DC566A-A: Demo Board for the LTC6910 Digitally Controlled Programmable Gain Amplifiers in SOT-23.

DC623A: Demo Board for the LTC3801 Micropower Constant Frequency Step-Down DC/DC Controllers in ThinSOT.

Demonstration circuit 649 is a Telecom isolated DC/DC converter featuring the LTC3803 constant frequency current mode flyback controller. The DC649 converts an isolated 36V to 72V input and provides 2A of output current at 5V. The 200kHz constant frequency operation is maintained down to very light load to reduce low frequency noise generated over a wide range of load current. The converter provides high output voltage accuracy (typically ±2%) over wide load range with no minimum load requirement.

DC1836A-B: Demo Board for the LTC2955 Pushbutton On/Off Controller with Automatic Turn-On.

Demonstration circuit 2024A features the LTC4282 high current Hot Swap™ controller. The LTC4282 is well suited to high power applications because the precise monitoring capability and accurate current limiting reduces the extremes in which both loads and power supplies must safely operate. Non-volatile configuration allows for flexibility in the autonomous generation of alerts and response to faults.

Demonstration circuit 1590B is a dual output synchronous buck converter featuring the LTC3880EUJ, a dual output peak current mode controller with digital power system management. There are two versions of the board available: DC1590B-A senses the output current across a sense resistor and has a default switching frequency of 350kHz, and DC1590B-B senses output current with the inductor DCR and has a default switching frequency of 425kHz. Either version can be populated with the LTC3880EUJ-1 (which allows the user to provide bias power to the IC from an external power supply) instead of the LTC3880EUJ. These boards provide two programmable outputs of 20A each. The factory default settings are 1.8V for each output.

DC817A: Demo Board for the LTC2927 Single Power Supply Tracking Controller.

Demonstration circuit 2190A is a high output voltage, high efficiency synchronous PolyPhase® buck converter featuring the LTC3892EFE-1. This demo circuit is available in two versions. The input voltage range of both versions is from 16V to 55V. The DC2190A-A is configured using two each LTC3892EFE-1 devices with 4-phase interleaving operation which provides a 12V/60A output, while the DC2190A-B is configured using one LTC3892EFE-1 device with 2-phase interleaving operation which provides a 12V/30A output.

Demonstration circuit 2278A features the LTC4281 hot swap controller. The LTC4281 is well suited to high power applications because the precise monitoring capability and accurate current limiting reduces the extremes in which both loads and power supplies must safely operate. Non-volatile configuration allows for flexibility in the autonomous generation of alerts and response to faults.

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.