Texas Instruments

The UCC25640x is a fully featured LLC controller with integrated high-voltage gate driver. It has been designed to pair with a PFC controller to provide a complete power system using a minimum of external components. The resulting power system is designed to meet the most stringent requirements for standby power without the need for a separate standby power converter. UCC25640x provides a highly efficient burst mode with soft-on and soft-off periods to minimize audible noise at standby operation. The burst power level and hysteresis are programmable, simplifying the optimization of efficiency and burst mode operation. Burst mode can also be disabled through pin configuration. UCC25640x uses hybrid hysteretic control to provide best in class line and load transient response. UCC25640x includes a range of features designed to make LLC converter operation well controlled and protected. It can be used with UCC28056 or UCC28064A PFC controllers, along with UCC24624 synchronous rectifier controller to offer a complete power supply solution. The UCC25640x is a fully featured LLC controller with integrated high-voltage gate driver. It has been designed to pair with a PFC controller to provide a complete power system using a minimum of external components. The resulting power system is designed to meet the most stringent requirements for standby power without the need for a separate standby power converter. UCC25640x provides a highly efficient burst mode with soft-on and soft-off periods to minimize audible noise at standby operation. The burst power level and hysteresis are programmable, simplifying the optimization of efficiency and burst mode operation. Burst mode can also be disabled through pin configuration. UCC25640x uses hybrid hysteretic control to provide best in class line and load transient response. UCC25640x includes a range of features designed to make LLC converter operation well controlled and protected. It can be used with UCC28056 or UCC28064A PFC controllers, along with UCC24624 synchronous rectifier controller to offer a complete power supply solution.

The UCC25660x family is a high-frequency LLC controller implementing Input-Power Proportional Control (IPPC) scheme, along with an enhanced light-load management and multiple protection features. IPPC widens the control range of the LLC converter simplifies the design of wide input and output-voltage range applications such as LED drivers, battery chargers. It can even work without a PFC for non-universal input applications. The UCC25660x family’s enhanced light-load management improves while minimizing audible noise. To minimize standby power, the UCC25660x family can directly disable the PFC controller when operating in burst mode. The automatic capacitive region avoidance scheme along with the adaptive soft start with reverse recovery avoidance scheme ensures that the device can never work in a mode where there is a potential to damage the FET’s. This scheme makes the controller ideal for working with a pre-biased load. The UCC25660x family comes with robust protection to help you design a reliable power supply. The UCC25660x family has options supporting high-voltage startup, X-capacitor (X-cap) discharge, OVP response, and extended Gain range. See details in the device comparison table. The UCC25660x family is a high-frequency LLC controller implementing Input-Power Proportional Control (IPPC) scheme, along with an enhanced light-load management and multiple protection features. IPPC widens the control range of the LLC converter simplifies the design of wide input and output-voltage range applications such as LED drivers, battery chargers. It can even work without a PFC for non-universal input applications. The UCC25660x family’s enhanced light-load management improves while minimizing audible noise. To minimize standby power, the UCC25660x family can directly disable the PFC controller when operating in burst mode. The automatic capacitive region avoidance scheme along with the adaptive soft start with reverse recovery avoidance scheme ensures that the device can never work in a mode where there is a potential to damage the FET’s. This scheme makes the controller ideal for working with a pre-biased load. The UCC25660x family comes with robust protection to help you design a reliable power supply. The UCC25660x family has options supporting high-voltage startup, X-capacitor (X-cap) discharge, OVP response, and extended Gain range. See details in the device comparison table.

