THAT4301A Datasheet, PDF (1/12 Pages) List of Unclassifed Manufacturers – THAT Analog Engine® IC Dynamics Processor

T H AT Corporation
FEATURES
· High-Performance Voltage
Controlled Amplifier
· High-Performance RMS-Level
Detector
· Three General-Purpose Opamps
· Wide Dynamic Range: >115 dB
· Low THD: <0.03%
· Low Cost: $4.39 (‘000s)
· DIP & Surface-Mount Packages
THAT Analog Engine^®
IC Dynamics Processor
THAT 4301, 4301A
APPLICATIONS
· Compressors
· Limiters
· Gates
· Expanders
· De-Essers
· Duckers
· Noise Reduction Systems
· Wide-Range Level Meters
Description
THAT 4301 Dynamics Processor, dubbed
“THAT Analog Engine,” combines in a single IC
all the active circuitry needed to construct a
wide range of dynamics processors. The 4301
includes a high-performance, exponen-
tially-controlled VCA, a log-responding
RMS-level sensor and three general- purpose
opamps.
The VCA provides two opposing-polarity, volt-
age-sensitive control ports. Dynamic range ex-
ceeds 115 dB, and THD is typically 0.003% at 0
dB gain. In the 4301A, the VCA is selected for
low THD at extremely high levels. The RMS de-
tector provides accurate rms-to-dc conversion
over an 80 dB dynamic range for signals with
crest factors up to 10. One opamp is dedicated
as a current-to-voltage converter for the VCA,
while the other two may be used for the signal
path or control voltage processing.
The combination of exponential VCA gain con-
trol and logarithmic detector response — “deci-
bel-linear” response — simplifies the
mathematics of designing the control paths of
dynamics processors. This makes it easy to de-
sign audio compressors, limiters, gates, ex-
panders, de-essers, duckers, noise reduction
systems and the like. The high level of integra-
tion ensures excellent temperature tracking be-
tween the VCA and the detector, while
minimizing the external parts count.
18
11
17
14
13
19
-
OA1
20 +
VCC
SYM
IN _VCA OUT
EC-
EC+
THAT4301
-
OA3
+
1
IN ^RMS OUT
IT
CT
GND VEE
+
OA2
-
2
5
4
9
10
8
6
12
15
16
7
Figure 1. Block Diagram (pin numbers are for DIP only)
THAT Corporation; 45 Sumner Street; Milford, Massachusetts 01757-1656; USA
Tel: [phone]; Fax: [phone]; Web: www.thatcorp.com