THAT Corporation THAT4311 Datasheet

THAT Corporation

Low-voltage, Low-power

Analog Engine

®

Dynamics Processor

THAT 4311

FEATURES

High Performance VCA, RMS-Level

·

Detector, and three 0pamps in one
package
Wide Dynamic Range: >105 dB

·

Low THD: <0.09%

·

Low Power: 7 mA typ.

·

Surface-Mount Package

·

5 VDC Operation

·

Description

The THAT 4311 Low Power Dynamics Proces
sor combines in a single IC all the active circuitry
needed to construct a wide range of dynamics
processors. The 4311 includes a high perfor­mance, voltage controlled amplifier, a log re­sponding RMS-level sensor and three opamps,
one of which is dedicated to the VCA, while the
other two may be used for the signal path or con­trol voltage processing.

The exponentially-controlled VCA provides
two opposing-polarity, voltage sensitive control
ports. Dynamic range exceeds 105 dB, and THD
is typically 0.09% at 0dB gain. The RMS detector
provides accurate RMS to DC conversion over an

APPLICATIONS

Wireless microphone systems

·

Wireless in-ear monitors

·

Compressors and Limiters

·

Gates

·

De-Essers

·

Duckers

·

-

80 dB dynamic range.

Though originally designed for use in micro
phone noise reduction systems, the 4311 is a use
ful building block in a number of analog signal
processing applications. The combination of ex­ponential VCA gain control and logarithmic detec­tor response - “decibel-linear” response ­simplifies the mathematics of designing the con­trol paths of dynamics processors, making it easy
to develop audio compressors, limiters, gates, ex­panders, de-essers, duckers, and the like. The
high level of integration ensures excellent temper­ature tracking between the VCA and the detector,
while minimizing the external parts count.

-

-

Pin Name DMP20

RMS IN 1

)2

IT (I

18

19

OA1

20

17

16 15

EC-

IN

THAT4311

1

IN

RMS

IT

2

CT

OUT

3

5

4

14 13 12

SYM

EC+

OUT

VCA

OA2

11

VCC

OA3

VREF

VREF

VEE

6

7

9

8

10

Figure 1. THAT 4311 equivalent block diagram

TIME

OA2 -IN 3

RMS OUT 4

)5

CT (C

TIME

CLIP 6

OA2 OUT 7

CAP 8

VREF 9

VEE 10

VCC 11

OA3 OUT 12

VCA OUT 13

SYM 14

EC+ 15

EC- 16

VCA IN 17

OA1 OUT 18

OA1 -IN 19

OA1 +IN 20

Table 1. THAT 4311 pin assignments

THAT Corporation; 45 Sumner Street; Milford, Massachusetts 01757-1656; USA

Tel: [phone]; Fax: [phone]; Web: www.thatcorp.com

Page 2 Low-voltage, Analog Engine

Preliminary Information

®

Dynamics Processor

SPECIFICATIONS

1

Absolute Maximum Ratings (TA= 25°C)

Positive Supply Voltage (VCC) +15 V Power Dissipation (PD)(TA= 75°C) 700 mW

Operating Temperature Range (T

Max DE

-(EC-) ± 1V

CEC+

) -20 to +70°C Storage Temperature Range (TST) -40 to +125°C

OP

Recommended Operating Conditions

Parameter Symbol Conditions Min Typ Max Units

Positive Supply Voltage V

CC

Electrical Characteristics

Parameter Symbol Conditions Min Typ Max Units

Supply Current I

Reference Voltage V

CC

REF

No signal; VCC=+7 VDC — 7.0 9.0 mA

+5 +15 V

2

1.8 1.95 2.1 V

Encode and Decode – Companding Noise Reduction (VCC= +7V encoder, +15V decoder)

Encode Level Match LMe Encode mode; f = 1kHz -25.3 -23.0 -20.7 dBV

Encode Gain Accuracy Encode mode, f = 1kHz

Decode Level Match LMd Decode mode; f = 1kHz -18.3 -16.0 -13.7 dB

Decode Gain Accuracy Decode mode; f=1kHz

Max Input Voltage Vime Encode mode; THD = 3%; f = 1kHz 3 5 — dBV

Max Output Voltage Vomd Decode mode; THD = 3%; f = 1kHz 10.7 13.7 — dBV

Total Harmonic Distortion THDtrim End-to-end; Vin = LMe; f = 1kHz — 0.025 — %
(with trim)

Total Harmonic Distortion THDnotrim End-to-end; Vin = LMd; f = 1kHz — 0.15 0.7 %
(no trim)

Output Noise Vnod End-to-end ; Vin = short; A-weighted — 7 — µVrms

GAe1 Vin = LMe + 10dB +3.5 +5 +6.5 dB
GAe2 Vin = LMe - 40dB -23 -20 -17 dB

GAd1 Vin = LMd + 5dB +8.5 +10 +11.5 dB
GAd2 Vin = LMd - 20dB -43 -40 -37 dB

1. All specifications are subject to change without notice.

2. Unless otherwise noted, T

=25°C, test circuit as shown in Fig 2.

