Analog-to-digital converter

Claim 2

An analog to digital converter comprising: input means supplying an analog signal; means including a capacitor to hold a signal received from said input means; means to parallel convert the held signal at said holding means to produce the most significant bits of the held signal; means to convert said held signal into a ramp signal; said ramp converting means including means to discharge said capacitor to produce a voltage ramp; and means to determine when the voltage ramp from the discharge of said capacitor reaches a first threshold to produce the least significant bits of said held signal from said ramp signal.

Claim 3

The analog to digital converter according to claim 1 in which said parallel converting means includes comparing means to produce the most significant bits of the held signal.

Claim 4

The analog to digital converter according to claim 2 in which said ramp conversion means cooperates with said comparing means of said parallel converting means to obtain the least significant bits of the held signal after obtaining the most significant bits of said held signal.

Claim 5

The analog to digital converter according to claim 3 including: means to connect and disconnect said holding means and said input means; and said holding means holding the signal from said input means at the time of disconnection of said holding means from said input means.

Claim 6

The analog to digital converter according to claim 4 including: means to connect the output of said holding means to said input means to feed back the output of said holding means to said input means; and said connect and disconnect means includes means to disconnect said feedback connecting means when said holding means has its input disconnected from said input means.

Claim 7

The analog to digital converter according to claim 1 including: means to connect and disconnect said holding means and said input means; and said holding means holding the signal from said input means at the time of disconnection of said holding means from said input means.

Claim 8

The analog to digital converter according to claim 6 including: means to connect the output of said holding means to said input means to feed back the output of said holding means to said input means; and said connect and disconnect means includes means to disconnect said feedback connecting means when said holding means has its input disconnected from said input means.

Claim 9

A multichannel analog to digital converter comprising: a single input circuit; a plurality of first means with each of said first means sampling and holding a signal from said input circuit, said plurality of first means being equal to the number of channels; second means to control when each of said first means is connected to and disconnected from said input circuit; a plurality of parallel converting means equal in number to said first means; each of said parallel converting means being connected to a corresponding one of said first means to receive the output of said first means as an input; means to control when said parallel converting means produces a first output corresponding to the most significant bits of the signal held at said first means when said first means is disconnected from said input circuit; means to cause a ramp to be supplied from said first means to said connected parallel converting means; and means to produce a second output in accordance with the ramp from said first means with the second output being the least significant bits of the signal held at said first means when said first means is disconnected from said input circuit.

Claim 10

A multichannel analog to digital converter comprising: a single input circuit; a plurality of first means with each of said first means sampling and holding a signal from said input circuit, said plurality of first means being equal to the number of channels; second means to control when each of said first means is connected to and disconnected from said input circuit; a plurality of parallel converting means equal in number to said first means; each of said parallel converting means being connected to a corresponding one of said first means to receive the output of said first means as an input; means to control when said parallel converting means produces a first output corresponding to the most significant bits of the signal held at said first means when said first means is disconnected from said input circuit; means to cause a ramp to be supplied from said first means to said connected parallel converting means; and means to produce a second output in accordance with the ramp from said first means with the second output being the least significant bits of the signal held at said first means when said first means is disconnected from said input circuit.

Claim 11

The analog to digital converter according to claim 8 including: means to feed back the output of each of said first means to said input circuit as a feedback signal; and means to control when the output of each of said first means is fed back to said input circuit.

Claim 12

The analog to digital converter according to claim 9 in which said control means renders said feedback means effective to allow the output of each of said first means to be fed to said input circuit when said first means is connected to said input circuit by said second means to receive the signal therefrom as an input.

Claim 13

The analog to digital converter according to claim 8 in which each of said parallel converting means includes comparing means to produce the most significant bits of the signal held at said first means when said first means is disconnected from said input circuit by said second means.

Claim 14

The analog to digital converter according to claim 8 in which: each of said first means includes a capacitor holding the held signal; and means to cause discharge of said capacitor to produce the ramp.

Claim 15

The analog to digital converter according to claim 8 including threshold means responsive to the ramp from said first means.

Claim 16

A multichannel analog to digital converter comprising: a single input circuit; three channels connected to said input circuit; each of said channels including: means to hold a signal received from said input circuit; means to parallel convert the held signal at said holding means to produce the most significant bits of the held signal; means to convert said held signal to a ramp signal after obtaining said most significant bits; means to produce the least significant bits of the held signal from said ramp signal; and means to track the signal from said input circuit; and means to control each of said channels to cause each of said channels to have a different function occurring therein at the same time, said controlling means causing said parallel converting means to be effective in one of said channels while said ramp conversion means is effective in a second of said channels and said tracking means is effective in the third of the channels.

Claim 17

A multichannel analog to digital converter comprising: a single input circuit; three channels connected to said input circuit; each of said channels including: means to hold a signal received from said input circuit; means to parallel convert the held signal at said holding means to produce the most significant bits of the held signal; means to convert said held signal to a ramp signal after obtaining said most significant bits; means to produce the least significant bits of the held signal from said ramp signal; and means to track the signal from said input circuit; and means to control each of said channels to cause each of said channels to have a different function occurring therein at the same time, said controlling means causing said parallel converting means to be effective in one of said channels while said ramp conversion means is effective in a second of said channels and said tracking means is effective in the third of the channels.