Demonstration Circuit 2841A is a 42V, 15A synchronous step-down Silent Switcher 2 with spread spectrum frequency modulation featuring the LT8648S. The demo board is designed for 5V output from a 5.7V to 42V input. The wide input range allows a variety of input sources, such as automotive batteries and industrial supplies. The LT8648S is a compact, ultralow emission, high efficiency, and high speed synchronous monolithic stepdown switching regulator. The integrated bypass capacitors optimize 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 small as 25ns allows high step-down conversion even at high frequency. The LT8648S switching frequency can be programmed either via oscillator resistor or external clock over a 200kHz to 2.2MHz range. The default frequency of demo circuit 2841A is 400kHz. The SYNC/MODE pin on the demo board DC2841A 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). Figure 1 shows the efficiency of the circuit at 12V input and 24V input in force continuous mode without spread spectrum. To get accurate efficiency measurement, measure the input voltage at the VIN SENSE terminal and measure the output voltage at the VO SENSE terminal.  Figure  2 shows the LT8648S temperature rising on DC2841A demo board under different load conditions. The LT8648S is assembled in a 7mm × 4mm LQFN package with exposed pads for low thermal resistance. The rated maximum load current is 15A, while derating is necessary for certain input voltage and thermal conditions. The demo board has an EMI filter installed. The EMI performance of the board is shown on Figure 3. The red line in Radiated EMI Performance is CISPR25 Class 5 peak limit. The figure shows that the circuit passes the test with a wide margin. To achieve EMI performance as shown in Figure 3, the input EMI filter is required and the input voltage should be applied at VIN_EMI 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 LT8648S 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 DC2841A. 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 and Peak Output Current. Contact ADI applications engineer for support.

Demonstration circuit DC2846A is a DC/DC synchronous boost converter featuring the LTC7804 (MSE package), a spread spectrum or constant frequency current mode synchronous boost controller. The DC2846A generates a 24V output voltage and provides up to 6A of output current. The 500kHz constant switching frequency operation results in a small and efficient circuit. The main features of this board include: Wide input voltage range: from 6V to 24V Relatively high output power, up to 150W Extremely low quiescent current, it’s 15µA at sleep mode and as low as 1µA at shutdown Onboard low power bias supply Ability to select spread spectrum or fixed frequency Pulse-skipping mode, forced continuous operation or low ripple Burst Mode® operation at light loads Synchronization with external clock If VIN > VOUT, the DC2846A eliminates the usual boost topology losses by keeping the top MOSFET on continuously. The converter provides high output voltage accuracy (typically ±2%) over a wide load range with no minimum load requirement. The DC2846A supports two ways of biasing step-up controllers: directly from the input voltage or output rail. The third possibility is connecting voltage source to EXTVCC terminal. The DC2846A extremely wide switching frequency range from 100kHz to 3MHz. It can be synchronized to the external clock anywhere inside this range. The spread spectrum operation is used for reducing the peak radiated and conducted noise to simplify compliance with electromagnetic interference (EMI) standards. The DC2846A has small circuit footprint. It is a high performance and cost-effective solution for telecom, automotive and Power over Ethernet applications.

Demonstration circuit 2879A is a high efficiency, high power density hybrid converter. It can deliver 12V/25A with an input voltage from 36V to 60V (up to 65V during transients). This demo board features the LTM4660, which uses an architecture that merges soft-switching switched capacitor topology with a traditional step-down converter to provide superior efficiency compared to the traditional switching architectures. It offers a high efficiency/high density and cost effective solution for nonisolated intermediate bus applications in power distribution, datacom and telecom. Due to its current mode control architecture, multiple LTM4660s can be operated in a parallel, multiphase configuration with excellent current sharing and low output voltage ripple to enable much higher power applications. Other benefits include low EMI emissions due to a soft-switched front end and reduced MOSFET stress. The LTM4660 design eliminates the inrush current typically associated with switched capacitor circuits by pre-balancing the capacitors on start-up. The LTM4660 also monitors system voltage, current and temperature for faults. It stops switching and pulls the FAULT pin low when a fault condition occurs. An onboard timer can be set for appropriate restart/retry times. Additional features include ±1.5% output voltage accuracy over temperature, a clock output for multiphase operation, a power good output signal, short-circuit protection, monotonic output voltage start-up, optional external reference, undervoltage lockout and internal charge balance circuitry. The LTM4660 data sheet must be used in conjunction with this demo board manual.

Demonstration circuit DC2902A is a thermoelectric cooler (TEC) regulator featuring the LTM4663 μModule regulator. The demo board has a 2.7V to 5.5V input voltage range and can deliver up to 1.5A of sinking or sourcing current. Inside the LTM4663, a linear power stage works together with a PWM power stage to form an H-bridge configuration. The direction of the current fed through the TEC can be either positive (for cooling mode), or negative (for heating mode). The LTM4663 has two built-in zero drift, rail-to-rail chopper amplifiers which can serve as a thermistor input amplifier and form an analog temperature control loop. The LTM4663 provides a 1% accuracy 2.5V internal reference voltage to bias the thermistor temperature sensing circuit and to program the maximum TEC current and voltage limits for both the cooling and heating modes. The demo board has a default 2MHz switching frequency and can be synchronized to an external clock from 1.85MHz to 3.25MHz applied to the EN/SY input pin (JP1: EN/SY). The clock high level must be above 2.1V and the clock low level must be below 0.8V. Maximum TEC current limit can be programmed with a resistor, R7 (default: 1.5A for cooling mode; –1.5A for heating mode). Maximum TEC voltage limit can be programmed with a resistor, R10 (default: 5V for cooling mode; –4.8V for heating mode). Other features include VTEC output for TEC voltage monitor and ITEC output for TEC current monitor The LTM4663 datasheet gives a complete description of the operation and application information. The datasheet must be read in conjunction with the demo manual.

