LM1894

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SNAS551C – DECEMBER 1994 – REVISED APRIL 2013

Electrical Characteristics

VS = 8V, TA = 25°C, VIN = 300 mV at 1 kHz, circuit shown in Figure 1 unless otherwise specified

Parameter

Conditions

Min

Typ

Max

Units

Operating Supply Range

4.5

8

18

V

Supply Current

VS = 8V

17

30

mA

MAIN SIGNAL PATH

Voltage Gain

DC Ground Pin 9(1)

−0.9

−1

−1.1

V/V

DC Output Voltage

3.7

4.0

4.3

V

Channel Balance

DC Ground Pin 9

−1.0

1.0

dB

Minimum Balance

AC Ground Pin 9 with 0.1

675

965

1400

Hz

μFCapacitor(1)

Maximum Bandwidth

DC Ground Pin 9(1)

27

34

46

kHz

Effective Noise Reduction

CCIR/ARM Weighted(2)

−10

−14

dB

Total Harmonic Distortion

DC Ground Pin 9

0.05

0.1

%

Input Headroom

Maximum VIN for 3% THD

1.0

Vrms

AC Ground Pin 9

Output Headroom

Maximum VOUT for 3% THD

VS − 1.5

Vp-p

DC Ground Pin 9

Signal to Noise

BW = 20 Hz–20 kHz, re 300 mV

AC Ground Pin 9

79

dB

DC Ground Pin 9

77

dB

CCIR/ARM Weighted re 300 mV(3)

AC Ground Pin 9

82

88

dB

DC Ground Pin 9

70

76

dB

CCIR Peak, re 300 mV(4)

AC Ground Pin 9

77

dB

DC Ground Pin 9

64

dB

Input Impedance

Pin 2 and Pin 13

14

20

26

k

Ω

Channel Separation

DC Ground Pin 9

−50

−70

dB

Power Supply Rejection

C14 = 100

μF,

VRIPPLE = 500 mVrms,

−40

−56

dB

f = 1 kHz

Output DC Shift

Reference DVM to Pin 14 and

Measuree Output DC Shift from

4.0

20

mV

Minimum to Maximum Band-width(5)

(1)

To force the DNR system into maximum bandwidth, DC ground the input to the peak detector, pin 9. A negative temperature coefficient

of

−0.5%/°C on the bandwidth, reduces the maximum bandwidth at increased ambient temperature or higher package dissipation. AC

ground pin 9 or pin 6 to select minimum bandwidth. To change minimum and maximum bandwidth, see Application Hints.

(2)

The maximum noise reduction CCIR/ARM weighted is about 14 dB. This is accomplished by changing the bandwidth from maximum to

minimum. In actual operation, minimum bandwidth is not selected, a nominal minimum bandwidth of about 2 kHz gives

−10 dB of noise

reduction. See Application Hints.

(3)

The CCIR/ARM weighted noise is measured with a 40 dB gain amplifier between the DNR system and the CCIR weighting filter; it is

then input referred.

(4)

Measured using the Rhode-Schwartz psophometer.

(5)

Pin 10 is DC forced half way between the maximum bandwidth DC level and minimum bandwidth DC level. An AC 1 kHz signal is then

applied to pin 10. Its peak-to-peak amplitude is VDC (max BW) − VDC (min BW).

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