Intersil Corp. has introduced a new current mode PWM
controller that simplifies design through feature integration and
reduced component count. In addition, the ISL6726 improves circuit
reliability through a duty cycle clamp feature that reduces voltage
stress on external components.
The device is ideal for applications that require isolated active clamp
forward and asymmetric half-bridge converter topologies, such as power
systems in telecom and datacom equipment.
To provide improved reliability, the ISL6726 incorporates adjustable
peak current limit as well as average current limit protection. The
device includes both types of protection to ensure the output current is
always within a safe operating range. The average current limit
provides stable overload operation in applications requiring parallel or
redundant converters and constant current applications such as battery
chargers or LED drivers. For improved reliability in synchronous
rectifier applications, the controller protects the switching components
by clamping the minimum duty cycle. This prevents large negative output
inductor currents during load transients.
For higher power applications, the ISL6726 provides a flexible and
scalable solution that easily lends itself to design re-use. The ISL6726
includes a bi-directional synchronization option with 180° phase shift
that enables interleaved topologies. Interleaving reduces RMS input
current and simplifies thermal management. The controller also includes
soft-start and soft-stop functionality, limiting electrical stress
during the start-up and shut-down process.
The controller supports design of the active clamp reset topology that
improves conversion efficiency in applications requiring a transformer
isolated DC/DC converter. The ISL6726 further improves efficiency by
providing precise duty cycle and deadtime control, enabling designers to
use smaller power components to minimize board space.
The ISL6726 is available now in a 20-pin QSOP package, and is priced at $2.60 each in 1,000-unit quantities.