Overview
The NCP1246BD100R2G, 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, including dynamic self-supply, high-voltage current source, and brown-out detection. It is particularly suited for applications requiring high efficiency, low standby power consumption, and robust protection mechanisms.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Operating Frequency | 65 kHz / 100 kHz | - | - | kHz |
| VCC Power Supply Voltage | -0.3 | - | 28 | V |
| Maximum Voltage on HV Pin | -0.3 | - | 500 | V |
| DRV Pin Peak Current Capability | - | 500/800 mA | - | mA |
| Soft-Start Time | 8 ms / 4 ms (AL/BL Versions) | - | - | ms |
| No-Load Standby Power | - | - | < 30 mW | mW |
| Internal Thermal Shutdown | - | - | - | - |
Key Features
- Fixed-frequency current-mode operation with options for 65 kHz and 100 kHz frequencies.
- Frequency foldback and skip mode for optimized performance in light load and standby conditions.
- Timer-based overload protection with latched (Option A) or auto-recovery (Option B) 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.
- Internal thermal shutdown and no-load standby power < 30 mW.
- X2 capacitor discharge feature in EMI filter.
- Pb-free, halogen-free/BFR-free, and RoHS compliant.
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 are the operating frequencies of the NCP1246BD100R2G?
The NCP1246BD100R2G operates at fixed frequencies of 65 kHz and 100 kHz.
- What is the maximum voltage on the VCC pin?
The maximum voltage on the VCC pin is 28 V.
- What is the purpose of the dynamic self-supply feature?
The dynamic self-supply feature simplifies the design of the auxiliary supply and VCC capacitor by activating the internal startup current source during start-up, transients, and standby.
- How does the frequency foldback mode work?
In frequency foldback mode, the converter operates by modulating the switching frequency to regulate the output voltage for loads between approximately 32% and 10% of full rated power.
- What is the no-load standby power consumption of the NCP1246BD100R2G?
The no-load standby power consumption is less than 30 mW.
- Does the NCP1246BD100R2G have thermal protection?
Yes, it includes internal thermal shutdown protection.
- What is the purpose of the X2 capacitor discharge feature?
The X2 capacitor discharge feature is used to discharge the X2 capacitor in the EMI filter.
- Is the NCP1246BD100R2G RoHS compliant?
Yes, the device is Pb-free, halogen-free/BFR-free, and RoHS compliant.
- What are the typical applications of the NCP1246BD100R2G?
Typical applications include AC-DC adapters, offline battery chargers, consumer electronic power supplies, and auxiliary/housekeeping power supplies.
- How does the latch-off input work?
The latch-off input allows the controller to be latched off by pulling the pin up or down, and it also supports direct connection of an NTC for over-temperature detection.
