Figure 1. THAT 1510 / 1512 Equivalent Circuit Diagram
(
THAT 1512 values shown in
p
arentheses
)
121588RG2 111377V+ 91166Out 101055Ref 6744V- 5533+In 4422-In 3211RG1
SO14
Pkg
SO16
Pkg
SO8
Pkg
DIP8
Pkg
Pin
Name
Table 1. Pin Assignments
FEATURES
• Low Noise:
1 nV/√Hz input noise (60dB gain)
34 nV/√Hz input noise (0dB gain) (1512)
• Low THD+N (full audio bandwidth):
0.001% ≤ 40 dB gain
0.005% @ 60 dB gain
• Low Current: 6mA typ.
• Wide Bandwidth: 7MHz @ G=100
• High Slew Rate: 19 V/μs
• Wide Output Swing: ±13.3V on
±15V supplies
• Gain adjustable from 0 to >60 dB with
one external resistor
• Industry Standard Pinouts
APPLICATIONS
• Differential Low Noise Preamplifiers
• Differential Summing Amplifiers
• Differential Variable Gain Amplifiers
• Microphone Preamplifiers
• Moving-Coil Transducer Amplifiers
• Line Input Stages
• Audio
• Sonar
• Instrumentation
THAT 1510, 1512
The THAT 1510 and 1512 are high perform-
ance audio preamplifiers suitable for microphone
preamp and bus summing applications. The ICs
are available in a variety of packages and pin
configurations, making them pin compatible with
the Analog Devices SSM2019 and SSM2017
(discontinued), and the Texas Instruments
INA217 and INA163.
Gain for both parts is adjustable via one
external resistor, making it possible to control
gain over a wide range with a single-gang potenti-
ometer. The 1510 gain equation is identical to
that of the SSM 2019, reaching 6 dB gain with a
10 kΩ resistor. The 1512 reaches 0 dB gain with
a 10 kΩ resistor. Because the 1512 exhibits
significantly lower noise at lower gain settings, it
is recommended over the 1510 for new designs.
Designed from the ground up in THAT’s
complementary dielectric isolation process and
including laser-trimmed Si-Chrome thin film
resistors, the THAT 1510 and 1512 improve on
existing integrated microphone preamps by offer-
ing lower noise at low gains, wider bandwidth,
higher slew rate, lower distortion, and lower
supply current. The parts feature internal ESD
overload protection on all critical pins.
In short, the THAT 1510 and 1512 provide
superior performance in a popular format at an
affordable price.
Description
Low-Noise, High Performance
Audio Preamplifier IC
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; US
A
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2009, THAT Corporation. Document 600031 Rev 07
V+
V-
-In
RG2
RG1
+In
Out
Ref
+
-
5k
5k
(10k)
5k
5k
(10k)
5k
5k
O utput Stage
In p ut Stage
RA
RB
-AV-AV
Table 2. Ordering Information
1512S14-UInquire1512S08-U1512P08-U
1512
1510S14-U1510W16-U1510S08-U1510P08-U
1510
SO14
Pkg
SO16
Pkg
SO8
Pkg
DIP8
Pkg
Part
Type
Document 600031 Rev 07 Page 2 of 8 THAT 1510/1512 Low-Noise
High Performance Audio Preamplifier IC
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; US
A
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2009, THAT Corporation
Positive Supply Voltage (VCC) +20 V
Negative Supply Voltage (VEE) -20 V
Input Voltage (VIN MAX)V
CC + 0.5V, VEE - 0.5V
Output Short-Circuit Duration (tSH) Continuous
Lead Temp. (TLEAD) (Soldering 10 sec) 260 °C
