LM13700MX/NOPB National Semiconductor, LM13700MX/NOPB Datasheet - Page 11

• Manufacturer Part Number: LM13700MX/NOPB
• Description: IC AMP DUAL OP TRANSCOND 16-SOIC
• Manufacturer: National Semiconductor

Specifications of LM13700MX/NOPB

• Amplifier Type: Transconductance
• Number Of Circuits: 2
• Output Type: Push-Pull
• Slew Rate: 50 V/µs
• Gain Bandwidth Product: 2MHz
• Current - Input Bias: 1µA
• Voltage - Input Offset: 300µV
• Current - Supply: 2.6mA
• Current - Output / Channel: 650µA
• Voltage - Supply, Single/dual (±): 10 V ~ 36 V, ±5 V ~ 18 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• -3db Bandwidth: -
• Other names: *LM13700MX; *LM13700MX/NOPB; LM13700MX

Stereo Volume Control
Noting that the gain of the LM13700 amplifier of Figure 3
may be controlled by varying the linearizing diode current I
as well as by varying I
using this approach. As V
(3V
ing diodes, the increase in I
as to hold V
Voltage Controlled Resistors
An Operational Transconductance Amplifier (OTA) may be
used to implement a Voltage Controlled Resistor as shown in
Figure 8. A signal voltage applied at R
the LM13700 which is then multiplied by the g
amplifier to produce an output current, thus:
BE
) to turn on the Darlington transistors and the lineariz-
O
at that level.
ABC
O
, Figure 7 shows an AGC Amplifier
reaches a high enough amplitude
D
reduces the amplifier gain so
X
generates a V
(Continued)
FIGURE 6. Four-Quadrant Multiplier
FIGURE 7. AGC Amplifier
m
of the
IN
to
D
11
where g
by R and R
range of the LM13700 input.
Figure 9 shows a similar VCR where the linearizing diodes
are added, essentially improving the noise performance of
the resistor. A floating VCR is shown in Figure 10, where
each “end” of the “resistor” may be at any voltage within the
output voltage range of the LM13700.
m
≈ 19.2I
A
is necessary to maintain V
ABC
at 25˚C. Note that the attenuation of V
00798113
00798114
IN
within the linear
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O