The UCC35701/UCC35702 family of pulse width modulators is intended for isolated switching power supplies using primary side control. They can be used for both off-line applications and DC/DC converter designs such as in a distributed power system architecture or as a telecom power source. The devices feature low startup current, allowing for efficient off-line starting, yet have sufficient output drive to switch power MOSFETs in excess of 500kHz. Voltage feed forward compensation is operational over a 5:1 input range and provides fast and accurate response to input voltage changes over a 4:1 range. An accurate volt-second clamp and maximum duty cycle limit are also featured. Fault protection is provided by pulse by pulse current limiting as well as the ability to latch off after a programmable number of repetitive faults has occurred. Two UVLO options are offered. UCC35701 family has turn-on and turn-off thresholds of 13V/9V and UCC35702 family has thresholds of 9.6V/8.8V. The UCC35701/2 and the UCC25701/2 are offered in the 14 pin SOIC (D), 14 pin PDIP (N) or in 14 pin TSSOP (PW) packages. The UCC15701/2 is offered in the 14 pin CDIP (J) package. The UCC35701/UCC35702 family of pulse width modulators is intended for isolated switching power supplies using primary side control. They can be used for both off-line applications and DC/DC converter designs such as in a distributed power system architecture or as a telecom power source. The devices feature low startup current, allowing for efficient off-line starting, yet have sufficient output drive to switch power MOSFETs in excess of 500kHz. Voltage feed forward compensation is operational over a 5:1 input range and provides fast and accurate response to input voltage changes over a 4:1 range. An accurate volt-second clamp and maximum duty cycle limit are also featured. Fault protection is provided by pulse by pulse current limiting as well as the ability to latch off after a programmable number of repetitive faults has occurred. Two UVLO options are offered. UCC35701 family has turn-on and turn-off thresholds of 13V/9V and UCC35702 family has thresholds of 9.6V/8.8V. The UCC35701/2 and the UCC25701/2 are offered in the 14 pin SOIC (D), 14 pin PDIP (N) or in 14 pin TSSOP (PW) packages. The UCC15701/2 is offered in the 14 pin CDIP (J) package.

The UCC35705 and UCC35706 devices are 8-pin voltage mode primary side controllers with fast over-current protection. These devices are used as core high-speed building blocks in high performance isolated and non-isolated power converters. UCC35705/UCC35706 devices feature a high speed oscillator with integrated feed-forward compensation for improved converter performance. A typical current sense to output delay time of 25 ns provides fast response to overload conditions. The IC also provides an accurate programmable maximum duty cycle clamp for increased protection which can also be disabled for the oscillator to run at maximum possible duty cycle. Two UVLO options are offered. The UCC35705 with lower turn-on voltage is intended for dc-to-dc converters while the higher turn-on voltage and the wider UVLO range of the UCC35706 is better suited for offline applications. The UCC35705/UCC35706 family is offered in 8-pin MSOP (DGK), SOIC (D) and PDIP (P) packages. The UCC35705 and UCC35706 devices are 8-pin voltage mode primary side controllers with fast over-current protection. These devices are used as core high-speed building blocks in high performance isolated and non-isolated power converters. UCC35705/UCC35706 devices feature a high speed oscillator with integrated feed-forward compensation for improved converter performance. A typical current sense to output delay time of 25 ns provides fast response to overload conditions. The IC also provides an accurate programmable maximum duty cycle clamp for increased protection which can also be disabled for the oscillator to run at maximum possible duty cycle. Two UVLO options are offered. The UCC35705 with lower turn-on voltage is intended for dc-to-dc converters while the higher turn-on voltage and the wider UVLO range of the UCC35706 is better suited for offline applications. The UCC35705/UCC35706 family is offered in 8-pin MSOP (DGK), SOIC (D) and PDIP (P) packages.

