ENS160 Digital Metal Oxide Multi-Gas Sensor ENS160 Datasheet Revision: 0.
Digital Metal-Oxide Multi-Gas Sensor The ENS160 is a digital multi-gas sensor solution, based on metal oxide (MOX) technology with four MOX sensor elements. Each sensor element has independent hotplate control to detect a wide range of gases e.g. volatile organic compounds (VOCs) including ethanol, toluene, as well as hydrogen and nitrogen dioxide with superior selectivity and accuracy.
Content Guide Key Features & Benefits .................... 2 14.2.2 SPI Timing Information ......... 21 Applications .................................. 2 14.2.3 SPI Read Operation.............. 22 Properties ..................................... 2 14.2.4 SPI Write Operation ............. 22 1 Block Diagram ............................ 4 15 Operation ............................... 23 2 Pin Assignment ........................... 5 16 Registers ................................
1 Block Diagram The ENS160 digital multi-gas sensor consists of four independent heaters and gas sensor elements, based on metal oxide (MOX) technology and a controller as shown in the functional block diagram below.
2 Pin Assignment Figure 2: Pin Diagram Bottom View Top View Pin 1 Corner Corner Area 1 8 7 3 4 5 2 9 6 2 9 6 3 4 5 1 8 7 Pin 1 Corner Corner Area Table 1: Pin Description Pins Pin Name Pin Type 1 MOSI / SDA Input / Output 2 SCLK / SCL Input 3 MISO / ADDR Input / Output 4 5 6 7 8, 9 VDD VDDIO INTn CSn VSS Supply Supply Output Input Supply Description SPI Master Output Slave Input / I²C Bus Bi-Directional Data SPI Serial Clock / I²C Bus Serial Clock Input SPI Master Inpu
3 Absolute Maximum Ratings Table 2: Absolute Maximum Ratings Symbol VDD VDDIO VIO1 VIO2 VSS ISCR ESDHBM ESDCDM MSL TBODY TSTRG RHSTRG TAMB1 RHAMB1 Parameter Supply Voltage I/O Interface Supply MOSI/SDA, SCLK/SCL MISO/ADDR, INTn, CSn Input Ground Input Current (latch-up immunity) Min Max Electrical Parameters -0.3 1.98 -0.3 3.6 -0.3 3.6 -0.3 VDDIO+0.3 -0.3 0.
4 Electrical Characteristics The following figure details the electrical characteristics of the ENS160. Table 3: Electrical Characteristics Symbol VDD VDDIO IDD IDD_PK VIH VIL VOH VOL Parameter Positive supply IO Supply Voltage Average1 Supply Current2 Peak Supply Current4 High-level input voltage Low-level input voltage High-level output voltage Low-level output voltage Conditions Min 1.71 1.71 DEEPSLEEP (OP_MODE 0x00)3 IDLE (OP_MODE 0x01)3 STANDARD (OP_MODE 0x02) STANDARD (OP_MODE 0x02) Typ 1.
5 Air Quality Signal Characteristics To satisfy a wide range of individual application requirements, the ENS160 offers a series of (indoor) air quality output signals that are derived from various national and international, as well as de-facto standards. Table 4 provides a summary of such signals, with further description in the following sections. Table 4: Air Quality Signal Output Characteristics Parameter TVOC eCO2 AQI-UBA1 5.
Figure 3: ENS160-based equivalent CO2 (eCO2) vs. NDIR-based CO2 during two meeting sessions Concentration [ppm] 4000 ENS160 NDIR CO2 3500 3000 2500 2000 1500 1000 500 0h 1h 2h 3h 4h 5h 6h The ENS160 reverses the proportional correlation of VOCs and CO2, by providing a standardized output signal in ppmCO2-equivalents from measured VOCs plus hydrogen, thereby adhering to today’s CO2-standards, as shown opposite: ENS160-based equivalent CO2 estimate vs.
The below table shows a typical classification of (equivalent) CO2 output levels.
