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Optional reset winding
(can help reduce peak voltage stresses)
- VOUT = (VIN * D)/N
- Most economical approach for low-to-
medium power applications (50-150W)
- Suitable for both 24V and 48V input
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IR Product Recommendations
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Primary Control Switch: |
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Universal 48/60V Telecom Bus Input (36-75V) |
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Reduced Range 48V Telecom Bus Input (36-60V) |
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Regulated 48V Telecom Bus Input (43-53V) |
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24V Mobile Comm. Bus Input (18-36V) |
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Primary and Secondary Diodes: Fast Recovery Diodes, Schottky Diodes |
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- Forward sync rectifier is driven directly
off the secondary winding
- Signal for Freewheeling sync rectifier is
generated at the primary derived by
inverting main FET gate drive signal
|
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IR Product Recommendations
|
|
|
Primary Control Switch: |
|
Universal 48/60V Telecom Bus Input (36-75V) |
|
|
Reduced Range 48V Telecom Bus Input (36-60V) |
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Regulated 48V Telecom Bus Input (43-53V) |
|
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24V Mobile Comm. Bus Input (18-36V) |
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Primary Reset Diode: Fast Recovery Diodes, Schottky Diodes |
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Secondary Switches: VOUT = 15 to 12V | |
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8V | |
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5V | |
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3.3V | |
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2.5V | |
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<1.8V | |
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- VOUT = (VIN * D)/N
- Very good performance at somewhat higher cost
- Ideal for self-driven synchronous rectification
|
|
IR Product Recommendations
|
|
Primary Control Switch and Clamp Switch: | |
|
Universal 48/60V Telecom Bus Input (36-75V) |
|
|
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Reduced Range 48V Telecom Bus Input (36-60V) | |
|
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Regulated 48V Telecom Bus Input (43-53V) | |
|
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24V Mobile Comm. Bus Input (18-36V) | |
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|
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Secondary Diodes: Fast Recovery Diodes, Schottky Diodes
|
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- Both Forward and Freewheeling sync rectifier are driven directly off the secondary
transformer winding.
- For lower output voltages, additional turn(s) can be added to the secondary winding to
generate enough gate drive voltage.
- Lowest cost sync rectification drive solution for a forward topology.
|
|
IR Product Recommendations
|
|
|
Primary Control Switch and Clamp Switch: |
|
Universal 48/60V Telecom Bus Input (36-75V) |
|
|
Reduced Range 48V Telecom Bus Input (36-60V) |
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|
|
Regulated 48V Telecom Bus Input (43-53V) |
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|
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24V Mobile Comm. Bus Input (18-36V) |
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Secondary Switches: VOUT = 15 |
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12V |
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8V |
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5V to 3.3V |
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<2.5V |
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