The UCC25710 device is an LLC half-bridge controller for accurate control of multi-string LED backlight applications. It is optimized for multi-transformer, multi-string LED architectures. Superior LED current matching in multiple strings can be achieved with this controller and architecture. Compared to existing LED backlight solutions, the multi-transformer architecture provides the highest overall efficiency from AC input to LED load. The LLC controller function includes a Voltage Controlled Oscillator (VCO) with programmable FMINand FMAX, half-bridge gate drivers with a fixed dead time of 500 ns and a GM current amplifier. The LLC power delivery is modulated by the controller’s VCO frequency. The VCO has an accurate and programmable frequency range. At very low power levels the VCO frequency goes from FMAXto zero to maximize efficiency at low LED currents. The LED current loop reference is set by a divider off the VREF 5-V output. The reference can be varied over a 0.5-V to 2.6-V range, allowing analog dimming to be combined with PWM dimming. PWM dimming is used to control an external LED series switch and also to gate on and off the LLC power stage. The LEDSW output along with a simple drive circuit is used to switch on and off the LED string current. This output responds directly to the input signal at the dimming input, DIM. The LLC is also ramped on and off with the dimming PWM input. The on and off LLC dimming edges are ramped at programmable slew rates to control audible noise. The dimming function includes duty-cycle compensation to allow optimization of overall efficiency and dimming linearity over a maximum range. The control voltage to the VCO is set by ICOMP (current amplifier output) during LED ON-times. During start-up the soft-start pin, SS, controls the VCO response until it exceeds ICOMP. During dimming the rise and fall rates of the VCO input are controlled by the voltage at the dimming slew rate, DSR, pin while the pedestal of VCO control level continues to be controlled by ICOMP. The current amplifier output is connected to ICOMP only during the commanded dimming LED ON-time. The LLC on-time is extended beyond the LED current ON-time at low dimming duty-cycles to maintain closed-loop control of the LED current. Protection thresholds for LED string overvoltage and undervoltage conditions are set with external resistive dividers and accurate internal thresholds. Input current to the converter is monitored with both a restart and latchoff response depending on the overcurrent level. The controller also includes thermal shutdown protection. The auto restart response to any fault includes a 10-ms reset period followed by a soft start. In the case of a severe input overcurrent, restart is disabled until the input supply is cycled through its UVLO threshold. The UCC25710 device is an LLC half-bridge controller for accurate control of multi-string LED backlight applications. It is optimized for multi-transformer, multi-string LED architectures. Superior LED current matching in multiple strings can be achieved with this controller and architecture. Compared to existing LED backlight solutions, the multi-transformer architecture provides the highest overall efficiency from AC input to LED load. The LLC controller function includes a Voltage Controlled Oscillator (VCO) with programmable FMINand FMAX, half-bridge gate drivers with a fixed dead time of 500 ns and a GM current amplifier. The LLC power delivery is modulated by the controller’s VCO frequency. The VCO has an accurate and programmable frequency range. At very low power levels the VCO frequency goes from FMAXto zero to maximize efficiency at low LED currents. The LED current loop reference is set by a divider off the VREF 5-V output. The reference can be varied over a 0.5-V to 2.6-V range, allowing analog dimming to be combined with PWM dimming. PWM dimming is used to control an external LED series switch and also to gate on and off the LLC power stage. The LEDSW output along with a simple drive circuit is used to switch on and off the LED string current. This output responds directly to the input signal at the dimming input, DIM. The LLC is also ramped on and off with the dimming PWM input. The on and off LLC dimming edges are ramped at programmable slew rates to control audible noise. The dimming function includes duty-cycle compensation to allow optimization of overall efficiency and dimming linearity over a maximum range. The control voltage to the VCO is set by ICOMP (current amplifier output) during LED ON-times. During start-up the soft-start pin, SS, controls the VCO response until it exceeds ICOMP. During dimming the rise and fall rates of the VCO input are controlled by the voltage at the dimming slew rate, DSR, pin while the pedestal of VCO control level continues to be controlled by ICOMP. The current amplifier output is connected to ICOMP only during the commanded dimming LED ON-time. The LLC on-time is extended beyond the LED current ON-time at low dimming duty-cycles to maintain closed-loop control of the LED current. Protection thresholds for LED string overvoltage and undervoltage conditions are set with external resistive dividers and accurate internal thresholds. Input current to the converter is monitored with both a restart and latchoff response depending on the overcurrent level. The controller also includes thermal shutdown protection. The auto restart response to any fault includes a 10-ms reset period followed by a soft start. In the case of a severe input overcurrent, restart is disabled until the input supply is cycled through its UVLO threshold.

