Overview
The NCP1200AP100G, produced by onsemi, is a PWM current-mode controller designed for low-power universal off-line supplies. It is housed in either an SOIC-8 or PDIP-8 package, making it ideal for ultra-compact switch-mode power supplies. This controller simplifies the design of reliable and cost-effective offline converters with features such as current-mode control, skip-cycle capability, and internal output short-circuit protection. It operates at fixed frequencies of 40 kHz, 60 kHz, or 100 kHz and can drive low gate-charge switching devices like IGBTs or MOSFETs, requiring minimal operating power.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Switching Frequency | 86 | 103 | 116 | kHz (100 kHz version) |
| Peak Current Source/Sink Capability | - | 250 | - | mA |
| Internal IC Consumption (No Output Load) | - | 710 | 880 | μA |
| Internal IC Consumption (1 nF Output Load, FSW = 100 kHz) | - | 1.9 | 2.2 | mA |
| Output Voltage Rise-time @ CL = 1 nF | - | 67 | - | ns |
| Output Voltage Fall-time @ CL = 1 nF | - | 28 | - | ns |
| Maximum Duty Cycle | 74 | 80 | 87 | % |
| VCC Increasing Level at Which the Current Source Turns-off | 10.3 | 11.4 | 12.5 | V |
| VCC Decreasing Level at Which the Current Source Turns-on | 8.8 | 9.8 | 11 | V |
Key Features
- No Auxiliary Winding Operation: Self-supplied from the DC rail, eliminating the need for an auxiliary winding.
- Internal Output Short-Circuit Protection: Ensures protection against output short circuits.
- Extremely Low No-Load Standby Power: Minimizes power consumption during standby mode.
- Current-Mode with Skip-Cycle Capability: Automatically enters skip cycle mode at light loads for excellent efficiency.
- 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.
- Direct Optocoupler Connection: Simplifies feedback loop design.
- 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: Protects the IC from overheating.
- Pb-Free Packages are Available: Compliant with RoHS standards.
Applications
- AC-DC Adapters: Ideal for compact and efficient power adapters.
- Offline Battery Chargers: Simplifies the design of battery chargers with few external components.
- Auxiliary/Ancillary Power Supplies: Suitable for USB, appliances, TVs, and other auxiliary power needs.
Q & A
- What is the NCP1200AP100G used for?
The NCP1200AP100G is used for designing low-power universal off-line power supplies, including AC-DC adapters, offline battery chargers, and auxiliary power supplies.
- What are the available switching frequencies for the NCP1200AP100G?
The NCP1200AP100G operates at fixed frequencies of 40 kHz, 60 kHz, or 100 kHz.
- Does the NCP1200AP100G require an auxiliary winding?
No, the NCP1200AP100G does not require an auxiliary winding as it is self-supplied from the DC rail.
- What is the skip cycle mode in the NCP1200AP100G?
The skip cycle mode is a feature where the IC automatically skips switching cycles when the output power demand drops below a certain level, improving efficiency at light loads.
- How does the NCP1200AP100G protect against output short circuits?
The NCP1200AP100G has integrated output short-circuit protection, ensuring the IC can handle output short circuits safely.
- What is the maximum duty cycle of the NCP1200AP100G?
The maximum duty cycle of the NCP1200AP100G is between 74% and 87%.
- Does the NCP1200AP100G generate acoustic noise at light loads?
No, the NCP1200AP100G does not generate acoustic noise at light loads due to its skip cycle mode operation.
- Is the NCP1200AP100G RoHS compliant?
- What is the purpose of the built-in frequency jittering in the NCP1200AP100G?
The built-in frequency jittering reduces electromagnetic interference (EMI).
- Are SPICE models available for the NCP1200AP100G?
