aFEATURES
Transformer-Like Balanced Output
Drives 10 V RMS Into a 600 V Load
Stable When Driving Large Capacitive Loads and Long
CablesLow Distortion
0.006% typ 20 Hz–20 kHz, 10 V RMS into 600 V
High Slew Rate
15 V/ms typ
Low Gain Error(Differential or Single-Ended); 0.7% typ
Outputs Short-Circuit Protected
Available In Space-Saving 8-Pin Mini-DIP Package
Low Cost
APPLICATIONS
Audio Mix Consoles
Distribution Amplifiers
Graphic and Parametric Equalizers
Dynamic Range Processors
Digital Effects Processors
Telecommunications Systems
Industrial Instrumentation
Hi-Fi Equipment

GENERAL DESCRIPTIONThe SSM2142 is an integrated differential-output buffer
amplifier that converts a single-ended input signal to a balanced
output signal pair with high output drive. By utilizing low noise
thermally matched thin film resistors and high slew rate
amplifiers, the SSM2142 helps maintain the sonic quality ofaudio systems by eliminating power line hum, RF interference,voltage drops, and other externally generated noise commonly
encountered with long audio cable runs. Excellent rejection ofcommon-mode noise and offset errors is achieved by laser
trimming of the onboard resistors, assuring high gain accuracy.
The carefully designed output stage of the SSM2142 is capableof driving difficult loads, yielding low distortion performancedespite extremely long cables or loads as low as 600 Ω, and isstable over a wide range of operating conditions.

Balanced Line Driver
SSM2142FUNCTIONAL BLOCK DIAGRAM
VIN

50Ω+OUT FORCE+OUT SENSE
10kΩ– OUT SENSE

50Ω– OUT FORCEALL RESISTORS 30kΩ
UNLESS OTHERWISE
INDICATED

10kΩ

GND

Based on a cross-coupled, electronically balanced topology, theSSM2142 mimics the performance of fully balanced
transformer-based solutions for line driving. However, theSSM2142 maintains lower distortion and occupies much lessboard space than transformers while achieving comparable
common-mode rejection performance with reduced parts count.
The SSM2142 in tandem with the SSM2141 differential
receiver establishes a complete, reliable solution for driving andreceiving audio signals over long cables. The SSM2141 features
an Input Common-Mode Rejection Ratio of 100 dB at 60 Hz.
Specifications demonstrating the performance of this typicalsystem are included in the data sheet.

REV. B
Information furnished by Analog Devices is believed to be accurate andreliable. 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 orotherwise under any patent or patent rights of Analog Devices.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703

(VS = 618 V, –408C ≤ TA ≤ +858C, operating in differential mode unless otherwise

SSM2142–SPECIFICATIONS noted. Typical characteristics apply to operation at T = +258C.)A

