Gennum Corporation GS3028, GS3027 Datasheet

DynamEQ® II

WDRC System

FEATURES

• dual channel signal processing

• 2nd (4th) order state variable filter

• adjustable crossover frequency

• adjustable compression ratio from 1:1 to 4:1

• independent compression ratio adjustment for
low and high frequency band

• adjustable AGC threshold levels

• unique twin average detectors

• handles high input levels

• low THD and IMD distortion

• drives class D Integrated Receivers

• MPO range externally adjustable

STANDARD PACKAGING

Hybrid Typical Dimensions

0.180 in x 0.110 in x 0.080 in
(4.57 mm x 2.79 mm x 2.03 mm)

DEVICE DESCRIPTION

The DynamEQ

®

II hybrid family is a second generation Wide

Dynamic Range Compression (WDRC) system.
GS3027 (GS3028) Hybrid incorporates 12 dB/oct (24 dB/

oct) filtering and is designed to accommodate CIC and ITC
size requirements.

The gain and frequency response is dependant on the user’s
environment.

Twin averaging detector circuits are optimized for sound
quality during normal listening without sacrificing comfort
during sudden loud inputs.

All input signals to DynamEQ

®

II, are processed by 2:1

compression before subsequent band splitting.
The 12 dB/oct (24 dB/oct) band split filter ahead of the

expander/compressor circuits allows for independent
compression ratio adjustment (1:1 to 4:1) in high and low
frequency channels.

The gain setting stage is followed by a class D Integrated
Receiver preamplifier stage. Symmetrical peak clipping is
used to achieve MPO adjustment.

GS3027/GS3028 - DATA SHEET

Revision Date: May 1998

FUNCTIONAL BLOCK DIAGRAM

OUT

V

B

C

SAD

MPO

IN

GND

4:1

2:1

1:1

B

OUT

B

IN

F

OUT

R

ƒc

V

REG

R

TH

R

HI

R

LO

2

10n

C1

GS3027

C2

C5

C4

C3

0µ1

0µ1

0µ1

0µ2

SLOW

AVERAGE

DETECTOR

FAST

AVERAGE

DETECTOR

CONTROL

10k

RECTIFIER

R

AGC_IN

V

B

50k

REGULATOR

48k

48k

8k4

1M

1M

14k

12k

1

X

- B

- A

- C

12 dB / Oct
(24 dB / Oct)
BAND SPLIT

FILTER

High Frequency

Expander / Compressor

Low Frequency

Expander / Compressor

(GS3028)

1

23

4

5

6

7

8

9

10

11

12

13

14

15

16

17

R

H

R

L

All resistors in ohms, all capacitors
in microfarads, unless otherwise stated

Patent Pending

Document No. 521 - 34 - 03

GENNUM CORPORATION P.O. Box 489, Stn. A, Burlington, Ontario, Canada L7R 3Y3 tel. [phone]

Web Site: www.gennum.com E-mail: [e-mail]

521 - 34 - 03

2

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Hybrid Current I

AMP

- 370 530 µA
Minimum Voltage Vb 1.1 - - V
Total Harmonic Distortion THD V

IN

= -40dBV at 1kHz - 0.2 1.0 %

THD with Maximum Allowable Input THD

M

V

IN

= -23dBV, Rvc = 47kΩ -210%

Input Referred Noise IRN Aweight - 3.0 - µV

RMS

Total System Gain A

V

V

IN

= -90dBV 46 49 52 dB

Regulator Voltage V

REG

I

LOAD

= 30µA 890 930 1000 mV

AGC

Lower Threshold TH

LO

-91 -87 -83 dBV

Upper Threshold TH

HI

-36 -32 -28 dBV
Compression Gain Range ∆A Gain(-90dBVIN) -Gain(-30dBVIN) 37.5 40.5 43.5 dB
System Gain in Compression A

