Analog Devices SSM2018TS, SSM2018TP, SSM2118TS, SSM2118TP Datasheet

a	Trimless
	Voltage Controlled Amplifiers
	SSM2018T/SSM2118T*

FEATURES

117 dB Dynamic Range

0.006% Typical THD+N (@ 1 kHz, Unity Gain)

140 dB Gain Range

No External Trimming Required

Differential Inputs

Complementary Gain Outputs

Buffered Control Port

I–V Converter On-Chip (SSM2018T)

Differential Current Outputs (SSM2118T)

Low External Parts Count

Low Cost

GENERAL DESCRIPTION

The SSM2018T and SSM2118T represent continuing evolution of the Frey Operational Voltage Controlled Element (OVCE) topology that permits flexibility in the design of high performance volume control systems. Voltage (SSM2018T) and differential current (SSM2118T) output versions are offered, 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 combine the low noise of Class AB topologies with the low distortion of Class A circuits to offer an unprecedented level of sonic transparency. Additional features include differential inputs, a 140 dB gain range, and a high impedance control port. The SSM2018T provides an internal current-to-voltage converter; 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 packages and guaranteed for operation over the extended industrial temperature range of –40°C to +85°C.

*Protected by U.S. Patent Nos. 4,471,320 and 4,560,947.

REV. A

Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its 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.

FUNCTIONAL BLOCK DIAGRAMS

VC		SSM-2018T
	G	VG
+IN	GAIN	–IG
	CORE
–IN
	1–G	V1–G
		–I1–G

VC		SSM-2118T
		+IG
	G
		–IG
+IN	GAIN
	CORE
–IN
	1–G	V1–G
		–I1–G

One Technology Way, P.O. Box 9106, Norwood. MA 02062-9106, U.S.A. Tel: [phone] Fax: [phone]

SSM1018T/SSM2118T–SPECIFICATIONS

ELECTRICAL SPECIFICATIONS [VS = ±15 V, AV = 0 dB, RL = 100 kΩ, f = 1 kHz, 0 dBu = 0.775 V rms, simple VCA application circuit with 18 kΩ resistors, –VIN floating, and Class AB gain core bias (RB = 150 kΩ), –40°C < TA < +85°C, unless otherwise noted. Typical specifications apply at TA = +25°C.]

Parameter	Conditions	Min	Typ	Max	Units
AUDIO PERFORMANCE1
Noise	VIN = GND, 20 kHz Bandwidth		–95	–93	dBu
Headroom	Clip Point = 1% THD+N		+22		dBu
Total Harmonic Distortion plus Noise	2nd and 3rd Harmonics Only (+25°C to +85°C)
	AV = 0 dB, VIN = +10 dBu		0.006	0.025	%
	AV = +20 dB, VIN = –10 dBu		0.013	0.04	%
	AV = –20 dB, VIN = +10 dBu2		0.013	0.04	%
INPUT AMPLIFIER					μA
Bias Current	VCM = 0 V		0.25	1
Offset Voltage	VCM = 0 V		1	15	mV
Offset Current	VCM = 0 V		10	100	nA
Input Impedance			4		MΩ
Common-Mode Range			±13		V
Gain Bandwidth	VCA Configuration		0.7		MHz
	VCP Configuration		14		MHz
Slew Rate			5		V/μs
OUTPUT AMPLIFIER (SSM2018T)
Offset Voltage	VIN = 0 V, VC = +4 V		1.0	15	mV
Output Voltage Swing	IOUT = 1.5 mA
	Positive	+10	+13		V
	Negative	–10	–14		V
Minimum Load Resistance	For Full Output Swing		9		kΩ
CONTROL PORT					μA
Bias Current			0.36	1
Input Impedance			1		MΩ
Gain Constant	Device Powered in Socket > 60 sec		–30		mV/dB
Gain Constant Temperature Coefficient			–3500	±4	ppm/°C
Control Feedthrough	0 dB to –40 dB Gain Range		±1		mV
Maximum Attenuation	VC = +4 V		100		dB
POWER SUPPLIES		±5		±18
Supply Voltage Range					V
Supply Current			11	15	mA
Power Supply Rejection Ratio			80		dB

NOTES

1SSM2118T tested and characterized using OP275 as current-to-voltage converter, see figure next page. 2Guaranteed by characterization data and testing at AV = 0 dB.