Parameter

SymbolINPUT IMPEDANCEZININPUT CURRENT

IIN

Conditions

Min

Typ

Max

Units

10
VIN = ± 7.071 V± 750

GAIN, DIFFERENTIAL
GAIN, SINGLE-ENDED

Single-Ended Mode

GAIN ERROR, DIFFERENTIAL

RL = 600 Ω

kΩ
± 900

µA

5.8

5.98

dB

5.7

5.94

dB

0.7

2

%

POWER SUPPLY REJECTIONRATIO STATICPSRR

VS = ± 13 V to ± 18 V

60

80

dB

OUTPUT COMMON-MODE REJECTION

OCMR

See Test Circuit; f = 1 kHz

–38

–45

dB

OUTPUT SIGNAL BALANCE RATIO

SBR

See Test Circuit; f = 1 kHz

–35

–40

dB

TOTAL HARMONIC DISTORTION
Plus Noise

THD+N

20 Hz to 20 kHz,VO = 10 V rms, RL = 600 Ω

0.006

%

SIGNAL-TO-NOISE RATIOSNR

VIN = 0 V

–93.4

dBu

HEADROOMHRCLIP Level = 10.5 V rms

+93.4

dBu

SLEW RATE

SR

15

V/µs

OUTPUT COMMON-MODE
VOLTAGE OFFSET1VOOS

RL = 600 Ω

–250

25

250

mV

DIFFERENTIAL OUTPUT
VOLTAGE OFFSETVOOD

RL = 600 Ω

–50

15

50

mV

VIN = ± 7.071 V± 13.8± 14.14

45

50

55

Ω

5.5
70

7.0

60

mA
mA

DIFFERENTIAL OUTPUT
VOLTAGE SWINGOUTPUT IMPEDANCEZOSUPPLY CURRENTOUTPUT CURRENT, SHORT CIRCUIT

ISY
ISC

Unloaded, VIN = 0 V

V

NOTES
1
Output common-mode offset voltage can be removed by inserting dc blocking capacitors in the sense lines. See Applications Information.
Specifications subject to change without notice.

ABSOLUTE MAXIMUM RATINGS*PIN CONNECTIONS

Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 18 V
Storage Temperature . . . . . . . . . . . . . . . . . . –60°C to +150°C
Lead Temperature (Soldering, 60 sec) . . . . . . . . . . . . +300°C
Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . +150°C
Operating Temperature Range . . . . . . . . . . . . –40°C to +85°C
Output Short Circuit Duration (Both Outputs) . . . . Indefinite

8-Pin Plastic DIP(P Suffix)*Stresses above those listed under “Absolute Maximum Ratings” may cause
permanent damage to the device. These are stress ratings only; the functional
operation of the device at these or any other conditions above those indicated in theoperational sections of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.

ORDERING GUIDE

Model

OperatingTemperature Range

SSM2142P –40°C to +85°C
SSM2142S* –40°C to +85°C

Package
Description

Package
Option

Plastic DIP
SOL

N-8
R-16

16-Pin Wide Body SOL(S Suffix)
NC

1

16

NC

NC

2

15

NC

– FORCE

3

14+ FORCE– SENSE4

13+ SENSEGROUND

5

12

+V

VIN

6

11

–V

NC

7

10

NC

NC

8

9

NC

*For availability of SOIC package, contact your local sales office.

