The NCP1200A is a PWM current-mode controller suitable for universal off-line supplies featuring low standby power. It enhances the previous NCP1200 series by offering a reduced optocoupler current together with an increased drive capability. With its novel concept, the circuit allows the implementation of complete off-line AC-DC adapters, battery chargers, or SMPS where standby power is a key parameter. The controller operates at a fixed frequency of 40 kHz, 60 kHz, or 100 kHz and draws power from the high-voltage rail, eliminating the need for an auxiliary winding. This simplifies the design task in battery charger applications. The current-mode control provides excellent audio susceptibility and inherent pulse-by-pulse control. When the current setpoint falls below a given value, the IC automatically enters the skip cycle mode, providing excellent efficiency at light loads. This occurs at a user-adjustable low peak current, ensuring no acoustic noise. The NCP1200A features efficient protective circuitry that disables the output pulses in the presence of an overcurrent condition, entering a safe burst mode to attempt a restart. The device auto-recovers once the fault has been resolved.
The NCP1200A is a miniature PWM controller designed for high-power AC-DC wall adapters and offline battery chargers. It operates with an internal structure at fixed frequencies of 40 kHz, 60 kHz, or 100 kHz, allowing it to supply itself from the high-voltage rail without requiring an auxiliary winding.
The device features current-mode control with skip-cycle capability for excellent efficiency at light loads and inherent pulse-by-pulse control. It includes efficient protective circuitry that disables output pulses during overcurrent conditions and enters a safe burst mode before auto-recovering once the fault is cleared.
| Operating Frequency Options | 40 kHz, 60 kHz, and 100 kHz |
|---|---|
| Peak Current Capability | 250 mA |
| Maximum Junction Temperature | 150 °C |
| Temperature Shutdown Threshold | 145 °C |
| Storage Temperature Range | -60 to +150 °C |
| Power Supply Voltage (Vcc) | 16 V |
The device is suitable for AC-DC adapters, offline battery chargers, and auxiliary power supplies.
No, it supplies itself from the high-voltage rail and avoids the need for an auxiliary winding.