THAT4305 Datasheet, PDF (1/20 Pages) List of Unclassifed Manufacturers – Pre-trimmed Analog Engine® IC

T H AT Corporation
FEATURES
· Pre-trimmed Blackmer™ VCA &
RMS-level detector
· Wide supply voltage range:
±4.5V ~±16V
· Low supply current:
3.5 mA typ. (±15V)
· Wide dynamic range:
117 dB (VCA)
60 dB (RMS-level detector)
Pre-trimmed Analog Engine^® IC
THAT 4305
APPLICATIONS
· Compressors & Limiters
· Gates & Expanders
· AGCs
· Line-operated dynamics processors
· De-Essers
· Duckers
· Mixers
· Level indicators
· Companding noise reduction systems
Description
The THAT4305 is a single-chip Analog En-
gine optimized for low-cost applications. It incor-
porates a high-performance Blackmer voltage-
controlled amplifier (VCA) and log-responding
RMS-level sensor. The VCA and RMS detector
are pre-trimmed at wafer stage to deliver low dis-
tortion without further adjustment.
Available only in a small (QSOP) surface-
mount package, the 4305 is aimed at line-oper-
ated audio applications such as compressor/lim-
iters, gates, and other dynamic processors. The
part normally operates from a split supply volt-
age up to ±16Vdc, drawing only 3.5mA at ±15V.
This IC also works at supply voltages as low as
±4.5V, making it useful in some battery-operated
products as well.
The 4305 was developed specifically for use
in low-cost dynamics processors, drawing from
THAT's long history and experience with such
designs. Both VCA control ports and the detec-
tor input and output are available for the de-
signer to connect as s/he sees fit. As a result, the
part is extremely flexible and can be configured
for a wide range of applications including single-
and multi-band companders, digital overload
protectors, voltage-controlled faders, level indi-
cators, etc.
What really sets the 4305 apart from other
manufacturers’ offerings is the transparent sound
of its Blackmer VCA, coupled with its accurate
true-RMS level detector. This makes the IC useful
in a wide range of analog audio products.
VCA
VCA
NC
IN
NC OUT EC- EC+ NC VCC
16 15 14 13 12 11 10 9
VCA
IN
OUT
EC+ EC-
RMS
IN
OUT
CT
1
2
3
NC RMS NC
IN
4
5
6
7
8
CT RMS GND NC VEE
OUT
Figure 1. THAT4305 equivalent block diagram
Pin Name
No Connection
RMS IN
No Connection
CTIME
RMS OUT
GND
NC
Vee
V_CC
No Connection
EC+
EC-
VCA OUT
No Connection
VCA IN
No Connection
Pin Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Table 1. THAT 4305 pin assignments
Package
16 pin QSOP
Order Number
4305Q16-U
Table 2. Ordering Information
THAT Corporation; 45 Sumner Street; Milford, Massachusetts 01757-1656; USA
Tel: [phone]; Fax: [phone]; Web: www.thatcorp.com
Document 600067 Rev 00