Balanced Line Driver ICs
THAT 1280, 1283,THAT
1286 and
1260
1606,
1646_
FEATURES
•
APPLICATIONS
•
•
•
•
•
•
•
•
•
Balanced, transformer-like floating
output
OutSmarts® technology improves
clipping into single-ended loads
Stable driving long cables and
capacitive loads
High output: 18Vrms into 600 Ω
Low noise: -101 dBu
Low distortion: 0.0007% @ 1kHz
Industry-standard pinout
•
•
•
•
•
•
Differential Line Drivers
Audio Mixing Consoles
Distribution Amplifiers
Hi-Fi Equipment
Audio Equalizers
Dynamic Range Processors
Digital Effects Processors
Telecommunications Systems
Instrumentation
Description
The THAT 1606 and 1646 are a new generation
of monolithic audio differential line drivers offering
improved performance over conventional crosscoupled designs. Based on a high-performance, fully
differential opamp and laser-trimmed thin-film
resistors, both families exhibit low noise and
distortion, high slew rate, and wide output swing.
The parts are stable when driving difficult loads, and
have short-circuit protected outputs.
mode output currents, making the designs
inherently more stable and less sensitive to
component tolerances than common CCOSes. As a
result, THAT's topology prevents the loss of
common-mode feedback that plagues common
CCOS designs when clipping into single-ended loads.
This avoids excessive ground currents that would
otherwise upset power supplies and create
additional distortion, even in adjacent channels.
Designed from the ground up in THAT's
complementary dielectric isolation process, both
models incorporate THAT's patented OutSmarts1
technology. This is a dual feedback-loop design that
prevents the excessive ground currents typical of
cross-coupled output stages (CCOS) when clipping
into single-ended loads. OutSmarts uses two
individual negative-feedback loops to separately
control the differential output voltage and common
The 1646 is pin-compatible with the TI DRV134
and DRV135, as well as the Analog Devices
SSM2142. The 1606 offers an advanced commonmode offset voltage reduction scheme, which
requires a small single capacitor instead of the two
electrolytics required by the 1646 and its pincompatible cousins. Additionally, the 1606 features
differential inputs in a space-saving 16-pin QSOP
package. Both parts offer +6 dB gain.
THAT 1646
10k
Vcc
25
OutCEXT
Sns-
5k
In+
10k
Din+
Dout-
10k
Dout+
10k
Cin+
10p
20k
CinGnd
5k
Din-
20k
10k
Sns+
Vee
10k
CEXT
25
Out+
Figure 1. THAT 1646 Equivalent Circuit Diagram
1646
1606
Pin
DIP8
SO8
SO16W
QSOP16
1
OutOutNC
Gnd*
2
SnsSnsNC
NC
3
Gnd
Gnd
OutOut4
In
In
SnsCap1
5
Vee
Vee
Gnd
Gnd
6
Vcc
Vcc
In
In7
Sns+
Sns+
NC
In+
8
Out+
Out+
NC
Gnd*
9
—
—
NC
Gnd*
10
—
—
NC
NC
11
—
—
Vee
Vee
12
—
—
Vcc
Vcc
13
—
—
Sns+
Cap2
14
—
—
Out+
Out+
15
—
—
NC
NC
16
—
—
NC
Gnd*
* See "Thermal Considerations" section on page 10
Table 1. THAT 1606/1646 pin assignments
1. For complete details of OutSmarts, see Hebert, Gary K., "An Improved Balanced, Floating Output Driver IC", presented at the 108th AES Convention, February 2000.
Protected under US Patents numbers 4,979,218 and 6,316,970. Additional patents pending. THAT and OutSmarts are registered trademarks of THAT Corporation.
