文档介绍：NCP1215
Product
Preview
Low
Cost
Variable
OFF
Time
Switched
Mode
Power
Supply
Controller
The NCP1215 is a controller for low power off-line flyback
Switched Mode Power Supplies (SMPS) featuring low size, weight MARKING
and cost constraints together with a good low standby power DIAGRAMS
performance. The operating principle uses switching frequency
8
reduction at light load by increasing the OFF Time. Also, when OFF
SO-8
Time expands, the peak current is gradually reduced down to P1215
D SUFFIX ALYW
approximately 1/4 of the maximum peak current to prevent from 8 CASE 751
exciting the transformer mechanical resonances. The risk of acoustic 1 1
noise is thus greatly diminished while keeping good standby power
performance. TSOP-6 6
A low power internal supply block also ensures very low current 6 (SOT23-6, SC59-6)
FAAYW
consumption at start-up without hampering the standby power SN SUFFIX
1 CASE 318G
performance. 1
A special primary current sensing technique minimizes the impact
of SMPS switching on control IC operation. The choice of peak FAA = Specific Device Code
voltage across the current sense resistor allows dissipation to be A = Assembly Location
further reduced. The negative current sensing technique offers L = Wafer Lot
Y = Year
advantages over a traditional approach by avoiding the voltage drop W = Work Week
incurred by traditional MOSFET source sensing. Thus, the IC drive
capability is greatly improved.
PIN CONNECTIONS
Finally, the bulk input ripple ensures a natural frequency dithering
which smooths the EMI signature. SO-8
Features FB 18NC
• Variable OFF Time Control Method CT 2 7 NC
• Very Low Current Consumption at Start-up CS 3 6 VCC
• Natural Frequency Dithering for Improved EMI Signature GND 4 5 Gate
• Current Mode Control Operation
(Top View)
• Peak pression Reduces Transformer Noise
• Programmable Current Sense Resistor Peak Voltage TSOP-6
• Undervoltage Lockout CS 1 6 Gate
Typical Applications