Demonstration circuit 2896A-B demonstrates a high power boost converter and features the LT®8551 the phase expander with internal gate drivers. The DC2896A-B employs LTC3769, a single-phase boost controller as primary controller and LT8551 as the phase expander which added four more power phases. The increased number of power sections connected to the LT8551, results in greater higher level output power without a corresponding increase in the difficulty of the design or a sacrifice of primary controller LTC3769 features. The input voltage range of DC2896A-B is from 10V to 46V and the output is 48V. The maximum input current is 12A per power section, so the maximum input current of DC2896A-B is 60A. It’s reflected to 30A of output current and output power of 1,440W at an input voltage of 24V. Correspondingly output current will drop to 14.5A and output power will to 720W at a 12V input voltage, to keep the input current at the same level of 60A. Both values will increase at higher voltages. The input current value can be increased above 60A, if heat sinks are installed, see parts list below. The switching frequency is 250kHz and at a 24V input to 48VOUT at full load, the efficiency of DC2896A-B is 98%. As the input voltage decreases, the output current should be decreased as well, to prevent saturation of the DC2896A-B inductors, the derating curve presented on Figure 3. Efficiency curves presented on Figure 4. DC2896A-B resistors R114 to R119 program the phase relationship between the power sections, by setting the Total Distinct Phase Number (TDPN). For increasing efficiency and reducing switching losses at light loads DC2896A-B supports disconnecting some power sections. This mode of operation designated as the stage shedding and it is programed by the jumper J3 STAGE SHED. Jumper JP1 programs the LT8551 SYNC pin and it allows DC2896A-B to be synchronized to an external clock. The print circuit board of DC2896A also supports two phase expander controllers, the LT8561 and LT8551, with versions DC2896A-A and DC2896A-B correspondingly. The table [1] in the electrical schematic describes differences between both versions, including controller biasing and gate drive voltages. DC2896A-B has jumper SHDN (JP2) for manually enable or disable controller. The SYNC (E19) input can be used to sync LT8551 with an external signal. There are also terminals that make it easy to monitor the control logic of the LT8551 functional. The current sense resistors RSNS1 to RSNS5 used for implementation of current mode control, monitoring and sharing current between the phases. To further increase efficiency DC2896A-B supports optional DCR sensing of inductors L1 to L5. DC2896A-B includes sense line filters and filter options for inputs to the LT8551 in accordance with data sheet recommendations. Undervoltage shutdown, switching frequency and LT8551 ILIM current limit levels can all be adjusted by resistors or resistor jumpers. DC2896A-B comes with a housekeeping circuit based on U3 controller. It reduces the power dissipation that would otherwise occur at high input voltages in regulator transistor Q21. The housekeeping circuit also stabilizes converter biasing at sudden input voltage drops. A high level of available output power without a corresponding high level of design complexity makes the LT8551 attractive for high power DC bus and battery systems in commercial, industrial and automotive settings. DC2896A-B features the LT8551EUKG in a thermally enhanced 52-pin 7mm × 8mm QFN package. The LT8551 and LTC3769 data sheets must be read in conjunction with this demo manual to properly use or modify DC2896A-B.

Demonstration circuit 2897A is a low IQ, triple output, synchronous step-down supply featuring the LTC7819. The circuit is optimized for high efficiency. It provides outputs of 3.3V at 12A, 8.5V at 10A and 5.0V at 12A over an input voltage range of 10V to 36V with a switching frequency of 380kHz. Each rail uses a 3mΩ sense resistor to sense the current and provides optional footprints for DCR sensing. Typical applications include automotive, transportation, industrial, military and avionics systems. Features of the DC2897A include pin selectable light load operating modes of forced continuous mode, pulse-skipping and Burst Mode® operation. Optional spread spectrum modulation to reduce EMI, a PLLIN pin to synchronize to an external clock, optional DCR sensing footprints, an EXTVCC pin to reduce losses in the controller and optional footprints to parallel two or three channels. The LTC7819 data sheet provides a complete description of the part, operational details, and applications information. DC2897A must be read in conjunction with the data sheet.