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; USA
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2015, THAT Corporation; Document 600078 Rev. 07
Document 600078 Rev. 07
Page 2 of 12
THAT 1606/1646 Balanced Line Driver ICs
SPECIFICATIONS2
Absolute Maximum Ratings (TA = 25°C)
Postive Supply Voltage (VCC)
+20 V
Storage Temperature (TST)
-55 to +125°C
Negative Supply Voltage (VEE)
-20 V
Junction Temperature (TJ)
125°C
Output Short Circuit Duration
Continuous
Lead Temperature (TLEAD)(Soldering 60 sec)
300°C
Operating Temperature Range (TOP)
-40 to +85°C
1646 Electrical Characteristics3
Parameter
Symbol
Input Impedance
ZIN
Gain
G1
Gain
G2
Gain Error
Min.
Typ.
Max
Units
4.00
5.00
RL=100 kΩ per output
Balanced
Single Ended
5.80
5.76
6.00
5.96
6.20
6.16
dB
dB
RL= 600 Ω
Balanced
Single Ended
5.00
4.96
5.30
5.26
5.60
5.56
dB
dB
0.02
0.20
dB
kΩ
G1
RL=100 kΩ per output, Balanced
PSRR
±4V to ±18V
85
107
dB
CMRROUT
f=1kHz, BBC Method
46
65
dB
SBR
f=1kHz, BBC Method
35
54
dB
THD+N1
VO=10 VRMS, RL=600 Ω
20Hz-5kHz
20kHz
0.0007
0.002
0.005
%
%
VO=10 VRMS, RL=600 Ω
20Hz-5kHz
20kHz
0.0010
0.0030
0.0090
%
%
DC Power Supply
Rejection Ratio
Output Common-Mode
Rejection Ratio
Conditions
Output Signal Balance Ratio
THD+N (Balanced)
THD+N (Single Ended)
THD+N2
Output Noise
Onoise
Balanced, 22Hz -20kHz
-101
dBu
Maximum Output Level
VoMAX
0.1% THD+N
27.5
dBu
SR
CL=50pF/output
15
V/µS
CL=50pF/output
10
MHz
Slew Rate
Small Signal Bandwidth
Output Common Mode
Voltage Offset
VOCM1
VOCM2
Differential Output Offset
w/o Sense capacitors
w/ Sense capacitors
VOD
Output Voltage Swing, Positive
No Load
Output Voltage Swing, Negative
No Load
Output Impedance
ZO
-250
-15
±50
±3.5
250
15
mV
mV
-15
±4
15
mV
VCC–2.9
VCC–2.2
40
V
VEE+2.25
VEE+2.9
V
50
60
Ω
2. All specifications are subject to change without notice.
3. Unless otherwise noted,.all measurements taken with VS=±18V, T=25°C, RL = 600 Ω Balanced, RSOURCE = 0 Ω
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; USA
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2015, THAT Corporation; All rights reserved.
Document 600078 Rev. 07
Page 3 of 12
THAT 1606/1646 Balanced Line Driver ICs
1646 Electrical Characteristics (cont'd)
Parameter
Symbol
Maximum Capacitive Load
Conditions
Min.
Typ.
Stable Operation
Quiescent Supply Current
IS
Unloaded
4.9
Output Short Circuit Current
ISC
Both outputs to ground
70
Power Supply Voltage Range
Max.
Units
Unlimited
µF
5.75
mA
mA
±4
±18
V
Max.
Units
1606 Electrical Characteristics3
Parameter
Symbol
Input Impedance
ZIN
Gain
G1
Gain
G2
Gain Error
Min.
Typ.
