The LTC3871/LTC3871-1 is a high performance bidirectional buck or boost switching regulator controller that operates in either buck or boost mode on demand. It regulates in buck mode from VHIGH-to-VLOW and boost mode from VLOW-to-VHIGH depending on a control signal, making it ideal for 48V/12V automotive dual battery systems. An accurate current programming loop regulates the maximum current that can be delivered in either direction. The LTC3871/LTC3871-1 allows both batteries to supply energy to the load simultaneously by converting energy from one battery to the other.Its proprietary constant-frequency current mode architecture enhances the signal-to-noise ratio enabling low noise operation and provides excellent current matching between phases. Additional features include discontinuous or continuous mode of operation, OV/UV monitors, independent loop compensation for buck and boost operation, accurate output current monitoring and overcurrent protection. The LTC3871 and LTC3871-1 have different current limit foldback characteristics.Applications Automotive 48V/12V Dual Battery Systems Backup Power Systems

Demonstration circuit 2351A is a high voltage, high efficiency synchronous buck or boost DC/DC converter. It is designed to have 36V to 56V on one side and 8V to 14V on the other side. It can supply a 35A maximum output current in buck mode and delivers 7A of current in boost mode. The demo board features the LT8228EFE controller. This part can seamlessly transition from bucking to boosting. With built-in circuit breaker function and other protection features, the LT8228 is ideal for high reliability systems requiring N+1 redundancy or other protections in industrial, automotive, medical, military, and avionics applications. The DC2351A is designed to be paralleled with other DC2351A boards to increase the total output current. With adequate heatsinking or airflow, the output current can be increased.

The LT3952A is a current mode step-up DC/DC converter with an internal, 60V, 80m? DMOS power switch. The LT3952A is specifically designed to drive high power LEDs in multiple configurations. It combines input and output current regulation loops with output voltage regulation to operate as a flexible current/voltage source.Programmable switching frequency with optional spread-spectrum modulation provides EMI reduction, while still allowing optimization of the external components for efficiency or component size. The LED current is programmable with an external sense resistor, and can be adjusted from zero to full scale with a voltage at the CTRL pin. The external PWM input provides LED ON/OFF control and 4000:1 dimming ratio, and an internal PWM generator delivers the efficiency of PWM dimming to standalone or I/O limited applications. The LT3952A is available in the thermally enhanced 28-lead TSSOP package.Applications Display Backlighting Automotive and Avionic Lighting Accurate Current-Limited Voltage Regulators

Demonstration circuit 2362A is an adjustable 3A linear regulator featuring the LT3033. The LT3033 is a very low dropout voltage (VLDO™) linear regulator that operates from a single input supply down to 0.95V. The device supplies 3A output current with 95mV typical dropout voltage. The LT3033 is ideal for low input voltage to low output voltage applications, providing comparable electrical efficiency to a switching regulator. The LT3033 optimizes stability and transient response with low ESR ceramic output capacitors as small as 10µF. A 10nF bypass capacitor at REF/BYP pin typically reduces output voltage noise to 60µVRMS in a 10Hz to 100kHz bandwidth. Soft-start time is directly proportional to the REF/BYP capacitor value. The LT3033’s current limit, accurate to ±12% over a wide input voltage and temperature range, can be programmed by a single resistor. When the input-to-output differential voltage exceeds 5V, foldback current limit lowers the internal current limit level, which may override the external programmable current limit. LT3033 has a PWRGD pin which indicates when the ADJ pin is within 8% of its nominal value. By connecting an external pull-up resistor from PWRGD to either the IN or OUT pin, PWRGD is pulled low when the output falls below 90.1% of the regulated voltage. As the output voltage rises above 92% of its regulated voltage, the PWRGD pin voltage is pulled up. The LT3033 features output current monitoring by connecting a resistor from the IMON pin to GND. The IMON pin is the collector of a PNP current mirror that outputs 1/2650th of the power PNP current. This circuitry is active for VIMON ≤ (VOUT – 400mV). The LT3033 also features shutdown, reverse-battery protection, thermal limiting with hysteresis and reverse current protection. The LT3033 is available as an adjustable device with an output voltage down to the 200mV reference. The device is available in a thermally enhanced, low profile 3mm × 4mm × 0.75mm QFN package. The LT3033 data sheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with this quick start guide for demo circuit 2362A.

