DER-045: 12V @ 150mA, 85 ~ 265VAC in
Summary
This document is an engineering report describing a 12V, 150mA non-isolated power supply using a LNK304 from Power Integrations.
This document contains the power supply specification, schematic, bill of materials and measurements results.
The LNK304 is used in a non-isolated buck-boost topology. The voltage across L1 is rectified and smoothed by D1 and C2 during U1’s off-time. To a first order the forward voltage drop of D2 (slow diode used in the tests) and D1 (must be an ultrafast) can be considered similar. Therefore the voltage across Cfb tracks the output voltage. The voltage across Cfb is sensed and regulated via the resistor divider Rfb-Rbias connected to U1’s FB pin. The LNK304 switching algorithm regulates the FB pin to 1.65V +/- 7% over temperature. A small pre-load resistor has been added (Rload with 5mA current consumption) for operation down to 0mA output current.
This document contains the power supply specification, schematic, bill of materials and measurements results.
The LNK304 is used in a non-isolated buck-boost topology. The voltage across L1 is rectified and smoothed by D1 and C2 during U1’s off-time. To a first order the forward voltage drop of D2 (slow diode used in the tests) and D1 (must be an ultrafast) can be considered similar. Therefore the voltage across Cfb tracks the output voltage. The voltage across Cfb is sensed and regulated via the resistor divider Rfb-Rbias connected to U1’s FB pin. The LNK304 switching algorithm regulates the FB pin to 1.65V +/- 7% over temperature. A small pre-load resistor has been added (Rload with 5mA current consumption) for operation down to 0mA output current.
Specifications
| Manufacturer | Power Integrations |
|---|---|
| Category | AC/DC and DC/DC Conversion |
| Sub-Category | AC/DC SMPS - Single Output |
| Eval Board |
Board not Stocked
|
| AC Voltage |
115 V
230 V Universal (115 / 230V) |
| Outputs and Type |
1 Non-Isolated
|
| Voltage Out |
12 V
|
| Current Out |
150 mA
|
| Output Power |
1.8 W
|
| Features |
Current Limit (Adj. or Fixed)
Frequency Jitter for EMI Open Circuit Protection Short Circuit Protection Thermal Protection |
| Efficiency @ Conditions |
>65%, 120 ~ 265 VAC, 12V @ 150 mA
|
| No-load Input Power @ Voltage |
- Not Given
|
| Switching Frequency |
66 kHz
|
| Internal Switch |
Yes
|
| Component Count + Extras |
15 + 0
|
| Voltage In |
85 ~ 265 VAC
|
| Design Author |
Power Integrations
|
| Application / Target Market |
White Goods
|
| Main I.C. Base Part |
LNK304
|
| Date Created By Author | 2005-04 |
| Date Added To Library | 2014-07 |
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