4.00
5.00
RL=100 kΩ per output
Balanced
Single Ended
5.80
5.76
6.00
5.96
6.20
6.16
dB
dB
RL= 600 Ω
Balanced
Single Ended
5.00
4.96
5.30
5.26
5.60
5.56
dB
dB
0.02
0.20
dB
kΩ
G1
RL=100 kΩ / output, Balanced
PSRR
±4V to ±18V
85
107
dB
CMRROUT
f=1kHz, BBC Method
46
65
dB
CMRRIN
f=1kHz
40
60
dB
SBR
f=1kHz, BBC Method
35
54
dB
THD+N1
VO=10 VRMS, RL=600 Ω
20Hz-5kHz
20kHz
0.0007
0.002
0.005
%
%
VO=10 VRMS, RL=600 Ω
20Hz-5kHz
20kHz
0.0010
0.0060
0.0090
%
%
DC Power Supply
Rejection Ratio
Output Common-Mode
Rejection Ratio
Conditions
Input Common-Mode
Rejection Ratio
Output Signal Balance Ratio
THD+N (Balanced)
THD+N (Single Ended)
THD+N2
Output Noise
Onoise
Balanced, 22Hz -20kHz
-101
dBu
Maximum Output Level
VoMAX
0.1% THD+N
27.5
dBu
SR
CL=50pF/output
15
V/µS
CL=50pF/output
10
MHz
Slew Rate
Small Signal Bandwidth
Output Common Mode
Voltage Offset
VOCM1
VOCM2
Differential Output Offset
w/o CM coupling capacitor
w/ CM coupling capacitor
VOD
Output Voltage Swing, Positive
No Load
Output Voltage Swing, Negative
No Load
Output Impedance
ZO
Maximum Capacitive Load
Quiescent Supply Current
-250
-20
±50
-5
250
20
mV
mV
-15
±4
15
mV
VCC–2.9
VCC–2.2
40
VEE+2.25
VEE+2.9
V
50
60
Ω
Unlimited
µF
5.75
mA
Stable Operation
IS
Unloaded
V
4.9
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; USA
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2015, THAT Corporation; All rights reserved.
Document 600078 Rev. 07
Page 4 of 12
THAT 1606/1646 Balanced Line Driver ICs
1606 Electrical Characteristics (cont'd)
Parameter
Symbol
Conditions
ISC
Both outputs to ground
Output Short Circuit Current
Min.
Power Supply Voltage Range
Typ.
Max.
70
mA
±4
±18
V
THAT 1646
10k
Vcc
25
OutCEXT
Sns-
5k
In+
10k
Din+
Dout-
10k
Dout+
10k
Cin+
20k
10p
CinGnd
5k
Din-
20k
10k
Sns+
CEXT
25
10k
Vee
Out+
Figure 2. THAT 1646 Equivalent Circuit Diagram
CEXT
Cap2
Cap1
REXT
THAT 1606
25
Vcc
In+
10k
Din+
Dout-
Cin+
Cin-
In-
Out-
10k
5k
5k
10k
10p
7k
AD & AC
Din-
Gnd
Dout+
10k
7k
10k
Vee
10k
Units
25
Figure 3. THAT 1606 Equivalent Circuit Diagram
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; USA
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2015, THAT Corporation; All rights reserved.
Out+
Document 600078 Rev. 07
Page 5 of 12
THAT 1606/1646 Balanced Line Driver ICs
Theory of Operation
OutSmarts® technology
The THAT 1606 and 1646 family employs the
OutSmarts topology, a variation of circuitry originally
developed by Chris Strahm at Audio Teknology Inc.,
(and later acquired by Audio Toys, Inc.). THAT's
OutSmarts topology employs two negative-feedback
loops -- one to control the differential signal, and a
separate loop to control the common mode output
levels.
Figures 2 and 3 show the gain core common to
the 1606 and 1646. The gain core is a single
amplifier that includes two differential input pairs,
Cin+/- and Din+/-, and complementary outputs,
Vout+ and Vout-, related to each other by two gain
expressions, AD(s) and AC(s). The first pair of
differential inputs, Din+/-, is connected to the
differential feedback network between the outputs
and the input signal. The second differential input
pair, Cin+/-, is connected to a bridge circuit which
generates an error signal used to servo the commonmode behavior of the outputs. The loop equations are
then:
∆
,
where AD is the differential open-loop gain, and
Σ
,
where AC is the common-mode open-loop gain.
