Allegro MicroSystems, Inc. announces a new series of hybrid integrated circuits (HICs) with a built-in power MOSFET and a control IC designed for quasi-resonant type switch-mode power supplies (SMPS). In normal operation, the HIC provides high efficiency and low EMI noise with bottom-skip quasi-resonant operation during light output loads. Low power consumption is also achieved by blocking (intermittent) oscillation during an auto-standby mode (not available in the STR-X6729, STR-X6759N, or STR-X6768N) and reduced even further in a manually triggered (clamping an output voltage) standby mode. This new series is targeted at the consumer, office automation and industrial markets.

The HIC is supplied in a seven-pin fully-molded TO-3-style package with pin 2 deleted, which is suitable for downsizing and standardizing of an SMPS by reducing external component count and simplifying circuit design.

Key features and benefits include the following:
•  Blocking (or intermittent) oscillation operation in the auto-standby or manual standby modes
•  In addition to the standard quasi-resonant operation, a bottom-skip function is available for increased efficiency from light to medium load
•  Soft-start operation at start-up
•  Reduced switching noise (compared to conventional PWM hard-switching solution) with a step-drive function
•  Built-in avalanche-energy-guaranteed power MOSFET (to simplify surge-absorption circuit; no VDSS derating is required)
•  Overcurrent protection (OCP), overvoltage protection (OVP), overload protection (OLP), and maximum On-time control circuits are incorporated; OVP and OLP go into a latched mode

This new series is priced betrween $4.70 and $5.00 (1K quantity) dependent on package type. All devices have a 12 week typical lead-time to market.