MMBT6521LT1

http://onsemi.com

3

TYPICAL NOISE CHARACTERISTICS

Figure 4. Noise Voltage

f, FREQUENCY (Hz)

5.0

7.0

10

20

3.0

Figure 5. Noise Current

f, FREQUENCY (Hz)

2.0

10

20

50

100

200

500

1k

2k

5k

10k

100

50

20

10

5.0

2.0

1.0

0.5

0.2

0.1

BANDWIDTH = 1.0 Hz

100 mA

30 mA

BANDWIDTH = 1.0 Hz

10 mA

300 mA

300 mA

100 mA

30 mA

10 mA

10

20

50

100

200

500

1k

2k

5k

10k

NOISE FIGURE CONTOURS

Figure 6. Narrow Band, 100 Hz

500k

Figure 7. Narrow Band, 1.0 kHz

10

2.0 dB

BANDWIDTH = 1.0 Hz

Figure 8. Wideband

10

10 Hz to 15.7 kHz

Noise Figure is defined as:

NF

+ 20 log10

en2 ) 4KTRS ) In

2RS2

4KTRS

1 2

= Noise Voltage of the Transistor referred to the input. (Figure 3)

= Noise Current of the Transistor referred to the input. (Figure 4)

°K)

= Temperature of the Source Resistance (

°K)

= Source Resistance (Ohms)

K

T

3.0 dB 4.0 dB

6.0 dB

10 dB

50

100

200

500

1k

10k

5k

20k

50k

100k

200k

2k

20

30

50 70 100

200 300

500 700 1k

10

20

30

50 70 100

200 300

500 700 1k

500k

100

200

500

1k

10k

5k

20k

50k

100k

200k

2k

1M

500k

50

100

200

500

1k

10k

5k

20k

50k

100k

200k

2k

20

30

50 70 100

200 300

500 700 1k

BANDWIDTH = 1.0 Hz

1.0 dB

2.0 dB

3.0 dB

5.0 dB

8.0 dB

1.0 dB

2.0 dB

3.0 dB

5.0 dB

8.0 dB