These equations can be solved
standard op-amp loop equations.
much
like
For the differential case, using superposition, we
can see that this results in:
, and
,
Substituting and simplifying into the equation
that defines differential operation yields:
,
Dividing through by AD (assuming that AD >> 3)
and simplifying yields
,
2
as one would expect for a +6 dB line driver.
For the 1646, In- is hard-wired to ground (0v), so
the differential equation above simplifies to:
2
The common mode equation is more complicated
in that it is dependent on the attached load, and in
any event doesn't yield much insight into the device's
operation. For those who are interested, a more
complete discussion is given in the reference
mentioned in note 1.
In op-amp analysis using negative feedback loops,
the combination of negative feedback and high openloop gain usually results in the open-loop gain
"dropping out" of the equation, and the differential
inputs being forced to the same potential. This is true
for the core of the 1606 and 1646 ICs. If we start
with that assumption, the operation of the commonmode feedback loop can be intuited as follows:
Referring again to Figures 2 and 3, the commonmode input actually senses the sum of each IC's
output currents by way of two 25 Ω resistors and the
bridge network4. The resulting error signal is
amplified and then summed into both outputs, with
the net effect being to force the sum of the currents to
be zero, and thus the common mode output current
to zero.
To see why this is important, consider what
happens when the IC is loaded with a single-ended
load, which shorts one or the other output to ground.
Suppose Out- is grounded. In this case, the
differential feedback loop increases the voltage at
Dout+ to make up for most of the signal lost to the
short at Out-. The common-mode feedback loop
forces the current from Out- to be equal and opposite
to that from Out+. But, during peak signals which
drive Dout+ into clipping (exceeding its maximum
output voltage capability), the differential loop is
starved for feedback. Without the common-mode
feedback, the result would be for the voltage at Doutto decrease in an attempt to satisfy the differential
loop's demand for feedback. This is one significant
weakness of conventional cross-coupled output
designs – common-mode feedback is lost when one
output is clipped while the other is grounded.
With OutSmarts, however, the common mode
feedback loop senses this happening because of the
increase in current at Out- (compared to that at
Out+), and prevents the voltage at Out- from rising
out of control. This causes the OutSmarts design to
more closely mimic the behavior of a true floating
balanced source (such as a transformer), compared
to the behavior of a conventional CCOS design.
,
4. The 10 pF capacitor can be ignored for the purposes of this analysis. It simply limits the maximum frequency at which the current-sensing action occurs.
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; USA
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2015, THAT Corporation; All rights reserved.
Document 600078 Rev. 07
Page 6 of 12
THAT 1606/1646 Balanced Line Driver ICs
Applications
1. Circuit implementations using the 1606 and
1646 are relatively straightforward. A quiet, solid
ground reference, stiff voltage supplies, and adequate
supply bypassing are all that are required to achieve
excellent performance out of both ICs.
2. Both devices must be driven from a lowimpedance source, preferably directly from opamp
outputs, to maintain the specified performance.
3. Please refer to Figure 8 for a complete
applications circuit.
conductor-to-shield capacitance of 33 pF/ft (the
difference between 67 and 34) for each conductor.
For balanced signals, the load capacitance across the
1646 outputs will be 34 pF/ft + 16.5 pF/ft = 50.5
pF/ft. The corner frequency of the THAT 1646 driving
500 ft of this cable (25.25 nF) will be 126 kHz.
∙ ∙
∙
.
126
,
One must also consider the slew rate limitations
posed by excessive cable and other capacitances. We
know that
Stability and Load Capacitance
The devices are stable into any capacitive load,
and the maximum capacitance is limited only by slew
rate and frequency response considerations.
and that
For the purposes of the frequency response
calculation, the line driver's 25Ω sense resistors can
be lumped into a single 50Ω resistor. The correct
cable capacitance to use for the balanced-signal case
is the sum of the inter-conductor capacitance and the
two conductor-to-shield capacitances in series. Some
manufacturers only specify the inter-conductor
capacitance and the capacitance of one conductor to
the other while connected to the shield, and some
extraction may be required.
