JPS5910030A - Analog-digital converter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present invention relates to an eight-way conversion device for converting analog wind pressure into digital data, and its purpose is to stably perform one-resolution conversion using a low-resolution A-D converter. This provides a method for changing pitches.

Recently, microcomputers with a built-in A-D converter have been widely used in microwave ovens and room air conditioners made by Tsuru. The built-in A/D converter 6i1 is of low resolution (typically 8 hits) because high resolution ones are expensive.

However, in order to be able to perform control with as much precision as possible,
An inexpensive and stable converter with f, =^ decomposition rIr is W(
It's rare.

The present invention compares the input unknown voltage and the reference yU pressure to determine r'1.
It is determined whether the unknown input pressure u input belongs to the corresponding level division, and the lowest voltage of the determined level division is set as the input unknown ψ,
an amplification circuit that outputs a correction voltage subtracted from the voltage;
A ratio conversion type analog-to-digital converter in which the upper limit of the lowest level division of the Hilt reference pressure is applied to the digital conversion reference m pressure input terminal, and a correction voltage of 1 jir is applied to the conversion input terminal; A coater is provided to output a digital signal of N bits [where N2 is an integer] corresponding to the lowest market and king, and a coater is provided to output a digital signal of N bits [(u and %N, ?) of the ratio conversion type analog-to-digital converter. Integer] conversion output is the lower bit output, N2 bits of the DI Coco output are the upper bit output, and (N + N,) bits are the conversion output. By creating a correction voltage, it is possible to perform high-resolution digital conversion with an inexpensive low-resolution A-D converter. Since the upper limit voltage of the lowest level classification was applied when determining the level classification, the level DH[:A-D
'fmll's full scale matches, stable operation is W
It's something you can wait for.

Hereinafter, one embodiment of the present invention will be explained based on FIGS. 1 and 2. FIG. 1 shows a 10-bit ratio conversion type A-D converter (1) with an external circuit added. The configuration for obtaining conversion output is shown. (2) is the input unknown voltage Eil and the applied drag is R
82R2=R3. In (4) to (7), each reference voltage 0 port % el volt, direction volt, e3 volt is applied to the inverting input (=), and the input unknown voltage Ein is applied to the non-inverting input (+-), y, = With an operational amplifier,
The outputs of these amplifying fats (4) to (7) each have Ei
n, (Eirl-e+), (Ein h), (Ein
-es ) voltages 6(8) to αυ are the output voltages of the amplifiers (4) to (7), 1ζ1, E2
, a comparator that determines the level of E3, where Ai
A- at full scale F and S of A-D converter (1)
Set the input voltage of the DI converter (1) to EMAX (here, EMAX
= e+ ), each comparator (3) ~ 0υ
are respectively fI Eo < EMAX s Om El
<EMAX, 0≦E! < E MAX %0≦
The output is configured to switch to logic level "H" upon detecting E3<EMAX. @~aG is an analog switch whose one end is connected to the output of the operational amplifiers (4) to (7), and the other ends are connected to each other, and these analog switches 0~Uυ are each a comparator for that level division. (8) The outputs of ~αp are both grounded and reversed to Belpa I4'', and at this time it becomes a make state, and the converter (A-1) (
1) is applied to the input. ao is the comparator [8
]~acid 0AIIIJ of the level division to which the comparator whose output among aυ is inverted to logic level “H9’” belongs
, is a coater that outputs a 2-bit digital signal corresponding to the pressure, and the comparators (82 to 0υ are each inverted to logic level "l("). el se! 2 equivalent to he+
The signals shown in the table below are output as bit digital signals.

Table〉 Area J +; l Parallel - plane array converter, A-I) converter (1)
8 bits of the output are the lower bits, 2 of the coater Qf1 output
Accept the bit as the upper side person, and
Sequentially output variable grip output (to) in t+ column 2+, fJ:
ji, the above A-1) digital conversion reference paper ejection force of the capacitor, includes the reference voltage e as the upper limit value of the lowest level classification.
1 is applied.

Figure 2 shows the oil amplifier (4) for the input electric current [Ein].
~(7) represents the output direct pressure E, ~E3. For example, human power unknown flower, pressure 1. : If in is self≦Ein<e2, the comparator (output output is inverted and analog switch 03 becomes a makeup state, and (Ein el) becomes A-D
The signal is applied to the input of the f converter (1) and converted into an 8-bit digital signal (for example, "0ot) 00000". At this time, the coater 01) output becomes "01" from the table above,
Parallel-to-serial converter θ, 1 of “0100000000” in the order of upper bits
A 0-bit conversion output (T) is input in parallel bits.

In the above embodiment, each reference voltage o, e and e21 clause and the input unknown wI! is simultaneously compared with the pressure Ein using four Ii calculation amplifiers (4) to (7) to obtain the input unknown -1.
JL determined whether the pressure belongs to the level category of
The effect similar to IfL1 can be obtained even if the reference voltages are sequentially switched and the level divisions are determined in a time-sharing manner.

According to the A-I) conversion method of the present invention as explained in J and I, the external (B) path of the low arc minute 'F (r) converter and the It is possible to obtain a conversion output equivalent to A-D conversion with a low resolution and low price, and contribute to lowering the cost of low-quality products. In the lowest level division, when the digital conversion of the A-D"+2 converter reaches full scale, 47/'Award' and the judgment level division switches to the next higher level division. It is stable and has a capacity of 7 tons, so accurate digital conversion can be expected.

[Brief explanation of the drawing]

FIG. H41 is a block diagram of a specific embodiment of the A-Ds conversion method of the present invention, and FIG. 2 is an input/output characteristic diagram of FIG. 1. (1)... Violet conversion type A-Ll converter, (3)...
・Standard pressure noise, (4)~(7)...11ν1Φ#l藷, (+'l)~0υ...Comparator, hit~OQ...
・Analog switch, θG...Korg, Ein゛°"Input unknown pressure agent Yoshihiro Moriki

Claims (1)

[Claims] 1. Comparing the human power unknown voltage with a reference voltage to determine whether the human power unknown voltage belongs to a given level classification, and subtracting the lowest voltage of the determined level classification from the input unknown voltage by 1.
a ratio conversion type analog circuit in which the upper limit V voltage of the lowest level division of the reference voltages is applied to the digital conversion reference voltage input terminal and the correction voltage is applied to the conversion input terminal;・Provide a digital converter and a cog that outputs a digital f-word of N bits [however, N2 is an integer] corresponding to the minimum voltage, and convert the N1 heanote (((
F L-N+ is an integer] with the conversion output as the lower bit output, and the N bit of the oil coder output as the upper bit output, and (N+Nz) BiSoto as the conversion output f: A
-D hair replacement eyes.