Schottky Takes Forward Voltage Drop To New Low
A new Trench MOS Barrier Schottky (TMBS) rectifier from Vishay Intertechnology (www.vishay.com) is said to offer the lowest forward voltage drop (VF) for a 100-V rated device . The V60100C is a 60-A TMBS dual rectifier provided in a common-cathode 30 A X 2 configuration. The part delivers a forward voltage drop of 0.70 V max per leg at 30 A and 125°C, and 0.79 V max at 30 A and 25°C. A typical value for forward voltage drop per leg at 5 A and 125°C is just 0.360 V.
The V60100C is the latest offering in Vishay’s TMBS rectifier family of 100-V rated devices. These rectifiers use Trench MOS technology to achieve superior performance compared to conventional planar Schottkys. With their low forward voltage drops, TMBS rectifiers can perform the same functions with fewer devices, which saves pc-board space, simplifies designs, and reduces cost. Previously, Vishay introduced 30-A, 40-A, and 50-A rectifiers in the TMBS family including single and dual devices. A comparison of these devices, reveals that the new 60-A device offers the lowest VF (see table below).
Optimized for use in 70-W to 800-W high-frequency switchmode power supplies, the low forward voltage drop and superior switching performance of the V60100C reduce power losses and improve the efficiency of the OR-ing diode on the high-voltage output. The V60100C also offers an alternative to synchronous rectification. To demonstrate its potential advantages, the company compared the performance of the TMBS rectifiers with standard planar Schottkys and synchronous rectifiers in two separate power supply applications.
The first application was a 350-W switch-mode power supply in which the baseline design uses 20-A, 100-V planar Schottky rectifiers packaged in the TO-220. When operated at two-thirds its rated output (about 235 W), this design achieved 78.3% efficiency. When the planar Schottkys were replaced with 40-A, 100-V TMBS rectifiers in the TO-220 and tested under the same conditions, efficiency rose by 1.3%. This represents a savings of 3.72 W.
The second application was a 120-W adapter in which the baseline design used two 40-A, 100-V MOSFETs and a driver IC to provide synchronous rectification. When tested at the full rated power and with a 100-Vac input, this design achieved 87.1% efficiency. The test was then repeated with a pair of 40-A, 100-V TMBS rectifiers replacing the MOSFETs and driver chip. In this case, efficiency measured 87.0%. This experiment demonstrated how TMBS rectifiers could provide performance on par with synchronous rectification, while providing a simplified and more rugged design.
Packaged in the TO-220AB, samples and production quantities of the V60100C are available now. Unit pricing for U.S. delivery in 1,000-piece quantities starts at $2. For more information, see vishay.com
Table. V F performance of the V60100C and other TMBS family members.*
Device Number | Description | Package | VF at IF = 5 A and T J = 125 ° C |
VTS 40100CT | 40-A common cathode (20 A X 2 ) | TO-220AB | 0.375 V |
V60100C | 60-A common cathode (30 A X 2) | TO-220AB | 0.360 V |
V50100P | 5 0-A common cathode (25 A X 2 ) | TO-247 AD | 0.372 V |
V30100S | 30-A (30 A X 1) | TO-220AB | 0.385 V |
V F 30100S | 30-A (30 A X 1) full molded | I TO-220AB | 0.385 V |
V40100P | 40-A common cathode (20 A X 2 ) | TO-247 AD | 0.372 V |