–2–

REV. BSSM2142
300Ω
V OUT

300 Ω

V

VS = 0V

1

8

2

7

300Ω

3

6

+18V

4

5

–18V

600Ω
VIN = 10V p–p

300 Ω

1

8

2

7

3

6

+18V

4

5

–18V

600 Ω

V VOUT

V CMR = 10V p–p
SBR = 20 LOG∆VOUT
OCMR = 20 LOG
VCMR

Figure 1. Output CMR Test Circuit

∆VOUT
VIN

Figure 2. Signal Balance Ratio (BBC Method) Test Circuit

Typical Performance Characteristics
12140

POWER SUPPLY REJECTION – dB

OUTPUT VOLTAGE SWING – V rms

TA = +25°C
VS = ±18V

120∆VS = ±1V
100
–PSR
80
+PSR

60

40

20

TA = +25°C
VS = ±18V
RL = 600Ω
DIFF. MODE

1080.1% DISTORTION
0.01% DISTORTION
6

4

2

0

0
10

100

1k

10k

20

10

100k

FREQUENCY – Hz

Figure 3. Power Supply Rejection vs. Frequency

100

6.5

TA = +25°C
RL = 600Ω

10TA = +25°C
VIN = 0V

6.0

DIFF. MODE
FREQ. = 20kHz

SUPPLY CURRENT – mA

OUTPUT VOLTAGE SWING – V rms

50

Figure 4. Maximum Output Voltage Swing vs. Frequency

1280.1% DISTORTION
64NO LOAD
5.5

5.0

4.5

4.0

2

3.5

0
±2

±6

±10

±14

±18

±2

±6

±10

±14

±18

SUPPLY VOLTAGE – Volts

SUPPLY VOLTAGE – Volts

Figure 6. Supply Current vs. Supply Voltage

Figure 5. Output Voltage Swing vs. Supply Voltage

REV. B30
FREQUENCY – kHz–3–

SSM2142
THD PERFORMANCE

The following data, taken from the THD test circuit on an
Audio Precision System One using the internal 80 kHz noise
filter, demonstrates the typical performance of a balanced pairsystem based on the SSM2142/SSM2141 chip set. Both differential and single-ended modes of operation are shown, undera number of output load conditions which simulate various
application situations. Note also that there is no adverse effecton system performance when using the optional series feedback
capacitors, which reject dc cable offsets in order to maintain
optimal ac noise rejection. The large signal transient response of
the system to a 100 kHz square wave input is also shown,demonstrating the stability of the SSM2142 under load.
+18V

A

10µF*

C
V IN

4

6
7

SSM
3 2142

2

8

RL

1

B

SSM
2141

Figure 9. THD+N vs. Frequency at Point B(Differential Mode)

VOUT

5
10µF*

R1

R2

–18V
*USED ONLY IN THD PLOTS AS NOTED.
ALL CABLE MEASUREMENTS USE BELDEN 8451 CABLE.

Figure 7. THD Test Circuit

Figure 10. THD+N vs. Frequency at Point A(Single Ended)

Figure 8. THD+N vs. Frequency at Point B(Differential Mode)

Figure 11. THD+N vs. Frequency at Point C(SSM2141 Output)–4–

REV. BSSM2142
on-chip 50 Ω series damping resistors. The impedances in the
output buffer pair are precisely balanced by laser trimming
during production. This results in the high gain accuracy
needed to obtain good common-mode noise rejection, andexcellent separation between the offset error voltages common
to the cable pair and the desired differential input signal. As
shown in the test circuit, it is suggested that a suitable balanced,
high input-impedance differential amplifier such as theSSM2141 be used at the receiving end for best system
performance. The SSM2141 receiver output is configured for again of one half following the 6 dB gain of the SSM2142, inorder to maintain an overall system gain of unity.

100
90

10
0%

In applications encountering a large dc offset on the cable orthose wishing to ensure optimal rejection performance by
avoiding differential offset error sources, dc blocking capacitors
may be employed at the sense outputs of the SSM2142. As
shown in the test circuit, these components should present as
little impedance as possible to minimize low-frequency errors,such as 10 µF NP (or tantalum if the polarity of the offset is
known).

Figure 12. 100 kHz Square Wave Observed at Point B(Differential Mode). VO = 10 V rms, R1 = R2 = ∞, RL = 600 Ω

SYSTEM GROUNDING CONSIDERATIONS

Due to ground currents, supply variations, and other factors,
the ground potentials of the circuits at each end of a signal cable
may not be exactly equal. The primary purpose of a balanced
pair line is to reject this voltage difference, commonly called“longitudinal error.” A measure of the ability of the system toreject longitudinal error voltage is output common-mode
rejection. In order to obtain the optimal OCMR and noise
rejection performance available with the SSM2142, the user
should observe the following precautions:

100
90

10
0%

1. The quality of the differential output is directly dependent
upon the accuracy of the input voltage presented to thedevice. Input voltage errors developed across the impedanceof the source must be avoided in order to maintain system
performance. The input of the SSM2142 should be driven
directly by an operational amplifier or buffer offering low
source impedance and low noise.

Figure 13. 100 kHz Square Wave at Point B (Differential
Mode). VO = 10 V rms, R1 = R2 = ∞, RL = 600 Ω, with
Series Feedback Capacitors+15V

2. The ground input should be in close proximity to the singleended input’s source common. Ground offset errors encountered in the source circuitry also impair system performance.

