ld7576a Leadtrend Technology, ld7576a Datasheet
ld7576a
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ld7576a Summary of contents
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... Green-Mode PWM Controller with High-Voltage Start-Up Circuit and Adjustable OLP Delay Time REV. 00b General Description The LD7576A brings high performance, and combines highly integrated functions, protections and EMI-improve solution. It’s an ideal solution for those cost-sensitive systems, reducing component count and overall system cost ...
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... YYWWPP 1 2 Ordering Information Part number LD7576A GR LD7576A GS LD7576A GN The LD7576A is ROHS compliant/ Green Package. Pin Descriptions PIN NAME This pin is to program the frequency of a lower frequency timer. Connecting capacitor to ground sets the OLP delay time. Voltage feedback pin (same as the COMP pin in UC384X). Connecting a photo-coupler closes the control loop to achieve the regulation ...
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... Block Diagram Leadtrend Technology Corporation LD7576A-DS-00b November, 2009 ∑ 3 www.leadtrend.com.tw LD7576A ...
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... Recommended Operating Conditions Item Supply Voltage Capacitor CC CT Value COMP Pin Capacitor Leadtrend Technology Corporation LD7576A-DS-00b November, 2009 Min. Max 0.047 0.1 1 100 4 www ...
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... Input impedance Delay to Output Oscillator for Switching Frequency Frequency Temp. Stability Voltage Stability Low Frequency Timer (CT Pin) Low Frequency Period Temp. Stability Voltage Stability Leadtrend Technology Corporation LD7576A-DS-00b November, 2009 =15.0V) CC CONDITIONS Vcc< UVLO(on),HV=500V Vcc> UVLO(off),HV=500V V =0V COMP V =3V ...
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... Output High Level Rising Time Falling Time OLP (Over Load Protection) OLP Trip Level OLP Delay Time OTP (Over Temperature) OTP Level OTP Hysteresis Leadtrend Technology Corporation LD7576A-DS-00b November, 2009 =15.0V) CC CONDITIONS VCC=15V, Io=20mA VCC=15V, Io=20mA Load Capacitance=1000pF Load Capacitance=1000pF CT=0.1μF CT=0.047μF 6 www ...
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... Temperature (°C) Fig Current Source vs. Temperature (HV=500V, Vcc=0V) 18.0 17.2 16.4 15.6 14.8 14.0 - Temperature (°C) Fig. 3 UVLO (on) vs. Temperature - Temperature (°C) Fig. 5 Frequency vs. Temperature Leadtrend Technology Corporation LD7576A-DS-00b November, 2009 0.88 0.86 0.84 0.82 0.80 0.78 120 125 80 -40 12 11.2 10.4 9.6 8 120 125 - ...
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... Fig. 7 Frequency vs. Vcc - Temperature (°C) Fig. 9 Max Duty vs. Temperature 7.0 6.5 6.0 5.5 5.0 4.5 - Temperature (°C) Fig open loop voltage vs. Temperature COMP Leadtrend Technology Corporation LD7576A-DS-00b November, 2009 120 125 -40 6.0 5.5 5.0 4.5 4 ...
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... As the Vcc voltage rises higher than UVLO(on) to power on the LD7576A and further to deliver the gate drive signal, the high-voltage current source is disabled and the supply current is solely provided from the auxiliary winding of the transformer ...
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... The voltage feedback signal is provided from the TL431 on t the secondary side through the photo-coupler to the COMP pin of LD7576A. The input stage of LD7576A, like the UC384X, is with 2 diodes voltage offset to feed the voltage divider with 1/3 ratio, that is, A pull-high resistor is embedded internally. Generally, an external capacitor in parallel to photo-coupler is required in application ...
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... Over Load Protection (OLP) - Auto Recovery To protect the circuit from being damaged during over load condition and short or open loop condition, the LD7576A is implemented with smart OLP function. LD7576A features auto recovery function, the waveform of which is exemplified in figure 17. In the example of the fault ...
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... MOSFETs are GS mostly for 30V. To prevent the V GS LD7576A is implemented with OVP function on Vcc. Whenever the Vcc voltage is higher than the OVP threshold, the output gate drive circuit will be shutdown simultaneously and the switching of the power MOSFET is disabled until the next UVLO(on). ...
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... Frequency Trembling The LD7576A is built in with adjustable frequency trembling function, which provides the power supply designers to optimize EMI performance and system cost. The Trembling frequency was internally set for ±4KHz when incorporating with 65KHz switching frequency www.leadtrend.com.tw ...
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... CT pin except of the capacitor to minimize the affect on modulating frequency. Fig. 23 On-Chip OTP An internal OTP circuit is embedded inside the LD7576A to provide the worst-case protection for this controller. When the chip temperature rises higher than the trip OTP level, the output will be disabled until the chip is cooled down below the hysteresis window ...
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... Reference Application Circuit --- 10W (5V/2A) Adapter Leadtrend Technology Corporation LD7576A-DS-00b November, 2009 15 www.leadtrend.com.tw LD7576A ...
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... Package Information SOP-7 Symbols θ Leadtrend Technology Corporation LD7576A-DS-00b November, 2009 Dimensions in Millimeters Dimensions in Inch MIN MAX 4.801 5.004 0.189 3.810 3.988 0.150 1.346 1.753 0.053 0.330 0.508 0.013 1.194 1.346 0.047 0.178 0.229 0.007 0.102 ...
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... Package Information SOP-8 Symbols θ Leadtrend Technology Corporation LD7576A-DS-00b November, 2009 Dimensions in Millimeters Dimensions in Inch MIN MAX 4.801 5.004 0.189 3.810 3.988 0.150 1.346 1.753 0.053 0.330 0.508 0.013 1.194 1.346 0.047 0.178 0.229 0.007 0.102 ...
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... Important Notice Leadtrend Technology Corp. reserves the right to make changes or corrections to its products at any time without notice. Customers should verify the datasheets are current and complete before placing order. Leadtrend Technology Corporation LD7576A-DS-00b November, 2009 Dimension in Millimeters Dimensions in Inches Min ...
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... Revision History Rev. Date Change Notice 00 3/17/2009 Original Specification. 00a 5/26/2009 Package option: SOP-7 00b 11/29/2009 Implementation: Absolute Maximum Rating Leadtrend Technology Corporation LD7576A-DS-00b November, 2009 19 www.leadtrend.com.tw LD7576A ...