US 11,888,499 B2
Transition-state output device, time-to-digital converter, and analog-to-digital converter circuit
Masayoshi Todorokihara, Suwa (JP)
Assigned to SEIKO EPSON CORPORATION
Filed by Seiko Epson Corporation, Tokyo (JP)
Filed on Nov. 23, 2021, as Appl. No. 17/533,373.
Claims priority of application No. 2020-197280 (JP), filed on Nov. 27, 2020.
Prior Publication US 2022/0173749 A1, Jun. 2, 2022
Int. Cl. H03M 1/12 (2006.01); H03M 1/50 (2006.01); H03K 3/03 (2006.01)
CPC H03M 1/502 (2013.01) [H03K 3/0315 (2013.01); H03M 1/1255 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A transition-state output device comprising:
a ring oscillator circuit starting to oscillate based on a trigger signal;
a state machine changing in state according to a change in state of the ring oscillator circuit;
a transition-state acquisition section acquiring and holding state information including a signal output from the ring oscillator circuit and a signal output from the state machine, synchronously with a reference signal; and
an internal-state calculation section calculating an internal state corresponding to a number of changes in state of the ring oscillator circuit, based on the state information held by the transition-state acquisition section, wherein
a time until the internal state, after transitioning from a first internal state to a second internal state, transitions to the first internal state again is longer than a time interval of updating the state information held by the transition-state acquisition section.