Overview
The NCP1207ADR2G, produced by onsemi, is a PWM current-mode controller designed for free-running quasi-resonant operation. This IC combines a true current mode modulator and a demagnetization detector to ensure full borderline/critical conduction mode in various load and line conditions. It features high-voltage technology, allowing direct connection to the high-voltage DC rail, and incorporates several key features to simplify and enhance the design of switch-mode power supplies (SMPS).
Key Specifications
| Parameter | Description | Value |
|---|---|---|
| Operating Frequency | Maximum frequency for NCP1207A and NCP1207B | Up to 125 kHz (NCP1207A), up to 200 kHz (NCP1207B) |
| Peak Current Capability | Maximum current source/sink capability | 500 mA |
| Minimum TOFF | Internal blanking delay after TON | 8.0 μs (NCP1207A), 4.5 μs (NCP1207B) |
| Operating Temperature | Minimum and maximum operating temperatures | -40°C to +150°C |
| Package Type | Package style and pin count | SOIC-8 (Pb-Free) |
| VCC Supply | VCC supply voltage range | Below 10 V for undervoltage lockout |
| Soft-Start Time | Internal soft-start duration | 1.0 ms |
Key Features
- Free-Running Borderline/Critical Mode Quasi-Resonant Operation: Ensures efficient operation by delaying the turn-on event to minimize EMI and turn-on losses.
- Current-Mode with Adjustable Skip-Cycle Capability: Allows the controller to enter burst mode when power demand is low, preventing audible noise.
- No Auxiliary Winding VCC Operation: Dynamic Self-Supply (DSS) feature eliminates the need for an auxiliary winding, simplifying transformer design.
- Auto-Recovery Overcurrent Protection: Continuous feedback signal monitoring with overcurrent fault protection circuitry ensures rugged and reliable operation.
- Latching Overvoltage Protection: Permanently latches off upon detecting an overvoltage condition, ensuring protection against voltage spikes.
- Internal Temperature Shutdown: Protects the IC from overheating by shutting down when the temperature exceeds a certain threshold.
- Direct Optocoupler Connection: Facilitates easy integration with optocouplers for feedback signal transfer.
Applications
- AC-DC Adapters for Notebooks and Other Devices: Ideal for low-cost, high-efficiency power supplies.
- Offline Battery Chargers: Suitable for battery charging applications with variable output voltages.
- Consumer Electronics: Used in devices such as DVD players, set-top boxes, and TVs.
- Auxiliary Power Supplies: Applicable for USB, appliances, and other auxiliary power needs).
Q & A
- What is the maximum operating frequency of the NCP1207A and NCP1207B?
The NCP1207A operates up to 125 kHz, while the NCP1207B operates up to 200 kHz.
- What is the peak current capability of the NCP1207ADR2G?
The peak current source/sink capability is 500 mA.
- What is the purpose of the Dynamic Self-Supply (DSS) feature?
The DSS feature eliminates the need for an auxiliary winding, simplifying transformer design by providing a fully independent VCC level.
- How does the overvoltage protection work in the NCP1207ADR2G?
The IC samples the plateau voltage on the demagnetization winding and latches off permanently upon detecting an overvoltage condition.
- What is the internal soft-start duration of the NCP1207ADR2G?
The internal soft-start duration is 1.0 ms.
- What are the typical applications of the NCP1207ADR2G?
Typical applications include AC-DC adapters, offline battery chargers, consumer electronics, and auxiliary power supplies.
- How does the skip cycle capability work in the NCP1207ADR2G?
The controller enters burst mode when the power demand falls below a predetermined level, preventing audible noise.
- What is the operating temperature range of the NCP1207ADR2G?
The operating temperature range is -40°C to +150°C.
- What type of package does the NCP1207ADR2G come in?
The NCP1207ADR2G comes in an SOIC-8 (Pb-Free) package.
- Does the NCP1207ADR2G have built-in overcurrent protection?
Yes, it features auto-recovery overcurrent protection with continuous feedback signal monitoring.
