MBRF1045

3

Rectifier Device Data

Figure 5. Capacitance

150

200

300

500

700

1000

1500

0.05 0.1

0.2

0.5

1

5

10

20

50

VR, REVERSE VOLTAGE (VOLTS)

2

TYPICAL

MAXIMUM

HIGH FREQUENCY OPERATION

Since current flow in a Schottky rectifier is the result of

majority carrier conduction, it is not subject to junction diode

forward and reverse recovery transients due to minority

carrier injection and stored charge. Satisfactory circuit

analysis work may be performed by using a model consisting

of an ideal diode in parallel with a variable capacitance. (See

Figure 5.)

Rectification efficiency measurements show that operation

will be satisfactory up to several megahertz. For example,

relative waveform rectification efficiency is approximately 70

percent at 2.0 MHz, e.g., the ratio of dc power to RMS power

in the load is 0.28 at this frequency, whereas perfect

rectification would yield 0.406 for sine wave inputs. However,

in contrast to ordinary junction diodes, the loss in waveform

efficiency is not indicative of power loss; it is simply a result of

reverse current flow through the diode capacitance, which

lowers the dc output voltage.

Figure 6. Test Circuit for dv/dt and Reverse Surge Current

2.0

µs

1.0 kHz

12 V

100

12 Vdc

VCC

2N2222

100

CARBON

2N6277

1.0 CARBON

1N5817

D.U.T.

4.0

µF

+

2.0 k

Ω

+150 V, 10 mAdc

CURRENT

AMPLITUDE

ADJUST

0 – 10 AMPS