an8027 Panasonic Corporation of North America, an8027 Datasheet
an8027
Related parts for an8027
an8027 Summary of contents
Page 1
... Adopting a 9-pin single inline package (E-9S: available to manufacturing in overseas). AN8027: Transformer resetting is detected from the high- or low-level signal on the TR pin. AN8037: Transformer resetting is detected from the falling edge of the high-level signal on the TR pin. Refer to the "[1] operation descriptions 7. local resonance operation" section in the application notes. ...
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... AN8027, AN8037 Block Diagram 3.8 V OVP 8 SD Timer 0 OCP I conv. (0.7 V) High-side clamp 1 TR Low-side clamp ( 0.15 V) Absolute Maximum Ratings Parameter Supply voltage Constant output current Peak output current TR pin allowable application current OCP pin allowable application voltage CLM pin allowable application voltage ...
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... CLL- TH-CLM V FB pin Open 200 pF H- pin Open 200 pF L1- 0.5 mA 200 pF L2- pin Open, I 750 A ION- ON- 0.4 mA OFF1-CF FB AN8027, AN8037 Min Typ Max Unit 13.4 14.9 16.4 V 7.7 8.6 9.5 V 19.4 20.5 21.6 V 3.5 3.9 4.3 V 0.4 0.8 1.2 V 0.05 0.15 0.3 V 1.0 1.5 2.0 V 7.3 8.1 8.9 V 3.0 4.0 5.0 mA Open 1 ...
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... AN8027, AN8037 Electrical Characteristics at V Parameter Oscillator (CF) minmum off-period current 2 Minimun off-period threshold feedback current Overcurrent protection (OCP) pin source current Output oscillator frequency Pre-startup low-level output voltage V Low-level output voltage High-lebel output voltage Pre-startup circuit current 1 Circuit current 1 Circuit current 2 ...
Page 5
... IC detects transformer resetting and the fall- ing edge of a high-level signal is input to this pin of the AN8037 or a low-level signal is input to the same pin of the AN8027, the level of the Out pin becomes high. However, the transformer reset signal is ignored if the signal is shorter than the minimum off-pe- riod determined by the CF pin ...
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... AN8027, AN8037 Pin Descriptions (continued) Pin No. Pin name I/O 6 Out O Output used to directly drive a power MOSFET. A totem pole structure is adopted in this output circuit. The absolute maximum ratings for the output current are: Peak DC: 150 Power supply. CC This pin monitors supply voltage and has the threshold for the start, stop, OVP, and OVP reset levels ...
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... typ. I 250 A typ NB/ 0.7 V typ. (I 200 typ. (I 200 AN8027, AN8037 Startup Voltage supplied from bias winding a Startup state c Startup failure b Figure 1 reaches the startup CC connected CF ) and changing the off-period for FB H- ...
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... When the input voltage is low, the maximum on-period overcurrent protection is possible. When the input voltage is high, the CLM pulse-by-pulse overcurrent protection is possible shortened ON because large E IN increases AN8027, AN8037 Current mirror Current mirror Out 250 A GND typ. ...
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... FB I 160 A typ. OFF GND (I 0.6 mA pin voltage V 2.4 V TH(OFF 0 1 Out pin voltage 0 V AN8027, AN8037 TH(OFF 0.6 mA) OFF2 0 large large OFF(min) T OFF(min ...
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... (C)CF pin voltage 2 1 (D)Out pin voltage Off 0 V (F)Current Current on on secondary bias winding winding 0 A Heavy <Circuit diagram> (B) TR AN8027, AN8037 CLM Off On Input voltage correction E ; large short ON On Off On (E)Current on primary winding Load ...
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... A <Circuit diagram> (B) TR AN8027, AN8037 CLM CF (C) On Off T is acceptable ON only after CF pin voltage reaches OFF(min) T (OFF) On Off (E)Current (F)Current on primary on secondary winding winding ( (A) Out (D) (G) AN8027, AN8037 Off T is unacceptable ON during T period. OFF(min) On Off (F) 11 ...
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... (H)CLM pin voltage 0.2 V CLM threshold voltage 4 V (C)CF pin voltage 2 voltage 1 (D)Out pin voltage Off 0 A <Circuit diagram> (B) TR AN8027, AN8037 CLM CF 12 Off On Off On Off On Off On Off ( (A) Out (D) (C) (G) Voltage Regulators Off ...
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... FB voltage. Refer to figure 4. FB 7.1 V 200 A typ Primary side Secondary side Figure 4. Power output control 0.2 0.4 0.6 Figure 5. Feedback current vs. V characteristics FB AN8027, AN8037 Power output on secondary side PC A minimum required for biasing the AN1431T/M. AN1431T/M 0.8 1.0 I (mA ...