Demonstration circuit 2365A highlights the LTC2358 family of buffered input ADCs. The LTC2358/LTC2357/LTC2353/LTC2333 are low noise, high speed, 16-/18- bit successive approximation register (SAR) ADCs with integrated front end buffers. These ADCs accept a wide common mode range. Pico-amp inputs and high CMRR enable these ADCs to connect directly to a wide range of sensors without compromising measurement accuracy. The following text refers to the LTC2358-18 but applies to all parts in the family, the only differences being the number of bits, number of channels and the maximum sample rate. The LTC2358-18 has a flexible SoftSpan™ interface that allows conversion-by-conversion control of the input voltage span on a per-channel basis. An internal 2.048V reference and 2X buffer simplify basic operation while an external reference can be used to increase the input range and the SNR of the ADC.

Demonstration circuit 2365A highlights the LTC2358 family of buffered input ADCs. The LTC2358/LTC2357/LTC2353/LTC2333 are low noise, high speed, 16-/18-bit successive approximation register (SAR) ADCs with integrated front end buffers. These ADCs accept a wide common mode range. Pico-amp inputs and high CMRR enable these ADCs to connect directly to a wide range of sensors without compromising measurement accuracy. The demo manual refers to the LTC2358-18 but applies to all parts in the family, the only differences being the number of bits, number of channels and the maximum sample rate. The LTC2358-18 has a flexible SoftSpan™ interface that allows conversion-by-conversion control of the input voltage span on a per-channel basis. An internal 2.048V reference and 2X buffer simplify basic operation while an external reference can be used to increase the input range and the SNR of the ADC.

Demonstration circuit 2365A highlights the LTC2358 family of buffered input ADCs. The LTC2358/LTC2357/LTC2353/LTC2333 are low noise, high speed, 16-/18- bit successive approximation register (SAR) ADCs with integrated front end buffers. These ADCs accept a wide common mode range. Pico-amp inputs and high CMRR enable these ADCs to connect directly to a wide range of sensors without compromising measurement accuracy. The demo manual refers to the LTC2358-18 but applies to all parts in the family, the only differences being the number of bits, number of channels and the maximum sample rate. The LTC2358-18 has a flexible SoftSpan™ interface that allows conversion-by-conversion control of the input voltage span on a per-channel basis. An internal 2.048V reference and 2X buffer simplify basic operation while an external reference can be used to increase the input range and the SNR of the ADC.

Demonstration circuit 2374A is a multi-chemistry battery charger with optional maximum power point tracking (MPPT) featuring the LTC4013. The LTC4013 has configurable 3 stage and 4 stage lead acid and Li-Ion battery algorithms in addition to 2 stage CC/CV charge cycles. The DC2374A is set up to operate from a 21.5V to 35V supply or from a solar panel and charges a six cell lead acid battery at 5A. It also can be configured to operate down to 5V. There are optional input and output capacitors plus large inductor pads and parallel top and bottom FET pads to allow high power charging. The operating frequency, charge voltage, low battery (LB) voltage setting and timing are configurable with external resistors and a capacitor. The different charging algorithms are jumper-selectable, set by two tri-state mode pins and the TIMER pin.

Demonstration Circuit 2375A is a dual output 350mA step down charge pump with a post-regulator LDO and watchdog timer featuring the LTC3256EMSE. The LTC3256 operates with a wide input voltage range from 5.5V to 38V and is engineered for diagnostic coverage in ISO262262 systems. The LTC3256 can provide up to 350mA of output current from a 12V battery with 2W less power dissipation than 2 ideal linear regulators. The DC2375A was populated with automotive grade components for evaluation. Because of the wide input operating range it is possible to exceed the specified operating junction temperature and even reach thermal shutdown with heavy loads. Please refer to the data sheet for additional information on the thermal limitations of the device.

The LTC2664 is a family of four-channel, 16-/12-bit ?10V digital-to-analog converters with integrated precision references. They are guaranteed monotonic and have built-in rail-to-rail output buffers. These SoftSpan? DACs offer five output ranges up to ?10V. The range of each channel is independently programmable, or the part can be hardware-configured for operation in a fixed range.The integrated 2.5V reference is buffered separately to each channel; an external reference can be used for additional range options. The LTC2664 also includes A/B toggle capability via a dedicated pin or software toggle command.The SPI/Microwire-compatible 3-wire serial interface operates on logic levels as low as 1.71V at clock rates up to 50MHz.Applications Optical Networking Instrumentation Data Acquisition Automatic Test Equipment Process Control and Industrial Automation