UC1846-DIESpace-grade, 40-V input, 1.5-A dual-output 500-kHz PWM controller in DIE | Power Supply Controllers, Monitors | 1 | Active | The UC1846 control IC provides all of the necessary features to implement fixed-frequency, current-mode control schemes, while maintaining a minimum external parts count. The superior performance of this technique can be measured in improved line regulation, enhanced load-response characteristics, and a simpler, easier-to-design control loop. Topological advantages include inherent pulse-by-pulse current-limiting capability, automatic symmetry correction for push-pull converters, and the ability to parallel power modules, while maintaining equal current sharing.
Protection circuitry includes built-in undervoltage lockout and programmable current limit, in addition to soft-start capability. A shutdown function is also available, which can initiate either a complete shutdown with automatic restart or latch the supply off.
Other features include fully latched operation, double pulse suppression and deadline adjust capability.
The UC1846 features low outputs in the OFF state.
The UC1846 control IC provides all of the necessary features to implement fixed-frequency, current-mode control schemes, while maintaining a minimum external parts count. The superior performance of this technique can be measured in improved line regulation, enhanced load-response characteristics, and a simpler, easier-to-design control loop. Topological advantages include inherent pulse-by-pulse current-limiting capability, automatic symmetry correction for push-pull converters, and the ability to parallel power modules, while maintaining equal current sharing.
Protection circuitry includes built-in undervoltage lockout and programmable current limit, in addition to soft-start capability. A shutdown function is also available, which can initiate either a complete shutdown with automatic restart or latch the supply off.
Other features include fully latched operation, double pulse suppression and deadline adjust capability.
The UC1846 features low outputs in the OFF state. |
UC1846-SPRadiation-tolerant QMLV, 40-V input, 0.5-A dual-output 500-kHz PWM controller | Power Management (PMIC) | 1 | Active | The UC1846-SP control devices provide all of the necessary features to implement fixed frequency, current mode control schemes while maintaining a minimum external parts count. The superior performance of this technique can be measured in improved line regulation, enhanced load response characteristics, and a simpler, easier-to-design control loop. Topological advantages include inherent pulse-by-pulse current limiting capability, automatic symmetry correction for push-pull converters, and the ability to parallelpower moduleswhile maintaining equal current sharing.
Protection circuitry includes built-in UVLO and programmable current limit in addition to soft-start capability. A shutdown function is also available which can initiate either a complete shutdown with automatic restart or latch the supply off.
Other features include fully latched operation, double-pulse suppression, deadline adjust capability, a ±1% trimmed bandgap reference, and low outputs in the OFF state.
The UC1846-SP control devices provide all of the necessary features to implement fixed frequency, current mode control schemes while maintaining a minimum external parts count. The superior performance of this technique can be measured in improved line regulation, enhanced load response characteristics, and a simpler, easier-to-design control loop. Topological advantages include inherent pulse-by-pulse current limiting capability, automatic symmetry correction for push-pull converters, and the ability to parallelpower moduleswhile maintaining equal current sharing.
Protection circuitry includes built-in UVLO and programmable current limit in addition to soft-start capability. A shutdown function is also available which can initiate either a complete shutdown with automatic restart or latch the supply off.
Other features include fully latched operation, double-pulse suppression, deadline adjust capability, a ±1% trimmed bandgap reference, and low outputs in the OFF state. |
| Integrated Circuits (ICs) | 1 | Active | |
| PFC (Power Factor Correction) | 2 | Active | |
UC1854BEnhanced High Power Factor Preregulator | Power Management (PMIC) | 2 | Active | The UC3854A/B products are pin compatible enhanced versions of the UC3854. Like the UC3854, these products provide all of the functions necessary for active power factor corrected preregulators. The controller achieves near unity power factor by shaping the ac input line current waveform to correspond to the ac input line voltage. To do this the UC3854A/B uses average current mode control. Average current mode control maintains stable, low distortion sinusoidal line current without the need for slope compensation, unlike peak current mode control.
A 1%, 7.5-V reference, fixed frequency oscillator, PWM, voltage amplifierwith soft-start, line voltage feedforward (VRMSsquarer), input supply voltage clamp, and over current comparator round out the lilst of feataures.
Available in the 16-pin N (PDIP), DW (SOIC Wide), and J (CDIP) and 20-pin Q (PLCC) package. See Ordering Information table for availability by temperature range.
The UC3854A/B products improve upon the UC3854 by offering a wide bandwidth, low offset current amplifier, a faster responding and improved accuracy enable comparator, a VREF GOOD comparator, UVLO threshold options (16 V/10 V for offline, 10.5 V/10 V for startup from an auxiliary 12-V regulator), lower startup supply current, and an enhanced multiply/divide circuit. New features like the amplifier output clamps, improved amplifier current sinking capability, and low offset VAC pin reduce the external component count while improving performance. Improved common mode input range of the multiplier output/current amplifier input allow the designer greater flexibility in choosing amethod for current sensing. Unlike its predecessor, RSETcontrols only oscillator charging current and has no effect on clamping the maximum multiplier output current. This current is now clamped to a maximum of 2 × IACat all times which simplifies the design process and provides foldback power limiting during brownout and extreme low line conditions.
The UC3854A/B products are pin compatible enhanced versions of the UC3854. Like the UC3854, these products provide all of the functions necessary for active power factor corrected preregulators. The controller achieves near unity power factor by shaping the ac input line current waveform to correspond to the ac input line voltage. To do this the UC3854A/B uses average current mode control. Average current mode control maintains stable, low distortion sinusoidal line current without the need for slope compensation, unlike peak current mode control.
A 1%, 7.5-V reference, fixed frequency oscillator, PWM, voltage amplifierwith soft-start, line voltage feedforward (VRMSsquarer), input supply voltage clamp, and over current comparator round out the lilst of feataures.
Available in the 16-pin N (PDIP), DW (SOIC Wide), and J (CDIP) and 20-pin Q (PLCC) package. See Ordering Information table for availability by temperature range.
The UC3854A/B products improve upon the UC3854 by offering a wide bandwidth, low offset current amplifier, a faster responding and improved accuracy enable comparator, a VREF GOOD comparator, UVLO threshold options (16 V/10 V for offline, 10.5 V/10 V for startup from an auxiliary 12-V regulator), lower startup supply current, and an enhanced multiply/divide circuit. New features like the amplifier output clamps, improved amplifier current sinking capability, and low offset VAC pin reduce the external component count while improving performance. Improved common mode input range of the multiplier output/current amplifier input allow the designer greater flexibility in choosing amethod for current sensing. Unlike its predecessor, RSETcontrols only oscillator charging current and has no effect on clamping the maximum multiplier output current. This current is now clamped to a maximum of 2 × IACat all times which simplifies the design process and provides foldback power limiting during brownout and extreme low line conditions. |
| Integrated Circuits (ICs) | 1 | Active | |
| Power Management (PMIC) | 1 | Active | |
| DC DC Switching Controllers | 2 | Active | |
| Integrated Circuits (ICs) | 2 | Active | |
| DC DC Switching Controllers | 1 | Active | |
