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.

Demo board DC2783A features the LT3040, a 200mA high performance, robust voltage reference/DAC buffer. LT3040 has ultralow output noise, ultrahigh power supply rejection ratio (PSRR) and low dropout voltage for powering noise sensitive, high accuracy systems. DC2783A has two inputs: V+ and VIN. V+ supplies power to the buffer, operating over a range from 2V to 20V. VIN is the regulation set-point for the output with a range from 0V to 15V. Current limit is programmable by connecting a resistor, R3, from ILIM to GND. The ILIM can also serve as a current monitor pin with a range from 0V to 300mV. LT3040 has fast start capability. Connecting FS pin across an input low pass filter resistor, R2, fast starts the LT3040. Fast start circuitry is typically triggered active if VFS − VIN ≥ 100mV and stays active until VFS – VIN ≤ 7mV. If fast start functionality is not needed, connect FS to VIN by setting R2 to 0Ω and applying the input voltage at FS. LT3040 has a fault flag to indicate faults at the output. Built-in protection includes reverse battery protection, reverse current protection, internal current limit with foldback and thermal limit with hysteresis. The LT3040 datasheet gives a complete description of the part, operation and applications information. The datasheet must be read in conjunction with this Demo Manual for demonstration circuit DC2783A. The LT3040 is assembled in a 12-lead MSOP and a 10-lead (3mm x 3mm) plastic DFN package with an exposed pad on the bottom-side of the IC. Proper board layout is essential for maximum thermal performance.

Demonstration circuit 2785A-A features the LTM4668 µModule® regulator, a Quad 1.2A high efficiency step-down regulator. DC2785A-A has an operating input voltage range of 2.7V to 17V and can provide an output current of up to 1.5A. The output voltage can be programmed from 0.6V up to 1.8V. The LTM4668 is a complete DC/DC point of load regulator in a thermally enhanced 6.25mm × 6.25mm × 2.1mm BGA package requiring only a few input and output capacitors. External clock synchronization is available through the CLKIN turret. The LTM4668 data sheet must be read in conjunction with this demo manual for working on or modifying demo circuit 2785A-A.

The ADP1882 / ADP1883?are versatile current-mode, synchronous step-down controllers that provide superior transient response, optimal stability, and current-limit protection by using a constant on-time, pseudo-fixed frequency with a programmable current-limit, current-control scheme. In addition, these devices offer optimum performance at low duty cycles by using valley current-mode control architecture. This allows the ADP1882 / ADP1883 to drive all N-channel power stages to regulate output voltages as low as 0.8 V.The ADP1883 is the power saving mode (PSM) version of the device and is capable of pulse skipping to maintain output regulation while achieving improved system efficiency at light loads (see the Power Saving Mode (PSM) Version (ADP1883) section for more information).Available in three frequency options (300 kHz, 600 kHz, and 1.0 MHz, plus the PSM option), the ADP1882 / ADP1883 are well suited for a wide range of applications. These ICs not only operate from a 2.75 V to 5.5 V bias supply, but they also can accept a power input as high as 20 V.In addition, an internally fixed soft start period is included to limit input in-rush current from the input supply during startup and to provide reverse current protection during soft start for a pre-charged output. The low-side current-sense, current-gain scheme and integration of a boost diode, along with the PSM/forced pulse-width modulation (PWM) option, reduce the external part count and improve efficiency.The ADP1882 / ADP1883 operate over the -40?C to +125?C junction temperature range and are available in a 10-lead MSOP.