Dennis Bohn of Rane Corporation has
published work specifying some of the requirements
for a balanced line driver, including a) stability into
reactive loads, b) differential output voltage swing of
at least ±11 volts peak (+20dBu), and c) reliability5.
This work suggests a reasonable rule by which to
calculate the output current requirements at 20 kHz.
The author concludes that the actual worst case peak
level for various types of music and speech will be
flat out to 5 kHz, and roll off at 6dB/octave above this
frequency. Thus the peak levels at 20 kHz will be
12 dB below those at 5 kHz.
As an example, Belden 8451 is specified as
having with 34 pF/ft of inter-conductor capacitance
and 67 pF/ft of conductor to "other conductor +
shield capacitance". Thus, we can assume a single
2 ∙ ∙
Using these, we can calculate the required slew
rate and current drive. For the +26 dBu output
Vcc
C4
100n
6
7
Vcc
4
Sns+
In
In
3
8
Out+
Gnd Sns- Out1
Vee
U1
2
5
THAT1646
Out+
Out-
C5
100n
Vee
Figure 4. THAT 1646 without common-mode offset reduction
5. Dennis A. Bohn, “Practical Line-Driving Current Requirements“(Rane Note 126), Rane Corporation, 1991, revised 5/1996. Available at www.rane.com/note126.html.
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; USA
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2015, THAT Corporation; All rights reserved.
Document 600078 Rev. 07
Page 7 of 12
undue problems being overdriven at their inputs
when the outputs are clipping into single-ended
loads.
levels that the 1646 is capable of, VPeak is 22 V
(below 5 kHz), and at 20 kHz, VPeak is 5.5 V.
Therefore,
0.69
2 ∙ 5.5 ∙ 20
1646 circuits
As a consequence,
500
∙ 34
16.5
∙ 0.69
THAT 1606/1646 Balanced Line Driver ICs
17.5
Figure 4 shows the most basic connection for a
1646. The only external components needed are the
local 100 nF bypass capacitors. These should be
within 1 inch of the 1646 pins.
.
Thus, driving this 25.25 nF cable requires
17.5 mAPeak, which is well within the capability of the
1606 and 1646.
Output DC offset
Because the 1646's outputs are connected
directly to their respective sense inputs, this circuit
may produce up to 250 mV of common-mode dc
offset at its outputs. As shown, the outputs are DC
coupled to the output connector, so this dc will
appear directly at the output of the system.
Gain structure
The 1606 and 1646 both provide +6 dB gain
(factor of 2) between their inputs and differential
outputs. This is appropriate, since with a balanced
output, twice the voltage between the power supply
rails is available at the output of the stage. The
single-ended input of the 1646 can accept signals
that swing to nearly the power supply rails without
distortion, when driving into a differential (floating)
load. The balanced input of the 1606 can accept
signals at each input that swing to nearly one-half the
power supply rails without distortion, when driving
into differential loads.
The output common-mode offset of a 1646 may
be reduced by adding capacitors in the feedback
loop, as shown in Figure 5. Capacitors C1 and C2 accouple the common-mode feedback loop. This
changes the loop operation from servoing the
common-mode output current at audio frequencies
to servoing the common-mode output voltage to 0 at
DC. This results in much lower common-mode
output offset voltage, as indicated in the
specifications section. C1 and C2 are typically high
quality non-polarized electrolytic capacitors.
Both devices, when driving single-ended loads,
will clip at about half the output voltage as compared
to a differential load. This is because only one of the
two output signals will be available. Despite the
output clipping, the input to the devices does not
need to be constrained - they will work without
Vcc
C1
C4
100n
In
6
4
3
In
7
Vcc
Sns+
10u
NP
Out+
8
Out+
Gnd Sns- Out1
Vee
U1
2
5
THAT1646
Out-
C2
C5
100n
Vee
10u
NP
Figure 5. THAT 1646 with common-mode offset reduction
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; USA
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2015, THAT Corporation; All rights reserved.
