Housed in SO-8 or DIP8 package, the NCP1203 represents a major leap toward ultra-compact Switch-Mode Power Supplies and represents an excellent candidate to replace the UC384X devices.Thanks to its proprietary SmartMOS Very High Voltage Technology, the circuit allows the implementation of complete off-line AC/DC adapters, battery charger and a high-power SMPS with few external components.

With an internal structure operating at a fixed 40 kHz, 60 kHz or 100 kHz switching frequency, the controller features a high-voltage start-up FET which ensures a clean and loss-less start up sequence. Its current-mode control naturally provides good audio susceptibility and inherent pulse-by-pulse control.

When the current set point falls below a given value, e.g. the output power demand diminishes, the IC automatically enters the so-called skip cycle mode and provides improved efficiency at light loads while offering excellent performance in standby conditions. Because this occurs at a user adjustable low peak current, no acoustic noise takes place.

The NCP1203 also includes an efficient protective circuitry which, in presence of an output over load condition, disables the output pulses while the device enters a safe burst mode, trying to restart. Once the default has gone, the device auto-recovers. Finally, atemperature shutdown with hysteresis helps building safe and robust power supplies.

特性
High-Voltage Start Up Current Source
Auto-Recovery Internal Output Short-Circuit Protection
Extremely Low No-Load Standby Power
Current-Mode with Adjustable Skip-Cycle Capability
Internal Leading Edge Blanking
250 mA Peak Current Capability
Internally Fixed Frequency at 40 kHz, 61 kHz and 100 kHz
Direct Optocoupler Connection
Undervoltage Lockout at 7.6 V Typical
SPICE Models Available for TRANsient and AC Analysis
Pin to Pin Compatible with NCP1200
Pb-Free Packages are Available

应用
AC/DC Adapters for Notebooks, etc. Offline Battery Chargers Auxiliary Power Supplies (USB, Appliances, TVs, etc.)