EP0255326A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Current mode control arrangement with load dependent ramp signal added to sensed current waveform
Assignee: AT&T Inc
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Filing: 1987-07-28
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Granted: —
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Expires: 2007-07-28
Abstract
Abstract A switching converter in which current mode voltage regulation is implemented includes circuitry to add ramp compensation to the sensed current signal at light load and reduce or disable this ramp signal compensation at heavy load 257, 258, 259, 260. This load dependent ramp signal improves the stability of the converter and maintains its inherent current limit performace over a wide range of loading.
Inventors
- 👤 James Harold Murdock
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 22:35
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/325; H02M3/335; H02M3/33538; H02M3/33546
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
150 words
A converter circuit comprising; an input and an output, a power switch periodically enabled to interconnect the input and the output, means for regulating a voltage level at the output including, means for generating a current control signal proportionate to a difference between a voltage regulation value and the voltage level at the output, means for sensing a current in the power switch and producing a current feedback signal proportionate to current flow in the power switch, and a ramp waveform source, CHARACTERIZED BY means for controlling a magnitude of the ramp waveform in response to a magnitude of the current feedback signal, means for summing the ramp waveform with the current feedback signal, and means for comparing an output of the means for summing with the current control signal and disabling the power switch when the output of the means for summing achieves equality with the current control signal.
Claim 2
Dependent Claim
150 words
A converter circuit comprising; an input and an output, a power switch periodically enabled to interconnect the input and the output, means for regulating a voltage level at the output including, means for generating a current control signal proportionate to a difference between a voltage regulation value and the voltage level at the output, means for sensing a current in the power switch and producing a current feedback signal proportionate to current flow in the power switch, and a ramp waveform source, CHARACTERIZED BY means for controlling a magnitude of the ramp waveform in response to a magnitude of the current feedback signal, means for summing the ramp waveform with the current feedback signal, and means for comparing an output of the means for summing with the current control signal and disabling the power switch when the output of the means for summing achieves equality with the current control signal.
Claim 3
Dependent Claim
59 words
A converter circuit as defined in claim 1 CHARACTERIZED IN THAT the means for controlling includes diode switch means for coupling the ramp waveform to the means for summing when the current feedback signal is below a predetermined threshold and decoupling the ramp waveform from the means for summing when the current feedback at least equals the predetermined threshold.
Claim 4
Dependent Claim
34 words
A converter circuit as defined in claim 2 CHARACTERIZED IN THAT the means for coupling and decoupling further includes a resistive network responsive to the current feedback signal magnitude for biasing the diode switch.
Claim 5
Dependent Claim
36 words
A converter circuit as defined in claim 1 CHARACTERIZED IN THAT the means for controlling includes means for reducing a magnitude of the ramp waveform proportionate to an increase in magnitude of the current feedback signal.
Claim 6
Dependent Claim
39 words
A converter circuit as defined in claim 4 CHARACTERIZED IN THAT the means for controlling include a high impedance and diode switch connected in shunt with each other and coupling the ramp waveform source to the means for summing.
References Cited (Backward Citations)
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