LTC Intros New LTC3709 Synchronous DC-DC Controller
Linear Technology Corp. (LTC, Milpitas, CA) introduced its new LTC3709, a two-phase, step-down, synchronous dc-dc controller with fast transient response, which eliminates voltage errors introduced by PCB traces and high-load currents. The LTC3709 is used in applications such as servers, large memory arrays, industrial single-board computers and control systems.
The LTC3709 is a current mode step-down synchronous controller that drives N-channel MOSFETs. It operates from 4 V to 30 V input supplies and uses a constant on-time, valley current, control architecture to deliver low duty cycles. An integrated differential amplifier measures the output voltage directly at the load and compensates for voltage drop error. It also rejects common-mode signals that are capacitively or inductively coupled into the feedback pin through PC traces.
With a 100 ns on-time, the LTC3709 responds quickly to load transients and reduces the size of output capacitors. The IC uses on-chip, phase-lock loops to achieve phase separation between the two output channels and locking onto an external clock. The LTC3709 can deliver up to 40 A to loads as low as 0.6 V with fewest input and output capacitors.
The LTC3709 is housed in two packages of 5 mm x 5 mm QFN and 36-lead SSOP. It is rated for operation from -40 °C to +85 °C. Pricing in 1,000-piece quantities starts at $4.90.