Operating Temperature Range (TOP) -40 to +85°C
Storage Temperature Range (TST) -40 to +125°C
Junction Temperature (TJ) 150°C
Absolute Maximum Ratings2,3
SPECIFICATIONS1
1510 1512
Parameter Symbol Conditions Min Typ Max Min Typ Max Units
Supply Current ICC, -IEE No signal — 6.0 7.9 — 6.0 7.9 mA
VCC = -VEE = 20V — — 8.0 — — 8.0 mA
Input Bias Current IBNo signal; Either input — 4.8 14 — 4.8 14 µA
connected to GND
Input Offset Current IB-OFF No signal -1.4 — +1.4 -1.4 — +1.4 µA
Offset Voltage
Output Stage Output Offset VosOO No Signal, VCM=0 -5 — +5 -5 — +5 mV
Input Stage Input Offset VosII -250 — +250 -250 — +250 µV
Total Output Offset G=voltage gain -5-0.25G 5+0.25G -5-0.25G 5+0.25G mV
Input Voltage Range
Common Mode VIN-CM Common mode, all gains — ± 13 — — ± 13 — V
Differential Mode VIN-UNBAL Unbalanced -13 — +13 -13 — +13 V
One input to GND, 0dB gain
Differential Gain Gdiff 0 — 70 -6 — 64 dB
Ref Input Voltage Range — ± 8 — — ± 8 — V
Ref Input Impedance — 10 — — 15 — kΩ
Ref Input Gain to Output — 0 — — 0 — dB
Input Impedance ZIN-DIFF Differential
0dB gain — 32||1.9 — — 37||1.9 — MΩ||pF
20dB gain — 32||2.0 — — 37||2.0 — MΩ||pF
40dB gain — 32||2.5 — — 36||3.1 — MΩ||pF
60dB gain — 29||8.0 — — 31||13.9 — MΩ||pF
ZIN-CM Common mode
all gains — 8||7.7 — — 9||7.7 — MΩ||pF
Electrical Characteristics2
1. All specifications are subject to change without notice.
2. Unless otherwise noted, TA=25ºC, VCC=+15V, VEE= -15V.
3. 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 the operational sections of this specification is not impli ed. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.
Parameter Symbol Conditions Min Typ Max Units
Positive Supply Voltage VCC +5 +20 V
Negative Supply Voltage VEE -5 -20 V
Recommended Operating Conditions
THAT 1510/1512 Low-Noise Page 3 of 8 Document 600031 Rev 07
High Performance Audio Preamplifier
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; US
A
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2009, THAT Corporation
1510 1512
Parameter Symbol Conditions Min Typ Max Min Typ Max Units
Common Mode Rejection CMR VCM =± 10V; DC to 60 Hz
0 dB gain 45 60 — 45 60 — dB
20 dB gain 65 80 — 65 80 — dB
40 dB gain 85 100 — 85 100 — dB
60 dB gain 105 120 — 105 120 — dB
Power Supply Rejection PSR VCC= -VEE; ±5V to ±20V; DC to 60 Hz
0 dB gain — 85 — — 60 — dB
20 dB gain — 105 — — 105 — dB
40 dB gain — 120 — — 120 — dB
60 dB gain — 124 — — 124 — dB
Total Harmonic Distortion THD+N VOUT = 7Vrms; RL = 5 kΩ
f = 1kHz; BW = 20 kHz
0 dB gain — 0.0005 — — 0.001 — %
20 dB gain — 0.0012 — — 0.004 — %
40 dB gain — 0.0016 — — 0.005 — %
60 dB gain — 0.005 — — 0.008 — %
Equivalent Input Noise en(OUT) f = 1kHz,
0 dB gain — 57 — — 34 — nV/√Hz
20 dB gain — 7 — — 4.6 — nV/√Hz
40 dB gain — 1.7 — — 1.4 — nV/√Hz
60 dB gain — 1 — — 1 nV/√Hz
Input Current Noise in60 dB gain — 2.0 — — 2.0 — pA/√Hz
Noise Figure NF 60 dB gain
RS = 150 Ω— 1.6 — — 1.6 — dB
RS = 200 Ω— 1.3 — — 1.3 — dB
Slew Rate SR RL = 2 kΩ
CL = 50 pF 13 19 — 13 19 — V/µs
Bandwidth -3dB BW-3dB RL = 2 kΩ; CL = 10 pF
0 dB gain — 15 — — 11 — MHz
20 dB gain — 8 — — 9 — MHz
