by Susan Nordyk @ edn.com:
Intended to drive logic levels of 3.3 V down to 1.8 V, the LTC6752 comparator from Linear Technology achieves fast rise and fall times of 1.2 ns and a toggle frequency of 280 MHz, making it one of the fastest CMOS-output comparators on the market. The device exhibits a propagation delay of only 2.9 ns and overdrive dispersion of just 1.8 ns. Jitter is 4.5 ps for a 100-mV pk-pk, 100-MHz sinusoidal input, and the outputs swing to within 200-mV of the rails with up to 8 mA of load current.
The LTC6752 offers five options in different packages with unique combinations of features, such as separate input and output supplies, low-power shutdown, output latch, adjustable hysteresis, and complementary outputs. Inputs extend beyond both rails, which is useful for single-supply operation. All five variants of the LTC6752 are capable of driving 3.3-V and 2.5-V logic. Three versions have separate input and output supplies, decoupling the input and output voltage levels and enabling them to drive 1.8-V logic.
High-speed comparator cuts delays to 2.9 ns - [Link]
A synchronous buck-boost DC/DC converter that accepts 2.2 V to 18 V on each of its two inputs, the LTC3118 from Linear Technology enables high-efficiency operation from either input source to a programmable output voltage above, below, or equal to the inputs. Its dual-input capability is suitable for applications that employ batteries or supercaps as secondary or backup inputs, as well as those that use multiple sources, such as a wall adapter and Li-Ion cells.
The current-mode converter has a fixed 1.2-MHz switching frequency and furnishes up to 2 A of continuous output current from a wide range of power sources, including single or multiple-cell batteries, supercapacitor stacks, and wall adapters. Output voltage is programmable from 2 V to 18 V. Integrated low-loss PowerPath control is also user-programmable to prioritize and seamlessly transition between inputs, while maintaining output voltage regulation.
Buck-boost converter works with dual inputs - [Link]
The LT®8570 and LT8570-1 are PWM DC/DC converters. The LT8570 contains a 0.5A, 65V power switch, while the LT8570-1 contains a 0.25A, 65V power switch. The LT8570 and LT8570-1 can be configured as either a boost, SEPIC or inverting converter.
The LT8570/LT8570-1 have an adjustable oscillator, set by a resistor from the RT pin to ground. Additionally, the LT8570/LT8570-1 can be synchronized to an external clock. The switching frequency of the part may be free running or synchronized, and can be set between 200kHz and 1.5MHz.
LT8570 – Boost/SEPIC/Inverting DC/DC Converter with 65V Switch, Soft-Start and Synchronization - [Link]
The LTC®3899 is a high performance triple output (buck/ buck/boost) DC/DC switching regulator controller that drives all N-channel synchronous power MOSFET stages. The constant frequency current mode architecture allows a phase-lockable frequency of up to 850kHz. The LTC3899 operates from a wide 4.5V to 60V input supply range. When biased from the output of the boost converter or another auxiliary supply, the LTC3899 can operate from an input supply as low as 2.2V after start-up.
LTC3899 – 60V Low IQ, Triple Output, Buck/Buck/Boost Synchronous Controller - [Link]
The LT®3042 is a high performance low dropout linear regulator featuring LTC’s ultralow noise and ultrahigh PSRR architecture for powering noise sensitive RF applications. Designed as a precision current reference followed by a high performance voltage buffer, the LT3042 can be easily paralleled to further reduce noise, increase output current and spread heat on the PCB.
The device supplies 200mA at a typical 350mV dropout voltage. Operating quiescent current is nominally 2mA and drops to <<1μA in shutdown. The LT3042’s wide output voltage range (0V to 15V) while maintaining unitygain operation provides virtually constant output noise, PSRR, bandwidth and load regulation, regardless of the programmed output voltage. Additionally, the regulator features programmable current limit, fast start-up capability and programmable power good to indicate output voltage regulation.
LT3042 – 20V, 200mA, Ultralow Noise, Ultrahigh PSRR RF Linear Regulator - [Link]
by Susan Nordyk @ edn.com:
A synchronous PWM controller for negative-to-negative or negative-to-positive DC/DC conversion, the LT8709 from Linear Technology is easily configured for buck, boost, buck-boost, and inverting topologies to accommodate a wide range of power-supply designs. The device’s synchronous operation means that the output diode is replaced with a high-efficiency P-channel MOSFET, increasing efficiency and allowing for higher output currents of up to 20 A. It also eliminates the heat sink typically required in medium- to high-power applications.
The LT8709 operates over an input range of -4.5 V to -80 V and produces an output from -0.1 V to as high as 60 V or from -1.4 V to as low as -80 V. Its rail-to-rail output-current monitor and control enable the device to be configured as a current source. The controller has an EN/FBIN pin that accepts slowly varying input signals, as well as an adjustable undervoltage lockout function.
Buck/boost/inverting controller delivers up to 20 A - [Link]
Linear Technology announces the LT3790, a synchronous buck-boost DC/DC controller that delivers up to 250 W of power with a single IC. Its 4.7 V to 60 V input voltage range makes it ideal for a wide variety of automotive and industrial applications. Its output voltage can be set from 0 V to 60 V, making it well suited as a voltage regulator or battery/supercapacitor charger. The LT3790’s internal 4-switch buck-boost controller operates from input voltages above, below or equal to the output voltage, making it ideal for applications such as automotive, where the input voltage can vary dramatically during stop/start, cold crank and load dump scenarios. Transitions between buck, pass-through and boost operating modes are seamless, offering a well regulated output in spite of wide variations of supply voltage. The LT3790’s unique design utilizes three control loops to monitor input current, output current and output voltage to deliver optimal performance and reliability.
60V, Synchronous Buck-Boost Controller - [Link]
LT3795 – 110V LED Controller with Spread Spectrum Frequency Modulation. by elektor.com:
It’s standard practice to use Pulse Width Modulated (PWM) signals to control electrical energy delivered to a load. Special precautions are however necessary to mitigate the effects of electromagnetic interference (EMI) generated when high-energy loads are regulated in this way. Spectral analyses of the interference generated show strong peaks at the fundamental and harmonics of the PWM frequency. For high-power switch-mode drivers used to control LED car headlights it is important to ensure the interference cannot disrupt radio or GPS reception. EMI filters and gate resistors can be used to slow down switching edges but have the effect of increasing energy losses.
Spread Spectrum LED driver - [Link]
Linear Technology Corporation announces the LTC3371, a highly integrated general-purpose power management solution for systems requiring multiple low voltage power supplies. The device features four synchronous buck converters, each powered from independent 2.25 V to 5.5 V inputs, and each configurable to share up to four of eight available 1 A power stages. With eight unique output current configurations, the LTC3371 provides substantial flexibility and ease of reuse across many different applications. The device is ideal for a wide variety of multichannel industrial, automotive, communications and distributed power systems.
Configurable Buck DC/DCs Deliver a Total of 8A from 2 to 4 Independent Outputs for Power System Flexibility - [Link]
by Maurice O’Brien @ edn.com:
Wideband communication systems usually require an ultra-low noise regulator to power the VCOs and PLLs. The regulator must also be able to reject any ripple presented at its input. In a typical system, an ac input is converted to an isolated dc supply rail, –48-V, for example. This rail is then converted to an isolated 12-V or 5-V system rail that powers the main components in the communication system.
Ultra-low noise linear regulators for powering PLL/VCO and clocking ICs - [Link]