SSM2118T_15 Datasheet, PDF (1/16 Pages) Analog Devices – Trimless Voltage Controlled Amplifiers

a
Trimless
Voltage Controlled Amplifiers
SSM2018T/SSM2118T
FEATURES
FUNCTIONAL BLOCK DIAGRAMS
117 dB Dynamic Range
0.006% Typical THD+N (@ 1 kHz, Unity Gain)
140 dB Gain Range
V_C
SSM-2018T
No External Trimming Required
Differential Inputs
Complementary Gain Outputs
G
V_G
OBSOLETE ^{Buffered Control Port}
I–V Converter On-Chip (SSM2018T)
Differential Current Outputs (SSM2118T)
+IN
Low External Parts Count
–IN
Low Cost
GENERAL DESCRIPTION
The SSM2018T and SSM2118T represent continuing evolu-
tion of the Frey Operational Voltage Controlled Element
(OVCE) topology that permits flexibility in the design of high
performance volume control systems. Voltage (SSM2018T)
V_C
and differential current (SSM2118T) output versions are of-
fered, both laser-trimmed for gain core symmetry and offset. As
a result, the SSM2018T is the first professional audio quality
VCA to offer trimless operation. The SSM2118T is ideal for
low noise summing in large VCA based systems.
Due to careful gain core layout, the SSM2018T/SSM2118T
+IN
GAIN
CORE
1–G
–I_G
V_1–G
–I_1–G
SSM-2118T
+I_G
G
–I_G
GAIN
combine the low noise of Class AB topologies with the low dis-
–IN
CORE
tortion of Class A circuits to offer an unprecedented level of
sonic transparency. Additional features include differential in-
1–G
V_1–G
puts, a 140 dB gain range, and a high impedance control port.
The SSM2018T provides an internal current-to-voltage con-
–I_1–G
verter; thus no external active components are required. The
SSM2118T has fully differential current outputs that permit
high noise-immunity summing of multiple channels.
Both devices are offered in 16-pin plastic DIP and SOIC pack-
ages and guaranteed for operation over the extended industrial
temperature range of –40°C to +85°C.
REV. A
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use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
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