Datasheet (Asahi Kasei Microdevices) - 4
| Manufacturer | Asahi Kasei Microdevices |
| Description | LED Driver and Sensor AFE for NDIR Gas Sensing |
| Pages / Page | 34 / 4 — 5. Block Diagram and Functions. 5.1. Block Diagram. 5.2. Functions |
| File Format / Size | PDF / 1.3 Mb |
| Document Language | English |
5. Block Diagram and Functions. 5.1. Block Diagram. 5.2. Functions
Model Line for this Datasheet
Text Version of Document
[AK9723AJ]
5. Block Diagram and Functions 5.1. Block Diagram
Figure 5.1 Block Diagram
5.2. Functions
Table 5.1 Block Functions Block Function OSC Oscillator VIREF Reference voltage and reference current generator TSENS Temperature sensor Convert the IR photo detector output current path1 (IR1 path) to AFE1 voltage. Cancel the offset of IR photo detector. Convert the IR photo detector output current path2 (IR2 path) to AFE2 voltage. Cancel the offset of IR photo detector. ADC1 / 2 Sigma delta 2nd order analog-to-digital converter LED DRIVER LED constant current driver REGU Generate 1.6V for digital circuit Communicate with MCU by SCL and SDA in I2C protocol. I2C I/F Support 400kHz fast mode. SEQUENCER Control of analog circuit REGISTER Register to store the measurement data, operation mode, timing value ADVREF GEN1 / 2 Reference voltage generator for ADC SH Sample and hold circuit PRE SH Sample and hold circuit 018015111-E-01 2019/8 - 4 -
5. Block Diagram and Functions 5.1. Block Diagram
Figure 5.1 Block Diagram
5.2. Functions
Table 5.1 Block Functions Block Function OSC Oscillator VIREF Reference voltage and reference current generator TSENS Temperature sensor Convert the IR photo detector output current path1 (IR1 path) to AFE1 voltage. Cancel the offset of IR photo detector. Convert the IR photo detector output current path2 (IR2 path) to AFE2 voltage. Cancel the offset of IR photo detector. ADC1 / 2 Sigma delta 2nd order analog-to-digital converter LED DRIVER LED constant current driver REGU Generate 1.6V for digital circuit Communicate with MCU by SCL and SDA in I2C protocol. I2C I/F Support 400kHz fast mode. SEQUENCER Control of analog circuit REGISTER Register to store the measurement data, operation mode, timing value ADVREF GEN1 / 2 Reference voltage generator for ADC SH Sample and hold circuit PRE SH Sample and hold circuit 018015111-E-01 2019/8 - 4 -