60

V

IN

=-60dBV 26 29 32 dB

Min. Compression Ratio CMP

1 :1

VIN=3kHz, -60dBV to -40dBV,
Rhp=1:1 Rlp=1:1 0.9 1.0 1.1 Ratio

Max. Comp. Ratio CMP

4 :1

VIN =3kHz, -60dBV to -40dBV,
Rhp=4:1, Rlp=4:1 3.6 4.0 4.3 Ratio

Fast Detector Time Constant τ

FAST

-10-ms

Slow Detector Time Constant τ

SLOW

- 220 - ms

FILTER

Maximum Cross-over Frequency ƒ

c_0

Rƒc=0Ω 3.0 3.9 - kHz

Nominal Cross-over Frequency ƒ

c_22

Rƒc=22kΩ 1.5 1.9 2.3 kHz

Minimum Cross-over Frequency ƒ

c_220

Rƒc=220kΩ - 0.9 1.4 kHz

Filter Rolloff Rate (GS3027) - 12 - dB/oct

(GS3028) - 24 - dB/oct
STAGE A and B ---
Open Loop Gain (B) A

OL_B

-52-dB

Input Impedance (A) R

IN

91113 kΩ

OUTPUT STAGE

Stage Gain A

C

VIN=-30dBV 7 9 11 dB
Max Output Level MPO RVC=220kΩ,VIN=-25dBV -14.5 -12.5 -10.5 dBV
MPO Range ∆MPO R

MPO

=0Ω to 50kΩ 13 15 17 dB

Output Resistance R

OUT

-24-kΩ

CAUTION

CLASS 1 ESD SENSITIVITY

ABSOLUTE MAXIMUM RATINGS

PARAMETER VALUE / UNITS

Supply Voltage 3 VDC
Power Dissipation 25 mW
Operating Temperature Range -10° C to 40° C
Storage Temperature Range -20° C to 70° C

PAD CONNECTION

Conditions: Supply Voltage VB = 1.3 V, Frequency = 1 kHz, Temperature = 25°C

ELECTRICAL CHARACTERISTICS

R

HI

V

B

R

LO

4:1

2:1

1:1

C

SAD

B

OUT

B

IN

R

ƒc

F

OUT

OUT

MPO

V

REG

Rth

IN

GND

1 2 3 4

14 15 16 17

13 12 11 10 9 8

6

7

5

1 2 3 4 6

14 15 16 1 7

13 12 11 10 9 8

7

5

2:1

MPO

R

TH

All conditions and parameters remain as shown in Test Circuit unless otherwise stated in "Conditions" column.

521 - 34 - 03

3

0µ22

0µ22

R

MPO

=0

RTH= ∞

= 22k

RVC=100k

3.9k

2µ2

50k

V

IN

V

B

R

ƒc

2

10n

C1

GS3027

C2

C5

C4

C3

0µ1

0µ1

0µ1

0µ2

SLOW

AVERAGE

DETECTOR

FAST

AVERAGE

DETECTOR

CONTROL

10k

RECTIFIER

R

AGC_IN

V

B

50k

REGULATOR

48k

48k

8k4

1M

1M

14k

12k

1

X

- B

- A

- C

12 dB / Oct
(24 dB / Oct)
BAND SPLIT

FILTER

High Frequency

Expander / Compressor

Low Frequency

Expander / Compressor

(GS3028)

1

23

4

5

6

7

8

9

10

11

12

13

14

15

16

17

R

L

R

H

Fig. 1 Production Test Circuit

All resistors in ohms, all capacitors
in microfarads, unless otherwise stated

Fig. 2 Maximum Flexibility Hearing Instrument Application

All resistors in ohms, all capacitors
in microfarads, unless otherwise stated

Any Knowles
or
Microtronics
microphone

0µ22

0µ22

R

MPO

R

TH

100k
Log

R

ƒc

100k Log

50k
Log

R

VC

100k Log

200k Linear

200k Linear

2µ2

2

Any
Knowles
Class D
receiver

V

B

V

B

R

HI

R

LO

2

10n

C1

GS3027

C2

C5

C4

C3

0µ1

0µ1

0µ1

0µ2

SLOW

AVERAGE

DETECTOR

FAST

AVERAGE

DETECTOR

CONTROL

10k

RECTIFIER

R

AGC_IN

V

B

50k

REGULATOR

48k

48k

8k4

1M

1M

14k

12k

1

X

- B

- A

- C

12 dB / Oct
(24 dB / Oct)
BAND SPLIT

FILTER

High Frequency

Expander / Compressor

Low Frequency

Expander / Compressor

(GS3028)

1

23

4

5

6

7

8

9

10

11

12

13

14

15

16

17

R

H

R

L