Texas Instruments

The UCC28730-Q1 isolated-flyback power supply controller provides constant-voltage (CV) and constant-current (CC) output regulation without the use of an optical coupler. A minimum switching frequency of 30 Hz achieves less than 5 mW of no-load power. This device processes information from the primary power switch and an auxiliary flyback winding for precise control of output voltage and current. An internal 700-V start-up switch, dynamically- controlled operating states and a tailored modulation profile support ultra-low stand-by power without sacrificing start-up time or output transient response. Control algorithms in the UCC28730-Q1 allow operating efficiencies to meet or exceed applicable standards. Discontinuous conduction mode (DCM) operation with valley-switching reduces switching losses. Modulation of the switching frequency and primary current peak amplitude (FM and AM) keeps the conversion efficiency high across the entire load and line ranges. The UCC28730-Q1 isolated-flyback power supply controller provides constant-voltage (CV) and constant-current (CC) output regulation without the use of an optical coupler. A minimum switching frequency of 30 Hz achieves less than 5 mW of no-load power. This device processes information from the primary power switch and an auxiliary flyback winding for precise control of output voltage and current. An internal 700-V start-up switch, dynamically- controlled operating states and a tailored modulation profile support ultra-low stand-by power without sacrificing start-up time or output transient response. Control algorithms in the UCC28730-Q1 allow operating efficiencies to meet or exceed applicable standards. Discontinuous conduction mode (DCM) operation with valley-switching reduces switching losses. Modulation of the switching frequency and primary current peak amplitude (FM and AM) keeps the conversion efficiency high across the entire load and line ranges.

The UCC28740 isolated-flyback power-supply controller provides Constant-Voltage (CV) using an optical coupler to improve transient response to large-load steps. Constant-Current (CC) regulation is accomplished through Primary-Side Regulation (PSR) techniques. This device processes information from opto-coupled feedback and an auxiliary flyback winding for precise high-performance control of output voltage and current. An internal 700-V startup switch, dynamically controlled operating states, and a tailored modulation profile support ultra-low standby power without sacrificing startup time or output transient response. Control algorithms in the UCC28740 allow operating efficiencies to meet or exceed applicable standards. The drive output interfaces to a MOSFET power switch. Discontinuous conduction mode (DCM) with valley-switching reduces switching losses. Modulation of switching frequency and primary current-peak amplitude (FM and AM) keeps the conversion efficiency high across the entire load and line ranges. The controller has a maximum switching frequency of 100 kHz and always maintains control of the peak-primary current in the transformer. Protection features keep primary and secondary component stresses in check. A minimum switching frequency of 170 Hz facilitates the achievement of less than 10-mW no-load power. The UCC28740 isolated-flyback power-supply controller provides Constant-Voltage (CV) using an optical coupler to improve transient response to large-load steps. Constant-Current (CC) regulation is accomplished through Primary-Side Regulation (PSR) techniques. This device processes information from opto-coupled feedback and an auxiliary flyback winding for precise high-performance control of output voltage and current. An internal 700-V startup switch, dynamically controlled operating states, and a tailored modulation profile support ultra-low standby power without sacrificing startup time or output transient response. Control algorithms in the UCC28740 allow operating efficiencies to meet or exceed applicable standards. The drive output interfaces to a MOSFET power switch. Discontinuous conduction mode (DCM) with valley-switching reduces switching losses. Modulation of switching frequency and primary current-peak amplitude (FM and AM) keeps the conversion efficiency high across the entire load and line ranges. The controller has a maximum switching frequency of 100 kHz and always maintains control of the peak-primary current in the transformer. Protection features keep primary and secondary component stresses in check. A minimum switching frequency of 170 Hz facilitates the achievement of less than 10-mW no-load power.

The UCC28740-Q1 isolated-flyback power-supply controller regulates the output using an optical coupler to provide fast transient response to large-load steps. An internal 700-V startup switch, dynamically controlled operating states, and a tailored modulation profile support ultra-low standby power without sacrificing startup time or output transient response. Control algorithms in the UCC28740-Q1 allow operating efficiencies to meet or exceed applicable standards. The drive output interfaces to a MOSFET power switch. Discontinuous conduction mode (DCM) with valley-switching reduces switching losses. Modulation of switching frequency and primary current-peak amplitude (FM and AM) keeps the conversion efficiency high across the entire load and line ranges. The controller has a maximum switching frequency of 100 kHz and always maintains control of the peak-primary current in the transformer. Protection features keep primary and secondary component stresses in check. A minimum switching frequency of 170 Hz facilitates the achievement of less than 10-mW no-load power. The UCC28740-Q1 isolated-flyback power-supply controller regulates the output using an optical coupler to provide fast transient response to large-load steps. An internal 700-V startup switch, dynamically controlled operating states, and a tailored modulation profile support ultra-low standby power without sacrificing startup time or output transient response. Control algorithms in the UCC28740-Q1 allow operating efficiencies to meet or exceed applicable standards. The drive output interfaces to a MOSFET power switch. Discontinuous conduction mode (DCM) with valley-switching reduces switching losses. Modulation of switching frequency and primary current-peak amplitude (FM and AM) keeps the conversion efficiency high across the entire load and line ranges. The controller has a maximum switching frequency of 100 kHz and always maintains control of the peak-primary current in the transformer. Protection features keep primary and secondary component stresses in check. A minimum switching frequency of 170 Hz facilitates the achievement of less than 10-mW no-load power.

