THAT1206P08-U THAT Corporation, THAT1206P08-U Datasheet - Page 8

• Manufacturer Part Number: THAT1206P08-U
• Description: LINE RECEIVER, BALANCED, 1206, DIP8
• Manufacturer: THAT Corporation

Specifications of THAT1206P08-U

• Device Type: Differential
• Supply Voltage Range: ± 3V To ± 18V
• Driver Case Style: DIP
• No. Of Pins: 8
• Operating Temperature Range: 0°C To +85°C
• Operating Temperature Max: 85°C
• Operating Temperature: RoHS Compliant
• Bandwidth: 22MHz
• Base Number: 1206
• Rohs Compliant: Yes

Page 8
Basic Application
very little external support circuitry. As is shown in
the basic application circuit of Figure 9, they need lit-
tle else beyond positive and negative power supplies,
a ground reference, the common-mode bootstrap ca-
pacitor, and input and output connections. Because
all 1200-series ICs are wide bandwidth parts, it is
important to provide bypass capacitors for both posi-
tive and negative supply rails within an inch or so of
the part. Sharing supply bypass capacitors across
several 1200-series ICs separated by several inches
on a circuit board (as, for example, along the back
panel of a multi-input product) is not recom-
mended
Bootstrap Capacitor Polarity
be large (see formula on page 7) an electrolytic or
tantalum capacitor is a logical choice. Such capaci-
tors are normally polarized, though non-polarized
types
1200-series, a polarized capacitor is appropriate,
with the positive end towards CM
of the direction of the input bias currents for internal
opamps OA
never has much voltage across it
support a few tens of mV. Therefore, we recommend
a 220 uF , 3V capacitor for C
1
to draw excessive current when operated near their upper temperature limits. Close bypassing prevents this phenomenon.
2
R
3
complex subject. We refer the interested reader to:
Lack of proper bypassing may not cause obvious problems at normal temperatures. We have seen cases in which improperly bypassed parts begin
Even at DC, C
Good practice to protect inputs against RFI is a science in itself, and it is beyond the scope of this data sheet to provide more than a glimpse of this
11
Considerations in Grounding and Shielding Audio Devices, by Stephan R. Macatee, JAES Volume 43, Number 6, pp.472-483; June 1995;
Noise Susceptibility in Analog and Digital Signal Processing Systems, by Neil A. Muncy, AES 97th Convention Preprint 3930, October 1996.
In-
In+
. With OA
At its most basic, THAT’s 1200-series ICs need
Because the bootstrap capacitor, C
Figure 9. Basic 1200-series application circuit
are
1
.
4
configured for unity gain, both ends of C
b
1
available
will not see much voltage, because the signal at the junction of R
and OA
220uF
C b
THAT Corporation; 45 Sumner Street; Milford, Massachusetts 01757-1656; USA
2
5
3
+
CM
IN-
IN+
IN
Tel: [phone]; Fax: [phone]; Web: www.thatcorp.com
2
at
. Furthermore, because C
8
1
OUT
120X
REF
CM
b
higher
.
4
Vcc
7
Vee
Vcc
Vee
out
2
, it only needs to
OUT
100nF
U1
100nF
C4
(pin 8), because
cost.
C3
b
, will usually
6
b
see the same signal - AC and DC - except for offsets.
For
OUT
Applications
the
b
RFI Protection
tible to RF interference (RFI). Like most semiconduc-
tor devices, if high levels of RF are permitted at the
input pins of 1200-series parts, they may become
nonlinear, which can create audible interference.
Therefore, it is good design practice to filter un-
wanted high frequencies at the input of any product
in which the 1200-series is used.
should be to prevent RF from entering the chassis,
and especially, the circuit board of any devices using
a 1200-series part. Generally, this is done by means
of small capacitors connected between the signal in-
puts and chassis ground, with the capacitors located
as physically close to the input connectors as possi-
ble.
cuit to protect the 1200 series against RFI. For many
non-demanding applications, this simple circuit will
suffice. C
and 3 of the input XLR connector to chassis ground
and the XLR connector's shell (which are tied to-
gether, ideally only at the XLR connector jack). RF
picked up on the cable plugged into the connector is
conducted by C
ground should connect to circuit ground through one
(and only one) low inductance path, usually at the
power supply connector.
7
InGenius High-CMRR Balanced Input Line Receiver ICs
C2
C1
and R
As an input stage, the 1200-series ICs are suscep-
Figure 10 shows a basic, simple application cir-
5 4
2
2
8
3 1
3
should closely equal the signal at the junction of R
100pF NPO
1
100pF NPO
1
Figure 10. THAT1200 application with
and C
J1
XLR-F
1
simple RFI protection
2
and C
3
provide RF bypassing from pins 2
2
to chassis ground. Chassis
220uF
C b
2
5
3
+
CM
IN-
IN+
IN
8
120X
1
OUT
CM
REF
Vcc
7
4
Vcc
Vee
Vee
The objective
OUT
100nF
U1
100nF
C4
C3
6
10
OUT
and