The UCC3580 family of PWM controllers is designed to implement a variety of active clamp/reset and synchronous rectifier switching converter topologies. While containing all the necessary functions for fixed frequency, high performance pulse width modulation, the additional feature of this design is the inclusion of an auxiliary switch driver which complements the main power switch, and with a programmable deadtime or delay between each transition. The active clamp/reset technique allows operation of single ended converters beyond 50% duty cycle while reducing voltage stresses on the switches, and allows a greater flux swing for the power transformer. This approach also allows a reduction in switching losses by recovering energy stored in parasitic elements such as leakage inductance and switch capacitance. The oscillator is programmed with two resistors and a capacitor to set switching frequency and maximum duty cycle. A separate synchronized ramp provides a voltage feedforward pulse width modulation and a programmed maximum volt-second limit. The generated clock from the oscillator contains both frequency and maximum duty cycle information. The main gate drive output (OUT1) is controlled by the pulse width modulator. The second output (OUT2) is intended to activate an auxiliary switch during the off time of the main switch, except that between each transition there is deadtime where both switches are off, programmed by a single external resistor. This design offers two options for OUT2, normal and inverted. In the -1 and -2 versions, OUT2 is normal and can be used to drive PMOS FETs. In the -3 and -4 versions, OUT2 is inverted and can be used to drive NMOS FETs. In all versions, both the main and auxiliary switches are held off prior to startup and when the PWM command goes to zero duty cycle. During fault conditions, OUT1 is held off while OUT2 operates at maximum duty cycle with a guaranteed off time equal to the sum of the two deadtimes. Undervoltage lockout monitors supply voltage (VDD), the precision reference (REF), input line voltage (LINE), and the shutdown comparator (SHTDWN). If after any of these four have sensed a fault condition, recovery to full operation is initiated with a soft start. VDD thresholds, on and off, are 15V and 8.5V for the -2 and -4 versions, 9V and 8.5V for the -1 and -3 versions. The UCC1580-x is specified for operation over the military temperature range of –55°C to 125°C. The UCC2580-x is specified from –40°C to 85°C. The UCC3580-x is specified from 0°C to 70°C. Package options include 16-pin surface mount and dual in-line. The UCC3580 family of PWM controllers is designed to implement a variety of active clamp/reset and synchronous rectifier switching converter topologies. While containing all the necessary functions for fixed frequency, high performance pulse width modulation, the additional feature of this design is the inclusion of an auxiliary switch driver which complements the main power switch, and with a programmable deadtime or delay between each transition. The active clamp/reset technique allows operation of single ended converters beyond 50% duty cycle while reducing voltage stresses on the switches, and allows a greater flux swing for the power transformer. This approach also allows a reduction in switching losses by recovering energy stored in parasitic elements such as leakage inductance and switch capacitance. The oscillator is programmed with two resistors and a capacitor to set switching frequency and maximum duty cycle. A separate synchronized ramp provides a voltage feedforward pulse width modulation and a programmed maximum volt-second limit. The generated clock from the oscillator contains both frequency and maximum duty cycle information. The main gate drive output (OUT1) is controlled by the pulse width modulator. The second output (OUT2) is intended to activate an auxiliary switch during the off time of the main switch, except that between each transition there is deadtime where both switches are off, programmed by a single external resistor. This design offers two options for OUT2, normal and inverted. In the -1 and -2 versions, OUT2 is normal and can be used to drive PMOS FETs. In the -3 and -4 versions, OUT2 is inverted and can be used to drive NMOS FETs. In all versions, both the main and auxiliary switches are held off prior to startup and when the PWM command goes to zero duty cycle. During fault conditions, OUT1 is held off while OUT2 operates at maximum duty cycle with a guaranteed off time equal to the sum of the two deadtimes. Undervoltage lockout monitors supply voltage (VDD), the precision reference (REF), input line voltage (LINE), and the shutdown comparator (SHTDWN). If after any of these four have sensed a fault condition, recovery to full operation is initiated with a soft start. VDD thresholds, on and off, are 15V and 8.5V for the -2 and -4 versions, 9V and 8.5V for the -1 and -3 versions. The UCC1580-x is specified for operation over the military temperature range of –55°C to 125°C. The UCC2580-x is specified from –40°C to 85°C. The UCC3580-x is specified from 0°C to 70°C. Package options include 16-pin surface mount and dual in-line.