Demonstration circuit 2535A is a 42V, dual channel, 2A synchronous step-down regulator featuring the LT8653S. The LT8653S is a compact, high efficiency, high speed synchronous monolithic step-down switching regulator which features the second generation Silent Switcher® technology that minimizes EMI and reduces PCB layout sensitivity. The demo board is designed for two outputs: 5V and 3.3V from a 5.5V to 42V input. Each output can source up to 2A continuous current at the same time. The wide input range allows a variety of input sources, such as automotive batteries and industrial supplies. The integrated power switches and other necessary circuitry reduce the external component count and simplify design. Selectable spread spectrum mode of operation can further improve EMI/EMC performance. Ultralow quiescent current in Burst Mode® operation achieves high efficiency at very light loads. The DC2535A demo board is 3" by 3" in size and has four layers with 2oz copper on the outer layers and 1oz copper on the inner layers. The DC2535A operates at 2MHz switching frequency by default to minimize solution size. The LT8653S is assembled in a small thermally enhanced 4mm × 3mm LQFN package. The IC temperature rises about 50°C when both channels operate at full load, 2A each, with the default switching frequency of 2MHz. The jumper JP2 on the demo board determines the configuration of the SYNC pin of the LT8653S. By default, the SYNC pin on the demo board is grounded for low ripple Burst Mode operation. Moving JP2 to FCM W/SSM enables the spread spectrum mode of operation by tying the SYNC pin to VCC pin. To synchronize to an external clock, move JP2 to FCM W/O SSM OR SYNC position and apply the external clock on the SYNC turret. The jumpers JP3 and JP4 on the demo board determine the configuration of the output voltage select bit pins D0 and D1. On the DC2535A, the D0 and D1 pins are by default floating. This combination connects internal feedback resistor divider between the FB1/FB2 pins and the error amplifier which means that FB1 and FB2 pins are regulated to 5V and 3.3V respectively. On the DC2535A, FB1/FB2 pins are by default connected through 0Ω resistors to the output nodes. Refer to the LT8653S data sheet for more information on the D0 and D1 pin settings. The demo board has an EMI filter installed. The EMI performance of the demo board (with EMI filter) is shown in Figure 1 and Figure 2. The black lines in Figure 2 are CISPR 25 class 5 limits. To achieve EMI/EMC performance as shown in Figure 2, the input EMI filter is required and the input voltage should be applied at VEMI terminal. The LT8653S data sheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with this manual for demo circuit 2535A.

Demonstration Circuit 2836A is a dual-output PolyPhase® DC/DC synchronous step-down regulator with 4V to 20V input range featuring LT7182S. Each output can supply 6A continuous/9A maximum transient load current. LT7182S is a dual 6A monolithic step-down regulator utilizing second-generation Silent Switcher® technology to minimize EMI and reduce PCB layout sensitivity. It also integrates digital power system management function allowing for programmability and telemetry with a PMBus/I2C compliant serial interface. Please see LT7182S data sheet for more detailed information. The demonstration circuit 2836A runs at 1MHz to minimize solution size. The peak efficiency at 12V input is 83.2% for 1.2V rail and 91.1% for 3.3V rail. The IC temperature rise is 70°C when both channels run at full load, 6A each, at 1MHz. The demo board has EMI filters installed for both channels. The conducted and radiated EMI performances of the board (with EMI filters) are shown in Figure 2 of the demo manual. The red lines in Figure 2 are CISPR25 CLASS 5 limit. DC2836A powers up to default settings and produces power based on configuration resistors without the need for any serial bus communication. This allows easy evaluation of the DC/DC converter. To fully explore the power system management features of the part, download the GUI software LTpowerPlay® onto your PC and use ADI’s I2C/SMBus/PMBus dongle DC1613A to connect to the board. LTpowerPlay allows the user to reconfigure the part on the fly and store the configuration in EEPROM, view telemetry of voltage, current, temperature and fault status. GUI Download The software can be downloaded from: LTpowerPlay  The LT7182S data sheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with the demo manual for DC2836A. For more details and instructions of LTpowerPlay, please refer to LTpowerPlay GUI for LT7182S Quick Start Guide.

