DC1012A-C: Demo Board for the LTC2495 16-Bit 8-/16-Channel ΔΣ ADC with PGA, Easy Drive and I2C Interface

DC1066A: Demo Board for the LTC4355 Positive High Voltage Ideal Diode-OR with Input Supply and Fuse Monitors.

DC1090A: Demo Board for LTC2954 Push Button On/Off Controller with µP Interrupt

DC1113A: Demo Board for the LTC6102 Precision Zero Drift Current Sense Amplifier

Demonstration circuit DC2342A is a 60V synchronous boost LED controller featuring the LT®3762. It drives a single string of LEDs at 2A up to 32V when VIN is between 7V and 28V. It runs down to 4VIN with reduced ILED and can withstand VIN transients as high as 30V. DC2342A runs at approximately 300kHz switching frequency. Spread spectrum frequency modulation (SSFM) can be turned on with a simple jumper, reducing EMI. DC2342A is designed for high power step-up LED controller applications that require excellent efficiency across the VIN range. This demonstration circuit is protected against both open and short LED conditions, each having its own flag. The LT3762 has an input range from 2.5V to 42V. It has an adjustable switching frequency between 100kHz and 1MHz. Enabling SSFM spreads the switching frequency from fSW down to fSW – 30% for reduced EMI. SSFM speed is set by placing a capacitor from the SSFM pin of the LT3762 to ground, and can be disabled by shorting this pin to GND. DC2342A has a simple jumper option to enable/disable spread spectrum frequency modulation. The LT3762 can be PWM dimmed with an external PWM signal, as well as an internally generated PWM signal. A capacitor from PWM to GND of the LT3762 sets the PWM frequency, while the PWM duty cycle is determined by the voltage on the DIM terminal. Between 0V and 3V, VDIM gives between 0.4% and 97% PWM duty cycle. DC2342A has a jumper that can be set to switch between internally generated PWM signal, externally generated PWM signal, and no PWM signal (100% on). When run with both PWM dimming and spread spectrum enabled, the spread spectrum aligns itself with the PWM signal for flicker free operation. DC2342A can also be analog dimmed by placing a voltage source at either of its two CTRL turrets. Small ceramic input and output capacitors are used to save space and cost. The open LED overvoltage protection uses the IC’s constant voltage regulation loop to regulate the output to approximately 35.5V if the LED string is opened, although it may reach almost 40V peak during the transient caused by an open circuit. There is a protection diode from LED+ to GND to prevent negative ringing during a short-circuit. Undervoltage lockout can be adjusted on the circuit with a few simple resistor choices. Further modifications can be made to DC2342A to reconfigure the circuit from a boost topology to operate as a buck-mode or buck-boost mode LED driver. Please consult the factory for details. The LT3762 data sheet gives a complete description of the part, operation and applications information. The data sheet must be read in conjunction with this Demo Manual for demonstration circuit DC2342A. The LT3762EUFD is assembled in a 28-lead plastic 4mm × 5mm QFN package with a thermally enhanced ground pad. Proper board layout is essential for maximum thermal performance. See the data sheet section Layout Considerations.

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.

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 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.

The LTC2325-16 is a low noise, high speed quad 16?bit successive approximation register (SAR) ADC with differential inputs and wide input common mode range. Operating from a single 3.3V or 5V supply, the LTC2325-16 has an 8VP-P differential input range, making it ideal for applications which require a wide dynamic range with high common mode rejection. The LTC2325-16 achieves ?2LSB INL typical, no missing codes at 16 bits and 82dB SNR.The LTC2325-16 has an onboard low drift (20ppm/?C max) 2.048V or 4.096V temperature-compensated reference. The LTC2325-16 also has a high speed SPI-compatible serial interface that supports CMOS or LVDS. The fast 5Msps per channel throughput with one cycle latency makes the LTC2325-16 ideally suited for a wide variety of high speed applications. The LTC2325-16 dissipates only 40mW per channel and offers nap and sleep modes to reduce the power consumption to 90?W for further power savings during inactive periods.Applications High Speed Data Acquisition Systems Communications Optical Networking Multiphase Motor Control

The LTC2984 measures a wide variety of temperature sensors and digitally outputs the result, in ?C or ?F, with 0.1?C accuracy and 0.001?C resolution. The LTC2984 can measure the temperature of virtually all standard (type B, E, J, K, N, S, R, T) or custom thermocouples, automatically compensate for cold junction temperatures and linearize the results. The device can also measure temperature with standard 2-, 3-, or 4-wire RTDs, thermistors, and diodes. It has 20 reconfigurable analog inputs enabling many sensor connections and configuration options. The LTC2984 includes excitation current sources and fault detection circuitry appropriate for each type of temperature sensor as well as an EEPROM for storing custom coefficients and channel configuration data.The LTC2984 allows direct interfacing to ground referenced sensors without the need for level shifters, negative supply voltages, or external amplifiers. All signals are buffered and simultaneously digitized with three high accuracy, 24-bit ?? ADC's, driven by an internal 10ppm/?C (maximum) reference.Applications Direct Thermocouple Measurements Direct RTD Measurements Direct Thermistor Measurements Custom Sensor Applications