The LTC2672 is a family of five-channel, 12-/16-bit current source, digital-to-analog converters (DACs) that provide five high compliance, current source outputs with guaranteed 0.6 V dropout at 200 mA. There are eight current ranges that are programmable per channel with full-scale outputs of up to 300 mA. The channels can be paralleled to allow either ultrafine adjustments of large currents or combined outputs of up to 1.5 A. A dedicated supply pin is provided for each output channel. Each channel can be operated from 2.1 V to VCC, and internal switches allow any output to be pulled to the optional negative supply. The LTC2672 includes a precision integrated 1.25 V reference (10 ppm/?C maximum), with the option to use an external reference. The serial peripheral interface (SPI)-compatible, 3?wire serial interface operates on logic levels as low as 1.71 V and at clock rates as high as 50 MHz.Note that throughout this data sheet, multifunction pins, such as CS/LD, are referred to by the entire pin name or by a single function of the pin.APPLICATIONS Tunable lasers Semiconductor optical amplifier biasing Resistive heaters Current mode biasing

The LTC2672 is a family of five-channel, 12-/16-bit current source, digital-to-analog converters (DACs) that provide five high compliance, current source outputs with guaranteed 0.6 V dropout at 200 mA. There are eight current ranges that are programmable per channel with full-scale outputs of up to 300 mA. The channels can be paralleled to allow either ultrafine adjustments of large currents or combined outputs of up to 1.5 A. A dedicated supply pin is provided for each output channel. Each channel can be operated from 2.1 V to VCC, and internal switches allow any output to be pulled to the optional negative supply. The LTC2672 includes a precision integrated 1.25 V reference (10 ppm/?C maximum), with the option to use an external reference. The serial peripheral interface (SPI)-compatible, 3?wire serial interface operates on logic levels as low as 1.71 V and at clock rates as high as 50 MHz.Note that throughout this data sheet, multifunction pins, such as CS/LD, are referred to by the entire pin name or by a single function of the pin.APPLICATIONS Tunable lasers Semiconductor optical amplifier biasing Resistive heaters Current mode biasing

The LTC2686 is an 8-channel, 16-bit, ?15 V digital-to-analog converter (DAC) with an integrated precision reference. The LTC2686 is guaranteed monotonic and has built in rail-to-rail output buffers that can source or sink up to 55 mA. This SoftSpan? DAC offers five output ranges up to ?15 V. The range of each channel is independently programmable.The internal 4.096 V precision reference sets the accuracy of the output voltage. An external reference can be used for additional range options. Three toggle pins support Input Register A and Input Register B toggle or sinusoidal dither at multiple frequencies. An analog multiplexer simplifies measurement of pin voltages, load currents, and junction temperature.Programmable offset and gain registers improve the accuracy of the DAC outputs.The serial peripheral interface (SPI) and MICROWIRE?-compatible, 3-wire serial interface operates on logic levels as low as 1.71 V and clock rates up to 50 MHz.APPLICATIONS Optical networking Instrumentation Data acquisition Automatic test equipment Process control and industrial automation

The LTC4238 is a high voltage high current Hot Swap controller that allows a board to be safely inserted and removed from a live backplane. Dual 12V gate drive is well suited for high power applications to either share safe operating area across parallel MOSFETs or support a 2-stage start-up that first charges the load capacitance followed by enabling a low on-resistance path to the load.The device features active current limiting (ACL) with two foldback options as VDS increases. The constant power profile limits the power dissipation to be no higher than a fixed value, while the high power profile allows the part to ride through large input steps during operation.The LTC4238 notifies when output power is good. In addition, it has protection features that respond to input undervoltage, overvoltage; and generate a fault when there is an overcurrent or FET bad condition.Applications Live Board Insertion in 12V, 24V and 48V Systems Industrial High Side Switch/Circuit Breaker Computers, Servers Vehicle Electrical Systems

The LTC4238 is a high voltage high current Hot Swap controller that allows a board to be safely inserted and removed from a live backplane. Dual 12V gate drive is well suited for high power applications to either share safe operating area across parallel MOSFETs or support a 2-stage start-up that first charges the load capacitance followed by enabling a low on-resistance path to the load.The device features active current limiting (ACL) with two foldback options as VDS increases. The constant power profile limits the power dissipation to be no higher than a fixed value, while the high power profile allows the part to ride through large input steps during operation.The LTC4238 notifies when output power is good. In addition, it has protection features that respond to input undervoltage, overvoltage; and generate a fault when there is an overcurrent or FET bad condition.Applications Live Board Insertion in 12V, 24V and 48V Systems Industrial High Side Switch/Circuit Breaker Computers, Servers Vehicle Electrical Systems

Demonstration circuit 2989A features the LTM4657 µModule® regulator, a high performance, high efficiency step-down regulator. The LTM4657 is a complete DC/DC point-of-load regulator in a thermally enhanced 6.25mm x 6.25mm x 3.87mm BGA package. The LTM4657 has an operating input voltage range of 3.1V to 20V and provides an output current up to 8A. The output voltage is programmable from 0.6V to 5.5V and can be remotely sensed. The stacked inductor design improves thermal dissipation and significantly reduces the package area.  Output voltage tracking is available through the TRACK/SS pin for supply rail sequencing. External clock synchronization is available through the SYNC/MODE pin. For high efficiency at low load currents, select DCM mode operation using the MODE jumper (JP7) in less noise sensitive applications. The LTM4657 data sheet must be read in conjunction with this demo manual for working on or modifying DC2989A.