Overview
The NCP1370BDR2G is a PWM current mode controller developed by onsemi, designed to target isolated flyback and non-isolated constant current topologies. This controller operates in a quasi-resonant mode, enhancing efficiency by switching in the valley of the MOSFET drain-source voltage. It utilizes a novel control method to precisely regulate a constant LED current from the primary side, eliminating the need for secondary side feedback circuitry, biasing, and an opto-coupler. The device is highly integrated, requiring a minimal number of external components, and features a robust suite of safety protections to simplify design. It supports both analog and digital dimming, with the option to combine these modes for enhanced dimming precision. The NCP1370BDR2G also includes a programmable peak current limit and a standby mode with reduced current consumption.
Key Specifications
| Parameter | Unit | Typical | Minimum | Maximum |
|---|---|---|---|---|
| Operating Temperature Range | °C | - | -40 | 125 |
| Storage Temperature Range | °C | - | -60 | 150 |
| ESD Capability, HBM model | kV | - | - | 4 |
| ESD Capability, MM model | V | - | - | 200 |
| VCC Voltage Range | V | - | - | 12 |
| Drive Current Capability (Sink) | mA | - | - | 500 |
| Drive Current Capability (Source) | mA | - | - | 300 |
| Rise Time (10% to 90%) | ns | 40 | - | - |
| Fall Time (90% to 10%) | ns | 30 | - | - |
| Voltage Reference for Current Regulation | mV | 500 ± 1.2% | - | - |
| Dimming Pin Voltage for Maximum Output Current | V | 3 | 2.9 | 3.1 |
Key Features
- Quasi-Resonant Peak Current-Mode Control Operation: Optimizes efficiency by switching in the valley of the MOSFET drain-source voltage.
- Primary Side Sensing: No opto-coupler needed for feedback.
- Precise LED Constant Current Regulation: ±1% typical accuracy.
- Line Feed-Forward for Enhanced Regulation Accuracy: Improves regulation accuracy.
- Low LED Current Ripple: Minimizes current ripple.
- Programmable Cycle-by-Cycle Peak Current Limit: Optimizes design compatibility.
- Analog or Digital Dimming: Supports both modes and their combination for enhanced precision.
- Wide Temperature Range: Operates from -40°C to +125°C.
- Robust Protection Features: Includes LED open circuit protection, VCC over voltage protection, secondary diode short protection, output short circuit protection, and more.
- Standby Mode with Reduced Current Consumption: Low power consumption in standby mode.
Applications
- TV Backlight: Ideal for LED backlighting in TV applications.
- Lighting with Auxiliary Power Supply: Suitable for various lighting applications with auxiliary power supplies.
- LED Power Supply: Used in LED power supply units.
- LED Light Engines: Applicable in LED light engine designs.
Q & A
- What is the primary function of the NCP1370BDR2G?
The NCP1370BDR2G is a PWM current mode controller designed for isolated flyback and non-isolated constant current topologies, particularly for LED applications.
- What is the advantage of quasi-resonant operation in the NCP1370BDR2G?
The quasi-resonant operation optimizes efficiency by switching in the valley of the MOSFET drain-source voltage, reducing switching losses.
- Does the NCP1370BDR2G require secondary side feedback circuitry?
No, the NCP1370BDR2G uses primary side sensing, eliminating the need for secondary side feedback circuitry and an opto-coupler.
- What types of dimming does the NCP1370BDR2G support?
The NCP1370BDR2G supports both analog and digital dimming, and these modes can be combined for enhanced precision.
- What are the key protection features of the NCP1370BDR2G?
The device includes LED open circuit protection, VCC over voltage protection, secondary diode short protection, output short circuit protection, brown-out protection, and thermal shutdown.
- What is the operating temperature range of the NCP1370BDR2G?
The NCP1370BDR2G operates from -40°C to +125°C.
- How does the NCP1370BDR2G handle VCC over voltage protection?
The controller stops the DRV pulses and shuts down when the VCC voltage exceeds the VCC(OVP) threshold. It can operate in either auto-recovery or latched mode depending on the version.
- What is the significance of the standby mode in the NCP1370BDR2G?
The standby mode reduces current consumption, allowing the device to be powered by a standby power supply.
- Can the NCP1370BDR2G be used in various lighting applications?
Yes, the NCP1370BDR2G is suitable for various lighting applications, including those with auxiliary power supplies.
- What package type is the NCP1370BDR2G available in?
The NCP1370BDR2G is available in an SOIC-8 package.
