Overview
The NCP1217AD65R2G, produced by ON Semiconductor, is an enhanced PWM controller designed for high-power AC/DC converters. It operates in current-mode control topology and is housed in an SO-8 or PDIP-7 package. This controller is an advanced version of the NCP1203-based controllers, offering high drive capability, internal ramp compensation, and built-in overvoltage protection. It is particularly suited for applications requiring low part-count and high performance, such as in TV power supplies, offline adapters for notebooks, and telecom DC-DC converters.
Key Specifications
| Parameter | Min | Max | Unit | |
|---|---|---|---|---|
| Oscillation Frequency (65 kHz Version) | 58.5 | 65 | 71.5 | kHz |
| Oscillation Frequency (100 kHz Version) | 90 | 100 | 110 | kHz |
| Oscillation Frequency (133 kHz Version) | 120 | 133 | 146 | kHz |
| Maximum Duty-Cycle (NCP1217) | 69 | 74 | 80 | % |
| Maximum Duty-Cycle (NCP1217A) | 42 | 46.5 | 50 | % |
| Maximum Junction Temperature | 150 | °C | ||
| Storage Temperature Range | -60 | 150 | °C | |
| ESD Capability (HBM Model) | 2.0 kV | |||
| ESD Capability (Machine Model) | 200 V | |||
| Peak Current Capability | 500 mA |
Key Features
- Current-Mode with Adjustable Skip-Cycle Capability: The NCP1217 features a current-mode control architecture with the ability to adjust the skip cycle level, ensuring efficient operation at light loads.
- Built-in Internal Ramp Compensation: Prevents subharmonic oscillations in continuous conduction mode designs through internal ramp compensation.
- Auto-Recovery Internal Output Short-Circuit Protection: The device enters a safe burst mode in case of an overcurrent condition and auto-recovers once the fault is cleared.
- Internal 1.0 ms Soft-Start (NCP1217A Only): Ensures a smooth startup sequence.
- Limited Duty-Cycle to 50% (NCP1217A Only): Limits the duty cycle to 50% for enhanced control.
- Full Latchoff if Adjustment Pin is Brought High: Permanently disables the output pulses if the adjustment pin is brought above a certain voltage level.
- Extremely Low No-Load Standby Power: Optimized for low power consumption during standby.
- Internal Temperature Shutdown: Protects the device from overheating.
- Direct Optocoupler Connection: Allows for direct connection to optocouplers for feedback control.
- Internal Leading Edge Blanking: Reduces noise and improves stability.
- SPICE Models Available: For transient and AC analysis.
Applications
- High Power AC/DC Converters for TVs, Set-Top Boxes, etc.: Ideal for high-power applications requiring efficient and reliable power conversion.
- Offline Adapters for Notebooks: Suitable for notebook power adapters due to its high efficiency and low standby power.
- Telecom DC-DC Converters: Used in telecom equipment for efficient DC-DC conversion.
- All Power Supplies: General-purpose use in various power supply applications.
Q & A
- What is the NCP1217AD65R2G used for?
The NCP1217AD65R2G is used in high-power AC/DC converters, offline adapters, telecom DC-DC converters, and other power supply applications.
- What are the key features of the NCP1217AD65R2G?
Key features include current-mode control with adjustable skip-cycle capability, built-in internal ramp compensation, auto-recovery short-circuit protection, and extremely low no-load standby power.
- What are the different oscillation frequencies available for the NCP1217AD65R2G?
The NCP1217AD65R2G is available in versions with oscillation frequencies of 65 kHz, 100 kHz, and 133 kHz.
- How does the skip cycle mode work in the NCP1217AD65R2G?
The skip cycle mode is activated when the output power demand drops below a certain level, preventing unnecessary switching cycles and ensuring quiet, noise-free operation.
- What is the maximum junction temperature for the NCP1217AD65R2G?
The maximum junction temperature is 150°C.
- Does the NCP1217AD65R2G have built-in overvoltage protection?
Yes, the NCP1217AD65R2G includes built-in overvoltage protection.
- How does the auto-recovery short-circuit protection work?
In case of an overcurrent condition, the device enters a safe burst mode and auto-recovers once the fault is cleared.
- What is the purpose of the internal leading edge blanking?
The internal leading edge blanking reduces noise and improves stability in the switching operation.
- Are SPICE models available for the NCP1217AD65R2G?
Yes, SPICE models are available for transient and AC analysis.
- What is the typical application of the NCP1217AD65R2G in telecom equipment?
The NCP1217AD65R2G is used in telecom DC-DC converters for efficient power conversion.