6 Single Gas Signal Characteristics Figure 5: Example Response of the ENS160 to Various Gases Since metal oxide sensors exhibit a broadband sensitivity to both reducing and oxidizing gases, their raw output signals represent the resulting sum of the entire gas mixture, present. Such sum-signals are beneficial when it comes to wideband TVOC- or AQI-applications, but unsatisfactory for the detection of single gases.
7 Gas Sensor Raw Resistance Signals For two of its sensing elements the ENS160 provides individual outputs of raw sensor values. Table 8: Gas Sensor Raw Resistance Signals Sensor Raw Value Range Unit Gen. Purpose Register 1 R1raw [0..65535] - GPR_READ[0:1] 4 R4raw [0..65535] - GPR_READ[6:7] Comment Arbitrary logarithmic units no resistance values.
The following figures show the response of eight ENS160s to various nitrogen dioxide concentration steps (upper diagram) and the corresponding raw sensor resistance Riraw (lower diagram). Figure 8: Raw Sensor Signal Response to Nitrogen Dioxide Note: Due to the nature of sensor raw resistance values, these signals are not conditioned, i.e. not compensated for drift, ageing or cross-sensitivity (interference of background gases including humidity). ENS160 Datasheet v0.
8 Signal Conditioning Chemical gas sensors are relative sensors that are susceptible to changes in their chemical and physical environments. Typical drivers are changes of the target gas(es), of the interfering background gas mixture and changes of the physical environment (air pressure, humidity, etc.). 8.1 Baselining As part of the TrueVOC™ technology the ENS160 deploys an automatic baseline correction, featuring compensation for oxidizing gases such as ozone.
9 Output Signal Accuracy1 Figure 10: Output Signal Accuracy for Hydrogen The ENS160 exhibits an measurement accuracy and device variation. excellent device-to- The opposite diagrams show the nonlinearity of several devices (left) and typical and maximum accuracies (bottom) for various hydrogen concentrations. A typical error of <12% of the measured value can be stated.
11 Gas Sensor Status and Signal Rating The status flag is an additional feature assessing the current operational mode and the reliability of the output signals. It aids the application obligation to manage timings efficiently, in particular during initial start-up or after re-powering. Furthermore, a simple signal quality assessment and a system self-check is provided.
14 Host Communication The ENS160 is an I2C or SPI Slave device. If the CSn is held high, the interface behaves as an I²C slave. At power-up the condition of the MISO/ADDR pin is used to determine the LSB of the I²C address. The I²C slave address is 0x52 (MISO/ADDR low) or 0x53 (MISO/ADDR high). If the CSn pin is asserted (low) the interface behaves as an SPI slave. This condition is maintained until the next Power-on Reset. Both the SPI and I²C slave interfaces use the same register map for communication.
Table 12: ENS160 I2C Timing Parameters1 Parameter Symbol SCLK clock frequency Hold time (repeated) START condition.
I2C Read Operation 14.1.3 After the START condition, in the first transaction: • The I²C Master sends the 7-bit slave address and 0 into the R/W bit (the byte sent would be 0xA4 or 0xA6 dependent on the power-up value of MISO/ADDR). • The I²C Master then sends the address of the first register to read. Then either after a RESTART condition (i.e.
I2C Write Operation 14.1.4 After the START condition, in a single continuous transaction: • The I²C Master sends the 7-bit slave address and 0 into the R/W bit (the byte sent would be 0xA4 or 0xA6 dependent on the power-up value of MISO/ADDR). • The I²C Master then sends the address of the first register to write. • The I²C Master then sends 1-n data bytes which are written into sequential registers (if valid) until the transaction is concluded with a STOP condition.
14.2 SPI Specification 14.2.1 SPI Description The SPI interface is a slave bus operating up to 10MHz clock-frequency. It shares pins with the I²C interface. SPI is selected and SPI transfer initiated by asserting the CSn line low. Once the CSn line has been asserted low the ENS160 will not accept I²C transactions until the next Power-On Reset. Data is clocked in on the rising edge of SCLK; most significant bit first. 14.2.
