Demonstration circuit 1734A features the dual channel LT8582 in boost and inverting regulator configurations. The circuit is designed to convert a 5V to 10V input source to 12V at 900mA and –12V at 590mA. To limit the temperature rise of the chip to 40°C, on the demo board with no air flow, the maximum combined output power is 15W. Additional input bulk capacitance may be needed, subject to source impedance. DC1734A is designed to survive output short circuit events.

DC194A-B: Demo Board for the LT1317 Micropower, 600kHz PWM DC/DC Converters.

DC204A-B: Demo Board for the LT1776 Wide Input Range, High Efficiency, Step-Down Switching Regulator.

Demonstration Circuit 2114A features the LT8603 with triple monolithic buck regulators and a boost controller. The demo circuit is designed for 8.0V, 5.0V, 3.3V, and 1.8V outputs from a nominal 12V input. The 4th channel is set as a boost converter and is powered from a wide input range with output VOUT4 regulated at 8V if 3V < VIN < 8.5V. It works as diode pass through if the input is above 8.5V. The two high voltage buck regulators are powered from the boost converter. VOUT1 is regulated at 5V with 1.5A maximum output load current, and VOUT2 is at 3.3V with 2.5A maximum output load current. Thanks to the pre-boost converter, they can ride through a cold crank in automotive applications while providing constant output voltages 5V and 3.3V. The low voltage buck is powered from the VOUT2 (3.3V), and the output VOUT3 is regulated at 1.8V with 1.8A maximum load current.

The LT1611 and LT1613 are 5-lead SOT-23, current mode DC/DC converters. Intended for small, low power applications, both operate from inputs as low as 1V and switch at 1.4MHz, allowing the use of tiny, low cost capacitors and inductors. DC233 contains three switching regulator circuits. Two of these demonstrate the use of the LT1613CS5 in a simple boost regulator circuit and in an uncoupled SEPIC circuit. Both circuits produce 3.3V or 5V (jumper selected). The boost circuit produces 200mA in a typical application and occupies less than 0.2 square inches of circuit board area. The SEPIC circuit allows operation from input voltages either higher or lower than the output, making this circuit suitable for single Li-Ion cell to 3.3V conversion or four alkaline cells to 5V conversion. Typical output current for the SEPIC circuit is 120mA. The third circuit demonstrates the LT1611CS5 in a low noise inverting circuit. This circuit can convert 5V to –5V at 160mA.

DC235A: Demo Board for the LTC1530 High Power Synchronous Switching Regulator Controller.

The LTC5562 is a versatile low power mixer optimized for applications requiring very wide input bandwidth, low distortion, and low LO leakage. This mixer can be used for either upconverting or downconverting applications, and provides a nominal conversion gain of 1dB. Demonstration circuit 2483A-A showcases the LTC5562 mixer for upconverting applications while demonstration circuit 2483A-B is tuned for downconverting applications. The differential inputs are optimized for use with 1:1 transmission- line baluns, allowing very wideband impedance matching. The LTC5562 uses a 3.3V supply for low power consumption and an enable pin allows the part to be shut down for further power savings. The total mixer current is adjustable, allowing for even further power savings. The standard match frequency ranges for each board are outlined in the table below.

Demonstration circuit 2616A-C features a polyphase design using the LTM4645EY, a 25A high efficiency, switch mode step-down power µModule regulator. The input voltage range is from 6V to 15V. To use DC2616A-C for input voltage range from 4.7V to 6V, connect INTVCC to SVIN (change R22, R42, R55, R68 from OPT to 0Ω), DRVCC to VIN (change R21, R38, R52, R65 from 0Ω to OPT, R2, R39, R53, R66 from OPT to 0Ω). The output voltage range is 0.6V to 1.8V. The DC2616A-C can deliver a nominal 100A output current with four LTM4645 modules in parallel. As explained in the data sheet, output current derating is necessary for certain VIN, VOUT, and thermal conditions. The board operates in continuous conduction mode in heavy load conditions. For high efficiency at low load currents, the MODE_PLLIN jumper selects pulseskipping mode for noise sensitive applications or burst mode operation in less noise sensitive applications. The MODE_PLLIN pin also allows the LTM4645 to synchronize to an external clock signal. The phase shift between two adjacent phases is 90 degrees. DC2616A-C has the option of choosing both internal and external compensation circuit for LTM4645. The LTM4645 data sheet must be read in conjunction with this demo manual prior to working on or modifying demo circuit DC2616A-C.

Demonstration circuit DC1198B-B features the LTM4607EV, a high efficiency, high density switch mode buck-boost power module. The LTM4607EV can regulate its output voltage from input voltage both above and below the output. The board accepts an input voltage from 6V to 36V and is set for an output voltage of 12V. The rated load current is 5A in boost mode and 12A in step-down operation. Derating is necessary for certain VIN, VOUT and thermal conditions. The switching frequency can be synchronized to external clock operating from 200kHz to 400kHz. This clock input can be used to reduce undesirable frequency harmonics and reduce input and output ripple when paralleling LTM4607 modules for even higher output current.

Demonstration circuit EVAL-LT8685S-AZ is a 4-rail power supply featuring the LT8685S, a 42V quad monolithic synchronous step-down silent switcher. The demo circuit is designed for 5V, 3.3V, 1.8V, and 1.2V outputs from a nominal 12V input. The 5V and 3.3V rails are powered from the 12V input, while the 1.8V and 1.2V rails are powered from one of the high voltage buck regulators of 5V or 3.3V. The current capability is 2.5A for the channels 1 and 2. The current ratings for the low voltage channels are 4A. The two 42V regulators may be combined to provide up to 5A of output current using a single inductor. Similarly, the two 8V regulators may be combined to provide up to 8A of output current using a single inductor. Individual track/soft-start, current limit, independent enable and power good for each channel simplify the complex design of quad-output power converters. All regulators can be synchronized to a common external clock input or internal oscillator that can be programmed with a single resistor for switching frequency from 350kHz to 3MHz, allowing for optimal system design per specific applications. The Performance Summary table in the demo manual summarizes the performance of the demo board at room temperature. The circuit can be easily modified for different applications. The LT8685S data sheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with the quick start guide for demo circuit EVAL-LT8685S-AZ.