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

Tel: +1 508 478-9200; Fax: +1 508 478-0990; Web: www.thatcorp.com

THAT 1510, 1512

Description

The THAT 1510 and 1512 are high perfor-

mance audio preamplifiers suitable for micro-
phone preamp and bus summing applications.
The ICs are pin compatible with the Analog De-
vices SSM2017 in both the 8-pin DIP and
16-pin SOIC packages.

The THAT1512 follows a different gain

equation than the 1510, but exhibits signifi-
cantly lower noise at lower gain settings and is
recommended for new designs.

Designed from the ground up in THAT's

complementary

bipolar,

dielectric

isolation

process, the THAT 1510 and 1512 improve on
existing integrated microphone preamps by of-
fering lower noise at low gains, better distor-
tion characteristics, lower power consumption,
higher slew rate and bandwidth, and increased
output voltage swing. The parts are fully pro-
tected against ESD on all critical pins, and reli-
ability is further enhanced by their reduced
power requirements.

In short, the THAT 1510 and 1512 provide

superior performance in a popular format at an
affordable price.

T H A T

C o r p o r a t i o n

Low Noise, High Performance

Microphone Preamplifier IC

FEATURES

Excellent noise performance
through the entire gain range

Exceptionally low THD+N over the
full audio bandwidth

Low power consumption: 7mA typ.

Wide bandwidth: 3MHz typ. @
G=1000 (THAT 1510)

High Slew Rate: 28 V/

ms @ G=10

and C

=50pF (THAT 1510)

Wide Output Swing: ±13V typ. on
±15V supplies

Gain adjustable from 1 to >1000
with a single external resistor

Drop-in compatible with SSM-2017
(THAT 1510)

APPLICATIONS

Mixing Consoles

Public Address Systems

Analog and Digital Snakes

Breakout Boxes for
Digital Systems

Sonar

Paging and Intercom systems

Instrumentation

V+

V-

-In

RG2

RG1

+In

Out

Ref

(10k)

Figure 1. THAT 1510 / 1512 Equivalent Circuit Diagram

(THAT 1512 values shown in parentheses)

Pin Name

DIP

SO16

RG1

-In

+In

V-

Ref

Out

V+

RG2

Table 1. 1510 / 1512 pin assignments

Gain Equation

DIP-8

SO16

= +

1510P

1510S

0 5

1512P

1512S

Table 2. Ordering Information

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

Tel: +1 508 478-9200; Fax: +1 508 478-0990; Web: www.thatcorp.com

Page 2

THAT 1510 / 1512 Microphone Preamplifier

Preliminary Information

Absolute Maximum Ratings (T

= 25°C)

Positive Supply Voltage (V

)

+20 V

Operating Temperature Range (T

)

-40 to +85°C

Negative Supply Voltage (V

)

-20 V

Storage Temperature Range (T

)

-40 to +125°C

Output Short-Circuit Duration (t

)

Continuous

Junction Temperature (T

)

150°C

Lead Temp. (T

LEAD

) (Soldering 10 sec)

260

°C

Electrical Characteristics

1510

1512

Parameter

Symbol

Conditions

Min

Typ

Max

Min

Typ

Max

Units

Supply Current

, |I

No signal

6.1

8.2

6.1

8.2

= |V

| = 20V

8.4

Input Bias Current

No signal; Either input

8.6

connected to GND

Input Offset Current

B-OFF

No signal

±2.5

Output Referred Offset Voltage

Vos

No Signal, V

± 50

± 25

Input Referred Offset Voltage

Vos

60 dB gain

± 1.2

Input Voltage Range

Common Mode

IN-CM

Common mode, all gains

± 13

Normal Mode

IN-UNBAL

Unbalanced

± 13

One input to GND, 0dB gain

Differential Gain

diff

Ref Input Voltage Range

± 8

Ref Input Impedance

Ref Input Gain to Output

Input Impedance

IN-DIFF

Differential

0dB gain

32||1.9

37||1.9

W||pF

20dB gain

32||2.0

37||2.0

W||pF

40dB gain

32||2.5

36||3.1

W||pF

60dB gain

29||8.0

-- 31||13.9 --

W||pF

IN-CM

Common mode

all gains

8||7.7

9||7.7

W||pF

Recommended Operating Conditions

Parameter

Symbol

Conditions

Min

Typ

Max

Units

Positive Supply Voltage

+20

Negative Supply Voltage

-5

-20

SPECIFICATIONS

1. All specifications are subject to change without notice.

2. Unless otherwise noted, V

= +15V, V

= -15V, T

=25°C,

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

Tel: +1 508 478-9200; Fax: +1 508 478-0990; Web: www.thatcorp.com

600031 Rev. 7/23/02

Page 3

Preliminary Information

Electrical Characteristics (Cont'd)