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.

DC1449A: Demo Board for the LT8415 Ultralow Power Boost Converter with Dual Half-Bridge Switches.

Demonstration circuit 2523A is an 18V, 8.5A (continuous)/12A (peak) synchronous step-down Silent Switcher® with 16µA quiescent current featuring the LT8652S. The LT8652S is a compact, high efficiency, high speed synchronous monolithic step-down switching with the second generation Silent Switcher structure that minimizes EMI and reduces PCB layout sensitivity. Top and bottom power switches, compensation components and other necessary circuits are inside of the LT8652S to minimize external components and simplify design. The demo board has two outputs: 3.3V and 1.2V from a 3.6V to 18V input. The wide input range allows a variety of input sources, such as automotive batteries and industrial supplies. The SYNC pin on the demo board is grounded by default for low ripple Burst Mode® operation. Move JP2 to FCM without SSM position can change the operation mode to forced continuous mode operation. Once JP2 is on FCM with SSM position, VCC is applied to the SYNC pin for low EMI spread spectrum operation. To synchronous to an external clock, move JP2 to SYNC and apply the external clock to the SYNC turret. The demonstration circuit 2523A runs at 2MHz to minimize solution size. The peak efficiency is 90%. The IC temperature rise is less than 70°C when both channels run at full load, 8.5A each, at 2MHz. The demo board has EMI filters installed for both channels. To use the EMI filter, the input should be tied to VEMI1/VEMI2, not VIN1/VIN2. The LT8652S data sheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with this demo manual for DC2523A.

Demonstration circuit 3162A is a 18V, 10A synchronous step-down Silent Switcher® with spread spectrum frequency modulation featuring the LT8642-1. The demo board is designed for 1.2V output from a 2.8V to 18V input. The LT8642-1 is a compact, low emission, high efficiency, and high speed synchronous monolithic stepdown switching regulator. Special Silent Switcher architecture minimizes EMI emissions. Selectable spread spectrum mode can further improve EMI performance. Fast minimum on-time of 20ns enables high VIN to low VOUT conversion at high frequency. The LT8642-1 switching frequency can be programmed either via a resistor or external clock over a 200kHz to 3MHz range. The default frequency of demo circuit 3162A is 2MHz. The LT8642-1 SYNC/MODE pin on the demo board is grounded (JP1 at BURST position) by default for low ripple Burst Mode® operation. Spread spectrum mode and forced continuous mode can be selected respectively by moving JP1 shunt. To synchronize to an external clock, move JP1 to FCM/SYNC and apply the external clock to the SYNC terminal. The LT8642-1 data sheet gives a complete description of the part, operation, and application information. The data sheet must be read in conjunction with this demo manual for demo circuit 3162A. The LT8642-1 is assembled in a 3mm × 4mm LQFN package with exposed pads for low thermal resistance. The layout recommendations for low EMI operation and maximum thermal performance are available in the data sheet section Low EMI PCB Layout and Thermal Considerations.