40 dB gain — 7 — — 7 — MHz
60 dB gain — 3 — — 1.6 MHz
Output Gain Error GER (OUT) f = 1kHz; RL = 2 kΩ
RG =infinite, G=0 dB -0.5 — +0.5 — — — dB
RG = 1.1 kΩ, G=20 dB -0.5 — +0.5 — — — dB
RG = 101 Ω, G=40 dB -0.5 — +0.5 — — — dB
RG = 10 Ω, G=60 dB -0.5 — +0.5 — — — dB
RG = 10 kΩ, G=0 dB — — — -0.5 — +0.5 dB
RG = 526.3 Ω, G=20 dB — — — -0.5 — +0.5 dB
RG = 50.3 Ω, G=40 dB — — — -0.5 — +0.5 dB
RG = 5 Ω, G=60 dB — — — -0.5 — +0.5 dB
Output Voltage Swing VORL = 2 kΩ
all gains ±13 ±13.3 — ±13 ±13.3 — V
Output Short Circuit Current ISC RL = 0 Ω— ± 17 — — ± 17 — mA
Minimum Resistive Load RLmin 2—— 2—— kΩ
Maximum Capacitive Load CLmax — — 300 — — 300 pF
Gain Equation AV=1+10 k
RGAV=0.5 +5k
RG
Electrical Characteristics (con’t)2
Gain Setting
A single external resistor (RG) 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: or
AV=1+10k
RG
for the 1512: whereAV=0.5 +5k
RG
AV is the voltage gain of the part.
Either part may reach unity gain, but the value
of RG required varies significantly between the two
parts. For the 1510, gain is 0dB when RG is infinite
(open); this is the minimum gain for the 1510. At
infinite RG, the 1512 reaches -6dB gain; this is the
minimum gain for the 1512. With RG=10kΩ, the
1512 reaches 0dB gain.
Overall gain accuracy depends on the tolerance
of RG and the accuracy of the internal thin-film resis-
tors connected to pins RG1 and RG2 in the 1510/1512
(RA & RB in Figure 1). These internal resistors have a
typical initial accuracy (at room temperature) of
±0.5%, and are typically stable with temperature to
within ±100 ppm/°C. Gain will drift with tempera-
ture based on the mismatch between the temperature
coefficient of the external RG and that of the internal
resistors RA & RB.
For variable-gain applications where gain
accuracy is important, THAT recommends using
discrete, switched resistors for RG. Where continuous
control is required, or where gain accuracy is less
critical, a potentiometer may be used. In such appli-
cations, designers should take care in specifying the
element construction to avoid excess noise. The
potentiometer taper will set the circuit’s characteris-
tic of gain vs. pot rotation. Typically, reverse log
(reverse audio) taper elements offer the desired
behavior in which gain increases with clockwise
rotation (and lower values for RG). See THAT Design
Note 138 for a discussion of potentiometer taper and
gain for the 1510 and 1512 compared to similar
parts from other manufacturers.
Noise Performance
Both parts exhibit excellent voltage noise
performance of ~1 nV/√Hz at high gains. With
~2 pA/√Hz current noise, they are optimized for
relatively low source impedance applications, such as
dynamic microphones with typically a few hundred
ohm output impedances. But, because they have
different internal gain structures, the 1510 has
higher equivalent input noise at 0dB gain
(~57 nV/√Hz) than the 1512, which runs 4.5 dB
lower at ~34 nV/√Hz. The unusual and superior
topology of the THAT 1512 makes its noise perform-
ance comparable to some of the better discrete
designs currently available.