Specifications subject to change without notice.

–2–

REV. A

SSM2018T/SSM2118T

ABSOLUTE MAXIMUM RATINGS1

Supply Voltage

Dual Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±18 V

Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±VS Operating Temperature Range . . . . . . . . . . . . .–40°C to +85°C

Storage Temperature . . . . . . . . . . . . . . . . . . . –65°C to +150°C Junction Temperature (TJ) . . . . . . . . . . . . . . . . . . . . . +150°C Lead Temperature (Soldering, 60 sec) . . . . . . . . . . . . . +300°C

THERMAL CHARACTERISTICS

Thermal Resistance2

16-Pin Plastic DIP

θJA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76°C/W θJC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33°C/W

16-Pin SOIC

θJA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92°C/W θJC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27°C/W

TRANSISTOR COUNT

Number of Transistors

SSM2018T . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 SSM2118T . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

ESD RATINGS
883 (Human Body) Model . . . . . . . . . . . . . . . . . . . . . . .	500 V
EIAJ Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	100 V

1Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

2θJA is specified for worst-case conditions, i.e., θJA is specified for device in socket for P-DIP and device soldered in circuit board for SOIC package.

50pF

18k

					VOUT
		1	16		V–
	V+	2	15
		3	14
		4	SSM2018T 13	150k
1 F
	18k	5	12		V+
VIN+		6	11		VCONTROL
VIN–		7	10	1 F	3k
					1k
1 F	18k	8	9
		47pF

SSM2018T Typical Application Circuit

PIN CONFIGURATIONS

16-Lead Plastic DIP

16-Lead Plastic DIP

and SOL

and SOL

+I1–G

1

16

V1–G

BAL

1

16

V+

V+

2

15

BAL

V1–G

2

15

–IG

–IG

3

14

VG

+I1–G

3

14

+IG

–I1–G

4 SSM2018T 13

GND

–I1–G

4

SSM2118T

13

GND

COMP 1

5

TOP VIEW

12

MODE

COMP 1

5

TOP VIEW

12

MODE

(Not to Scale)

(Not to Scale)

+IN

6

11

VC

+IN

6

11

VC

–IN

7

10

V–

–IN

7

10

V–

COMP 2

8

9

COMP 3

COMP 2

8

9

COMP 3

ORDERING GUIDE

Model

Temperature Range

Package Option*

SSM2018TP

–40°C to +85°C

N-16

SSM2018TS

–40°C to +85°C

R-16

SSM2118TP

–40°C to +85°C

N-16

SSM2118TS

–40°C to +85°C

R-16

*N = Plastic DIP; R = SOL.

FROM

ADDITIONAL

SSM2118Ts

GLOBAL

SYMMETRY

TRIM

50pF

OPTIONAL

47k

500k

TRIM

18k

47k

470k

V+

A2

VOUT

1

16

50pF*

V–

2

15

10k

18k

3

14

10k

4 SSM2118T 13

150k

A1

1 F 18k

5

12

A1, A2: OP275

VIN+

6

11

V–

1 F

3k

VCONTROL

VIN–

7

10

1k

1 F 18k

8

9

47pF

*FOR MORE THAN 2 SSM2118Ts

SSM2118T Typical Application Circuit

CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the SSM2018T/SSM2118T features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality.

WARNING!