Demonstration circuit 2779A is an 8V, 16A synchronous step-down Silent Switcher® 2 with spread spectrum frequency modulation featuring the LT8644S. The demo board is designed for 1.2V output from a 2.7V to 8V input. The LT8644S is a compact, ultralow emission, high efficiency, and high speed synchronous monolithic stepdown switching regulator. The integrated bypass capacitors optimize all the fast current loops and make it easier to minimize EMI emissions by reducing layout sensitivity. Selectable spread spectrum mode further improves EMI performance, making it perfect solution to the noise sensitive applications. Peak current mode control with minimum on-time of as low as 20ns allows high step-down conversion even at high frequency. The LT8644S switching frequency can be programmed either via an external resistor or an external clock over a 300kHz to 3.5MHz range. The default frequency of demo circuit 2779A is 2MHz. The SYNC/MODE pin on the demo board DC2779A is grounded (JP1 at BURST position) by default for low ripple Burst Mode® operation. It can be configured into different operation modes through JP1 and SYNC terminal (Table 1 in the demo manual). Figure 4 in the demo manual shows the efficiency of the circuit at 3.3V input and 5V input in force continuous mode operation (input from VIN terminal). To get accurate efficiency measurement, measure the input voltage at the VIN_SENSE/GND terminals and measure the output voltage at the VOUT+ SENSE/VOUT– SENSE terminals. Figure 5 shows the LT8644S temperature rise on DC2779A demo board at 3.3V input and 5V input in forced continuous mode. The LT8644S is assembled in a 4mm × 4mm LQFN package with exposed pads for low thermal resistance. The rated maximum continuous load current is 16A, while derating may be necessary for certain input voltage and thermal conditions. The demo board has an EMI filter installed. This EMI filter can be included by applying the input voltage at the VEMI terminal. The EMI performance of the board (with EMI filter) is shown on Figure 6 in the demo manual. The red lines in EMI Performance are CISPR25 Class 5 limits. The figure shows that the LT8644S circuit passes the test with a wide margin. To achieve EMI performance as shown in Figure 6, the input EMI filter is required and the input voltage should be applied to VEMI terminal, and the test setup can be referred to the CISPR25 standards. If the input is applied to VIN terminal, the EMI filter is bypassed. The LT8644S data sheet gives a complete description of the part, the operation and application information. The data sheet must be read in conjunction with the demo manual for demo circuit 2779A. The layout recommendations for low EMI operation and maximum thermal performance are available in the data sheet section Low EMI PCB Layout and Thermal Considerations. Contact ADI applications engineer for support.

DC355A: Demo Board for the LT1959 4.5A, 500kHz Step-Down Switching Regulator.

Demonstration circuit 1267A is a step-up DC/DC regulator featuring the LTC3125EDCB and is ideally suited for pulsed load applications where the input current needs to be limited. Demonstration circuit 1267A is configured for 500mA maximum input current limit and can handle pulsed load currents of up to 2A, with duty cycles of up to 15%. The input voltage range is 3.3V ±10%.

Demonstration Circuit 2745A features the LTC3309A 5V, 6A synchronous step-down silent switcher operating as a 2MHz 3.3V to 1.2V 6A buck regulator. The LTC3309A supports adjustable output voltages from 0.5V to VIN, operating frequencies from 1MHz up to 3MHz. The LTC3309A is a compact, ultralow emission, high efficiency, and high speed synchronous monolithic step-down switching regulator. Fast minimum on-time of 22ns enables high VIN to low VOUT conversion at high frequency. DC2745A operating mode may be selected as Burst Mode® operation, skip or forced continuous (FC) mode. Setting JP1 to the FC/SYNC position will allow the LTC3309A to sync to a clock frequency from 1MHz to 3MHz. The LTC3309A operates in forced continuous mode when syncing to an external clock. RT is connected to VIN through a 0Ω resistor, R9, which sets the operating frequency to 2MHz. The frequency can be easily changed by removing R9 and setting an appropriate resistor in the R4 location to obtain the desired frequency. Refer to the LTC3309A data sheet for the proper RT value. The DC2745A also has an EMI filter to reduce conducted EMI. This EMI filter can be included by applying the input voltage at the VIN EMI terminal. The EMI performance of the board is shown in the EMI Test Results section. The red lines in the EMI performance graphs illustrate the CISPR25 Class 5 peak limits for the conducted and radiated emission tests. The LTC3309A data sheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with this demo. The LTC3309A is assembled in a 3mm × 3mm LQFN package with exposed pads for low thermal  resistance. The layout recommendations for low EMI operation and maximum thermal performance are available in the data sheet section Low EMI PCB Layout. The Efficiency vs Load graph shows the efficiency and the power loss of the circuit with a 3.3V input in Burst Mode operation. The LTC3309A is available in a 12-lead 2mm × 2mm LGA package.