Inputs
Simple Configurations
As shown in Figure 2, the 1510/1512 includes
protection diodes at all pins except V+ and V-.
Document 600031 Rev 07 Page 4 of 8 THAT 1510/1512 Low-Noise
High Performance Audio Preamplifier IC
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; US
A
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2009, THAT Corporation
V+
V-
-In
RG2
RG1
+In
Out
Ref
+
-
5k
5k
(10k)
5k
5k
(10k)
5k
5k
Output StageIn put Stage
RA
RB
-AV
-AV
Figure 2. THAT 1510 / 1512 Equivalent Circuit with Protection Diodes
Applications
These diodes reduce the likelihood that accidental
electrostatic discharge (ESD) or electrical over stress
(EOS) will damage the ICs. Other diodes across the
base-emitter junctions of the input transistors
prevent excessive reverse biasing of these junctions
(which would degrade the noise performance of the
input devices).
Other than the protection diodes, the 1510/1512
input pins are connected only to the bases of their
respective input devices. For proper operation, the
bases must be provided a source of dc bias that will
maintain the inputs within the IC's input common-
mode range. Figure 3 shows the simplest approach;
dc bias is supplied via R1 and R2. At 1 kΩ each, they
will minimize pickup of unwanted noise and interfer-
ence, as well as generate relatively little noise due to
input current noise in the 1510/1512. However, at
high gains, their inherent voltage noise, plus the
1510/1512's input current noise drawn across these
resistors, adds significantly to the noise at the
1510/1512's output.
Because RG is dc coupled in the circuit of
Figure 3, the dc level at the output of the 1510/1512
will vary with gain. In most applications, the output
should be ac-coupled to the next stage. For applica-
tions where RG is variable (via a pot or switched
resistors) to allow gain adjustment, RG should be
ac-coupled as shown in Figure 4. By adding CG in
series with RG, dc gain is fixed (at unity for the 1510,
and ½ for the 1512). This constrains the output dc
offset to just over +/-5 mV, and prevents it from
varying with gain. With this low offset, ac coupling of
the output is usually unnecessary.
CG must be large enough not to interfere with
low-frequency response at the smallest values of RG.
For 60 dB gain, RG=10 Ω (1510) or RG=5 Ω (1512).
For a -3 dB point of approximately 5 Hz,
CG=3,300 μF (1510), or CG=6,800 μF (1512). For
other maximum gains or minimum frequencies, scale
CG accordingly.
Phantom Power
Phantom power is required for many condenser
microphones. THAT recommends the circuit of
Figure 5 when phantom power is included4. R3, R4,
and D1 - D6 are used to limit the current that flows
through the 1510/1512 inputs when the circuit
inputs (-In and +In) are shorted to ground while
phantom power is turned on. This causes C4 and/or
C5 to discharge through other circuit components,
often generating transient currents of several amps.
R3 and R4 should be at least 10 Ω to limit destructive
THAT 1510/1512 Low-Noise Page 5 of 8 Document 600031 Rev 07
High Performance Audio Preamplifier
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; US
A
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2009, THAT Corporation
RG
+In
Out
-In
RG2
RG1
U1
THAT
1510/1512
-15
+15
-In
+In
R1
1k
R2
1k
C1
470p
C2
470p
C3
47p
Out
C6
100n
C9
100n
V+
V-Ref
Figure 3. Basic 1510 / 1512 Circuit
4. In revisions 0 and 1 of this data sheet, we recommended using Schottky diodes (1N5819 types) at D1 ~ D4 to protect the 1510/1512 inputs against overloads. Subse-
quently, we discovered that the leakage of these diodes could cause problems with DC fluctuations (hence noise) at the 1510/1512 output. Upon further investigation, we
concluded that conventional rectifier diodes like the 1N4004 (the glass-passivated GP version) provide adequate protection and do not introduce unacceptable leakage.
