lnk520 Power Integrations, Inc., lnk520 Datasheet
lnk520
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lnk520 Summary of contents
Page 1
... LinkSwitch is specifically designed to replace low power linear transformer/RCC chargers and adapters at equal or lower system cost with much higher performance and energy efficiency. LNK520 is equivalent to LNK500 but optimized for use with bias winding feedback and has improved switching characteristics for significantly reduced EMI. In addition, if bias and output ...
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... V - 4.7 V HYSTERETIC THERMAL SHUTDOWN COMPARATOR LOW FREQUENCY OPERATION Figure 3. Pin Configuration. DRAIN CURRENT LIMIT ADJUST CURRENT LIMIT COMPARATOR - + LEADING EDGE EDGE BLANKING SOURCE PI-2777-032503 LNK520 Package (DIP-8B) G Package (SMD-8B) PI-3790-121503 ...
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... I when C LIM 3.8% characteristic C Frequency f that depends on power OSC f OSC(low the desired value Figure 4. CONTROL Characteristics Figure 5. Power Supply Schematic outline. LNK520 Auto-restart CONTROL Current I C Auto-restart I CD1 I DCS CONTROL Current I C Auto-restart CONTROL Current I C PI-3579-031004 LinkSwitch ...
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... LinkSwitch R1 LNK520 for U1 current and VR1 slope resistance should be consulted to determine whether R5 is required. When the power supply operates in the constant current (CC) region, for example at start up and when charging a battery, the output voltage is below the voltage feedback threshold defi ...
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... In some applications it may be necessary to avoid any output current overshoot, independent of the direction of load variation. LNK520 PI-2788-092101 Tolerance envelope without optocoupler Typical inherent ...
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... LinkSwitch (a) Figure 9. High-side Configuration Using LNK520: (a) Schematic Outline; (b) Typical Output Characteristic Envelope. To achieve this goal, the minimum voltage feedback threshold should be set This will ensure that the voltage at the O(MAX transition point of the inherent characteristic will always occur below the voltage feedback threshold ...
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... This limits the peak DRAIN voltage due to leakage inductance. Resistor R2 allows the use of a slow, low cost rectifier diode by limiting the reverse current through D5 when U1 turns on. The selection of a slow diode improves radiated EMI and also improves CV regulation, especially at no-load. LNK520 5.5 V, 500 11DQ06 330 µ ...
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... LNK520 The output during CV operation is equal to the primary-side bias voltage multiplied by the turns ratio. The bias voltage, in turn, is the sum of the CONTROL pin voltage (approximately 5.7 V), the voltage across the bias feedback resistor R4 and the forward voltage of D6B. Resistor R3 can be neglected as proportionally the voltage drop across this resistance is small. In ...
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... Both the device tolerance and external circuit govern the overall tolerance of the LinkSwitch power supply output characteristic. Estimated peak power point tolerances for a LNK520, 2.75 W design are ±10% for voltage and ±24% for current limit for overall variation in high volume manufacturing. This includes device and transformer tolerances (± ...
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... L overall tolerance limits are met. Selecting Between LNK500 and LNK520 The LNK500 and LNK520 differ in the circuit location of the LinkSwitch device. The LNK500 is designed for high-side operation and the LNK520 is designed for low-side operation. The LNK520 can, however, be used in the high-side configuration in certain applications ...
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... Y1- Capacitor Transformer Output Capacitor Figure 12. Recommended Circuit Board Layout for LinkSwitch using LNK520. LinkSwitch Out + LNK520 Input Filter Capacitor + HV DC Input - PI-3732-103003 11 E 2/05 ...
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... EMI shielding or filtering exists The LNK500 is recommended for cost sensitive applications in larger systems with Summary existing EMI filtering (e.g. white goods). Table 2. Comparison of LNK500 and LNK520. 30.0 Figure 13. Comparison of LNK520 and LNK500 Showing 2/05 LNK500 • Very low cost CV/CC implementation • Source connected to quiet low-side primary return - easy layout & ...
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... OSC(LOW) J Frequency = °C OSC(LOW 1 °C C DCT °C J See Figure DCT °C C DCT J LNK520 (1, ° oz. (610 g/m ) copper clad oz. (610 g/m ) copper clad Min Typ Max 34 2.7 4.1 5.5 2.0 3.5 5 -0.37 -0 ...
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... LNK520 Parameter Symbol SHUTDOWN/AUTO-RESTART CONTROL Pin I Charging Current C(CH) I Control/Supply/ CD1 Discharge Current I CD2 Auto-Restart V Threshold Voltage C(AR) Auto-Restart V Hysteresis Voltage C(AR)hyst Auto-Restart Duty DC Cycle (AR) Auto-Restart f Frequency (AR) CIRCUIT PROTECTION Self-Protection I Current Limit LIM I f Coefficient Current Limit at I Auto-Restart LIM(AR) ...
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... A See Note 6 ° See Note E to correlate to power supply output current (it is multiplied by DCT specification by ramping the DRAIN pin voltage DSS . DSS LNK520 Min Typ Max 700 36 50 further would C ) vs. DRAIN voltage (Figure 16) for low ...
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... LNK520 Figure 14. LinkSwitch General Test Circuit. VOLTAGE Figure 15. Duty Cycle Measurement. Typical Performance Characteristics 5. 1.6 1.2 0.8 0 DRAIN Voltage (V) Figure 16. I vs. DRAIN Voltage 2/05 750 Ω 10 kΩ 0.22 µ 90% DRAIN 10 100 Figure 17. CONTROL Pin I-V Characteristic. ...
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... Figure 21. Current Limit vs. Temperature. 1.200 1.000 0.800 0.600 0.400 0.200 0.000 100 125 150 Figure 23. I LNK520 -50 - 100 125 150 Junction Temperature (°C) -50 - 100 125 150 Junction Temperature (°C) -50 - ...
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... LNK520 Typical Performance Characteristics (cont.) 1.2 1 0.8 0.6 0.4 0 Temperature (°C) Figure 24. PWM Gain vs. Temperature. PART ORDERING INFORMATION LNK 520 2/05 300 250 200 150 100 50 0 100 150 Figure 25. Output Characteristics (DRAIN Current vs. LinkSwitch Product Family Series Number Package Identifier ...
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... Solder Pad Dimensions .057 (1.45) .068 (1.73) (NOTE 5) .004 (.10) .009 (.23) .004 (.10) .036 (0.91) .012 (.30) .044 (1.12) LNK520 (NOTE 7) PI-2551-121504 Notes: 1. Controlling dimensions are inches. Millimeter sizes are shown in parentheses. 2. Dimensions shown do not include mold flash or other protrusions. Mold flash or protrusions shall not exceed .006 (.15) on any side. ...
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... LNK520 Revision Notes C 1) Released Final Data Sheet Added lead-free ordering information Minor descriptive change and formatting correction. For the latest updates, visit our website: www.powerint.com Power Integrations reserves the right to make changes to its products at any time to improve reliability or manufacturability. Power Integrations does not assume any liability arising from the use of any device or circuit described herein ...