14.2.3 SPI Read Operation During a Read operation, data is clocked out on the falling edge of SCLK so it is stable for the following riding edge. MISO stays in high impedance mode until the device is selected (CSn low). Data on MISO is only valid on a Read operation. A transaction starts with the target address and R/W control bit in the first byte followed by the read or write data. In a Read operation Auto-increment of the address enables multiple registers to be read in sequence.
15 Operation At power-up, the ENS160 configures itself from a reset state and prepares for commands over the serial bus via either I2C or SPI Protocols. The default state is OPMODE 0x01, which is an IDLE condition that enables ENS160 so that it may respond to several commands. In this mode it is not operating as a gas sensor. OPMODE 0x00 is a very low power standby state, called DEEP SLEEP. Active OPMODEs are described further in the OPMODE Register section.
16 Registers This section describes the registers of the ENS160 which enable the host system to • Identify the Device and version information • Configure the ENS160 and set the operating mode • Read back STATUS information, the calculated gas concentrations and Air Quality Indices 16.1 Register Overview Note that some registers are spread over multiple addresses. For example, PART_ID at address 0 is spread over 2 addresses (its “Size” is 2).
16.2 Detailed Register Description 16.2.1 PART_ID (Address 0x00) This 2-byte register contains the part number in little endian of the ENS160. The value is available when the ENS160 is initialized after power-up. Table 17: Register PART_ID Address 0x00 Bits Field Name 0:7 PART_ID_LSB 8:15 PART_ID_MSB 16.2.2 Default 0x60 0x01 Access read read PART_ID Field Description Lower Byte of Part ID Upper Byte of Part ID OPMODE (Address 0x10) This 1-byte register sets the Operating Mode of the ENS160.
Table 19: Register CONFIG Address 0x11 Bits Field Name 7 6 INTPOL Default 0b0 0b0 Access R/W 5 INT_CFG 0b0 R/W 4 3 INTGPR 0b0 0b0 R/W 2 1 INTDAT 0b0 0b0 R/W 0 INTEN 0b0 R/W 16.2.
16.2.5 TEMP_IN (Address 0x13) This 2-byte register allows the host system to write ambient temperature data to ENS160 for compensation. The register can be written at any time. TEMP_IN_LSB should be written first as the update is recognized on a write to TEMP_IN_MSB.
16.2.7 DATA_STATUS (Address 0x20) This 1-byte register indicates the current STATUS of the ENS160. Table 26: Register DATA_STATUS Address 0x20 Bits Field Name 7 STATAS Default 0b0 Access - 6 STATER 0b0 R 5 4 - 0b0 0b0 R R 2-3 VALIDITY FLAG 0b00 R 1 NEWDAT 0b0 R 0 NEWGPR 0b0 R DATA_STATUS Field Description High indicates that an OPMODE is running High indicates that an error is detected. E.g. Invalid Operating Mode has been selected.
16.2.9 DATA_TVOC (Address 0x22) This 2-byte register reports the calculated TVOC concentration in ppb. Table 28: Register DATA_TVOC Bits 0:7 8:15 Address 0x22 Field Name TVOC_LSB TVOC _MSB Default 0x00 0x00 Access R R DATA_TVOC Field Description Lower Byte of DATA_TVOC Upper Byte of DATA_TVOC See section “TVOC – Total Volatile Organic Compounds” for further information. 16.2.
Table 32: Format of Temperature Data 7 6 Byte 0x30 5 4 3 2 1 0 TEMP_IN Integer Part (Kelvin) 7 6 5 Byte 0x31 4 3 2 1 TEMP_IN Fractions 0 The DATA_T storage format is: temperature in Kelvin * 64 (with Kelvin = Celsius + 273.15). Example: For a stored DATA_T value of 0x4A8A the temperature in °C is calculated as follows: 0x4A8A / 64 - 273.15 = 25°C. See section “TEMP_IN” for further information. 16.2.
