.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Electrical Characteristics (continued) (VDD = 1.8V, VLED+ = 5.0V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = 25°C.) (Note 2) PARAMETER SYMBOL Hold Time (Repeated) START Condition CONDITIONS MIN TYP MAX UNITS tHD,STA 0.6 µs SCL Pulse-Width Low tLOW 1.3 µs SCL Pulse-Width High tHIGH 0.6 µs Setup Time for a Repeated START Condition tSU,STA 0.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Typical Operating Characteristics (VDD = 1.8V, VLED+ = 5.0V, TA = +25°C, unless otherwise noted.) RED LED SUPPLY HEADROOM 60 50 40 30 ILED = 20mA 20 10 ILED = 50mA 50 40 30 ILED = 20mA 20 1 2 3 4 0 5 0 1 2 VLED VOLTAGE (V) 45000 0.8 40000 0.7 35000 COUNTS (SUM) SUPPLY CURRENT (mA) 50000 0.9 0.6 0.5 0.4 0.3 0.1 0.0 0.5 1 1.5 2 20000 RED 10000 0 2.5 GREEN 0 10 15 0.11 VLED = 5.25V 0.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Typical Operating Characteristics (continued) (VDD = 1.8V, VLED+ = 5.0V, TA = +25°C, unless otherwise noted.) RED LED PEAK WAVELENGTH vs. TEMPERATURE toc10 675 80 60 40 20 665 660 655 MODE = FLEX LED ADC RES = 18 BITS ADC SR = 400 SPS ADC FULL SCALE = 2048nA 650 0 400 450 500 550 600 650 645 700 -50 0 WAVELENGTH (nm) toc13 MODE = FLEX LED ADC RES = 18 BITS ADC SR = 100 SPS ADC FULL SCALE = 2048nA 30 20 10 1.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Typical Operating Characteristics (continued) (VDD = 1.8V, VLED+ = 5.0V, TA = +25°C, unless otherwise noted.) PHOTODIODE QUANTUM EFFICIENCY vs. WAVELENGTH toc19 1.0 0.9 QUANTUM EFFICIENCY 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 400 500 600 700 800 900 1000 1100 WAVELENGTH (nm) www.maximintegrated.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Pin Configuration N.C. 1 SCL 2 SDA 3 12 GND PGND 4 11 VDD R_DRV 5 IR_DRV 6 G_DRV 7 14 N.C. SENSOR MAX30105 LEDs 13 INT 10 VLED+ 9 VLED+ 8 N.C. Pin Description PIN NAME FUNCTION 1, 8, 14 N.C. No Connection. Connect to PCB pad for mechanical stability.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Functional Diagram VDD VLED+ RED IR AMBIENT LIGHT CANCELLATION GREEN ANALOG VISIBLE+IR ADC 660nm 880nm 527nm DIE TEMP IR_DRV G_DRV SCL DATA REGISTER LED DRIVERS I2C COMMUNICATION SDA INT The MAX30105 is a complete particle detection sensor system solution module. The MAX30105 maintains a very small solution size without sacrificing optical/electrical performance.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Register Maps and Descriptions REGISTER B7 B6 B5 B4 A_FULL DATA_ RDY ALC_ OVF PROX_ INT B3 B2 B1 B0 REG ADDR POR STATE R/W PWR_ RDY 0x00 0X00 R 0x01 0x00 R 0x02 0X00 R/W 0x03 0x00 R/W STATUS Interrupt Status 1 Interrupt Status 2 DIE_TEMP _RDY Interrupt Enable 1 A_FULL_ EN DATA_ ALC_ RDY_EN OVF_EN PROX_ INT_EN Interrupt Enable 2 DIE_TEMP _RDY_EN FIFO FIFO Write Pointer FIFO_WR_PTR[4:0] 0x04 0x0
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Register Maps and Descriptions (continued) REG ADDR POR STATE R/W RESERVED 0x13– 0x17 0xFF R/W RESERVED 0x180x1E 0x00 R 0x1F 0x00 R 0x20 0x00 R 0x21 0x00 R 0x22– 0x2F 0x00 R/W PROX_INT_THRESH[7:0] 0x30 0x00 R/W Revision ID REV_ID[7:0] 0xFE 0xXX* R Part ID PART_ID[7] 0xFF 0x15 R REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DIE TEMPERATURE Die Temp Integer TINT[7:0] Die Temp Fraction TFRAC[3:0] Di
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Interrupt Status (0x00–0x01) REGISTER B7 B6 B5 B4 Interrupt Status 1 A_FULL DATA_ RDY ALC_OVF PROX_ INT Interrupt Status 2 B3 B2 B1 DIE_ TEMP_RDY B0 REG ADDR POR STATE R/W PWR_ RDY 0x00 0X00 R 0x01 0x00 R Whenever an interrupt is triggered, the MAX30105 pulls the active-low interrupt pin into its low state until the interrupt is cleared.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications The interrupts are cleared whenever the interrupt status register is read, or when the register that triggered the interrupt is read. For example, if the particle-sensing sensor triggers an interrupt due to finishing a conversion, reading either the FIFO data register or the interrupt register clears the interrupt pin (which returns to its normal HIGH state). This also clears all the bits in the interrupt status register to zero.