+15V

V

4

IN

3

7

6

3

7
8

SSM
2142
2
5

2

1
SHIELDED
TWISTED-PAIR
CABLE

SSM
2141/
2143

5
6

3. Make sure that the SSM2142 is adequately decoupled with
0.1 µF bypass capacitors located close to each supply pin.

V OUT

1

4. Avoid the use of passive circuitry in series with the SSM2142
outputs. Any reactive difference in the line pair will causesignificant imbalances and affect the gain error of the device.
Snubber networks or series load resistors are not required tomaintain stability in SSM2142 based systems, even whendriving signals over extremely long cables.

4
–15V

–15V

Figure 14. Typical Application of the SSM2142 andSSM2141

5. Efforts should be made to maintain a physical balance in thearrangement of the signal pair wiring. Capacitive differences
due to variations in routing or wire length may cause unequal
noise pickup between the pair, which will degrade the system
OCMR. Shielded twisted-pair cable is the preferred choice inall applications. The shield should not be utilized as a signal
conductor. Grounding the shield at one end, near the output
common, avoids ground loop currents flowing in the shieldwhich increase noise coupling and longitudinal errors.

APPLICATIONS INFORMATIONThe SSM2142 is designed to provide excellent common-mode
rejection, high output drive, and low signal distortion and noise
in a balanced line-driving system. The differential output stage
consists of twin cross-coupled unity gain buffer amplifiers with

REV. B–5–

SSM2142
THE CABLE PAIROUTLINE DIMENSIONSThe SSM2142 is capable of driving a 10 V rms signal into
600 Ω and will remain stable despite cable capacitances of up to
0.16 µF in either balanced or single-ended configurations. Low
impedance shielded audio cable such as the standard Belden
8451 or similar is recommended, especially in applications
traversing considerable distances. The user is cautioned that theso-called “audiophile” cables may incur four times the capacitance per unit length of the standard industrial-grade product.
In situations of extreme load and/or distance, adding a second
parallel cable allows the user to trade off half of the total line
resistance against a doubling in capacitive load.

Dimensions shown in inches and (mm).

8C1496–15–1/91

8-Lead Plastic DIP
50.280 (7.11)0.240 (6.10)
410.070 (1.77)
0.045 (1.15)

0.430 (10.92)
0.348 (8.84)

SINGLE-ENDED OPERATION

0.015(0.381) TYP

0.210(5.33)MAX

The SSM2142 is designed to be compatible with existingbalanced-pair interface systems. Just as in transformer-based
circuits, identical but opposite currents are generated by theoutput pair which can be ground-referenced if desired andtransmitted on a single wire. Single-ended operation requiresthat the unused side of the output pair be grounded to a solid
return path in order to avoid voltage offset errors at the nearby
input common. The signal quality obtained in these systems isdirectly dependent on the quality of the ground at each end of
the wire. Also note that in single-ended operation the gain
through the device is still 6 dB, and that the SSM2142 incurs
no significant degradation in signal distortion or output drive
capability, although the noise rejection inherent in balancedpair systems is lost.

0.325 (8.25)
0.300 (7.62)

0.130(3.30)
MIN

0.160 (4.06)
0.115 (2.92)

0.022 (0.558)
0.014 (0.356)

SEATING
PLANE

0.100
(2.54)
BSC

0.015 (0.381)
0.008 (0.203)

0 - 158-Lead Cerdip
0.005 (0.13) MIN

0.055 (1.35) MAX

8

50.310 (7.87)
0.220 (5.59)
4

1

POWER SUPPLY SEQUENCING

0.070 (1.78)
0.030 (0.76)

A problem occasionally encountered in the interface system environment involves irregular application of the supplies. The
user is cautioned that applying power erratically can inadvertently bias parts of the circuit into a latch-up condition. The
small geometries of an integrated circuit are easily breached anddamaged by short-risetime spikes on a supply line, which usually demonstrate considerable overshoot. The questionable
practice of exchanging components or boards while underpower can create such an undesirable sequence as well. Possible
options which offer improved board-level device protection
include: additional bypass capacitors, high-current reversebiased steering diodes between both supplies and ground, various transient surge suppression devices, and safety grounding
connectors.