A

THAT Corporation; 45 Sumner Street; Milford, Massachusetts 01757-1656; USA

Tel: [phone]; Fax: [phone]; Web: www.thatcorp.com

Rev. 08/30/01 Page 3
Preliminary Information

Electrical Characteristics (con’t)

Parameter Symbol Conditions Min Typ Max Units

Op amp OA1

Offset Voltage V

Equivalent Input Noise V

nOA1

Total Harmonic Distortion THD

Open Loop Gain A

VO-OA1

Gain Bandwidth Product GBW

Slew Rate SR

Op amp OA2

Offset Voltage V

Equivalent Input Noise V

Total Harmonic Distortion THD

Open Loop Gain A

Gain Bandwidth Product GBW

Slew Rate SR

nOA1

VO-OA1

IO

OA1

IO

OA1

OA1

OA1

OA1

OA1

RL=2kW — ±0.5 ±6 mV

A-weighted 6.5 10

nV

1kHz, AV=1; RL= 10kW — 0.0007 0.003 %

RL= 10kW--115 --

at 50kHz — 5 —

—2—

RL=2kW — ±0.5 ±6 mV

A-weighted 7.5 12

nV

1kHz, AV=1; RL= 10kW — 0.0007 0.003 %

RL= 10kW--110 --

at 50kHz — 5 —

—2—

Hz

Hz

Input

XLR1

XLR-F

2

5

4

TP1

RMS Input

+40dB +60dB

+20dB

+

R10

100R 5%

Bypass

Capacitors

D3
1N4004

D4
1N4004

C15
1000u

+

0dB

V+

+

C10
22u

+

C13
22u

V+

Sym

1

3

3

1

2

R1
100k

External

Control

Input

C6

+

47u

R11

23k2

3
2
1

CN1

Iset2TC

THAT4311

R12
261k

V-

R2

10k0

R21

10k0

U1B

IN1OUT

RMS

R3

10k0

C12
3u3

R20

10k0

C9
3u3

R26

4

5

100R

5%

+

C7

10u

VREF

50k

R7

C4

47u

R8

cw

300k

V-

VREF

R5

17

20k0

R4

1k33

2

3

81

R29

1k33

TP2

RMS Output

RMS Output

3
2

1

CN1

5%

R9

51R

5%

1415

EC+ SYM

OUT

IN

EC-

16

VCA

VREF

CONTROL-VOLTAGE

6

U1
OP-27

VREF

Power
Input

3
2
1

CN2

13

C5

47p

R6

20k0

U1A

OA3

THAT4311

NPO

12

C11
100n
(U1)

V-

R24

2k80

SW1F

C19
1000u

SW1C

16

R15

31k6

C14
100n

(U1)

611

C16

47u

R23

280R

512

SW1E

R19

100k

+

R18

10k0

1

+40dB

R16

280R

C1

10u

R22

30R1

V+

10k0

3

VREF

V+

+

R27

19

20

+

C18

47u

R17

31k6

C8

OA2

U1C
THAT4311

U1E

11

VCC

VEE

10

THAT4311

R14

31k6

OA1

U1D
THAT4311

47p

SW1B

2

6

7

VREF

C17

47p

VREF

CAP

15

10u

Output

SW1A

XLR2

XLR-M

1

3

3

1

2

5

2

4

R25

18

100R

5%

R28

100R 5%

VREF

9

8

+

+

C3

C2

22u

Fig 2. THAT 4311 test circuit

THAT Corporation; 45 Sumner Street; Milford, Massachusetts 01757-1656; USA

Tel: [phone]; Fax: [phone]; Web: www.thatcorp.com

Page 4 Low-voltage Analog Engine

Preliminary Information

Representative Data (Stand-alone)

®

Dynamics Processor

Fig 3. VCA Gain vs. Control Voltage (Ec-) at 25°C

Fig 5. VCA 1kHz THD+Noise vs. Input, +15 dB Gain Fig 6. VCA 1kHz THD+Noise vs. Input, 0 dB Gain

Fig 4. VCA 1kHz THD+Noise vs. Input, -15 dB Gain

Fig 7. VCA THD vs. Frequency, 0 dB gain, 1 Vrms Input

Fig 9. Departure from Ideal Detector Law vs. Level

THAT Corporation; 45 Sumner Street; Milford, Massachusetts 01757-1656; USA

Tel: [phone]; Fax: [phone]; Web: www.thatcorp.com

Fig 8. RMS Output vs. Input Level, 1 kHz & 10 kHz

Fig 10. Detector Output vs. Frequency at Various Levels