Shensi Ling vigorously promotes new digital temperature sensor products

Recently, Shensilin, relying on its technological accumulation in the thermal management segment, launched the bus-type pulse counting interface digital temperature sensor chip product CT1721. Its output pulse supports two modes: continuous output and single output, which meets the processing requirements of high, medium and low-end MCUs, especially low-cost MCUs, for pulse interrupt technology.

In a system with multiple temperature control points, if a common I2C temperature sensor is mounted on the I2C/SMBus bus, multiple device addresses are required to distinguish different temperature sensors. This will cause the hardware driver development to be unable to find a suitable device address space address, which will hinder project development. Or the temperature monitoring points are reduced, but the system performance cannot be stably improved. If different device addresses are used, software development and hardware device screening are limited.

To this end, Shenshiling applied for an invention patent named "Register Address Configurable Temperature Sensor" (application number: 202010188598.7) on March 17, 2020, and the applicant was Shanghai Shenshiling Microelectronics Technology Co., Ltd.

Figure 1. Schematic diagram of temperature sensor connection with configurable register address

FIG1 is a connection diagram of a temperature sensor with configurable register address proposed by the present invention. The sensor includes an analog-to-digital conversion circuit, a configurable register address circuit, a digital interface circuit, and a register group circuit. The analog-to-digital conversion circuit further includes: an internal diode array, an analog current source, an ADC conversion circuit, and a digital code stream control. The digital interface circuit includes: an interface start detection, a register address matching circuit, a device address detection, a register address detection, a read operation, and a write operation. The register group circuit includes: a temperature register, a configuration register, a status register, a temperature high threshold register, a temperature low threshold register, and a temperature comparison circuit. The configurable register address circuit includes: a delay circuit and an encoding circuit.

The analog current source controls the opening and closing of the internal diode array. The current flowing through the diode array is related to the temperature. The ADC conversion circuit converts this current into a digital code stream, and the digital code stream control converts this digital code stream into a 12-bit, 14-bit, or 16-bit temperature value. The register group circuit accepts the temperature value output by the digital code stream control and stores it in the temperature register. The digital interface circuit can read or modify the configuration register, the temperature high threshold register, and the temperature low threshold register. The temperature register and the status register can only be read, not written. The temperature comparison circuit sets the bit of the status register according to the temperature register and the high and low threshold registers.

The interface start detection circuit of the digital interface circuit detects the start signal of I2C and SMBus. At the same time, the device address is detected. If the device address sent by the host is different from the internal address of the temperature sensor, the subsequent commands will not respond. If the device address is correct, the temperature chip will accept the register address. If the received register address does not match the register address configured by the external pin, the subsequent read and write commands will not respond. If they match, the subsequent read register command and write register command will be received. The configurable register address circuit detects the level and jump of the delay circuit at the start command of SMBus or I2C, so as to determine whether the connection of the external pin is connected to the power supply, ground line, SCL line or SDA line.

In short, Shenshiling's temperature sensor patent effectively saves device address resources by allowing only one temperature sensor to access the same register in a parallel connection. It is more convenient to use in systems that require multi-point temperature measurement, effectively improves system performance, and has great economic value.

Shensi Ling Microelectronics is a semiconductor technology company that focuses on the design, development, manufacturing and sales of environmental sensor IC products. It innovatively combines novel sensor technology with more mature integrated circuit process design technology. Shensi Ling will become a leader in environmental sensors in the future.