Additionally, 1N4004 diodes are much cheaper and more readily available than the Schottky types.
Since publishing revision 4, we determined that the internal reverse-bias diodes between the pins +In/RG2 and -In/RG1 may be damaged by phantom power faults under
certain conditions. Small-signal diodes (D5 and D6) avoid this problem by appearing in parallel with the internal diodes, diverting excess current around the 1510/1512.
currents. (Hi
g
her values further limit current flow,
but introduce additional source impedance and
noise.) D1 through D4 prevent the IC’s inputs from
significantly exceeding the supply rails. D5 and D6
steer currents around the input stage in the
1510/1512, preventing damage.
The series combination of C4 and C5 should be
made large to minimize high-pass filtering of the
signal based upon the sum of the values of R1+R2. As
well, keeping their reactance low relative to the exter-
nal microphone's source impedance will avoid
increasing the effects of low-frequency current noise
in the 1510/1512 input stage.
Other manufacturers have recommended, and
many pro audio products include, a zener diode
arrangement connected to the bridge rectifier instead
of the connection to V+ and V- as shown in Figure 5.
THAT does not recommend this approach, because
we find that R3 and R4 must be made much larger
(e.g., ≥ 51 Ω) in order to limit peak currents enough
to protect reasonably sized zener diodes (eg. 1/2 W).
Such large series input resistors will limit the noise
performance of the preamp. The ultimate floor is set
by the impedance of the microphone, but any
additional series resistance further degrades
performance.
For further insights into this subject, see the
Audio Engineering Society preprints "The 48 Volt
Phantom Menace," by Gary K. Hebert and Frank W.
Thomas, presented at the 110th
A
ES Convention and
“The 48 Volt Phantom Menace Returns”, by Rosal-
fonso Bortoni and Wayne Kirkwood presented at the
127th AES Convention.
Impedance and Line Input Configurations
A higher common-mode input impedance is
desirable (compared with that of Figures 3 and 4)
when input coupling capacitors (C4 and C5) are used
to block phantom power. At low frequencies where
the reactance of C4 and C5 become significant
(compared to the common-mode input impedances),
the two capacitors interact with the common-mode
input impedance (seen looking to the right-side of
both capacitors) to form voltage dividers for
common-mode signals. Differences in the two capaci-
tors' values leads to different voltage dividers, spoil-
ing the low-frequency common-mode rejection of the
stage. Since C4 and C5 are generally large, electrolytic
types, precise matching is difficult and expensive to
achieve. High common-mode input impedance
reduces the matching requirement by decreasing the
frequency at which the capacitive reactance becomes
significant inversely with the common-mode input
impedance.
The "T-bias" circuit (R1, R2, and R7) shown in
Figure 5 accommodates this objective. In this circuit,
R1 and R2 are connected to a third resistor R7, boost-
ing the low-frequency common mode input
Document 600031 Rev 07 Page 6 of 8 THAT 1510/1512 Low-Noise
High Performance Audio Preamplifier IC
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; US
A
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2009, THAT Corporation
RG
CG
+In
Out
-In
RG2
RG1
U1
THAT
1510/1512
-1
5
+15
-In
+In
R1
1k
R2
1k
C1
470p
C2
470p
C3
47p
Out
C6
100n
C9
100n
V+
V-Ref
Figure 4. Basic 1510 / 1512 Circuit with Variable Gain
impedance (as "seen lookin
g
in" from the couplin
g
capacitors) to the value of R1 + (2*R7) -- approxi-
mately 45 kΩ with the values shown. The increased
common mode impedance from T-bias improves LF
common mode rejection by reducing capacitor
matching requirements by more than a factor of ten
over the simpler circuit wherein R7=0 Ω. The circuit
works well with the values shown.
Note also that the overall common-mode input
impedance of the circuit is dominated by the
phantom-power resistors (R5 and R6). For the circuit
of Figure 5, this is approximately 5.9 kΩ per leg.