1510

1512

Parameter

Symbol

Conditions

Min

Typ

Max

Min

Typ

Max

Units

Common Mode Rejection

CMR

=± 10V; DC to 60 Hz

0 dB gain

20 dB gain

40 dB gain

60 dB gain

115

Power Supply Rejection

PSR

= |V

|; ±5V to ±20V; DC to 60 Hz

0 dB gain

20 dB gain

105

40 dB gain

120

60 dB gain

124

Total Harmonic Distortion

THD+N

OUT

= 7Vrms; R

= 5 k

f = 1kHz; BW = 20 kHz

0 dB gain

0.0005

20 dB gain

0.0005

40 dB gain

0.0005

60 dB gain

0.005

f = 20kHz; BW = 80 kHz

0 dB gain

0.002

60 dB gain

0.005

Equivalent Input Noise

n(OUT)

f = 1kHz,

0dB gain

nV/

ÖHz

20dB gain

4.6

nV/

ÖHz

40dB gain

1.7

1.4

nV/

ÖHz

60dB gain

nV/

ÖHz

Input Current Noise

60dB gain

2.3

pA/

ÖHz

Noise Figure

60dB gain

= 150

1.6

= 200

1.3

Slew Rate

= 2 k

= 50 pF

Bandwidth -3dB

-3dB

= 2 k

W; C

= 10 pF

0dB gain

MHz

20dB gain

MHz

40dB gain

MHz

60dB gain

1.6

MHz

Output Gain Error

ER (OUT)

f = 1kHz; R

= 2 k

0dB gain

± 0.25

± 1

± 0.25

± 1

20dB gain

± 0.20

± 1

± 0.20

± 1

40dB gain

± 0.20

± 1

± 0.20

± 1

60dB gain

± 0.05 ± 0.5

Output Voltage Swing

= 2 k

all gains

±13

±13.3

±13

±13.3

Output Short Circuit Current

= 0

±17

± 17

Minimum Resistive Load

Lmin

Maximum Capacitive Load

Lmax

200

Gain Equation

= +

0 5

Gain Resistor (ideal values)

0dB gain

10k

20dB gain

1,100

526.3

40dB gain

101

50.3

60dB gain

Applications

Gain Setting

A single external resistor between the RG1 and

RG2 pins is all that is needed to set the gain of the
THAT 1510 / 1512, according to the formulae

for the 1510:

= +

for the 1512:

0 5

For unity gain operation on the 1510, RG1 and

RG2 may be left open. RG should be set to 10k

W in

the 1512. To avoid excess noise and ensure tempera-
ture stability, non-inductive wirewound or metal-film
resistors are recommended for RG.

Total gain accuracy will depend on both the toler-

ance on RG, and on the gain equation accuracy of the
THAT 1510/1512.

Total gain drift will result from

the mismatch between the tempco of RG and the

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

Tel: +1 508 478-9200; Fax: +1 508 478-0990; Web: www.thatcorp.com

Page 4

THAT 1510 / 1512 Microphone Preamplifier

Preliminary Information

+In

Out

-In

RG1

RG2

THAT
1510/1512

-15

+15

-In

+In

C1
470p

C2
470p

47p

Out

100n

V+

V-

Ref

Figure 2. Basic 1510 / 1512 Circuit

+In

Out

-In

RG1

RG2

THAT 1510/1512

-In

+In

R1
1k

R2
1k

C1
470p

C2
470p

47p

Out

353

100n

510k

-15

+15

100n

V+

V-

Ref

Figure 3. 1510 / 1512 Circuit with Output Offset Correction

tempco of the internal resistors (±20 ppm/°C typi-
cal).

Noise Performance

Thoughtful design results in these devices having

significantly lower noise at low gains than similar IC
microphone preamps. At zero dB gain, equivalent in-

put noise of the THAT 1510 is 55 nV/

ÖHz, nearly

6 dB better than competitive IC designs.

The un-

usual topology of the THAT 1512 results in an equiv-

alent input noise of 34 nV/

ÖHz at zero dB gain, which

makes it comparable to some of the better discrete
designs currently available.

At 1 kHz, the equivalent

input noise for both devices is 1 nV/

ÖHz at 60 dB

gain.

Inputs

Protection diodes are employed at all pins except

V+ and V- of the THAT 1510/1512. These diodes re-
duce the likelihood of accidental ESD/EOS damage to
the IC. Other diodes across the base-emitter junc-
tions of the input transistors prevent reverse bias of
these junctions and consequent degradation of their
noise performance.

The inputs of the THAT 1510 and1512's are float-

ing, so a dc bias connection is required to maintain
the inputs within the IC's input common-mode range.

Four different schemes are shown in Figures 2, 3, 4,
and 5. Note that the values of R1 and R2 in these fig-
ures should be kept small to minimize pickup of un-

wanted noise and interference.

A value of 1 k

W is

often used, since some microphones require a differ-
ential input impedance of this magnitude. Unfortu-
nately, one would usually desire a significantly higher
common mode input impedance to minimize the
common mode degradation caused by unbalanced
source impedances.

Figure 5 shows a technique

which allows higher common mode input impedance
while maintaining a lower differential source imped-
ance.

Reference Terminal

The "Ref" pin provides the reference for the out-

put signal, and is normally connected to analog
ground. If necessary, the "Ref" pin can be used for
offset correction or DC level shifting. A non-zero ref-
erence source resistance will reduce the IC's com-
mon-mode

rejection

(CMR)

the

ratio

10 k

W/R

REF

Phantom Power

Phantom power is required for condensor micro-

phones. A phantom power circuit is shown in Fig-
ure 4.

Diodes D1 through D6 are necessary to

protect the THAT 1510/1512 from transient voltages

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

Tel: +1 508 478-9200; Fax: +1 508 478-0990; Web: www.thatcorp.com

600031 Rev. 7/23/02

Page 5

Preliminary Information

+In

Out

-In

RG1

RG2

THAT 1510

In-

In+

470p

47p

Out

47u

1N757

51R

6k8

+48V

1N5818

-15

+15

100n

Ref

V-

V+

Figure 4. Typical 1510 / 1512 Circuit with Phantom Power

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