Overview
The NCP1251BSN65T1G is a highly integrated current-mode PWM (Pulse Width Modulation) controller designed by onsemi for use in offline power supplies. This component is packaged in a compact TSOP-6 (SC-74) surface mount package, making it ideal for applications where space is limited. The NCP1251BSN65T1G is part of the NCP1251 series, which is known for its robust performance, low part count, and cost-effectiveness, particularly in low-cost AC-DC adapters and open-frame power supplies.
Key Specifications
| Attribute | Value |
|---|---|
| Supply Voltage | 8.8V to 28V |
| Supply Current (Max) | 2.2mA |
| Frequency (Max) | 61kHz to 71kHz |
| Topology | Flyback |
| Duty Cycle (Max) | 84% |
| Operating Temperature Range | -40°C to +125°C |
| Storage Temperature Range | -60°C to +150°C |
| Thermal Resistance | 360°C/W |
| Package Style | TSOP-6 (SC-74) |
| Mounting Method | Surface Mount |
| Output Current Range | -500...300mA |
Key Features
- Current-Mode Operation: The NCP1251BSN65T1G operates in peak current mode control with an internal ramp compensation signal to eliminate sub-harmonic oscillations.
- Internal OPP (Over Power Protection): This feature allows for non-dissipative OPP, enhancing performance in no-load conditions through a simple external resistor configuration.
- Frequency Foldback: The controller reduces its switching frequency as the load decreases, improving efficiency at light loads. The NCP1251F version offers an enhanced foldback scheme for better efficiency.
- Latched Over Voltage Protection (OVP): Combined with OPP on the same pin, this feature ensures robust protection against overvoltage conditions.
- Compact Package: The TSOP-6 package makes it suitable for space-constrained designs.
Applications
The NCP1251BSN65T1G is designed for use in various power supply applications, including:
- Low-Cost AC-DC Adapters: Ideal for cost-effective and compact adapter designs.
- Open-Frame Power Supplies: Suitable for applications requiring high performance and reliability in a small form factor.
- SMPS (Switch-Mode Power Supplies): The controller’s features make it a good fit for SMPS designs that require efficient and robust performance.
Q & A
- What is the operating voltage range of the NCP1251BSN65T1G?
The operating voltage range is from 8.8V to 28V. - What is the maximum switching frequency of the NCP1251BSN65T1G?
The maximum switching frequency is 71kHz. - What is the topology of the NCP1251BSN65T1G?
The topology is flyback. - What is the maximum duty cycle of the NCP1251BSN65T1G?
The maximum duty cycle is 84%. - What is the operating temperature range of the NCP1251BSN65T1G?
The operating temperature range is from -40°C to +125°C. - What type of package does the NCP1251BSN65T1G come in?
The package style is TSOP-6 (SC-74). - How does the NCP1251BSN65T1G handle over power protection (OPP)?
The NCP1251BSN65T1G features internal OPP that can be set using external resistors, ensuring non-dissipative protection. - What is the purpose of the frequency foldback feature in the NCP1251BSN65T1G?
The frequency foldback feature reduces the switching frequency as the load decreases, improving efficiency at light loads. - What kind of protection does the NCP1251BSN65T1G offer against overvoltage conditions?
The NCP1251BSN65T1G offers latched over voltage protection (OVP) combined with OPP on the same pin. - In what types of applications is the NCP1251BSN65T1G commonly used?
The NCP1251BSN65T1G is commonly used in low-cost AC-DC adapters, open-frame power supplies, and SMPS designs).