UCC28750 is a highly-integrated current-mode, continuous-conduction-capable, PWM controller optimized for high performance, low standby power, and cost effective offline flyback converter applications using an opto-coupler. During light-load conditions the device enters frequency foldback and burst modes, improving light-load efficiency. The burst-mode algorithm used in UCC28750 controls the minimum effective switching frequency to prevent audible noise during light-load conditions. Frequency dithering improves EMI performance, and is active in normal, frequency foldback, and power boost operations. UCC28750 provides protection features that enable a robust converter design with minimal external components. Output over-power protection (OPP) and cycle-by-cycle over-current limit protect the load and power-stage components from electrical stress. Over-voltage and under-voltage lockout (OVLO and UVLO) prevent switching in unwanted input conditions. The FLT pin provides line brown-out sensing and protection, or external over-temperature and over-voltage protection, depending on the device variant. The FLT pin is also used to disable the device through external control by pulling the pin to ground, regardless of the device variant. UCC28750 is a highly-integrated current-mode, continuous-conduction-capable, PWM controller optimized for high performance, low standby power, and cost effective offline flyback converter applications using an opto-coupler. During light-load conditions the device enters frequency foldback and burst modes, improving light-load efficiency. The burst-mode algorithm used in UCC28750 controls the minimum effective switching frequency to prevent audible noise during light-load conditions. Frequency dithering improves EMI performance, and is active in normal, frequency foldback, and power boost operations. UCC28750 provides protection features that enable a robust converter design with minimal external components. Output over-power protection (OPP) and cycle-by-cycle over-current limit protect the load and power-stage components from electrical stress. Over-voltage and under-voltage lockout (OVLO and UVLO) prevent switching in unwanted input conditions. The FLT pin provides line brown-out sensing and protection, or external over-temperature and over-voltage protection, depending on the device variant. The FLT pin is also used to disable the device through external control by pulling the pin to ground, regardless of the device variant.

UCC28780 is a high-frequency active-clamp flyback controller that enables high-density AC-to-DC power supplies that comply with stringent global efficiency standards such as DoE Level VI and EU CoC V5 Tier-2. User programmable advanced control law features allow performance to be optimized for both Silicon (Si) and Gallium Nitride (GaN) power FETs. Direct operation with switching devices that combine driver and GaN FETs is further enhanced with logic-level gate signals and enable outputs. Zero voltage switching (ZVS) is achieved over a wide operating range with advanced auto-tuning techniques, adaptive dead-time optimization, and variable switching frequency control law. Using adaptive multimode control that changes the operation based on input and output conditions, UCC28780 enables high efficiency while mitigating audible noise. With a variable switching frequency of up to 1 MHz and accurate programmable over-power protection, which provides consistent power for thermal design across wide line range, the size of passive components can be further reduced and enable high power density. UCC28780 works with VDS-sensing synchronous rectifier controllers, such asUCC24612, to achieve higher conversion efficiency and very compact designs. UCC28780 is a high-frequency active-clamp flyback controller that enables high-density AC-to-DC power supplies that comply with stringent global efficiency standards such as DoE Level VI and EU CoC V5 Tier-2. User programmable advanced control law features allow performance to be optimized for both Silicon (Si) and Gallium Nitride (GaN) power FETs. Direct operation with switching devices that combine driver and GaN FETs is further enhanced with logic-level gate signals and enable outputs. Zero voltage switching (ZVS) is achieved over a wide operating range with advanced auto-tuning techniques, adaptive dead-time optimization, and variable switching frequency control law. Using adaptive multimode control that changes the operation based on input and output conditions, UCC28780 enables high efficiency while mitigating audible noise. With a variable switching frequency of up to 1 MHz and accurate programmable over-power protection, which provides consistent power for thermal design across wide line range, the size of passive components can be further reduced and enable high power density. UCC28780 works with VDS-sensing synchronous rectifier controllers, such asUCC24612, to achieve higher conversion efficiency and very compact designs.

The UCC28781 is a zero-voltage-switching (ZVS) controller which can be used at very high switching frequencies to minimize the size of the transformer and enable high power density. With direct synchronous rectifier (SR) control, the controller does not need a separate SR controller, as it can drive the SR FET directly to maximize efficiency and simplify design. (For isolated applications, an isolated gate-driver IC is required.) Using adaptive dead-time control for ZVS, switching losses and EMI are minimized. This design results in a controller with extremely high conversion efficiency across the entire operating range. The programmable adaptive burst mode (ABM) gives flexibility to control when the controller enters and exits standby mode to optimize standby power in light and no-load conditions. ABM also helps to reduce ripple and minimize audible noise. The controller offers multiple protection modes with automatic restart (retry) responses. The UCC28781 is a zero-voltage-switching (ZVS) controller which can be used at very high switching frequencies to minimize the size of the transformer and enable high power density. With direct synchronous rectifier (SR) control, the controller does not need a separate SR controller, as it can drive the SR FET directly to maximize efficiency and simplify design. (For isolated applications, an isolated gate-driver IC is required.) Using adaptive dead-time control for ZVS, switching losses and EMI are minimized. This design results in a controller with extremely high conversion efficiency across the entire operating range. The programmable adaptive burst mode (ABM) gives flexibility to control when the controller enters and exits standby mode to optimize standby power in light and no-load conditions. ABM also helps to reduce ripple and minimize audible noise. The controller offers multiple protection modes with automatic restart (retry) responses.