MC1458, C

3

MOTOROLA ANALOG IC DEVICE DATA

Figure 1. Burst Noise versus Source Resistance

Figure 2. RMS Noise versus Source Resistance

Figure 3. Output Noise versus Source Resistance

Figure 4. Spectral Noise Density

Figure 5. Burst Noise Test Circuit

Unlike conventional peak reading or RMS meters, this system

was especially designed to provide the quick response time

essential to burst (popcorn) noise testing.

The test time employed is 10 sec and the 20

µV peak limit

refers to the operational amplifier input thus eliminating errors

in the closed loop gain factor of the operational amplifier .

RS, SOURCE RESISTANCE (Ω)

0

10

100

1000

10

100

1.0 k

10 k

100 k

1.0 M

BW = 1.0 Hz to 1.0 kHz

RS, SOURCE RESISTANCE (Ω)

0.1

1.0

10

100

10

100

1.0

10 k

100 k

1.0 M

BW = 1.0 Hz to 1.0 kHz

RS, SOURCE RESISTANCE (Ω)

0

0.1

1.0

10

10

100

1.0 k

10 k

100 k

1.0 M

AV = 1000

10

1.0

100

f, FREQUENCY (Hz)

10

100

1.0 k

100 k

10 k

140

120

100

80

40

20

0

60

AV = 10, RS = 100 kΩ

+

1.0 k

Operational Amplifier

Under Test

Low Pass Filter

1.0 Hz to 1.0 kHz

100 k

X 500

X 2

To Pass / Fail

Indicator

–

100 k

100 k

+

+

–

–

Positive

Threshold

Voltage

Negative

Threshold

Voltage