The ADP2105 / ADP2106 / ADP2107 are low quiescent current,synchronous, step-down dc-to-dc converters in a compact 4 mm ?4 mm LFCSP package. At medium to high load currents, thesedevices use a current mode, constant frequency pulse-widthmodulation (PWM) control scheme for excellent stability andtransient response. To ensure the longest battery life in portableapplications, the ADP2105 / ADP2106 / ADP2107 use a pulsefrequency modulation (PFM) control scheme under light loadconditions that reduces switching frequency to save power.The ADP2105 / ADP2106 / ADP2107 run from input voltages of2.7 V to 5.5 V, allowing single Li+/Li? polymer cell, multiplealkaline/NiMH cells, PCMCIA, and other standard power sources.The output voltage of ADP2105 / ADP2106 / ADP2107 is adjustablefrom 0.8 V to the input voltage (indicated by ADJ), whereas theADP2105 / ADP2106 / ADP2107 are available in preset outputvoltage options of 3.3 V, 1.8 V, 1.5 V, and 1.2 V (indicated by x.x V).Each of these variations is available in three maximum currentlevels: 1 A (ADP2105), 1.5 A (ADP2106), and 2 A (ADP2107).The power switch and synchronous rectifier are integrated forminimal external part count and high efficiency. During logiccontrolled shutdown, the input is disconnected from the output,and it draws less than 0.1 ?A from the input source. Other keyfeatures include undervoltage lockout to prevent deep batterydischarge and programmable soft start to limit inrush current atstartup.Applications Mobile handsets PDAs and palmtop computers Telecommunication/networking equipment Set top boxes Audio/video consumer electronics

The ADP2108 is a high efficiency, low quiescent current step-down dc-to-dc converter manufactured in two different packages. The total solution requires only three tiny external components. It uses a proprietary, high speed current mode, constant frequency PWM control scheme for excellent stability and transient response. To ensure the longest battery life in portable applications, the ADP2108 has a power save mode that reduces the switching frequency under light load conditions.The ADP2108 runs on input voltages of 2.3 V to 5.5 V, which allows for single lithium or lithium polymer cell, multiple alkaline or NiMH cell, PCMCIA, USB, and other standard power sources. The maximum load current of 600 mA is achievable across the input voltage range.The ADP2108 is available in fixed output voltages of 3.3 V, 3.0 V, 2.5 V, 2.3 V, 1.82 V, 1.8 V, 1.5 V, 1.3 V, 1.2 V, 1.1 V, and 1.0 V. All versions include an internal power switch and synchronous rectifier for minimal external part count and high efficiency. The ADP2108 has an internal soft start and is internally compensated. During logic controlled shutdown, the input is disconnected from the output and the ADP2108 draws less than 1 ?A from the input source.Other key features include undervoltage lockout to prevent deep battery discharge and soft start to prevent input current over-shoot at startup. The ADP2108 is available in 5-ball WLCSP and 5-lead TSOT packages. The ADP2109 provides the same features and operations as the ADP2108 and has the additional function of a discharge switch in the WLCSP package.APPLICATIONS PDAs and palmtop computers Wireless handsets Digital audio, portable media players Digital cameras, GPS navigation units

The ADP2108 is a high efficiency, low quiescent current step-down dc-to-dc converter manufactured in two different packages. The total solution requires only three tiny external components. It uses a proprietary, high speed current mode, constant frequency PWM control scheme for excellent stability and transient response. To ensure the longest battery life in portable applications, the ADP2108 has a power save mode that reduces the switching frequency under light load conditions.The ADP2108 runs on input voltages of 2.3 V to 5.5 V, which allows for single lithium or lithium polymer cell, multiple alkaline or NiMH cell, PCMCIA, USB, and other standard power sources. The maximum load current of 600 mA is achievable across the input voltage range.The ADP2108 is available in fixed output voltages of 3.3 V, 3.0 V, 2.5 V, 2.3 V, 1.82 V, 1.8 V, 1.5 V, 1.3 V, 1.2 V, 1.1 V, and 1.0 V. All versions include an internal power switch and synchronous rectifier for minimal external part count and high efficiency. The ADP2108 has an internal soft start and is internally compensated. During logic controlled shutdown, the input is disconnected from the output and the ADP2108 draws less than 1 ?A from the input source.Other key features include undervoltage lockout to prevent deep battery discharge and soft start to prevent input current over-shoot at startup. The ADP2108 is available in 5-ball WLCSP and 5-lead TSOT packages. The ADP2109 provides the same features and operations as the ADP2108 and has the additional function of a discharge switch in the WLCSP package.APPLICATIONS PDAs and palmtop computers Wireless handsets Digital audio, portable media players Digital cameras, GPS navigation units

