Low-profile planar active clamp forward transformers with synchronous rectification — 20N1, G45, G45AH2 and G45R2 series for Linear Technology® / Analog Devices® controllers.
Low-profile planar active clamp forward transformers with synchronous rectification. The 20N1 series covers the opto-isolated LT3753 topology; G45, G45AH2 and G45R2 add the Analog Devices® reference-design part numbers, with G45R2 driving the secondary rectifiers directly from the secondary winding. Each series lists its recommended part numbers in the table below and in the linked data sheet.
Opto-isolated LT3753 active clamp forward with synchronous rectification. 9–18 | 18–36 | 36–72 Vin, 30–80 W · 17.8 × 21.0 × 7.0 mm.
| Part Number | Vin (V) | Vout (V) | Iout (A) | Output Power (W) | Frequency (kHz) | Reference Design | Output Inductor |
|---|---|---|---|---|---|---|---|
| 20N1-1202-80R | 36–72 | 3.3 | — | 60 | 240 | — | PQL2050-3R3-22 |
| 20N1-0802-80R | 36–72 | 5.0 | — | 60 | 240 | — | PQL2050-4R9-14 |
| 20N1-1005 | 36–72 | 12.0 | — | 60 | 240 | — | PQi2050-20-HX |
| 20N1-1012 | 36–72 | 24.0 | — | 60 | 240 | — | PQI2050-100-6-LTC |
| Part Number | Vin (V) | Vout (V) | Iout (A) | Output Power (W) | Frequency (kHz) | Reference Design | Output Inductor |
|---|---|---|---|---|---|---|---|
| 20N1-0702-40R | 18–36 | 3.3 | — | 60 | 240 | — | PQL2050-3R3-22 |
| 20N1-0603-40R | 18–36 | 5.0 | — | 60 | 240 | — | PQL2050-4R9-14 |
| 20N1-0606-40R | 18–36 | 12.0 | — | 60 | 240 | — | PQi2050-20-HX |
| 20N1-0612-40R | 18–36 | 24.0 | — | 60 | 240 | — | PQi2050-100-6-LTC |
| Part Number | Vin (V) | Vout (V) | Iout (A) | Output Power (W) | Frequency (kHz) | Reference Design | Output Inductor |
|---|---|---|---|---|---|---|---|
| 20N1-0302 | 9–32 | 3.3 | — | 60 | 240 | — | PQL2050-3R3-22 |
| 20N1-0303 | 9–32 | 5.0 | — | 60 | 240 | — | PQL2050-4R9-14 |
| 20N1-0306 | 9–32 | 12.0 | — | 60 | 240 | — | PQi2050-20-HX |
| 20N1-0312 | 9–32 | 24.0 | — | 60 | 240 | — | PQi2050-100-6-LTC |
LT3752 / LT3753 active clamp forward with synchronous rectification, 350 W bridge. 9–36 | 18–72 | 32–72 Vin · 21 × 23 × 10 mm.
| Part Number | Vin (V) | Vout (V) | Iout (A) | Output Power (W) | Frequency (kHz) | Reference Design | Output Inductor |
|---|---|---|---|---|---|---|---|
| G45R2-0502-05 | 18–72 | 5 | 25.0 | — | — | DC1317A-B (5V) | — |
| G45R2-0405-05 | 18–72 | 12 | 8.0 | — | — | DC1317A-C | PQI2050-10-LTC |
| G45R2-0408-04 | 18–72 | 24 | 5.0 | — | — | DC1317A-D | PQI2050-27-LTC |
| G45R2-0702-05 | 36–72 | 5 | 12.0 | — | — | DC1317A-E | — |
| G45R2-0302-07 | 9–36 | 3.3 | 20.0 | — | — | DC1317A-F | — |
| G45R2-0202-05 | 9–36 | 5 | 20.0 | — | — | DC1317A-F (5V) | — |
| G45R2-0306-06 | 9–36 | 12 | 8.0 | — | — | DC1317A-G | PQI2050-16-LTC |
| G45R2-0205-04 | 9–36 | 15 | 7.0 | — | — | DC1317A-G (15V) | PQI2050-27-LTC |
| G45R2-0207-05 | 9–36 | 18 | 6.0 | — | — | DC1317A-G (18V) | PQI2050-27-LTC |
| G45R2-0207-05 | 9–32 | 19.5 | 5.0 | — | — | DC1317A-G (19.5V) | PQI2050-57-LTC |
| G45R2-0324-06 | 9–36 | 48 | 1.5 | — | — | DC1317A-H | PQA2050-220-LTC |
| G45R2-0312-06 | 9–36 | 24 | 3.0 | — | — | DC1317A-H (24V) | PQA2050-100-LTC |
| G45R2-0601-04 | 34–75 | 3.3 | 30.0 | — | — | DC1317A-A † | PQL2050-0R650-HX |
| G45R2-0218-04 | 9–36 | 48 | 1.5 | — | — | DC1317A-H † | PQA2050-220-LTC |
| G45R2-0209-05 | 9–36 | 24 | 4.0 | — | — | DC1317A-H (24V) † | PQA2050-100-LTC |
G45 active clamp forward matched to the DC1994A and DC2050A demo boards. 18–72 Vin, 100–240 W · 21 × 23 × 10 mm.
| Part Number | Vin (V) | Vout (V) | Iout (A) | Output Power (W) | Frequency (kHz) | Reference Design | Output Inductor |
|---|---|---|---|---|---|---|---|
| G45AH2-0404-04 | 18–72 | 12.0 | 12.0 | — | — | DC1994A | — |
Active clamp forward with the secondary synchronous rectifiers driven directly from the secondary winding. 9–18 | 18–36 | 36–72 Vin to 24 Vout at 120 W · 21.3 × 23.3 × 9.6 mm.
| Part Number | Vin (V) | Vout (V) | Iout (A) | Output Power (W) | Frequency (kHz) | Reference Design | Output Inductor |
|---|---|---|---|---|---|---|---|
| G45R2-0808-S01-80R | 36–72 | 24 | 5.0 | — | 240 | DC2324A-A | PQA2050-39-LTC |
| G45R2-0408-S01-25R | 18–36 | 24 | 5.0 | — | 240 | DC2324A-B | PQA2050-39-LTC |
| G45R2-0208-S01-8R | 9–18 | 24 | 4.0 | — | 240 | DC2324A-C | PQA2050-39-LTC |
General notes — the 20N1, G45, G45AH2 and G45R2 series are designed for opto-isolated Active Clamp Forward circuits as described by the LT3753 controller (Analog Devices®); the secondary-side synchronous-rectifier FETs are typically controlled by the LT8311 secondary-side IC. Direct drive through the secondary winding is ideal for a 2:1 input range, and the G45R2 series is built for exactly that. Integer turns from 1T to 16T are available and can be used as primary or secondary; a wide variety of turns ratios is kept in stock but not all are listed. Surface mount, thru-hole, pad-to-pad, thermal pad and embedded planar windings are available options, and thermal pad or heat-sink versions lower the temperature rise. Contact the factory for any active clamp forward topology design.
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