Overview
The NCP1200AD60R2G, produced by ON Semiconductor, is a PWM Current-Mode Controller designed for low-power universal off-line supplies. This component is housed in an SOIC-8 or PDIP-8 package and represents a significant advancement in ultra-compact switchmode power supplies. It is particularly suited for applications where low part-count and high efficiency are crucial, such as in low-cost AC-DC adapters and offline battery chargers.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC Increasing Level at Which the Current Source Turns-off (VCCOFF) | 10.3 | 11.4 | 12.5 | V |
| VCC Decreasing Level at Which the Current Source Turns-on (VCCON) | 8.8 | 9.8 | 11 | V |
| Internal IC Consumption, No Output Load on Pin 5 (ICC1) | - | 710 | 880 | μA |
| Internal IC Consumption, 1 nF Output Load on Pin 5, FSW = 60 kHz (ICC2) | - | 1.4 | 1.6 | mA |
| High-voltage Current Source, VCC = 10 V (IC1) | 2.8 | 4.0 | - | mA |
| Oscillation Frequency, 60 kHz Version (fOSC) | 52 | 61 | 70 | kHz |
| Maximum Duty Cycle (Dmax) | 74 | 80 | 87 | % |
Key Features
- No Auxiliary Winding Operation: The NCP1200 is self-supplied from the DC rail, eliminating the need for an auxiliary winding.
- Internal Output Short-Circuit Protection: Ensures robust operation and protection against short circuits.
- Extremely Low No-Load Standby Power: Optimized for low power consumption during standby mode.
- Current-Mode with Skip-Cycle Capability: Automatically enters skip cycle mode at low peak currents to maintain efficiency and reduce noise.
- Internal Leading Edge Blanking: Reduces noise and improves reliability.
- 250 mA Peak Current Source/Sink Capability: Supports high current requirements.
- Internally Fixed Frequency at 40 kHz, 60 kHz, and 100 kHz: Provides flexibility in design and operation.
- Direct Optocoupler Connection: Simplifies feedback circuitry.
- Built-in Frequency Jittering for Lower EMI: Reduces electromagnetic interference.
- SPICE Models Available for Transient and AC Analysis: Facilitates detailed simulation and analysis.
- Internal Temperature Shutdown: Ensures safe operation by shutting down at high temperatures.
- Pb-Free, Halogen Free/BFR Free and RoHS Compliant: Meets environmental and safety standards.
Applications
- AC-DC Adapters: Ideal for low-cost, compact AC-DC adapters.
- Offline Battery Chargers: Suitable for battery charging applications with minimal external components.
- Auxiliary Supplies: Used in various auxiliary power supply applications where low part-count is essential.
Q & A
- What is the NCP1200AD60R2G used for?
The NCP1200AD60R2G is used in low-power universal off-line supplies, particularly in applications such as AC-DC adapters and offline battery chargers.
- What are the key features of the NCP1200AD60R2G?
Key features include no auxiliary winding operation, internal output short-circuit protection, extremely low no-load standby power, current-mode with skip-cycle capability, and more.
- What are the typical operating frequencies of the NCP1200AD60R2G?
The NCP1200AD60R2G operates at internally fixed frequencies of 40 kHz, 60 kHz, and 100 kHz.
- How does the NCP1200AD60R2G handle short circuits?
The NCP1200AD60R2G has integrated output short-circuit protection to ensure robust operation against short circuits.
- What is the significance of the Dynamic Self-Supply (DSS) feature?
The DSS feature allows the IC to be self-supplied from the DC rail, eliminating the need for an auxiliary winding and ensuring operation even at low output voltages or shorts.
- How does the skip cycle mode improve efficiency?
The skip cycle mode allows the IC to automatically enter a low-power state at low peak currents, maintaining high efficiency and reducing noise.
- What is the maximum duty cycle of the NCP1200AD60R2G?
The maximum duty cycle is between 74% and 87%.
- Is the NCP1200AD60R2G environmentally compliant?
Yes, the NCP1200AD60R2G is Pb-Free, Halogen Free/BFR Free, and RoHS Compliant.
- How does the built-in frequency jittering feature benefit the design?
The built-in frequency jittering reduces electromagnetic interference (EMI), making the design more reliable and compliant with EMI standards.
- What is the significance of the internal temperature shutdown feature?
The internal temperature shutdown feature ensures safe operation by shutting down the IC at high temperatures, preventing damage and ensuring reliability.
