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Details, datasheet, quote on part number:NCP1212DR2
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Datasheet text preview:
NCP1212 Current Mode PWM Controller for Both Forward and Flyback Converters
NCP1212 is a high performance current mode PWM controller specifically designed for off-line and dc-to-dc converter applications. The device requires very few external components and offers designer additional protection for better system reliability. The device features a trimmed oscillator for precise duty-cycle control, accurate bandgap voltage reference, high gain error amplifier, current sensing comparator and a high current totem pole output gate driver that ideally drives the external power MOSFET. Additionally, the device has built-in programmable Brownout Detect and Soft-Start features to enhance system reliability. Also, the 48%/82% selectable maximum turn on duty-cycle control and external programmable switching frequency capabilities make this device an ideal controller for both forward and flyback configurations. This device is available in both PDIP-8 and space saving SO-8 packages.
Features http://onsemi.com MARKING DIAGRAMS
8 SO-8 D SUFFIX CASE 751 1 8 PDIP-8 P SUFFIX CASE 626 8 1 1 NCP1212 AWL YYWW 1 N1212 ALYW
8
· Trimmed Oscillator Charge and Discharge Current for Precise · · · · · · · · · · · · · · · · · ·
Duty-Cycle Control Internal High Accuracy Bandgap Voltage Reference Current Mode Operation up to 200 kHz Inherent Feed Forward Compensation Latching PWM for Cycle-by-Cycle Current Limiting High Current Totem Pole Output Gate Driver Low Startup and Operating Current Internal Undervoltage Lockout with Hysteresis Internal Leading Edge Blanking for Current Feedback Direct Interface with Optocoupler for Secondary Sensing Built-in Soft-Start Function, Programmable by External Capacitor User Programmable 48%/82% Maximum Duty-Cycle Selection Output Overvoltage Protection Against Open Loop AC Line Brownout Detect Protection Output Overload Protection Irrespective of Auxiliary Voltage Level ATX PC Power Supply Universal Input Wall Mount Adaptors CRT Monitor All Flyback and Forward SMPS Systems
A WL, L YY, Y WW, W
= Assembly Location = Wafer Lot = Year = Work Week
PIN CONNECTIONS
FB BOK CS CT 1 2 3 4 (Top View) 8 7 6 5 SS/DMAX VCC DRV GND
ORDERING INFORMATION
Device NCP1212DR2 NCP1212P Package SO-8 PDIP-8 Shipping 2500 Tape & Reel 50 Units/Rail
Typical Applications
© Semiconductor Components Industries, LLC, 2003
1
August, 2003 - Rev. 1
Publication Order Number: NCP1212/D
F1 FUSE
RFI FILTER BR1 C2 10 nf/1 kv 1 R1 576 K 3 + 2 C1 470 mf/400 V R2 3.3 K Q1 R3 36 K D1 MUR180
T3 5V D2 MBR3045
AC Input + -
2
3
X2 Cap 0 1
X2 Cap
4
+ C7 3300 mf/ 10 V
Rsense 0.22/2 W GND Form Standby SMPS Auxiliary Winding IC1 NCP1212 FB BOK CS CT C4 1 nf SS/DMAX VCC DRV GND C3 0.1 mf C5 0.1 mf 4
Figure 1. Typical Application Circuit
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NCP1212
R6 220
2
PC817 1 2 IC2 3 U1 TL431 C6 R5 100 0.1 mf R8 300
+5 V 9K 3R FB R - + 8 mA
+5 V SS/DMAX ±
+ -
- + 28 mA ±
+ -
Overload
Shutdown
+ 0.5 V - OVLO (25 V) UVLO (10 V) VCC
45 mA
+ ±
+
1V -
-
SW2 BOK + 1.21 V - - +
Brownout Detection
S CLK Q D CLK D Q R F/F Q Totem Pole Drive S Q DRV
CT
OSC Clock
IMAX
Max. Duty Cycle 48% or 82% + 3.2 V -
+ -
Q S Q
Overload Enable GND
Reset - +
- +
Figure 2. Simplified Functional Block Diagram
CS +5 V
300 ns LEB
Current Limit - + 5V
Vref Regulator
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NCP1212
+ -
15 V
3
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