Analog Devices LT3952 | Demoboard DC2013A

Description

Demonstration Circuit DC2013A is a 60V LED driver with internal 4A switch featuring the LT®3952 monolithic LED driver. It accepts an input voltage from 5V to 36V (with transient to 42V) and boosts to a single string of LEDs up to 50V LEDs at 330mA. DC2013A features an integrated 4A switch, constant-current and constant-voltage output control as well as input current limit and monitoring.The LT3952 has a wide input voltage range down to 3V and up to 42V. It has adjustable switching frequency between 200kHz and 3MHz. It has an option for external frequency synchronization or spread spectrum frequencymodulation. It has high PWM dimming capability from an external signal and can be PWM dimmed with an internally generated PWM oscillator and analog input signal. It can be analog dimmed with a control voltage on its control pin. LT3952 features both Open-LED and Short-LED (LED+to GND) protection as well as fault output flags for each. Although DC2013A is assembled as a boost LED driver, it can be altered to be run as a buck mode, buck-boost mode or boost-buck LED driver.There is another demonstration circuit featuring LT3952 at 2.0MHz (DC2361A).DC2013A features an option to turn on spread spectrum by simply changing the position of a jumper from NO SPREAD to SPREAD or to EXTERNAL SYNC.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 55V if the LED string is opened There is undervoltage and overvoltage lockout that can beadjusted on the circuit with a few simple resistor choices.There is an EMI filter on the input of DC2013A. This EMIfilter has both an LC stage to reduce EMI below 20MHz and a ferrite bead to reduce higher frequency EMI. The PCB layout contains a small hot-loop for minimized highfrequency EMI. The EMI filter can be used by connecting to the “EMI VIN” terminal. However, if the EMI filter is not needed, the input connection can be directly to the PVIN terminal. If the EMI filter is not used, it is recommended to remove the EMI filter if EMI measurements are beingmade from the PVIN terminal for base EMI testing. It can be replaced for EMI testing at the EMI VIN terminalThe LT3952 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 2013A. The LT3952EFE is assembled in a 28-lead plastic TSSOP (FE) package with a thermally enhanced ground pad. Proper board layout is essential for maximum thermal performance. See the data sheet section “Layout Considerations”.

Features

Remarks

• IN Optional circuit 4.7uH inductor is used.

More information

• Datasheet
• IC product information