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications FIFO Data Register The circular FIFO depth is 32 and can hold up to 32 samples of data. The sample size depends on the number of LED channels configured as active. As each channel signal is stored as a 3-byte data signal, the FIFO width can be 3 bytes, 6 bytes, 9 bytes, or 12 bytes in size. The FIFO_DATA register in the I2C register map points to the next sample to be read from the FIFO. FIFO_RD_PTR points to this sample.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications FIFO Data Contains 3 Bytes per Channel The FIFO data is left-justified, meaning that the MSB is always in the same location regardless of the ADC resolution setting. FIFO DATA[18] – [23] are not used. Table 2 shows the structure of each triplet of bytes (containing the 18-bit ADC data output of each channel).
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Pseudo-Code Example of Reading Data from FIFO First transaction: Get the FIFO_WR_PTR: START; Send device address + write mode Send address of FIFO_WR_PTR; REPEATED_START; Send device address + read mode Read FIFO_WR_PTR; STOP; The central processor evaluates the number of samples to be read from the FIFO: NUM_AVAILABLE_SAMPLES = FIFO_WR_PTR – FIFO_RD_PTR (Note: pointer wrap around should be taken into account) NUM_SAMPLES_TO_READ
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications START; Send device address + write mode Send address of FIFO_RD_PTR; Write FIFO_RD_PTR; STOP; Third transaction: Write to FIFO_RD_PTR register. If the second transaction was successful, FIFO_RD_PTR points to the next sample in the FIFO, and this third transaction is not necessary. Otherwise, the processor updates the FIFO_RD_PTR appropriately, so that the samples are reread.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Mode Configuration (0x09) REGISTER B7 B6 Mode Configuration SHDN RESET B5 B4 B3 B2 B1 B0 MODE[2:0] REG ADDR POR STATE R/W 0x09 0x00 R/W Bit 7: Shutdown Control (SHDN) The part can be put into a power-save mode by setting this bit to one. While in power-save mode, all registers retain their values, and write/read operations function as normal. All interrupts are cleared to zero in this mode.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Bits 4:2: Particle-Sensing Sample Rate Control (Using 2 LEDs) These bits define the effective sampling rate with one sample consisting of one IR pulse/conversion and one RED pulse/conversion. The sample rate and pulse width are related in that the sample rate sets an upper bound on the pulse width time.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications LED Pulse Amplitude (0x0C–0x10) REGISTER B7 B6 LED Pulse Amplitude LED Pulse Amplitude B5 B4 B3 B2 B1 B0 POR STATE R/W LED1_PA[7:0] 0x0C 0x00 R/W LED2_PA[7:0] 0x0D 0x00 R/W LED3_PA[7:0] 0x0E 0x00 R/W 0x0F 0x00 R/W 0x10 0x00 R/W RESERVED Proximity Mode LED Pulse Amplitude REG ADDR PILOT_PA[7:0] These bits set the current level of each LED as shown in Table 8. Table 8.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications The purpose of PILOT_PA[7:0] is to set the LED power during the proximity mode, as well as in Multi-LED mode. Multi-LED Mode Control Registers (0x11–0x12) REGISTER B7 Multi-LED Mode Control Registers B6 B5 B4 B3 B2 B1 B0 REG ADDR POR STATE R/W SLOT2[2:0] SLOT1[2:0] 0x11 0x00 R/W SLOT4[2:0] SLOT3[2:0] 0x12 0x00 R/W In multi-LED mode, each sample is split into up to four time slots, SLOT1 through SLOT4.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Temperature Data (0x1F–0x21) REGISTER B7 B6 B5 Temp_Integer B4 B3 B2 B1 B0 TINT[7] Temp_Fraction TFRAC[3:0] Die Temperature Config TEMP_EN REG ADDR POR STATE R/W 0x1F 0x00 R/W 0x20 0x00 R/W 0x21 0x00 R Temperature Integer The on-board temperature ADC output is split into two registers, one to store the integer temperature and one to store the fraction.