0.405 (10.29) MAX

0.320 (8.13)
0.290 (7.37)

0.060 (1.52)
0.015 (0.38)

0.200(5.08)
MAX

0.150(3.81)
MIN

0.200 (5.08)
0.125 (3.18)

0.023 (0.58)
0.014 (0.36)

0.100 (2.54)
BSC

0.015 (0.38)
0.008 (0.20)

0 - 15SEATING PLANE

16-Lead Small Outline (SOIC)

16

Likewise, power should be applied to the device before theoutput is connected to “live” systems which may carry voltagesof sufficient magnitude to turn on the output devices of theSSM2142 and damage the device. In any case, of course, theuser must always observe the absolute maximum ratings shownin the specifications.

90.0500 (1.27)
0.0157 (0.40)

81

0.4133 (10.50)
0.3977 (10.10)

0.0118 (0.30)
0.0040 (0.10)

0.0291 (0.74)
0.0098 (0.25) x 45

0.1043 (2.65)
0.0926 (2.35)

SEATING
PLANE–6–0.0500(1.27)
BSC

0.0192 (0.49)
0.0138 (0.35)

0.0125 (0.32)
0.0091 (0.23)

SEE
DETAILABOVE

REV. B

PRINTED IN U.S.A.

0 -8
0.2992 (7.60)
0.2914 (7.40)

0.4193 (10.65)
0.3937 (10.00)

a
FEATURESHigh Common-Mode Rejection
DC: 100 dB typ
60 Hz: 100 dB typ
20 kHz: 70 dB typ
40 kHz: 62 dB typ
Low Distortion: 0.001% typ
Fast Slew Rate: 9.5 V/ms typ
Wide Bandwidth: 3 MHz typ
Low Cost
Complements SSM2142 Differential Line Driver
APPLICATIONSLine Receivers
Summing Amplifiers
Buffer Amplifiers–Drives 600 V LoadHigh Common-Mode Rejection
Differential Line Receiver
SSM2141
FUNCTIONAL BLOCK DIAGRAM

25kΩ

25kΩ

–IN 2

5 SENSE

7 +VCC

SSM2141

6 OUTPUT

4 –VEE
25kΩ

25kΩ

+IN 3

1 REFERENCEPIN CONNECTIONSGENERAL DESCRIPTIONThe SSM2141 is an integrated differential amplifier intended toreceive balanced line inputs in audio applications requiring ahigh level of noise immunity and optimum common-mode
rejection. The SSM2141 typically achieves 100 dB of commonmode rejection (CMR), whereas implementing an op amp withfour off-the-shelf precision resistors will typically achieve only
40 dB of CMR—inadequate for high-performance audio.

8-Pin Plastic Mini-DIP(P Suffix)
Narrow Body SO(S Suffix)
8 NC

REFERENCE 1–IN 2

SSM2141

7 V+

6 OUTPUTTOP VIEW(Not to Scale)
5 SENSE
V– 4

+IN 3

NC = NO CONNECT

The SSM2141 achieves low distortion performance by
maintaining a large slew rate of 9.5 V/µs and high open-loop
gain. Distortion is less than 0.002% over the full audio
bandwidth. The SSM2141 complements the SSM2142
balanced line driver. Together, these devices comprise a fully
integrated solution for equivalent transformer balancing ofaudio signals without the problems of distortion, EMI fields,
and high cost.
Additional applications for the SSM2141 include summing
signals, differential preamplifiers, and 600 Ω low distortion
buffer amplifiers. For similar performance with G = 1/2, see
SSM2143.