Document 600078 Rev. 07
Page 8 of 12
Vcc
C1
R1
100n
C4
100n
1M0
12
4
Vcc
14
7
In+ Cap1
Out+
6
InOut5 Gnd
Cap2
3
Vee
U1
13
11
THAT1606
In
THAT 1606/1646 Balanced Line Driver ICs
Out+
Out-
C5
100n
Vee
Figure 6. THAT 1606 with output common-mode offset reduction and single-ended input drive
Vcc
R1
100n
C4
100n
In+
C1
12
7
4
Vcc
In+ Cap1
Out+
14
Out+
InOut5 Gnd Cap2
3
Vee
U1
13
11
THAT1606
6
In-
1M0
Out-
C5
100n
Vee
Figure 7. THAT 1606 with output common-mode offset reduction and differential input drive
1606 circuits
Figures 6 and 7 show the basic amplifier
configurations for a 1606. The 1606 differs from the
1646 in two respects. First, the 1606 includes a
negative-sense input pin (pin 6), so offers a
differential input. This can be useful in connecting
the output driver to the output of modern D/A
converters, which usually present differential
outputs. Second, instead of two 10 uF capacitors, the
1606 uses an 0.1 uF capacitor (C1) and 1 MΩ (R1)
resistor to reduce common-mode dc offset.
Generally, these components will cost less, and take
up less space on the circuit board than the two large
capacitors required for the 1646. C1 should be a
high-quality film type capacitor to minimize lowfrequency distortion when driving single-ended loads.
RFI protection
These line drivers can easily drive cables
hundreds of feet in length without becoming
unstable, but such long cables can act as antennae
which can pick up RFI and direct it into the circuit.
The circuit of Figure 8 includes two 100 pF bypass
capacitors (C3 and C8) and two ferrite beads, whose
purpose is to redirect this RF energy to the chassis
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; USA
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2015, THAT Corporation; All rights reserved.
Document 600078 Rev. 07
Page 9 of 12
THAT 1606/1646 Balanced Line Driver ICs
Vcc
D4
1N4004
Input
Amplifier
Block
(from fig.
5, 6, or 7)
Vcc
Input
Gnd
Vee
U1
Out+
Out-
D3
1N4004
D5
1N4004
D6
1N4004
XLR (M)
L1
Ferrite Bead
L2
Ferrite Bead
1
C8
100p
2
3
C3
100p
Vee
Figure 8. THAT 16x6 applications circuit with output common-mode offset protection, RFI protection, and surge protection
before it can circulate inside the product's box and
couple RF into other portions of the circuit. The
capacitors should be located as close as possible to
the output connector and connected via a lowinductance path to chassis ground, with the ferrite
beads placed very nearby. These components ensure
that RFI current is directed to the chassis and not
through the relatively low-impedance output of the
1606/1646. The bypass capacitors and ferrite beads
will have no effect on the gain error of these line
drivers at audio frequencies.
control. The 1606/1646's internal protection network
will withstand this abuse for coupling capacitors up
to about 33 uF.
To protect against microphone preamplifiers
that incorporate larger values of capacitance, a pair
1N4004 diodes from each output to the supply rails,
as shown in Figure 8, is recommended. This shunts
the discharge current to the power supply bypass
and filter capacitors, thus protecting the output of
the 1606 or 1646.