The 1510/1512 can be used as a line input
receiver by adding attenuation to the preamplifier
inputs and changing the circuit topology to allow
switchin
g
of input, fixed attenuation, and
g
ain adjus
t
-
ment. The optimum circuit depends on the specific
requirements of the application. For more details
and specific applications advice, please consult
THAT's application notes, or our applications
engineers at the address and telephone below or via
email at apps_support@thatcorp.com.
Reference Terminal
The "Ref" pin provides a reference for the output
signal, and is normally connected to analog ground.
If necessary, the "Ref" pin can be used for offset
correction or DC level shifting. However, in order to
prevent spoiling the excellent common-mode rejec-
tion of the 1510/1512, the source impedance driving
the “Ref” pin should be under 1Ω.
THAT 1510/1512 Low-Noise Page 7 of 8 Document 600031 Rev 07
High Performance Audio Preamplifier
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; US
A
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2009, THAT Corporation
Figure 5. Recommended 1510 / 1512 Circuit with Phantom Power
RG
+In
Out
-In
RG2
RG1
U1
THAT
1510/1512
-In
+In
R1
1k2
R2
1k2
R7
22k
C1
470p
C2
470p
C3
47p
Out
C4
22u
C5
22u
D3
1N4004GP
D4
1N4004GP
D1
1N4004GP
D5
1N4148
D6
1N4148
D2
1N4004GP
+15
-15
R6
6k8
R5
6k8
+48V
R3
R4
10
-15
+15 C6
100n
C9
100n
Ref
V+
V-
10
CG
ON
Both the THAT 1510 and 1512 are available in
8-pin SOIC, 8-pin DIP, and 14-pin SOIC packages.
The 1510 is also available in a 16-pin (widebody)
SOIC package. Other version/package combinations
will be considered based on customer demand. The
package dimensions are shown in Figures 6, 7, 8, &
9, while pinouts are given in Table 1.
All versions of the 1510 and 1512 are lead free
and RoHS compliant. Material Declaration Data
Sheets on the parts are available at our web site,
www.thatcorp.com or upon request.
Document 600031 Rev 07 Page 8 of 8 THAT 1510/1512 Low-Noise
High Performance Audio Preamplifier IC
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; US
A
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2009, THAT Corporation
Package Information
B
A
KF
H
ED
G
JC
ITEM
A
B
C
D
E
F
G
H
J
K
1
MILLIMETERS
9.52±0.10
6.35±0.10
7.49/8.13
0.46
2.54
3.68/4.32
0.25
3.18±0.10
8.13/9.40
3.30±0.10
INCHES
0.375±0.004
0.250±0.004
0.295/0.320
0.018
0.100
0.145/0.170
0.010
0.125±0.004
0.320/0.370
0.130±0.004
Figure 6. 8-pin DIP package outline Figure 7. 16-pin SO Wide package outline
0.41/1.27H 0.016/0.05
0.228/0.244
0.0075/0.0098
0.053/0.068
0.014/0.018
0.189/0.196
INCHES
0.150/0.157
G
H
F
CB
D
F
G
D
E
A
B
C
ITEM MILLIMETERS
0.36/0.46
0.19/0.25
1.35/1.73
1.27
4.80/4.98
3.81/3.99
5.80/6.20
0.050
A
E
Figure 8. 8-pin SOIC package outline Figure 9. 14-pin SOIC package outline
E
C
B
D
A
H
F
G
1
0.41/1.27H 0.016/0.05
0.228/0.244
0.0075/0.0098
0.053/0.068
0.014/0.018
0.337/0.346
INCHES
0.150/0.157
F
G
D
E
A
B
C
ITEM MILLIMETERS
0.36/0.46
0.19/0.25
1.35/1.73
1.27
8.56/8.79
3.81/3.99
5.80/6.20
0.050