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... V OUT (Pin 6) CF (Pin 3) Start 14 Rectified AC AN8027, AN8037 , thus per- FB period is short. The ON immediately after the startup is 0 greater. 1 depends on the capacitance value of the C 1 Figure 7 Voltage Regulators Startup resistor ...
Page 15
... It may also prevent stabilization of the circuit. These are symp- toms of the case described here. (Refer to figures 9 and 10.) , although it depends on the value of R3. FB Rectified OUT OUT Out GND 0.7 V OUT and thus increased AN8027, AN8037 V DS Cgd Figure 9 GND Vex Control voltage Figure 10 15 ...
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... Note Former part number 7. Local resonance operation (power MOSFET turn-on delay circuit) Local resonance operation by using the AN8027 or AN8037 is possible with circuits as shown in figure 13 the resonance capacitor, and R9 and C9 form a delay circuit for adjusting the power MOSFET turn on time. When the power MOSFET is off, the voltage that occurs in the drive winding is input to the TR pin (pin 1) through R9 and C9 ...
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... Refer to the next section for details. 8. Bottom-on function (AN8037 only) Unlike the AN8027 or our conventional AN8026, AN8028, or AN8029 IC, which detects transformer resetting with the high or low level in comparison to the threshold voltage on the TR pin, the AN8037 detects transformer resetting on the falling edge across the threshold voltage. ...
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... AN8027, AN8037 Application Notes (continued) [1] Operation descriptions (continued) 8. Bottom-on function (AN8037 only) (continued) Select the constants of R9 and C9 to determine the turn-on delay time so that the power MOSFET will be turned frequency of half the resonant frequency. Practically, refer to figure 12 and determine the turn-on delay time so that the power MOSFET will be turned from the following formula ...
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... The pin voltage rises by charging the timer to trigger OVP Discharging Overcurrent FB detection OCP FB PC Timer capacitor discharging transistor On GND The timer period is set according to the capacitance. Figure 16 AN8027, AN8037 Schottky barrier diode Figure 8 Charging I TIM C TIM 19 ...
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... AN8027, AN8037 Application Notes (continued) [1] Operation descriptions (continued) 11. Timer latch (continued Power supply output voltage Power MOSFET current pin voltage 0 12. Setting the timer period The period between the detection of the erroneous power output and the moment OVP is triggered (hereinafter called timer period) needs to be longer than the rise time of the power supply ...
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... The following condition must be the microcomputer on the secondary side satisfied during on-period. and the timer period is adjusted OCP FB Figure 19 Standby mode Normal operation mode 40 70 Figure 20 AN8027, AN8037 R 100 A typ. OCP 250 A typ the timer period can ...
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... Secondary side output overvoltage threshold value th(OUT operating threshold value TH-SD1 V : Zener voltage (externally connected to OVP pin and SD pins as shown in figure 22 and take method 2) below to set the CC AN8027, AN8037 V V OVP-VCC OVP-SD 20.5 V typ. 3.9 V typ. Timer capacitor discharging transistor On Figure 21 ...
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... This prevents V from exceeding the absolute maximum rating of the IC CC caused by a decrease in current supply from the startup resistor Figure 23 AN8027, AN8037 Abnormal voltage applied from outside. pin through CC pin from this bias winding CC satisfies CC (i ...
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... Application Notes (continued) [1] Operation descriptions (continued) 14. Remote on/off function The SD pin of the AN8027 or AN8037 has a remote on/off function besides the following functions. Timer latch function Overvoltage protection function The remote on/off function turns the power supply output on and off remotely with external signals. ...
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... TR FF voltage applied; Correction operation D rs Out GND Determines the input voltage rs at which correction starts. Input voltage correction Determines the amount of correction Figure 27 AN8027, AN8037 Use a capacitor with excellent frequency characteristics Use resistor with no inductance. Figure ...
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... AN8027, AN8037 Application Notes (continued) [1] Operation descriptions (continued) 16. Overcurrent protection circuit (input voltage correction function) (continued CLM 17. Overcurrent protection circuit (Timer latch protection) The CLM pin is used for timer latch in addition to pulse-by-pulse overcurrent protection. ...
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... MA2C166 C16 (MA166 F/ SBD C7 2 200 pF R7 820 MA2C700 (MA700*) R15 R6 SBD 51 0.22 AN8027, AN8037 150 D6 SBD MA3F760 (MA760*) C14 22 F/ SBD MA3F750 (MA750*) C16 1 000 F/ SBD R10 MA3D798 750 (MA10798*) R12 C17 500 1 000 F R11 510 ...
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... AN8027, AN8037 Application Circuit Examples (continued) Evaluation board chart 28 Voltage Regulators ...