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Proximity Mode Interrupt Threshold (0x30) REGISTER B7 B6 B5 Proximity Interrupt Threshold B4 B3 B2 B1 B0 REG ADDR POR STATE R/W 0x30 0x00 R/W PROX_INT_THRESH[7:0] This register sets the IR ADC count that will trigger the beginning of particle-sensing mode. The threshold is defined as the 8 MSBs of the ADC count.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Particle-Sensing Temperature Compensation Red LED Current Settings vs. LED Temperature Rise The MAX30105 has an accurate on-board temperature sensor that digitizes the IC’s internal temperature upon command from the I2C master. Add estimated temperature rise to the module temperature reading to estimate the LED temperature and output wavelength.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Timing for Measurements and Data Collection width setting. Figure 3 shows an example of channel slot timing for a particle-sensing mode application with a 1kHz sample rate. Slot Timing in Multi-LED Modes The MAX30105 can support up to three LED channels of sequential processing (Red, IR, and Green). In multiLED modes, a time slot or period exists between active sequential channels.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Timing in Particle-Sensing Mode Using 2 LEDs The internal FIFO stores up to 32 samples, so that the system processor does not need to read the data after every sample (Figure 4). 15ms TO 300ms SAMPLE #1 LED OUTPUTS RED IR SAMPLE #2 RED IR SAMPLE #3 RED IR SAMPLE #16 SAMPLE #17 RED ~ INT IR RED IR RED IR RED IR ~ 29ms TEMP SENSOR TEMPERATURE SAMPLE I2C BUS ~ 1 2 3 4 5 6 Figure 4.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Timing in Particle-Sensing Mode Using 1 LED The internal FIFO stores up to 32 samples, so that the system processor does not need to read the data after every sample (Figure 5). 15ms TO 300ms LED OUTPUTS SAMPLE #1 SAMPLE #2 SAMPLE #3 IR IR IR ~ INT ~ I2C Bus ~ 1 SAMPLE #30 SAMPLE #31 IR IR 2 IR 3 IR 4 Figure 5. Timing for Data Acquisition and Communication When in Particle-Sensing Mode Using 1 LED Table 16.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Power Sequencing and Requirements Power-Up Sequencing Figure 6 shows the recommended power-up sequence for the MAX30105. It is recommended to power the VDD supply first, before the LED power supplies (VLED+). The interrupt and I2C pins can be pulled up to an external voltage even when the power supplies are not powered up.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications ID, the MAX30105 issues an ACK by pulling SDA low for one clock cycle. master retries communication. The master pulls down SDA during the 9th clock cycle to acknowledge receipt of data when the MAX30105 is in read mode. An acknowledge is sent by the master after each read byte to allow data transfer to continue. A not-acknowledge is sent when the master reads the final byte of data from the MAX30105, followed by a STOP condition.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Read Data Format For the read operation, two I2C operations must be performed. First, the slave ID byte is sent followed by the I2C register that you wish to read. Then a REPEAT START (Sr) condition is sent, followed by the read slave ID. The MAX30105 then begins sending data beginning with the register selected in the first operation.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Typical Application Circuit +1.8V 20mA +5.0V 200mA MAX 4.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Package Information (continued) For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. maxim integrated www.maximintegrated.
MAX30105 High-Sensitivity Optical Sensor for Smoke Detection Applications Revision History REVISION NUMBER REVISION DATE 0 5/16 Initial release 7/16 Updated title, General Description, Benefits and Features, Applications, System Diagram, Electrical Characteristics global conditions, LED supply voltage parameter, ADC count—PSRR (LED driver outputs) parameter conditions, Typical Operating Characteristics global conditions, Pin Configuration, Detailed Description, Temperature Sensor, Proximity Function
