PWM Controller simplifies isolated power supplies.
Share:
Press Release Summary:
Model LTC3723 push-pull synchronous controller integrates two 1.5 A sink, 1 A source primary MOSFET drivers as well as two synchronous secondary outputs. It converts high-voltage backplane rails ranging from 36-72 V to 12 V and lower at power levels between 100-750 W. Housed in 16-lead SSOP package, unit includes adjustable dead-time and synchronous timing, accurate current sense, adjustable slope compensation, under-voltage lockout, and low start-up current.
Original Press Release:
Synchronous PWM Controller Raises Efficiency Bar & Simplifies Isolated Power Supplies
MILPITAS, CA - February 11, 2004 - Linear Technology Corporation introduces the LTC3723 push-pull synchronous PWM controller specifically targeted towards compact and highly efficient isolated power supplies. The LTC3723 controller's basic features, its flexibility and support for secondary synchronous rectifiers (with adjustable timing) make it an excellent choice for virtually all isolated, synchronous topologies. The LTC3723 is especially suited for converting high voltage backplane (36-72V) rails to 12V (distributed bus) and lower voltages at power levels between 100W and 750W. Single ended synchronous topologies offer simple solutions to medium power applications. The push-pull and half/full-bridge configurations offer smaller input filter and output inductors (operating at twice the frequency of single-ended converters), up to 40% greater transformer utilization and balanced semiconductor dissipation over the input line range. The LTC3723 includes many new features, which simplify and reduce component count in all the isolated topologies.
The IC integrates two robust 1.5A sink, 1A source primary MOSFET drivers as well as two synchronous secondary outputs. The addition of secondary synchronous MOSFETs result in operating efficiencies of 90% to 96% (a 5% improvement over conventional non-synchronous solutions). The LTC3723 is equipped with adjustable dead-time and synchronous timing, leading edge blanking, accurate current sense, adjustable slope compensation, under-voltage lockout and low start-up current (for bootstrap start from high input voltages).
The LTC3723 is housed in a 16-lead SSOP package and can be used in applications such as industrial, automotive, avionics, and telecom isolated power supplies. The LTC3723 also provides short-circuit and over-temperature protection. The IC is offered in two versions, current mode (LTC3723-1) and voltage mode (LTC3723-2). The LTC3723-1 features peak current mode control with programmable slope compensation and leading edge blanking. The LTC3723-2 employs voltage mode control with voltage feed-forward capability. Both devices feature extremely low start-up and operating currents of 145uA and 3mA, respectively. The LTC3723-1 and LTC3723-2 are rated for operation from -40°C to 85°C. 1,000-piece pricing starts at $4.55 each.
Summary of Features: LTC3723
High Efficiency Synchronous Push-Pull PWM
1.5A Sink, 1A Source Output Drivers
Adjustable Push-Pull Dead-Time & Synchronous Timing
Adjustable System Undervoltage Lockout & Hysteresis
Adjustable Leading Edge Blanking
Low Start-Up & Quiescent Currents
Adjustable Slope Compensation
Company Background
Linear Technology Corporation was founded in 1981 as a manufacturer of high performance linear integrated circuits. Linear Technology products include operational, instrumentation and audio amplifiers; voltage regulators, power management devices, DC-DC converters and voltage references; comparators; monolithic filters; communications interface circuits; one-chip data acquisition sub-systems; pulse-width modulators and sample-and-hold devices; and high frequency devices. Applications for Linear Technology's high performance circuits include wireless and broadband telecommunications infrastructure, cellular telephones, networking products and satellite systems, notebook and desk top computers, computer peripherals, video/multimedia, industrial and medical instrumentation, automotive electronics, factory automation, process control, military and space systems, and high-end consumer products including digital cameras, MP3 players and other electronic products.