The ADP2114 is a highly versatile, synchronous step-down, switching regulator that can be configured to satisfy a wide range of customer point of load requirements. The two PWM channels can be configured to deliver independent outputs at 2 A and 2 A (or 3 A/1 A) or can be configured as a single interleaved output capable of delivering 4 A. The two PWM channels are 180? phase shifted to reduce input ripple current and reduce input capacitance.The ADP2114 provides high efficiency performance at full loads, enabling high switching frequencies at up to 1.2 MHz. At light loads, the ADP2114 can be set to operate in pulse skip mode for higher efficiency or in forced PWM mode to reduce EMI.The device is designed with an optimized gate slew rate to reduce ENI emissions, allowing the device to supply sensitive, high performance signal chain applications. The frequency can be set to 300 kHz, 600 kHz and 1.2 MHz and can be synchronized to an external clock signal, minimizing the system noise between converters. The bidirectional synchronization pin is also configurable as a 90? out-of-phase output clock, providing the possibility for a stackable multiphase power solution.The ADP2114 input voltage range is from 2.75 V to 5.5 V, and it converts to fixed outputs of 0.8 V, 1.2 V, 1.5 V, 1.8 V, 2.5 V, or 3.3 V that can be set independently for each channel using external resistors. Using a resistor divider, it is also possible to set the output voltage as low as 0.6 V. The ADP2114 operates over the ?40?C to +125?C junction temperature range.ApplicationsPoint-of-load regulationTelecom and networking systemsConsumer electronicsIndustrial and InstrumentationMedical

The ADP2119 / ADP2120 are low quiescent current, synchronous, step-down DC-to -DC regulators in a compact 3mm x 3mm LFCSP_WD package. Both Devices use current mode, constant frequency pulse-width modulation (PWM) control scheme for excellent stability and transient response. Under light load condition, they can be configured to operate in pulse frequency modulation (PFM) mode that reduces switching frequency to save power.The ADP2119 / ADP2120 can support input voltages from 2.3V to 5.5V. The output voltage can be adjusted from 0.6V to input voltage (VIN) for the adjustable version, while the fixed output version is available in preset output voltage options of 3.3V, 2.5V, 1.8V, 1.5V ,1.2V and 1.0V. The ADP2119 / ADP2120 require minimal external parts and provide a high efficiency solution with their integrated power switches, synchronous rectifier, and internal compensation. Each IC draws less than 3 ?A current from the input source when it is disabled. Other key features include under voltage lockout(UVLO), integrated soft start to limit inrush current at startup, overvoltage protection (OVP), over current protection (OCP) and thermal shutdown (TSD).APPLICATIONS Point of load conversion Communications and networking equipment Industrial and instrumentation Consumer electronics Medical appliances

The ADP2119?/ ADP2120 are low quiescent current, synchronous, step-down DC-to -DC regulators in a compact 3mm x3mm LFCSP_WD package. Both Devices use current mode, constant frequency pulse-width modulation (PWM) control scheme for excellent stability and transient response. Under light load condition, they can be configured to operate in pulse frequency modulation (PFM) mode that reduces switching frequency to save power.The ADP2119/ADP2120 can support input voltages from 2.3V to 5.5V. The output voltage can be adjusted from 0.6V to input voltage (VIN) for the adjustable version, while the fixed output version is available in preset output voltage options of 3.3V, 2.5V, 1.8V, 1.5V ,1.2V and 1.0V. The ADP2119/ADP2120 require minimal external parts and provide a high efficiency solution with their integrated power switches, synchronous rectifier, and internal compensation. Each IC draws less than 3 ?A current from the input source when it is disabled. Other key features include under voltage lockout(UVLO), integrated soft start to limit inrush current at startup, overvoltage protection (OVP), over current protection (OCP) and thermal shutdown (TSD).APPLICATIONS Point of load conversion Communications and networking equipment Industrial and instrumentation Consumer electronics Medical appliances