Temperature acquisition AD conversion circuit

Temperature control interface board: The temperature control interface board includes A/ D conversion circuit, D/A conversion circuit, etc. The A/D conversion circuit is mainly
composed of a successive comparison ADC 0809 conversion chip, and the input requirement is Vi,,<SV. The start signal of ADC 0809 is (2VCH-
28FH), and the A/ D conversion channel is determined by the data lines D2, Dl, DO. (OOH-03H). The CLK end is divided by 8 from the system clock,
which is about 500kHz. VREF(+) is +5v. VRDr[_>ground. The START (conversion start) and ALE (address latch) terminals
are controlled by IOW and chip select signals, and the ENABLE (allow output) terminal is controlled by IOR and chip select signals. ADC0809
converts the analog voltage of o-+5v into an 8-bit digital quantity O-FFH, and then sends it to the computer, which can realize temperature data collection.