PATENT CLAIM ANALYSIS

Application Number: 15971629
Application Type: Utility
Filing Date: 2018-05
Publication Date: 2018-09
Patent Classification: ["363", "021140"]

Abstract:
A flyback converter implements a Forced Zero Voltage Switching (ZVS) timing control by detecting a positive current excursion of the secondary winding current as the synchronous rectifier turn off trigger. The synchronous rectifier switch is turned on near the end of the switching cycle or the on duration is extended to develop a current ripple on the secondary winding current. The control circuit of the flyback converter detects a positive current excursion on the secondary winding current to turn off the synchronous rectifier and to start the next switching cycle. At this point, the voltage across the primary switch has been discharged and the primary switch can be turned on with zero drain-to-source voltage. In other embodiments, zero voltage switching for the off-transition of the primary switch is realized by coupling a capacitor across the primary switch or by coupling a capacitor across the primary winding, or both.

Claim (Index 1):
A flyback converter, comprising:\n a transformer having a primary winding receiving an input voltage and a secondary winding providing an output voltage; a primary switch coupled to the primary winding; a synchronous rectifier coupled to the secondary winding; an output capacitor coupled across the secondary winding; a controller coupled to generate control signals to drive the primary switch and the synchronous rectifier; and a positive current detect circuit configured to sense a secondary current flowing in the secondary winding and to generate a detection signal in response to detecting the secondary current having a positive current value, wherein the controller generates a control signal to turn the primary switch and the synchronous rectifier on and off alternately within a switching cycle, the synchronous rectifier being turned on for a first on-duration within the switching cycle in response to the primary switch being turned off and the controller generates the control signal to turn off the synchronous rectifier for the first on-duration in response to detecting the secondary current reaching a zero current value and the controller continues to monitor the output voltage, and in response to the output voltage being at or less than a reference voltage, the controller generates the control signal to turn on the synchronous rectifier for a second on-duration within the switching cycle, the controller thereby operating the flyback converter in a discontinuous conduction mode.

Metadata:
- Claim Count in Document: 35.0
- Percentile: 93.0
- Lexical Diversity: 2.13514
- Patent Class: 363.0
- Transitional Phrase Type: open
- Component Type: 1
- Foreign Priority: False
- Related Applications: ['15334170', '15334173', '15007262', '15944815', '15662301']

Analysis Scores:
- 35 USC 101 Eligibility (BERT): 0.8336960513677121
- 35 USC 102 Novelty (BERT): 0.6271727963509548
- Combined Prediction Score: 0.8130437258660363
- Mean Citation Score: 446.281148
- Max Citation Score: 589.254
- Similarity Product: 564.4217435134651

Labels:
- Claim Label 101: 1
- Claim Label 102: 1
- Claim Label 103: 1
- Claim Label 112: 1
- Combined Label: 1
- Label 101 Adjusted: 1

Dataset: test