REV. B
Information furnished by Analog Devices is believed to be accurate andreliable. 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 orotherwise under any patent or patent rights of Analog Devices.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703

SSM2141–SPECIFICATIONSELECTRICAL CHARACTERISTICS (@ V = 618 V, T = +258C, unless otherwise noted)
S

AParameter

SymbolConditionsMin

OFFSET VOLTAGE

VOS

VCM = 0 V

–1000

No Load, VIN = ± 10 V, RS = 0 Ω

GAIN ERRORINPUT VOLTAGE RANGE

IVR(Note 1)

± 10

COMMON-MODE REJECTION

CMR

VCM = ± 10 V

80

POWER SUPPLY REJECTION RATIOPSRR

VS = ± 6 V to ± 18 V

OUTPUT SWINGVO

RL = 2 kΩ± 13

SHORT-CIRCUIT CURRENT LIMIT

ISC

Output Shorted to Ground+45/–15

SMALL-SIGNAL BANDWIDTH (–3 dB)

BW

RL = 2 kΩ

SLEW RATESR

RL = 2 kΩ

THD

SSM2141
Typ Max

Units

1000

µV

0.001 0.01

%

25

V
100
0.7

dB
15

± 14.7

µV/V
V
mA

3

MHz

9.5

V/µs

RL = 100 kΩ
RL = 600 Ω

0.001
0.01

%

CAPACITIVE LOAD DRIVE CAPABILITY CL

No Oscillation

300

pF

SUPPLY CURRENTNo Load

2.5

3.5

mA

TOTAL HARMONIC DISTORTION

ISY

6

NOTES
1
Input Voltage Range Guaranteed by CMR test.
Specifications subject to change without notice

ELECTRICAL CHARACTERISTICS (@ V = 618 V, –408C ≤ T ≤ +858C)SAParameter

SymbolConditions

Min

Typ

Max

Units

OFFSET VOLTAGE

VOS

VCM = 0 V

–2500

200

2500

µV

0.002 0.02%

No Load, VIN = ± 10 V, RS = 0 Ω

GAIN ERRORINPUT VOLTAGE RANGE

IVR(Note 1)

± 10

COMMON-MODE REJECTION

CMR

VCM = ± 10 V

75

POWER SUPPLY REJECTION RATIOPSRR

VS = ± 6 V to ± 18 V

OUTPUT SWINGVO

RL = 2 kΩ

SLEW RATESR

SUPPLY CURRENT

ISY

V
90
1.0

± 13

dB
20

µV/V

± 14.7V

RL = 2 kΩ

9.5

V/µs

No Load

2.6

4.0

mA

NOTES
1
Input Voltage Range Guaranteed by CMR test.
Specifications subject to change without notice–2–

REV. BSSM2141
ABSOLUTE MAXIMUM RATINGS 1

Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 18 V
Input Voltage1 . . . . . . . . . . . . . . . . . . . . . . . . Supply Voltage
Output Short-Circuit Duration . . . . . . . . . . . . . . Continuous
Storage Temperature Range
P Package . . . . . . . . . . . . . . . . . . . . . . . –65°C to +150°C
Lead Temperature (Soldering, 60 sec) . . . . . . . . . . . . +300°C
Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . +150°C
Operating Temperature Range . . . . . . . . . . . . –40°C to +85°C

Package Type

uJA2

uJC

Units

8-Pin Plastic DIP (P)

103

43

°C/W

NOTES
1
For supply voltages less than ± 18 V, the absolute maximum input voltage is equal
to the supply voltage.
2
θJA is specified for worst case mounting conditions, i.e., θJA is specified for device
in socket for P-DIP package.

ORDERING GUIDE

Model

Operating Temperature
Range

Package
Description

Package
Option

SSM2141P
SSM2141SXIND (–40°C ≤ TA ≤ +85°C)
XIND (–40°C ≤ TA ≤ +85°C)

8-Pin Plastic DIP
8-Pin Narrow Body SO

N-8
SO-8

Typical Performance Characteristics

REV. B

Small Signal Transient Response

Large Signal Transient Response

Common-Mode Rejection vs. Frequency

Power Supply Rejection vs. Frequency

Total Harmonic Distortion vs. Frequency

Dynamic Intermodulation Distortion vs. Frequency–3–

SSM2141–Typical Performance Characteristics

Input Offset Voltage vs. Temperature

Closed-Loop Gain vs. Frequency

Closed-Loop Output Impedance
vs. Frequency

Gain Error vs. Temperature

Slew Rate vs. Temperature

Supply Current vs. Temperature

Supply Current vs. Supply Voltage

Maximum Output Voltage vs.
Output Current (Source)