Example: C-code to calculate MISR on the received DATA, to compare with DATA_MISR: // The polynomial used in the CRC computation in DATA_MISR // 76543210 bit weight factor #define POLY 0x1D // 0b00011101 = x^8+x^4+x^3+x^2+x^0 (x^8 is implicit) // The hardware register DATA_MISR is updated with every read from a // register in the range 0x20 to 0x37, using a CRC polynomial (POLY). // For every register read, call `misr_update()` to keep the software // variable `misr` in sync with the hardware register.
16.2.16 GPR_READ (Address 0x48) This 8-byte register is used by several functions for the ENS160 to pass data to the Host System. When New GPR_DATA is available the NEW_GPR bit of the DATA_STATUS register will be set and the INTn pin asserted (if configured).
17 Application Information 17.1 I2C Operation Circuitry The recommended application circuit for the ENS160 I2C interface operation is shown below: Figure 18: Recommended Application Circuit (I2C Operation) VDD 4 5 4k7 4k7 VDDIO 100nF Host Processor 10mF ENS160 GND GND 7 CSn SDA 1 SDA SCL 2 SCL INTn 6 INTn 3 ADDR 8, 9 GND Note(s): 1. CSn must be pulled high (directly to VDDIO) to ensure I2C interface is selected 2.
17.2 SPI Operation Circuitry The recommended application circuit for the ENS160 for SPI interface is shown below: Figure 19: Recommended Application Circuit (SPI Operation) VDD Host Processor 100k VDDIO 4 5 100nF GND 10mF ENS160 SPI_CSn 7 CSn SPI_MOSI 1 MOSI SPI_CLK 2 CLK INTn 6 INTn SPI_MISO 3 MISO 8, 9 GND Note(s): 1. Weak pull-up resistor may be required for MISO to define the level when tri-stated 2.
18 Soldering Information The ENS160 uses an open LGA package. This package can be soldered using a standard reflow process in accordance with IPC/JEDEC J-STD-020D. Figure 20: Solder Reflow Profile Graph Temperature [°C] TPEA K T3 T2 T1 tSOAK Time [s] t3 t2 t1 The detailed settings for the reflow profile are shown in the table below. Table 38: Solder Reflow Profile Parameter Reference Average temperature gradient in preheating Soak time Rate / Unit 2.5K/s tSOAK 2..
19 Package Drawings & Markings Figure 21: LGA Package Drawing Pin 1 Corner Index Area E A 0.8 0.8 Ø 0.3 D (Top View) (Side View) nXL 4 5 3 nXW e D1 6 2 7 1 0.1 Pin 1 Corner Index Area 8 e E1 (Bottom View) Table 39: LGA Package Dimensions Parameter Min A D E W 0.65 L 0.65 e n D1 Centre E1 Note: All dimensions are in mm Total thickness Body Size Lead Width Lead Length Lead Pitch Lead Count Edge Lead Centre to 36 Symbol Dimensions Nominal 0.83 3.0 3.0 0.7 0.7 1.05 9 2.1 2.1 Max 0.
Figure 22: Recommend LGA Land Pattern for ENS160 Top View 1 8 7 2 9 6 3 4 5 2.1 1.05 0.85 0.9 1.05 2.1 Note(s): 1. All dimensions are in millimeters 2. PCB land pattern in dotted lines 3. Add 0.05mm all around the nominal lead width and length for the PCB land pattern Figure 23: LGA Package Marking 160 XXXX ENS160 Datasheet v0.
20 RoHS Compliance & ScioSense Green Statement RoHS: The term RoHS compliant means that ScioSense B.V. products fully comply with current RoHS directives. Our semiconductor products do not contain any chemicals for all 6 substance categories, including the requirement that lead does not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, RoHS compliant products are suitable for use in specified lead-free processes.
22 Document Status Table 40: Document Status Document Status Product Preview Product Status PreDevelopment Preliminary Datasheet PreProduction Datasheet Production Datasheet (Discontinued) Discontinued 23 Definition Information in this datasheet is based on product ideas in the planning phase of development. All specifications are design goals without any warranty and are subject to change without notice.
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