Overview
The NCP1236BD65R2G is a fixed-frequency current-mode controller designed for flyback converters, manufactured by onsemi. This device is part of the NCP1236 family and is known for its Dynamic Self-Supply (DSS) feature, which simplifies the design of the auxiliary supply and VCC capacitor. It offers excellent efficiency in light load conditions and very low standby power consumption. The controller includes various protective features such as overpower protection, overload protection, and brown-out detection, ensuring a high level of safety in the final application.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Oscillator Frequency | 65 kHz | - |
| Frequency Foldback | Down to 27 kHz | - |
| VCC Operation Range | Up to 28 V | V |
| Peak Source / Sink Current Drive Capability | 500 mA | mA |
| Soft-Start Time | 4.0 ms | ms |
| Internal Thermal Shutdown | Yes | - |
| Package Type | SOIC-7 | - |
| Operating Temperature Range | -40°C to +125°C | °C |
| RoHS Compliance | Yes | - |
Key Features
- Fixed-Frequency Current-Mode Operation with Built-In Ramp Compensation: Ensures maximum safety and prevents sub-harmonic oscillations.
- Frequency Foldback and Skip Mode: Maximizes performance in light load and standby conditions.
- Timer-Based Overload Protection: Available in latched or auto-recovery modes.
- High-Voltage Current Source with Brown-Out Detection: Simplifies the design of the VCC capacitor and ensures clean start-up.
- Adjustable Overpower Compensation: Allows for adjustment based on the input voltage.
- Latch-Off Input for Severe Fault Conditions: Supports direct connection of an NTC for overtemperature protection.
- Internal Thermal Shutdown: Protects against self-overheating.
- Pin-to-Pin Compatibility with NCP12xx Series: Easy integration with existing designs.
Applications
- AC-DC Adapters for Notebooks, LCD, and Printers
- Offline Battery Chargers
- Consumer Electronic Power Supplies
- Auxiliary/Housekeeping Power Supplies
Q & A
- What is the primary function of the NCP1236BD65R2G?
The NCP1236BD65R2G is a fixed-frequency current-mode controller designed for flyback converters.
- What are the available oscillator frequencies for the NCP1236BD65R2G?
The NCP1236BD65R2G is available with an oscillator frequency of 65 kHz or 100 kHz, though the specific model NCP1236BD65R2G operates at 65 kHz.
- How does the frequency foldback feature work?
The frequency foldback feature reduces the switching frequency down to 27 kHz in light load conditions to maximize efficiency and reduce switching losses.
- What is the Dynamic Self-Supply (DSS) feature?
The DSS feature activates the internal startup current source to supply the controller during VCC voltage transients, simplifying the design of the auxiliary supply and VCC capacitor.
- What protective features does the NCP1236BD65R2G include?
The device includes timer-based overload protection, brown-out detection, overpower protection, and internal thermal shutdown.
- How does the latch-off input work?
The latch-off input can be triggered by either an overvoltage or an overtemperature condition, allowing direct connection of an NTC for overtemperature protection.
- What is the operating temperature range of the NCP1236BD65R2G?
The operating temperature range is -40°C to +125°C.
- Is the NCP1236BD65R2G RoHS compliant?
Yes, the NCP1236BD65R2G is RoHS compliant.
- What is the typical soft-start time for the NCP1236BD65R2G?
The soft-start time is 4.0 ms.
- What is the peak source/sink current drive capability of the NCP1236BD65R2G?
The peak source/sink current drive capability is 500 mA.
