September 6, 2005

Realized the World's Highest Speed (18ns) FMXJ Series
Fast Recovery Diode with low noise and high breakdown voltage

Sanken Electric Co., Ltd. has developed three types of fast recovery rectifier diodes under the FMX Series - low noise, high breakdown voltage and the shortest reverse recovery time in the world (18 ns*)- optimum for plasma TVs.
Samples will be available from September 15. Mass production will be launched at the end of 2005.
Sample price: 240 yen for FMXJ-1103S (300V, 10A), 260 yen for FMXJ-1104S (400V, 10A), and 300 yen for FMXJ-2164S (400V, 16A).

*Surveyed by Sanken Electric as of September 2005

1. Development background
  Recently, there have been growing demands for plasma TVs. In order for the driver circuits of the display panels to achieve higher efficiency for energy saving and lower electromagnetic noise for higher picture quality, fast recovery diodes are required to have shorter reverse recovery time (trr) for power-loss reduction and to have lower noise as well as high breakdown voltage.
However, the conventional fast recovery diodes, though easy in heightening the breakdown voltages, are limited in achieving the higher speeds and in lowering the power losses due to the structure. In addition, the noise tends to increase as the reverse recovery time is shortened - a sort of trade-off. Therefore, it is extremely difficult to achieve both higher speed and loss reduction at the same time.

Sanken Electric has developed the innovative structure JBS (*1) that combines into the structure of the fast recovery diode the structure of the schottky barrier diode which is easy in achieving higher speed and in lowering the power loss. Employing this structure and also Sanken's proprietary Lifetime Control technology (*2) has realized the new fast recovery diodes with high breakdown voltages (300V and 400V), extremely high speed (Reverse recovery time: 18 ns. Improves 40% or more at high temperature compared with Sanken's conventional counterparts) and low noise.

*1: JBS (Junction Barrier Schottky) structure
By allocating in parallel the PN junction of a fast recovery diode and the Schottky junction of a Schottky barrier diode, this structure realizes, at the same time, the high breakdown voltage of the former and the lower noise of the latter. The noise is reduced by controlling the reverse-recovery-time differences between PN and Schottky junctions.
*2: Lifetime Control technology
Diodes can be made faster by shortening the time during which minority carriers disappear at a reverse voltage. This can be realized by diffusion of heavy metal or by corpuscular radiation. Both techniques, however, cause an increase in noise. Lifetime Control technology developed by Sanken Electric controls the optimal balance between higher speed and lower noise.

2. Features
(1) JBS structure
  - Reduces noise (ringing noise) and so contributes to downsizing and component-count reduction.
  - Reduces power loss (Reverse direction loss during transient response), so decreases self-heating and realizes to downsize a heatsink.
(2) Lifetime Control ensures the faster operation in the entire temperature range so that the power loss is reduced at high-frequency operation.
  - trr=18ns max(Ta=25°C)
  - trr=35ns(Ta=100°C,reference value for FMXJ-2164S)
(3) Three types 200V/10A, 400V/10A, and 400V/16A available to suit various types of circuits.
(4) TO-220F (full mold) package
3. Application
Optimum for such circuits and power supplies that require high voltages and high-frequency outputs as follows:
- Panel driver circuit in plasma TVs
- Continuous mode PFC circuits
- Output rectifier circuits for SMPS, UPS, and DC-DC converters
- Fly-wheel diodes for inverters and choppers
4. Electrical Characteristics of FMXJ Series
Item Symbol Ratings Unit
FMXJ-1103S FMXJ-1104S FMXJ-2164S
Repetitive peak reverse voltage VRM 300 400 V
Average forward current IF(AV) 10 16 A
Forward voltage drop VF 1.35 max 1.40 max V
Reverse leakage current IR 100 max µA
Reverse leakage current under high temperature H·IR 25 max 20 max mA
Reverse recovery time trr 18 max ns
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