Maximum Output Voltage vs.
Output Current (Sink)–4–

REV. BSSM2141
1S

5mV

+1µV
0V
–1µV

0.1 TO 10Hz PEAK-TO-PEAK NOISE

Low Frequency Voltage Noise

Voltage Noise Density vs. Frequency

2mS

10mV

1mS

10mV

+10µV

+10µV

0V

0V

–10µV

–10µV
TA = +25°C

TA = +25°C

VS = ±15V

VS = ±15V

NOTE: EXTERNAL AMPLIFIER GAIN = 1000;
THEREFORE, VERTICAL SCALE = 10µV/DIV.

NOTE: EXTERNAL AMPLIFIER GAIN = 1000;
THEREFORE, VERTICAL SCALE = 10µV/DIV.

Voltage Noise from 0 kHz to 10 kHz

Voltage Noise from 0 kHz to 1 kHz

APPLICATIONS INFORMATIONThe SSM2141 represents a versatile analog building block. In
order to capitalize on fast settling time, high slew rate, and high
CMR, proper decoupling and grounding techniques must be
employed. For decoupling, place 0.1 µF capacitor located withinclose proximity from each supply pin to ground.

Slew Rate Test Circuit

REV. B–5–

SSM2141
MAINTAINING COMMON-MODE REJECTION

C1532–2.5–5/91

In order to achieve the full common-mode rejection capabilityof the SSM2141, the source impedance must be carefully
controlled. Slight imbalances of the source resistance will resultin a degradation of DC CMR—even a 5 Ω imbalance will
degrade CMR by 20 dB. Also, the matching of the reactive
source impedance must be matched in order to preserve the
CMRR over frequency.

Figure 5. Suitable Instrumentation Amplifier
Requirements can be Addressed by Using an
Input Stage Consisting of A1, A2, R1 and R2

OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).

Figure 1. Precision Difference Amplifier. Rejects[E1 + E 2 ]Common-Mode Signal =by 100 dB

8-Pin
Epoxy Mini-DIP
P-Suffix (N-8)

20.430 (10.92)
0.348 (8.84)
8

5

1

4

0.280 (7.11)0.240 (6.10)
0.060 (1.52)
0.015 (0.38)

PIN 1
0.210 (5.33)
MAX

0.195 (4.95)
0.115 (2.93)

0.130(3.30)
MIN

0.160 (4.06)
0.115 (2.93)
0.022 (0.558) 0.100 0.070 (1.77)
0.014 (0.356) (2.54) 0.045 (1.15)
BSC

Figure 2. Precision Unity Gain Inverting Amplifier

0.325 (8.25)
0.300 (7.62)

0.015 (0.381)
0.008 (0.204)

SEATING
PLANE

8-Pin Narrow Body SO
S-Suffix (SO-8)

Figure 3. Precision Summing Amplifier

0.1574 (4.00)
0.1497 (3.80)

PIN 1
0.0098 (0.25)
0.0040 (0.10)

SEATING
PLANE

8

5

1

4

0.2440 (6.20)
0.2284 (5.80)

0.0688 (1.75)
0.0532 (1.35)

0.0500 0.0192 (0.49)(1.27) 0.0138 (0.35)
BSC

0.0196 (0.50)
x 45°
0.0099 (0.25)

0.0098 (0.25)
0.0075 (0.19)

8°0°0.0500 (1.27)
0.0160 (0.41)

Figure 4. Precision Summing Amplifier with Gain

–6–

REV. B

PRINTED IN U.S.A.

0.1968 (5.00)
0.1890 (4.80)