Overview
The NCP1217D133R2G, produced by onsemi, is a second-generation PWM controller based on the NCP1203 architecture. It is designed to drive large gate-charge MOSFETs, making it an ideal component for modern AC/DC adapters and other high-power applications. The controller operates at a fixed frequency of 133 kHz and features a high-voltage startup FET, ensuring a clean and lossless startup sequence. Its current-mode control topology provides excellent input audio-susceptibility and inherent pulse-by-pulse control, along with internal ramp compensation to prevent subharmonic oscillations in continuous conduction mode designs.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Package Type | SOIC-8, PDIP-7 | - |
| Operating Frequency | 133 kHz | kHz |
| Maximum Duty Cycle | 69-80% (NCP1217), 42-50% (NCP1217A) | % |
| Peak Current Capability | ±500 mA | mA |
| Internal Current Setpoint | 0.9-1.1 V | V |
| Leading Edge Blanking Duration | 250 ns | ns |
| Maximum Junction Temperature | 150 °C | °C |
| Storage Temperature Range | -60 to +150 °C | °C |
| ESD Capability (HBM Model) | 2.0 kV | kV |
| ESD Capability (Machine Model) | 200 V | V |
Key Features
- Current-Mode Control with Adjustable Skip-Cycle Capability
- Built-in Internal Ramp Compensation
- Auto-Recovery Internal Output Short-Circuit Protection
- Internal 1.0 ms Soft-Start (NCP1217A Only)
- Limited Duty-Cycle to 50% (NCP1217A Only)
- Full Latchoff if Adjustment Pin is Brought High
- Extremely Low No-Load Standby Power
- Internal Temperature Shutdown
- Direct Optocoupler Connection
- Internal Leading Edge Blanking
- SPICE Models Available for Transient and AC Analysis
- Pb-Free Devices
Applications
- High Power AC/DC Converters for TVs, Set-Top Boxes, etc.
- Offline Adapters for Notebooks
- Telecom DC-DC Converters
- All Power Supplies
Q & A
- What is the operating frequency of the NCP1217D133R2G?
The NCP1217D133R2G operates at a fixed frequency of 133 kHz. - What is the maximum duty cycle of the NCP1217?
The maximum duty cycle for the NCP1217 is 69-80%, and for the NCP1217A, it is 42-50%. - What is the peak current capability of the NCP1217?
The peak current capability is ±500 mA. - How does the skip cycle mode work in the NCP1217?
The skip cycle mode is activated when the current setpoint falls below a given value, allowing the IC to enter a skip cycle mode to provide excellent efficiency at light loads. - What is the purpose of the internal ramp compensation in the NCP1217?
The internal ramp compensation prevents subharmonic oscillations in continuous conduction mode designs. - How does the overcurrent protection work in the NCP1217?
In the presence of an overcurrent condition, the output pulses are disabled, and the device enters a safe burst mode, trying to restart once the fault condition disappears. - What happens if the adjustment pin is brought above 3.1 V?
If the adjustment pin is brought above 3.1 V, the output pulses are permanently disabled, and the device latches off. - What is the maximum junction temperature for the NCP1217?
The maximum junction temperature is 150 °C. - Is the NCP1217 Pb-free?
Yes, the NCP1217 is a Pb-free device. - What are some typical applications of the NCP1217?
Typical applications include high power AC/DC converters, offline adapters for notebooks, telecom DC-DC converters, and all power supplies.
