AN8037 Panasonic Semiconductor, AN8037 Datasheet
AN8037
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AN8037 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. ...
Page 2
... AN8027, AN8037 Block Diagram OVP 8 SD Timer 2 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 ION- ON- 0.4 mA OFF1-CF FB AN8027, AN8037 Min Typ Max 13.4 14.9 16.4 7.7 8.6 9.5 19.4 20.5 21.6 3.5 3.9 4.3 0.4 0.8 1.2 0.05 0.15 0.3 1.0 1.5 2.0 7.3 8.1 8.9 3.0 4.0 5.0 Open 1.2 1.5 1.8 Open 3.6 4.5 5.4 270 A 68 102 136 1 ...
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... Overcurrent protection (OCP) power-on charge period Overcurrent protection (OCP) power-off charge period Output rise time Output fall time TR output response time CLM output response time Pre-startup circuit current 2 Only for AN8037 Timer period during startup (continued Symbol Conditions ...
Page 5
... Transformer reset detection input. When the 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 ...
Page 6
... 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 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 resistor OUT Startup Voltage supplied from bias winding a Startup state c Startup failure b Figure 1 reaches the startup and changing the off-period for ...
Page 8
... 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 TR Current mirror Current mirror 250 A typ ...
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... OFF Out FB (I 0.6 mA 160 A typ. OFF GND (I 0.6 mA pin voltage V TH(OFF Out pin voltage AN8027, AN8037 0.2 V (typical TH(OFF 0.6 mA) TH(OFF) OFF2 0 2 large FB T 0.2 V 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> AN8027, AN8037 CLM 10 On 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 On Off T is acceptable ON only after CF pin voltage reaches Off (E)Current (F)Current on primary on secondary winding winding ( (A) Out (D) (C) (G) AN8027, AN8037 Off T is unacceptable ON during T OFF(min) T (OFF) On Off (F) period. OFF(min) 11 ...
Page 12
... V (E) Current on primary winding (H)CLM pin voltage 0.2 V CLM threshold voltage 4 V (C)CF pin voltage 2 voltage 1 (D)Out pin voltage 0 A <Circuit diagram> AN8027, AN8037 CLM 12 Off On Off On Off On Off On ( Out CF (D) (C) (G) Voltage Regulators Off ...
Page 13
... Refer to figure 4. FB AN8027, AN8037 7 200 A typ Primary side Figure 4. Power output control 0.2 0.4 Figure 5. Feedback current vs. V AN8027, AN8037 Power output on secondary side PC A minimum required for biasing the AN1431T/M. AN1431T/M Secondary side 0.6 0.8 1.0 I (mA) FB characteristics ...
Page 14
... CF (Pin 3) Start 14 Rectified AC , 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 R1 AN8027, AN8037 PC1 R3 C4 Out CLM GND Figure 6 period is definite. If excessively ON ...
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... 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 AC ) OUT OUT GND 0.7 V OUT and thus increased AN8027, AN8037 Cgd Out Figure 9 GND Vex Control voltage Figure 10 15 ...
Page 16
... 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 ...
Page 17
... 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. This ensures the reliable local resonance operation of the IC regardless of input voltage fluctuations in a wide input range for worldwide use, thus eliminating difficulty in turning on the power MOSFET when V the minimum value ...
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... 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 ...
Page 19
... 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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... Timer capacitor charging condition The following condition must be . satisfied during on-period OCP FB Figure 19 7 Standby mode 2 40 Figure 20 AN8027, AN8037 R 100 A typ. OCP 250 A typ. and changing T , the timer period can OCP ...
Page 22
... 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 ...
Page 23
... 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 ...
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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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... Out GND 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 26 FB voltage applied; Shutdown FF voltage applied; Correction operation I DS Determines the input voltage at which correction starts. ...
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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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... C16 (MA166 F/ SBD C7 C11 1 800 pF 2 200 820 MA2C700 S1 (MA700*) R15 SBD 51 AN8027, AN8037 125 150 D6 SBD MA3F760 (MA760*) C14 22 F/ SBD MA3F750 (MA750*) C16 1 000 F/ SBD R10 MA3D798 750 (MA10798*) C17 1 000 F PC1 Q3 ...
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... AN8027, AN8037 Application Circuit Examples (continued) Evaluation board chart 28 Voltage Regulators ...