SSM2164PZ Analog Devices Inc, SSM2164PZ Datasheet - Page 9

• Manufacturer Part Number: SSM2164PZ
• Description: IC AMP AUDIO QUAD AB 20KHZ 16DIP
• Manufacturer: Analog Devices Inc

Specifications of SSM2164PZ

• Amplifier Type: Audio
• Number Of Circuits: 4
• Current - Input Bias: 10nA
• Current - Supply: 6mA
• Voltage - Supply, Single/dual (±): 8 V ~ 36 V, ±4 V ~ 18 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Through Hole
• Package / Case: 16-DIP (0.300", 7.62mm)
• No. Of Amplifiers: 4
• Bandwidth: 500kHz
• No. Of Channels: 1
• Supply Voltage Range: ± 4V To ± 18V
• Amplifier Case Style: DIP
• No. Of Pins: 16
• Operating Temperature Range: -40°C To +85°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Output Type: -
• Current - Output / Channel: -
• -3db Bandwidth: -
• Slew Rate: -
• Gain Bandwidth Product: -
• Voltage - Input Offset: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

REV. 0
30k
560pF
30k
560pF
30k
560pF
30k
560pF
500
500
500
500
MSB
LSB
WR
A0
A1
Figure 25. Four-Channel Mixer (4 to 1)
V
V
V
V
I
I
I
I
14
15
16
17
C
IN
C
IN
C
IN
C
IN
7
AND BIASING CIRCUITRY
V+
DAC8426
POWER SUPPLY
DATA BUS
GND
VCA1
VCA2
VCA3
VCA4
CONTROL
LOGIC
V–
REFERENCE
10V
MODE
I
I
I
I
IOUT
IOUT
IOUT
IOUT
FROM ADDITIONAL SSM2164s
FOR > 4 CHANNELS
LATCH A
LATCH B
LATCH C
LATCH D
V
Figure 26. Digital Control of VCA Gain
REF
OUT +10V
OP176
100pF
V
30k
4
SS
3
DAC A
DAC B
DAC C
DAC D
AGND
V
5
OUT
V
DD
+15V
18
–9–
If additional SSM2164s are added, the 100 pF capacitor may
need to be increased to ensure stability of the output amplifier.
Most op amps are sensitive to capacitance on their inverting
inputs. The capacitance forms a pole with the feedback resistor,
which reduces the high frequency phase margin. As more
SSM2164’s are added to the mixer circuit, their output capaci-
tance and the parasitic trace capacitance add, increasing the
overall input capacitance. Increasing the feedback capacitor will
maintain the stability of the output amplifier.
Digital Control of the SSM2164
One option for controlling the gain and attenuation of the
SSM2164 is to use a voltage output digital-to-analog converter
such as the DAC8426 (Figure 26), whose 0 V to +10 V output
controls the SSM2164’s attenuation from 0 dB to –100 dB. Its
simple 8-bit parallel interface can easily be connected to a
microcontroller or microprocessor in any digitally controlled
system. The voltage output configuration of the DAC8426
provides a low impedance drive to the SSM2164 so the attenua-
tion can be controlled accurately. The 8-bit resolution of the
DAC and its full-scale voltage of +10 V gives an output of
3.9 mV/bit. Since the SSM2164 has a –33 mV/dB gain con-
stant, the overall control law is 0.12 dB/bit or approximately
8 bits/dB. The input and output configuration for the
SSM2164 is the same as for the basic VCA circuit shown
earlier. The 4-to-1 mixer configuration could also be used.
DGND
6
20
19
2
1
V
V
V
V
OUTA
OUTB
OUTC
OUTD
V
V
V
V
I
I
I
I
IN
IN
IN
IN
C
C
C
C
+15V
AND BIASING CIRCUITRY
V+
POWER SUPPLY
GND
VCA1
VCA2
VCA3
VCA4
–15V
V– MODE
SSM2164
I
I
I
I
IOUT
IOUT
IOUT
IOUT