SSM2160S Analog Devices Inc, SSM2160S Datasheet - Page 9

• Manufacturer Part Number: SSM2160S
• Description: IC BALANCE/VOL CTRL DGITL 24SOIC
• Manufacturer: Analog Devices Inc
• Type: Stereo Audio Volume Controlr

Specifications of SSM2160S

• Rohs Status: RoHS non-compliant
• Applications: Decoders, Receivers, Surround Systems
• Mounting Type: Surface Mount
• Package / Case: 24-SOIC (7.5mm Width)

Signal Chain Considerations
The SSM2160 is capable of providing an extremely wide control
range, from –127 dB of attenuation (limited only by the noise
floor) to +31 dB of gain. When configuring the system, the
SSM2160 should be in the signal chain where input signals allow
the minimum VCA gain to be used, thus ensuring the lowest
distortion operation. In consumer products, sources that supply
line level signals include FM/AM tuner, phono preamp, cassette
deck, CD, laser disk, VCR, LINE, AUX, and microphone preamp.
Figure 5 shows a typical application where the SSM2160 has been
placed between a surround sound decoder and the power
amplification stages. This allows the user to adjust both volume
and balance between six speakers through the use of the master
and channel controls.
REV. A
CASSETTE DECK
LINE LEVEL INPUTS – STEREO PAIRS
PHONO PREAMP
COMPACT DISK
10 F
V+
FM/AM TUNER
MICROPHONE
10 F
REF
OUT
LASER DISK
Figure 4. Single-Supply Operation with V
Figure 5. Typical Signal Chain Using the SSM2160
+
+
VCR
0.1 F
0.1 F
MUX
12
13
1
3
2
V+
AGND
V–
DGND
V
SURROUND
DECODER
REF
SOUND
SSM2160
Figure 7. Interface Characteristics, DAC Address/Data Decoding Truth Table
7-BIT MASTER DAC
5-BIT CHANNEL DAC 1
5-BIT CHANNEL DAC 2
5-BIT CHANNEL DAC 3
5-BIT CHANNEL DAC 4
5-BIT CHANNEL DAC 5
5-BIT CHANNEL DAC 6
NO DAC SELECTED
CHn IN
VOLUME AND
CONTROLS
SELECTION
SSM2160
BALANCE
POWER AMPS
REF
MSB
1
1
1
1
1
1
1
1
Buffer
TO
SPEAKERS
X
X
X
X
X
X
X
X
X = DON'T CARE
SHADED AREA IS DATA
ADDRESS MODE
X
X
X
X
X
X
X
X
ADDRESS
X
X
X
X
X
X
X
X
–9–
X
X
X
X
X
X
X
X
Digital Control Range Plan
The SSM2160 may be modeled as six ganged potentiometers
followed by individual programmable gain channel amplifiers, as
shown in Figure 6. In actuality, each channel’s signal level is set by
a VCA that can give gain or attenuation, depending upon the control
voltage supplied. The input potentiometers have a maximum
gain 0 dB (unity), a minimum gain of –127 dB, and change in
1 dB steps. The channel amplifiers each have minimum gain of
0 dB and a maximum gain of 31 dB and also change in 1 dB steps.
The data settings for the attenuation of the master potentiometer
and the channel amplifier are shown in Table II.
Master
Channel
When using channel controls as balance controls, the center would
be with Channel = 10h (or 0Fh if desired). Increasing the gain
to the maximum would occur at Channel = 00h. Reducing the
gain to minimum would occur at Channel = 1Fh.
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
Figure 6. Potentiometer Representation of SSM2160
(One Channel Only)
LSB
0
1
0
1
0
1
0
1
MSB
0
0
0
0
0
0
0
0
Min Atten
Max Atten
Max Gain
Midgain
Min Gain
Table II. Master and Channel Control
MASTER
1
1
1
1
1
1
1
INPUT
X
X
X
X
X
X
X
DATA MODE
X
DATA
0 = MUTE
1 = UNMUTE
–127dB
0dB
+31dB 0dB
X
CHANNEL
X
X
dB
0
–127
+31
+15
0
LSB
X
Data
Hex
7F
00
00
10
1F
SSM2160
OUTPUT
Binary
1111111
0000000
00000
10000
11111