Analog Devices LTC3309B | Demoboard DC3054A-C

Description

Demonstration circuit 3054A-C features the LTC®3309B 5V, 6A synchronous step-down Silent Switcher® operating as a 6.6MHz, 3.3V to 1.8V 6A buck regulator. The LTC3309B supports adjustable output voltages from 0.5V to VIN, and operating frequencies from 3MHz up to 10MHz. The LTC3309B is a compact, ultralow emission,high efficiency, and high speed synchronous monolithic step-down switching regulator. A minimum on-time of 22ns enables high VIN to low VOUT conversion ratios at high switching frequencies.The DC3054A-C operating mode may be selected as Burst Mode® operation, skip or forced continuous (FC) mode. Setting JP1 to the FC/SYNC position will allow the LTC3309B to sync to a clock frequency from 3MHz to 10MHz. The LTC3309B operates in forced continuous mode when syncing to an external clock. The DC3054A-C is set to a fixed 6.6MHz.The DC3054A-C is set to a fixed 6.6MHz frequency by connecting RT to VIN through a 0Ω resistor, R9. The frequency can be easily changed by removing R9 and setting an appropriate resistor in the R4 location to obtain the desired frequency. Refer to the LTC3309B data sheet for the proper RT value for a desired switching frequency.The DC3054A-C also has an EMI filter to reduce conducted EMI. This EMI filter can be included by applying the input voltage at the VIN EMI terminal. The EMI performance of the board is shown in the EMI Test Results section.The red lines in the EMI performance graphs illustrate the CISPR25 Class 5 peak limits for the conducted and radiated emission tests.

Features

• Pin Compatible with LTC3307(3A) and LTC3308(4A)
• High Efficiency: 8mΩ NMOS, 31mΩ PMOS
• Programmable Frequency 3MHz-10MHz:
• Tiny Inductor and Capacitors
• Peak Current Mode Control:
• 22ns Minimum On-Time
• Wide Bandwidth, Fast Transient Response
• Silent Switcher™ Architecture:
• Ultralow EMI Emissions
• Low Ripple Burst Mode® Operation with IQ of 40µA
• Safely Tolerates Inductor Saturation in Overload
• VIN Range: 2.25V to 5.5V
• VOUT Range: 0.5V to VIN
• VOUT Accuracy: ±1% Over Temperature Range
• Precision 400mV Enable Threshold, 1µA in Shutdown -Power Good, Internal Compensation and Soft Start
• Thermally Enhanced 2mm × 2mm LQFN Package
• AEC-Q100 Qualified for Automotive Applications

Typical applications

• Distributed DC Power Systems (POL), FPGA, ASIC, µP Core Supplies.
• Automotive
• Optical Networking, Servers, Telecom, Communications,
• Industrial.

More information

• Datasheet
• IC product information