an8021l Panasonic Corporation of North America, an8021l Datasheet
an8021l
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an8021l Summary of contents
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... Voltage Regulators AN8021L, AN8021SB AC-DC switching power supply control IC Overview The AN8021L and AN8021SB are ICs which are suitable for controlling the switching power supply us- ing primary side control method. Those are most suited for a switching power supply of relatively small capacity. Less frequently used func- ...
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... AN8021L, AN8021SB Block Diagram 8 TIM/OVP OVP ( (13) OSC 2 RT (12) Note) The number shows the pin number for the AN8021SB. Pin Descriptions AN8021L Pin No. Symbol 1 SS Soft start pin 2 RT Resistor connection pin that determines charge and discharge current of triangular wave ...
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... V, I 100 100 OSC1 max1 FB-Du min FB-Du max CC AN8021L, AN8021SB Rating Unit 150 mA 1 000 658 mW 340 Unit k Min Typ Max Unit 13.0 14.2 15 ...
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... AN8021L, AN8021SB Electrical Characteristics at T Design reference data Note) The characteristics listed below are theoretical values based on the IC design and are not guaranteed. Parameter Oscillation frequency 2 Overcurrent protection delay time Output voltage rise time Output voltage fall time Terminal Equivalent Circuits Pin No ...
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... When the capacitor is charged to the threshold voltage of OVP, OVP starts to operate and the IC stays stop. IFB : The terminal into which the current feedback signal is input from the photocoupler of the power supply output. 500 9 (6) AN8021L, AN8021SB I ...
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... AN8021L, AN8021SB Application Notes [1] Main characteristics [Load Start/stop voltage characteristics Ambient temperature C) Standby bias current characteristics Ambient temperature ( C) Overcurrent protection threshold voltage characteristics V 220 210 200 190 180 ...
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... Feedback current at maximum duty characteristics 700 600 500 400 300 50 75 100 Pre-start low-level output voltage characteristics 0.85 0.80 0.75 0.70 0.65 75 100 50 AN8021L, AN8021SB 100 Ambient temperature ( 100 Ambient temperature ( ...
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... AN8021L, AN8021SB Application Notes (continued) [2] Operation descriptions 1. Start/stop circuit block Start mechanism When AC voltage is applied and the sup- ply voltage reaches the start voltage through the current from the start resistor, the IC starts operation. Then the power MOSFET driving starts. Thereby, bias is generated in the trans- former and the supply voltage is given from the bias coil to the IC ...
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... IC. Normally, the V CC 8.4 V typical: OVP release supply voltage) CC terminal voltage under normal operation OVP (to 7.1 V) (IC stop state (IC stop state) ( (IC stop state) Figure 2. Explanation of OVP operation AN8021L, AN8021SB voltage CC OUT V 7 Time Time Time Time 9 ...
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... AN8021L, AN8021SB Application Notes (continued) [2] Operation descriptions (continued) 3. Overvoltage protection circuit (OVP) (continued) After AC rectification Start resistor OVP V OUT GND Operating supply current characteristics While the OVP is operating, the decrease of the supply current causes the rise of the supply voltage V in the worst case, the guaranteed breakdown voltage of the IC (35 V) can be exceeded. In order to prevent the rise of supply voltage, the IC is provided with such characteristics as the supply current rises in the constant resistance mode ...
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... Since such level fluctuation increases the necessity of withstand capability for the parts to be used and in the worst case it means the cause of destruction, the accuracy of detection level is raised as much as possible for these ICs, the AN8021L and AN8021SB. CLM ( ) ...
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... AN8021L, AN8021SB Application Notes (continued) [2] Operation descriptions (continued) 5. Soft start At start of the power supply, the capacitor connected to the power supply output causes the power supply to rise under overload condition. Under this condition, the power supply output is low. For the normal PWM control, attempt is made to limit the current by the pulse-by-pulse overcurrent protection so that the power supply output can rise at maximum duty ...
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... V O Power supply output voltage Power MOSFET current 0 V OVP TIM/OVP terminal voltage 0 Figure 8. Timer latch basic operation AN8021L, AN8021SB Power supply stop Time Power supply stop Time Power supply stop OVP (typ.) TH Time 13 ...
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... However, after charge/discharge, particularly large current is not required to keep that condition. For the AN8021L or AN8021SB, capacitance value of the power MOSFET used is taking into account, and the capability of peak value ensured. The parasitic LC of the power MOSFET may produce ringing which makes the output pin go under the GND potential ...
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... A [Setting the C1] When the AN8021L or AN8021SB is started, the operating supply current of 7 required at V The current should be supplied with the discharge current of the C1 during the period from the soft start time up to the time when the supply current is supplied from the auxiliary bias coil. Therefore set the C1 as shown in ...
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... AN8021L, AN8021SB Application Circuit Example 16 5 GND 4 CLM IFB Voltage Regulators ...