Extending On-Time for Power Converter Control

Abstract

A power transistor is switched on and off with an on-time that is held constant and an off-time that is varied. When the off-time is detected to be less than a threshold value that is greater than a minimum off-time limit, the on-time is extended. Then the power transistor is switched on and off with the extended on-time that is held constant and the off-time that varies.

Description

[0001] related application

[0002] This application claims priority to U.S. Nonprovisional Patent Application No. 17 / 247,536, filed December 15, 2020, entitled "Extending On-Time for PowerConverter Control," which claims Priority to U.S. Provisional Patent Application No. 62 / 976,171, entitled "Extending On-Time for Power Converter Control," both of which are incorporated herein by reference for all purposes. Background technique

[0003] Power converters generally generate a regulated output voltage Vout from a received input voltage Vin. In applications such as USB-PD (Universal Serial Bus-Power Distribution) that require driving various loads across a complex power distribution network with rapidly changing load transient distribution and a wide range of input voltage Vin and output voltage Vout, A constant on-time control architecture can be used to achieve fast load transient response with relatively simple compensation. A constant on-time architecture typically has a d...

Examples

Embodiment Construction

[0009] figure 1 A simplified schematic diagram of a power converter 100 for providing power to a load circuit 101 is shown, the power converter having a PWM (pulse width modulation) extension circuit 102 (i.e., a PWM signal generator) by using The on-time is kept constant and the off-time is varied to generate a PWM signal (switching signal). In addition, when the off-time of the PWM control and extension circuit 102 approaches the minimum allowable off-time, but before the off-time reaches or falls below the minimum off-time, the PWM control and extension circuit 102 extends the on-time of the PWM signal. time, thereby allowing the disconnection time to also increase. Therefore, there is a safety buffer between the point at which the PWM control and extension circuit 102 extends the on-time of the PWM signal and the minimum allowable off-time. This feature differs from prior art systems which do not include such a safety buffer, but instead do not extend the on-time until t...

[0001] related application

[0002] This application claims priority to U.S. Nonprovisional Patent Application No. 17 / 247,536, filed December 15, 2020, entitled "Extending On-Time for PowerConverter Control," which claims Priority to U.S. Provisional Patent Application No. 62 / 976,171, entitled "Extending On-Time for Power Converter Control," both of which are incorporated herein by reference for all purposes. Background technique

[0003] Power converters generally generate a regulated output voltage Vout from a received input voltage Vin. In applications such as USB-PD (Universal Serial Bus-Power Distribution) that require driving various loads across a complex power distribution network with rapidly changing load transient distribution and a wide range of input voltage Vin and output voltage Vout, A constant on-time control architecture can be used to achieve fast load transient response with relatively simple compensation. A constant on-time architecture typically has a d...

Examples

Embodiment Construction

[0009] figure 1 A simplified schematic diagram of a power converter 100 for providing power to a load circuit 101 is shown, the power converter having a PWM (pulse width modulation) extension circuit 102 (i.e., a PWM signal generator) by using The on-time is kept constant and the off-time is varied to generate a PWM signal (switching signal). In addition, when the off-time of the PWM control and extension circuit 102 approaches the minimum allowable off-time, but before the off-time reaches or falls below the minimum off-time, the PWM control and extension circuit 102 extends the on-time of the PWM signal. time, thereby allowing the disconnection time to also increase. Therefore, there is a safety buffer between the point at which the PWM control and extension circuit 102 extends the on-time of the PWM signal and the minimum allowable off-time. This feature differs from prior art systems which do not include such a safety buffer, but instead do not extend the on-time until t...

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