NCP1256: Low Power Offline PWM Current Mode Controller with Brown-Out Protection
The NCP1256 includes everything to build cost-effective switch mode power supplies ranging from a few watts up to several tens of watts. Housed in a tiny TSOP-6 package, the part can be supplied up to 30 V. It hosts a jittered 65 or 100-kHz switching circuitry operated in peak current mode control. When the power in the secondary side starts to decrease, the controller 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.
NCP1256 comes with several protection features such as a timer-based auto-recovery short circuit protection, lossless OPP, and an easily adjustable Brown Out (BO) pin. Two inputs are provided to latch off the part in a practical way, for instance with OVP and OTP events. Several options exists to chose latch or auto-recovery.
Features- Frequency Foldback down to 26 kHz and Skip−cycle in Light Load Conditions
- 70−ms Timer−based Auto−recovery Short−circuit Protection
- Frequency Jittering in Normal and Frequency Foldback Modes
- +500 mA/ −500 mA Source/Sink Drive Capability
- Pb−Free Device
- Fixed−frequency 65−kHz or 100−kHz Current−mode Control Operation
- Adjustable Over Power Protection (OPP) Circuit, Disabled at Low Line
- Adjustable Brown Out Level
- Internally−fixed Slope Compensation Ramp
- Internally−fixed 4−ms Soft−start
- Double Hiccup Auto−recovery Short−circuit Protection
- Pre−short Ready for Latched OCP Option
- Latched OVP Protection on Vcc
- Latched Inputs for Improved Robustness (OVP and OTP implementations)
- EPS 2.0 Compliant
| Benefits- More efficient light load operation
- Short circuit operation for safety yet reliable with auto-recovery for flexible restart
- Jitter reduces EMI by spreading the switching sprectrum over a wider band
- Ability to drive larger FETs
- Environment friendly
|
Applications- Ac−dc Adapters for Portable Devices
- Ac−dc Adapters for Computers
- Ac−dc Adapters for Tablets
- General Ac−dc Adapters
| End Products |
Application Notes (3)
Data Sheets (1)
Evaluation Board Documents (4)
Package Drawings (1)
| Document Title | Document ID/Size | Revision |
|---|
| TSOP-6 | 318G-02 (64.1kB) | V |
Evaluation/Development Tool Information
| Product | Status | Compliance | Short Description |
|---|
| NCP1256B60WGEVB | Active | Pb-free | 60W, 19V Power Supply Evaluation Board |
Order Information
| Product | Status | Compliance | Package | MSL* | Container | Budgetary Price/Unit |
|---|
| NCP1256ASN100T1G | Active | Pb-free
Halide free | TSOP-6 | 318G-02 | 3 | Tape and Reel | 3000 | $0.2133 |
| NCP1256ASN65T1G | Active | Pb-free
Halide free | TSOP-6 | 318G-02 | 3 | Tape and Reel | 3000 | $0.2133 |
| NCP1256BSN100T1G | Active | Pb-free
Halide free | TSOP-6 | 318G-02 | 3 | Tape and Reel | 3000 | $0.2133 |
| NCP1256BSN65T1G | Active | Pb-free
Halide free | TSOP-6 | 318G-02 | 3 | Tape and Reel | 3000 | $0.2133 |
Specifications
| Product | Topology | Control Mode | fsw Typ (kHz) | Stand-by Mode | UVLO (V) | Short Circuit Protection | Latch | Soft Start | VCC Max (V) | Drive Cap. (mA) |
|---|
| NCP1256ASN100T1G | Flyback | Current Mode | 100 | Yes | 8.3 | Yes | Yes | Yes | 35 | 500 / 500 |
| NCP1256ASN65T1G | Flyback | Current Mode | 65 | Yes | 8.3 | Yes | Yes | Yes | 35 | 500 / 500 |
| NCP1256BSN100T1G | Flyback | Current Mode | 100 | Yes | 8.3 | Yes | No | Yes | 35 | 500 / 500 |
| NCP1256BSN65T1G | Flyback | Current Mode | 65 | Yes | 8.3 | Yes | No | Yes | 35 | 500 / 500 |