Closing thoughts
Output protection
The 1606 and 1646 each incorporate a
proprietary internal protection scheme, which will
suffice for many situations seen in the field. However,
one might foresee having the line driver's output
mistakenly plugged directly into a microphone
preamplifier input that has +48V phantom power
applied. When this happens, the ac coupling
capacitors on the preamp's input will discharge into
the low-impedance output of the 1606/1646. This can
result in surge currents of over 2 amperes6. The
amount of energy stored in these capacitors is
directly proportional to the capacitor value, which is,
of course, not under the 1606/1646 designer's
The integrated balanced line driver is one of
those highly useful, cost-effective functional blocks
that can provide significant improvement over
discrete designs. The THAT 1646 goes a step or two
further by improving over existing components. Both
incorporate OutSmarts technology to tame the
aberrant
single-ended
clipping
behavior
of
conventional cross-coupled output stages.
For more information on these or other THAT
Corporation integrated circuits, please contact us
directly, or through one of our international
distributors.
6. Hebert, Gary K., Thomas, Frank W., "The 48V Phantom Menace", presented at the 110th Audio Engineering Society Convention, May, 2001
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; USA
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2015, THAT Corporation; All rights reserved.
Document 600078 Rev. 07
Page 10 of 12
THAT 1606/1646 Balanced Line Driver ICs
Package and Soldering Information
Package Characteristics
Parameter
Symbol
Conditions
Typ
Units
SO-8
Package Style
Thermal Resistance
See Fig. 9 for dimensions
θJA
8 Pin SO
SO package soldered to board
Environmental Regulation Compliance
Soldering Reflow Profile
Moisture Sensitivity Level
150
ºC/W
Complies with July 21, 2011 RoHS 2 requirements
JEDEC JESD22-A113-D (250 ºC)
MSL
Above-referenced JEDEC soldering profile
MSL-1
DIP-8
Package Style
Thermal Resistance
See Fig. 10 for dimensions
θJA
8 Pin DIP
DIP package soldered to board
Environmental Regulation Compliance
Soldering Reflow Profile
Moisture Sensitivity Level
100
ºC/W
Complies with July 21, 2011 RoHS 2 requirements
JEDEC JESD22-A113-D (250 ºC)
MSL
Above-referenced JEDEC soldering profile
θJA
SO package soldered to board
MSL-1
SO-16
Package Style
Thermal Resistance
See Fig. 11 for dimensions
Environmental Regulation Compliance
16 Pin SO
ºC/W
Complies with July 21, 2011 RoHS 2 requirements
Soldering Reflow Profile
Moisture Sensitivity Level
80
JEDEC JESD22-A113-D (250 ºC)
MSL
Above-referenced JEDEC soldering profile
MSL-1
See Fig. 12 for dimensions
16 Pin QSOP
QSOP-16
Package Style
Thermal Resistance
θJA
QSOP package soldered to top-side
ground plane of 1 sq in or larger
Environmental Regulation Compliance
ºC/W
Complies with July 21, 2011 RoHS 2 requirements
Soldering Reflow Profile
Moisture Sensitivity Level
125
JEDEC JESD22-A113-D (250 ºC)
MSL
Above-referenced JEDEC soldering profile
The THAT1646 in available in 8-pin SO, 8-pin
mini-DIP and 16-pin wide SOIC packages. The 1606
comes in a 16-pin QSOP package. Package
dimensions are shown in Figures 9, 10, 11, and 12,
while pinouts are given in Table 1.
Thermal Considerations
As mentioned. the 1646 is available in an 8-pin
DIP, and 16-pin wide SO, and an 8-pin SO, with
junction-to-ambient
thermal
resistances
of
100°C/watt, 80°C/watt, and 150°C/watt, respectively,
assuming a 2-sided PCB with no ground planes.
Users of the SO-8 package should recognize driving
600 Ω loads or very long cables (several hundred
feet) at high ambient temperatures (above 55°C)
continuously could lead to internal die temperatures
that exceed the maximum rating and result in
performance degradation.
