NCP1124: High Voltage Switching Regulator for Offline SMPS
The NCP1124 switcher offers everything needed to build reliable and compact AC-DC switching power supplies with minimal surrounding elements. Incorporating an avalanche rated 650 V MOSFET, converters built with the NCP1124 can be safely designed for international conditions without jeopardizing the overall reliability. The NCP1124 implements peak current mode control with adjustable ramp compensation that ensures stability in Continuous Conduction Mode (CCM) operation. With an external resistor, the maximum peak current is adjustable, allowing the designer the ability to inject ramp compensation to stabilize CCM power supplies. A short circuit fault condition is independently detected from the auxiliary winding voltage resulting in improved short circuit protection with true overload detection. The Source pin provides access to the MOSFET source, allowing for overpower compensation. With a supply range up to 26 V, the switcher also provides a jittered 65 kHz or 100 kHz switching frequency operated in peak current mode control. When the power on the secondary side starts to decrease, the switcher automatically folds back its switching frequency down to a minimum level of 26 kHz. As the power further goes down, the part enters skip cycle while limiting the peak current.
Features- 650 V Avalanche Rated MOSFET
- Fixed−Frequency 65 or 100 kHz Current−Mode Control with Adjustable Internal Ramp Compensation
- Frequency Foldback Down to 26 kHz and Skip−Cycle for Light Load Efficiency
- Adjustable Current Limit with External Resistor
- 50 ms Timer-Based Auto-Recovery Short-Circuit Protection
- Frequency Jittering in Normal and Frequency Foldback Modes
- Option for Auto-Recovery or Latched Short-Circuit Protection
- Less than 100 mW Standby Power at High Line
| Benefits- Rugged MOSFET for robust design
- Ability to scale for efficiency or size
- Eliminate acoustic noise and improved efficiency at light loads
- Scale for various designs 5W~20W
- Provides more robust protection without worrying about the coupling of the aux winding
- Improved efficiency at light load / Improved EMI over the entire load
- Flexible protection options
- EPS 2.0 Compliant
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Applications | End Products- Power supply for DVD, STB, CD-Player
- Aux supply for TV, USB, Appliance
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Package Drawings (1)
Data Sheets (1)
Evaluation Board Documents (4)
Evaluation/Development Tool Information
| Product | Status | Compliance | Short Description |
|---|
| NCP1124DIPGEVB | Active | Pb-free | 10W SMPS Evaluation Board |
Order Information
| Product | Status | Compliance | Package | MSL* | Container | Budgetary Price/Unit |
|---|
| NCP1124AP100G | Active | Pb-free
Halide free | PDIP-8 | 626B | NA | Tube | 50 | $0.4 |
| NCP1124AP65G | Active | Pb-free
Halide free | PDIP-8 | 626B | NA | Tube | 50 | $0.4 |
| NCP1124BP100G | Active | Pb-free
Halide free | PDIP-8 | 626B | NA | Tube | 50 | $0.4 |
| NCP1124BP65G | Active | Pb-free
Halide free | PDIP-8 | 626B | NA | Tube | 50 | $0.4 |
Specifications
| Product | Control Mode | fsw Typ (kHz) | fJitter Typ (%) | Stand-by Mode | RDS(ON) Typ (Ω) | V(BR)DSS Max (V) | IPeak (mA) | HV Start-up Min (V) | DSS (mA) | UVLO | Short Circuit Protection | Over Power Compensation | Brown-out | Latch |
|---|
| NCP1124AP100G | Current Mode | 65 | +/- 5% of Fsw | Yes | 9 | 650 | | Yes | | 8.8 | Yes | No | No | Yes |
| NCP1124AP65G | Current Mode | 100 | +/- 5% of Fsw | Yes | 9 | 650 | | Yes | | 8.8 | Yes | No | No | Yes |
| NCP1124BP100G | Current Mode | 65 | +/- 5% of Fsw | Yes | 9 | 650 | | Yes | | 8.8 | Yes | No | No | No |
| NCP1124BP65G | Current Mode | 100 | +/- 5% of Fsw | Yes | 9 | 650 | | Yes | | 8.8 | Yes | No | No | No |
