Demonstration circuit 2918A is a 42V, 5A synchronous step-down SILENT SWITCHER with spread spectrum frequency modulation featuring the LT8636. The demo board is designed for 5V output from a 5.8V to 42V input. The wide input range allows a variety of input sources, such as automotive batteries and industrial supplies. The LT8636 is a compact, low emission, high efficiency, and high frequency synchronous monolithic step-down switching regulator. The proprietary silent switcher architecture minimizes electromagnetic emissions with simplified filter and reduced layout sensitivity. Selectable spread spectrum mode further improves EMI performance, making it perfect solution to the noise sensitive applications. The regulator’s ultralow 2.5μA quiescent current with the output in full regulation enables applications requiring highest efficiency at very light load currents, such as automotive and battery powered portable instruments. Peak current mode control with minimum on-time of as small as 30ns allows high step-down conversion even at high frequency. The LT8636 switching frequency can be programmed either via oscillator resistor or external clock over a 200kHz to 3MHz range. The default frequency of demo circuit 2918A is 2MHz. The SYNC/MODE pin on the demo board 2918A is grounded (JP1 at BURST position) by default for low ripple Burst Mode® operation. To synchronize to an external clock, move the Jump JP1 to SYNC/FCM and apply the external clock to the SYNC terminal on the 2918A. In sync mode, the part runs in forced continuous mode. Without external clock applied, the SYNC/MODE pin is floating, and the part runs in forced continuous mode. This mode offers fast transient response and full frequency operation over a wide load range. Alternatively, move the Jump JP1 to the SPREAD-SPECTRUM, and the SYNC/MODE is tied to INTVCC, the part runs in forced continuous mode with spread spectrum function enabled. To get accurate efficiency measurement, measure the input voltage at the VIN_SENSE and GND terminals, which are Kelvin connected to the input cap C2 through signal traces. The LT8636 is assembled in a 4mmx3mm LQFN package with exposed pads for low thermal resistance. The rated maximum load current is 5A, while derating is necessary for certain input voltage and thermal conditions. The demo board has an EMI filter installed. The red line in Radiated EMI Performance is CISPR25 Class 5 peak limit. The circuit passes the test with a wide margin. To achieve EMI/EMC performance, the input EMI filter is required and the input voltage should be applied at VEMI terminal, and the setup can be referred to the CISPR 25 standards. The LT8636 datasheet gives a complete description of the part, operation and application information. The datasheet must be read in conjunction with this demo manual for demo circuit 2918A. The layout recommendations for low EMI operation and best thermal performance are available in the datasheet section Low EMI PCB Layout and Thermal Considerations and Peak Output Current. Contact ADI applications engineer for support.

The LT8636/LT8637 synchronous step-down regulator features Silent Switcher architecture designed to minimize EMI emissions while delivering high efficiency at high switching frequencies. Peak current mode control with a 30ns minimum on-time allows high step-down ratios even at high switching frequencies.The LT8636?s ultralow 2.5?A quiescent current?with the output in full regulation?enables applications requiring highest efficiency at very small load currents. The LT8637 has external compensation to enable current sharing and fast transient response at high switching frequencies. A CLKOUT pin enables synchronizing other regulators to the LT8636/LT8637.Burst Mode operation enables ultralow standby current consumption, forced continuous mode can control frequency harmonics across the entire output load range, or spread spectrum operation can further reduce EMI emissions. Soft-start and tracking functionality is accessed via the TR/SS pin, and an accurate input voltage UVLO threshold can be set using the EN/UV pin.APPLICATIONS Automotive and Industrial Supplies General Purpose Step-Down

The LTC1773 is a current mode synchronous buck regulator controller that drives external complementary power MOSFETs using a fixed frequency architecture. The operating supply range is from 2.65V to 8.5V, making it suitable for 1- or 2-cell lithium-ion battery powered applications. Burst Mode? operation provides high efficiency at low load currents. 100% duty cycle provides low dropout operation which extends operating time in battery-operated systems.The operating frequency is internally set at 550kHz, allowing the use of small surface mount inductors. For switching-noise sensitive applications, it can be synchronized up to 750kHz. Peak current limit is user programmable with an external high side sense resistor. A SYNC/FCB control pin guarantees regulation of secondary windings regardless of load on the main output by forcing continuous operation. Burst Mode operation is inhibited during synchronization or when the SYNC/FCB pin is pulled low to reduce noise and RF interference. Soft-start is provided by an external capacitor.Synchronous rectification increases efficiency and eliminates the need for a Schottky diode, saving components and board space. The LTC1773 comes in a 10-lead MSOP package.Applications Cellular Telephones RF PA Supply Portable Instruments Wireless MODEMS Distributed Power Systems Notebook and Palm Top Computers, PDAs Single and Dual Cell Lithium-Ion Powered Devices

DC311A Demo Board for: LTC1629 PolyPhase, High Efficiency, Synchronous Step-Down Switching Regulator LTC1709-9 2-Phase, 5-Bit VID, Current Mode, High Efficiency, Synchronous Step-Down Switching Regulators

The LTC7811 is a high performance triple output (buck/buck/boost) DC/DC switching regulator controller that drives all N-channel power MOSFET stages. Its constant frequency current mode architecture allows a phase-lockable switching frequency of up to 3MHz. The LTC7811 operates from a wide 4.5V to 40V input supply range. When biased from the output of the boost converter or another auxiliary supply, the LTC7811 can operate from an input supply as low as 1V after start-up.The very low no-load quiescent current extends operating run time in battery powered systems. OPTI-LOOP? compensation allows the transient response to be optimized over a wide range of output capacitance and ESR values. The LTC7811 features a precision 0.8V reference for the bucks, 1.2V reference for the boost and a power good output indicator.The LTC7811 additionally features spread spectrum operation which significantly reduces the peak radiated and conducted noise on both the input and output supplies, making it easier to comply with electromagnetic interference (EMI) standards.APPLICATIONS Automotive and Transportation Industrial Military/Avionics

Demonstration circuit DC339-A is a low noise micropower voltage regulator using the 150mA output current LT1762 linear regulator in an 8-lead MSOP package. The demo board has an input voltage range from 2.3V to 20V and a jumper-selectable output votlage that can be set to 1.22V, 2.5V, 3.0V, 3.3V, 5V or a user-defined value. The LT1762's low 20µVRMS (10Hz to 100kHz bandwidth) output noise and low 30µA quiescent current make the device ideal for voltage-controlled oscillators, RF power supplies and local regulators in larger systems.

DC389A-C: Demo Board for LTC3778 Wide Operating Range, No RSENSE Step-Down Controller.

Demonstration circuit 392 is a dual output, step-down, synchronous buck converter featuring either the 150kHz to 300kHz LTC1628EUH controller (DC392A-A), the 250kHz to 550kHz LTC3728EUH (DC392A-B) or 250kHz to 550kHz LTC3728LUH (DC392A-C). It operates with an input voltage range of 7V to 24V and provides 3.3V @ 5A and 5V @ 4A at its output.

Demonstration circuit 438 is a triple phase, single output synchronous buck converter featuring the LTC3731CG. This circuit can be used for desktop computers and servers, notebook computers and other high output current DC/DC converters. The output voltage can be configured for either 2.5V or 1.8V and the maximum load current is 60A. The input voltage range of DC438 is 9V to 14V.

DC480A-F: Demo Board for the LTC3405A 1.5MHz, 300mA Synchronous Step-Down Regulator in ThinSOT.