Overview
The NCP1240FD065R2G, produced by onsemi, is a fixed-frequency current-mode controller designed for flyback converters. This device integrates several advanced features to simplify the design of power supplies, ensuring high efficiency and robust performance. It includes a dynamic self-supply function, which simplifies the design of the auxiliary supply and VCC capacitor by activating an internal startup current source during startup, transients, and standby modes. The controller also features a high-voltage detector for brown-out detection and X2 capacitor discharge, along with timer-based fault detection and adjustable overpower protection.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Operating Frequency | 65 kHz | - |
| Maximum VCC Voltage | -0.3 to 28 (peak: 30) | V |
| Maximum HV Voltage | -0.3 to 500 (peak: 20) | V |
| Maximum DRV Voltage | -0.3 to 20 (peak: 1000 mA) | V |
| Source/Sink Drive Peak Current | 500/800 mA | - |
| Soft-Start Time | 10 ms | - |
| No-Load Standby Power | < 30 mW | - |
| Thermal Shutdown | Internal | - |
| Package Type | SOIC-7 | - |
Key Features
- Fixed-frequency current-mode operation with frequency foldback and skip mode for light load and standby conditions.
- Timer-based overload protection with latched or auto-recovery operation.
- High-voltage current source with brown-out detection and dynamic self-supply.
- Frequency modulation for softened EMI signature.
- Adjustable overpower protection dependent on the bulk voltage.
- Latch-off input combined with overpower protection sensing input.
- VCC operation up to 28 V with overvoltage detection.
- X2 capacitor discharge feature in EMI filter.
- Internal thermal shutdown and 10 ms soft-start.
- No-load standby power consumption less than 30 mW.
Applications
- AC-DC adapters for notebooks, LCDs, and printers.
- Offline battery chargers.
- Consumer electronic power supplies.
- Auxiliary/housekeeping power supplies.
- Offline adapters for notebooks.
Q & A
- What is the operating frequency of the NCP1240FD065R2G?
The operating frequency is 65 kHz.
- What is the maximum voltage on the VCC pin?
The maximum voltage on the VCC pin is -0.3 to 28 V with a peak of 30 V.
- What is the maximum voltage on the HV pin?
The maximum voltage on the HV pin is -0.3 to 500 V with a peak of 20 V.
- What is the source/sink drive peak current capability?
The source/sink drive peak current capability is 500/800 mA.
- Does the NCP1240FD065R2G have internal thermal shutdown?
Yes, it has internal thermal shutdown.
- What is the no-load standby power consumption?
The no-load standby power consumption is less than 30 mW.
- What are the typical applications of the NCP1240FD065R2G?
Typical applications include AC-DC adapters, offline battery chargers, consumer electronic power supplies, auxiliary/housekeeping power supplies, and offline adapters for notebooks.
- Does the NCP1240FD065R2G support frequency modulation for EMI reduction?
Yes, it supports frequency modulation for a softened EMI signature.
- How does the dynamic self-supply function work?
The dynamic self-supply function activates an internal startup current source to supply the controller during startup, transients, and standby modes, simplifying the design of the auxiliary supply and VCC capacitor.
- What is the purpose of the high-voltage detector in the NCP1240FD065R2G?
The high-voltage detector performs functions such as brown-out detection, X2 capacitor discharge, and HV sensing for overpower protection.