ESD SENSITIVE DEVICE

REV. A

–3–

SSM2018T/SSM2118T–Typical Characteristics

0.1
	TA = +25°C
	VS = ±15V
	RF = 18kΩ				AV = +20dB
+ N – %
0.010				AV = –20dB
THD
			AV = 0dB
0.001	100			1k			10k	20k
20

FREQUENCY – Hz

1

TA = +25°C

VS = ±15V

RF = 18kΩ

0.1

THD + N – %

0.010

0.001

10m

0.1

1

2

AMPLITUDE – VRMS

Figure 1. SSM2018T THD + N Frequency (80 kHz Low-Pass Filter, for AV = 0 dB, VIN = 3 V rms; for AV = +20 dB,

VIN = 0.3 V rms; for AV = –20 dB, VIN = 3 V rms)

100

90TA = +25°C AV = 0dB

	80		300 UNITS
			VIN = 10dBu
	70		V	S = ±15V
UNITS	60
	50
	40
	30
	20
	10
	0
	0.000		0.005			0.010					0.015		0.020			0.025

DISTORTION – %

Figure 2. SSM2018T Distortion Distribution

1

TA = +25°C

RF = 18kΩ

VS = ±15V

0.1

THD + N – %

0.010
0.001	1	10	20
0.1

AMPLITUDE – VRMS

Figure 3. SSM2018T THD + N vs. Amplitude (Gain = 0 dB, fIN = 1 kHz, 80 kHz Low-Pass Filter)

Figure 4. SSM2018T THD + N vs. Amplitude (Gain = +20 dB, fIN =1 kHz, 80 kHz Low-Pass Filter)

1.0

TA = +25°C

VS = ±15V

RF = 18kΩ

0.1

THD + N – %

0.01

0.001
–60	–40	–20	0	20	40

GAIN – dB

Figure 5. SSM2018T THD + N vs. Gain (fIN = 1 kHz;

for –60 dB ≤ AV ≤ –20 dB, VIN = 10 V rms; for 0 dB ≤ AV ≤ +20 dB, VIN = 1 V rms)

0.1

TA = +25°C

RF = 18kΩ

%–

N+ 0.01 THD

0.001

0

±3

±6

±9

±12

±15

±18

SUPPLY VOLTAGE – Volts

Figure 6. SSM2018T THD + N vs. Supply Voltage

(AV = 0 dB, VIN = 1 V rms, fIN = 1 kHz, 80 kHz Low-Pass Filter)

–4–

REV. A

			500
					TA = +25°C
					VS = ±15V
			400
		nV/√Hz	300
		DENSITY –
			200
		NOISE	100
			0
			10		100		1k	10k	100k

FREQUENCY – Hz

Figure 7. SSM2018T Noise Density vs. Frequency

RF = 18kΩ

PEAK

TA = +25°C

– V

±20

RL = ∞Ω

SWING

±15

VOLTAGE

±10

RL = 10kΩ

OUTPUT

±5

0

±5

±10

±15

±20

0

SUPPLY VOLTAGE – Volts

Figure 8. SSM2018T Maximum Output Swing vs. Supply Voltage (THD = 1% max)

RF =

18kΩ

PEAK

±15

TA = +25°C

RL = ∞

VS = ±15V

– V

SWING

±12

RL = 10k

OUTPUT

±9

MAXIMUM

±6

±3

0

1k

10k

100k

FREQUENCY – Hz

Figure 9. SSM2018T Maximum Output Swing vs. Frequency (THD = 1 % max)

SSM2018T/SSM2118T

±15

RF

= 18kΩ

TA = +25°C

PEAK

±12

VS = ±15V

– V

OUTPUTSWING

±6

MAXIMUM

±9

±3

0

100

1k

10k

100k

LOAD RESISTANCE – Ω

Figure 10. SSM2018T Maximum Output Swing vs. Load Resistance, (THD = 1 % max)

	100
	90		TA = +25°C
	80		VS = ±15V
mV	70
–
OFFSET	60
OUTPUT	50
	30
	40
	20
	10
	0
	–80		–60		–40		–20		0	20		40

GAIN – dB

Figure 11. SSM2018T Output Offset vs. Gain

+10

TA

= +25°C

VS = ±15V

+5

0

Degrees

dB–

0

GAIN

GAIN

PHASE–

PHASE

–5

–45

–10

–90

–15

–135

100

1k

10k

100k

1M

FREQUENCY – Hz

Figure 12. SSM2018T Gain/Phase vs. Frequency

REV. A

–5–