NCP1256 Series

Low Power Offline PWM Current Mode Controller with Brown-Out Protection

Catalog

Low Power Offline PWM Current Mode Controller with Brown-Out Protection

Part	Voltage - Supply (Vcc/Vdd) [Min]	Voltage - Supply (Vcc/Vdd) [Max]	Fault Protection	Frequency - Switching	Internal Switch(s)	Duty Cycle	Voltage - Start Up	Topology	Operating Temperature [Min]	Operating Temperature [Max]	Supplier Device Package	Mounting Type	Package / Case	Output Isolation
ON Semiconductor NCP1256ASN65T1G	8.9 V	28 V	Over Power Over Voltage Short Circuit	65 kHz		80 %	18 V	Flyback	-40 °C	125 ¯C	6-TSOP	Surface Mount	SOT-23-6 Thin TSOT-23-6	Isolated

Catalog

Low Power Offline PWM Current Mode Controller with Brown-Out Protection

Key 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

• Fixed−frequency 65−kHz or 100−kHz Current−mode Control Operation

• Pb−Free Device

• 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

Description

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.