US 11,671,138 B2
Self-calibrating on-off keying based digital isolator
RR Manikandan, Bangalore (IN); Kumar Anurag Shrivastava, Chhattisgarh (IN); Robert Floyd Payne, McKinney, TX (US); Anant Shankar Kamath, Bangalore (IN); Swaminathan Sankaran, Allen, TX (US); Kishalay Datta, Kolkata (IN); Siraj Akhtar, Richardson, TX (US); Mark Edward Wentroble, Plano, TX (US); Suvadip Banerjee, Bangalore (IN); Rakesh Hariharan, Bangalore (IN); and Gurumurti Kailaschandra Avhad, Bangalore (IN)
Assigned to Texas Instruments Incorporated, Dallas, TX (US)
Filed by Texas Instruments Incorporated, Dallas, TX (US)
Filed on Sep. 29, 2021, as Appl. No. 17/489,483.
Claims priority of provisional application 63/223,704, filed on Jul. 20, 2021.
Prior Publication US 2023/0025757 A1, Jan. 26, 2023
Int. Cl. H03K 5/24 (2006.01); H04B 1/44 (2006.01); H03K 3/017 (2006.01); H04L 27/06 (2006.01); H04L 27/04 (2006.01)
CPC H04B 1/44 (2013.01) [H03K 3/017 (2013.01); H03K 5/24 (2013.01); H04L 27/04 (2013.01); H04L 27/066 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An on-off keying (OOK) digital isolation transceiver, the transceiver comprising:
a transmitter side calibration circuitry including a calibration signal output, the transmitter side calibration circuitry configured to output a calibration signal;
a multiplexer including an isolator input, a calibration signal input, a calibration enable input, and a multiplexer output, the isolator input adapted to receive a data signal, the calibration signal input coupled to the calibration signal output, and the calibration enable input adapted to receive a calibration enable signal, the multiplexer configured to output a signal corresponding to one of the isolator input or the calibration signal input in response to the calibration enable signal;
an OOK modulator including a modulator input and a modulator output, the modulator input coupled to the multiplexer output, the OOK modulator configured to selectively output a transmitted signal having a reference frequency in response to a value of the modulator input corresponding to an on state or an off state of the OOK modulator;
an OOK envelope detector including a detector input, a control input, and a detector output, the OOK envelope detector configured to:
output a signal having a first value in response to detecting a signal received via an isolation barrier;
output a signal having a second value in response to not detecting the signal received via the isolation barrier; and
change a duty cycle of the detector output in response to the control input; and
a receiver side calibration circuitry including a calibration input and a control output, the calibration input coupled to the detector output, the control output coupled to the control input, the receiver side calibration circuitry configured to detect a duty cycle distortion (DCD) of the detector output and to output the control output in response to the detected DCD.