Demonstration circuit DC290 is a constant-frequency step-down converter using an LTC1877 or an LTC1878 monolithic synchronous regulator. The LTC1878 has an input voltage range of 2.65V < VIN < 6V and the LTC1877 has an input voltage range of 2.65V < VIN < 10V. The LTC1878 is optimized for low voltage operation and is ideally suited for single Li-Ion cell or 3-NiCd/NiMH cell applications. The LTC1877, with its higher voltage capability, is ideally suited for two Li-Ion cells or 4- to 6-NiCd/NiMH cell applications.

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 LTC7802 is a high performance dual step-down synchronous DC/DC switching regulator controller that drives all N-channel power MOSFET stages. Constant frequencycurrent mode architecture allows a phase-lockable switching frequency of up to 3MHz. The LTC7802 operates from a wide 4.5V to 40V input supply range. Power loss and supply noise are minimized by operating the two controller output stages out-of-phase.The very low no-load quiescent current extends operating runtime in battery powered systems. OPTI-LOOP compensation allows the transient response to be optimizedover a wide range of output capacitance and ESR values. The LTC7802 features a precision 0.8V reference and power good output indicators. The MODE pin selects among Burst Mode operation, pulse-skipping mode, or continuous inductor current mode at light loads.The LTC7802 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.APPLICATIONSAutomotive and TransportationIndustrialMilitary/Avionics

Demonstration Circuit 3001A-A showcases the LTC4450 ideal diode controller with an integrated low RDS(ON) MOSFET. The board includes two independent LTC4450 ideal diodes sharing a common ground and operates over a range of 0V to 18V, carrying up to 12A. The board can be set up in a diode-OR configuration by connecting the output channels together.

Demonstration circuit 3006A is a compact no-opto isolated flyback converter featuring the LT3001. The DC3006A outputs 12V, and maintains tight regulation with as load current from 1.5mA up to 300mA over an input voltage from 4V to 32V. The output current capability increases with the input voltage, as shown in the Performance Summary table. Transformer leakage inductance causes a voltage spike on the primary side after the power switch turns off. The leakage inductance spike is limited within the MOSFET’s voltage rating of 65V with an RC snubber and a TVS clamp which damp the ringing and clamp the MOSFET drain voltage to a safe level.  The Performance Summary table summarizes the performance of the demo board at room temperature. The demo circuit can be easily modified for different applications with some pre-designed transformers. The LT3001 datasheet gives a complete description of the part, operation and application information. The datasheet must be read in conjunction with this quick start guide for demo circuit 3006A.

Demonstration circuit DC3016A is a buck-boost power supply featuring the LTM4693, ultrathin, highly efficient, 2A buck-boost μModule® regulator. The LTM4693 regulates an output voltage above, below, or equal to the input voltage. This demonstration circuit is designed to have an input voltage from 2.6V to 5.5V with selectable 1.8V, 2.5V, 3.3V, and 5V output voltage up to 2A load. Derating may be necessary for specific VIN, VOUT, and thermal conditions. This demo board includes a mode selector that allows the converter to run in CCM or Burst Mode® operation. Synchronization to an external clock is also possible. The switching frequency can be adjusted from 1MHz to 4MHz by a resistor. And the soft-start period is programmable by an external capacitor. The LTM4693 data sheet gives a complete description of these functions, operation, and application information. The data sheet must be read in conjunction with this quick start guide for demo circuit 3016A.

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

Demonstration circuit 3024A showcases the LT4200 50A hot swap E-fuse with guaranteed SOA. Included on the board are input voltage dividers for undervoltage and overvoltage protection, LEDs to indicate input voltage, output voltage, fault and power bad conditions, and jumpers to enable auto retry and to select circuit breaker delay. Turrets are provided for monitoring input voltage, output voltage, output status, and most of the pins on the LT4200.