MSL-1
The 1606 is supplied in a 16-pin QSOP package
in which pins 1, 8, 9, and 16 are fused to the die
paddle to assist in conducting heat away from the
die. These pins are connected to the die substrate,
which is, in turn, connected to the ground pin of the
device. When these pins are connected to a top-side
ground plane of 1 square inch area, the junction-toambient thermal resistance is 125°C/watt. Internal
planes on multi-layer PCBs will reduce the thermal
resistance further.
Model
1646
1606
SO8
Pkg
DIP8
Pkg
SO16W
Pkg
1646S08-U 1646P08-U 1646W16-U
—
—
—
Table 2. Order Number Information
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; USA
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2015, THAT Corporation; All rights reserved.
QSOP16
Pkg
—
1606Q16-U
Document 600078 Rev. 07
Page 11 of 12
THAT 1606/1646 Balanced Line Driver ICs
0-8°
F
E
B
J
C
1
B
H
1
G
A
C
K
hx45°
D
F
H
G
A
D
a1
ITEM
A
a1
B
C
D
E
F
G
H
h
MILLIMETERS
4.78/5.00
0.10/0.20
3.81/3.99
5.84/6.20
0.36/0.46
1.27
1.52/1.73
0.18/0.25
0.41/0.89
0.31/0.71
ITEM
A
B
C
D
E
F
G
H
J
K
INCHES
0.188/0.197
0.004/0.008
0.150/0.157
0.230/0.244
0.014/0.018
0.050
0.060/0.068
0.007/0.010
0.016/0.035
0.012/0.027
Figure 9. 8 pin SO package outline drawing
E
E
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 10. 8 pin DIP package outline drawing
F
1
D
B
A
C
H
1
D
G
A
E
B
C
G
J
H
J
I
ITEM
A
B
C
D
E
F
G
H
J
MILLIMETERS
10.11/10.31
7.40/7.60
10.11/10.51
0.36/0.46
1.27
2.44/2.64
0.23/0.32
0.51/1.01
0.10/0.30
INCHES
0.398/O.406
0.291/0.299
0.398/0.414
0.014/0.018
0.050
0.096/0.104
0.009/0.013
0.020/0.040
0.004/0.012
Figure 11. 16 pin wide SO package outline drawing
ITEM
A
B
C
D
E
G
H
I
J
0-8º
MILLIMETERS
4.80 - 4.98
3.81 - 3.99
5.79 - 6.20
0.20 - 0.30
0.635 BSC
1.35 - 1.75
0.10 - 0.25
0.40 - 1.27
0.19 - 0.25
INCHES
0.189 - 0.196
0.150 - 0.157
0.228 - 0.244
0.008 - 0.012
0.025 BSC
0.0532 - 0.0688
0.004 - 0.010
0.016 - 0.050
0.0075 - 0.0098
Figure 12. 16 pin QSOP package outline drawing
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; USA
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2015, THAT Corporation; All rights reserved.
Document 600078 Rev. 07
Page 12 of 12
THAT 1606/1646 Balanced Line Driver ICs
Revision History
Revision
ECO
Date
Changes
Page
00
—
9/26/2006
Released
—
3
6-9
8
01
—
1/12/2007
- Changed 1606 THD+N specification.
- Changed the XLR orientation in Figures 4 - 9.
- Changed the recommendation for common-mode offset
capacitors to be high quality film type.
02
—
8/6/2007
Reversed the SNS+ and SNS- pins in Figure 1 and 2.
1, 4
03
—
9/24/2007
- Changed the Quiescent Supply Current specification.
- Correction to the output pins in figures 4 through 9
2, 3
6-9
04
2323
10/16/2009
05
2526
5/11/2011
Revised Figures 4 - 9 and accompanying text to clarify the
recommended application circuits.
06
2765
2/19/2013
Changed the spec. for THD+N (Single-ended) @20kHz.
2, 3
07
2932
7/7/2015
Added the Package Characteristics table.
10
Changed Table 1. to include all the pin numbers including unused
and ground pins.
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; USA
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2015, THAT Corporation; All rights reserved.
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