THAT1206 THAT Corporation, THAT1206 Datasheet - Page 6

• Manufacturer Part Number: THAT1206
• Description: (THAT1200 / THAT1203 / THAT1206) Ingenius High-cmrr Balanced Input Line Receiver
• Manufacturer: THAT Corporation

Page 6
line-receiver that is pin-for-pin compatible with the
Analog Devices SSM2143 and Burr-Brown INA137.
Though the THAT 1200 series is not pin-compatible
with the THAT 1246, the PCB layouts shown in Fig-
ures 5 and 6 provide manufacturers with the option
to stuff a PCB with any of these input stages. Note
that these figures are not to scale. The interconnects
should be as short as practicable constrained only by
component size and relevant manufacturing consid-
erations.
tor Cb is connected between CM In and CM Out.
When the THAT 1246 (or SSM2143 or INA137) is
used, capacitor Cb is removed, and a jumper con-
nects the Vout and Sense pins.
circuitry at the IN+, IN-, and CM IN pins. The values
of R and R’ vary with actual part number as shown in
Table 3.
adequate to keep the combination of signal and com-
mon mode voltages from driving the internal inputs
beyond the power supply rails, the circuitry does not
provide adequate protection against most ESD inci-
dents. Since these ICs will very often connect directly
to the outside world, it is mandatory that additional,
external protection from ESD be provided. Any un-
protected InGenius input will fail when subjected to
ESD if this protection circuitry is omitted.
Figure 5. Dual PCB layout for THAT 1206 and THAT 1246
In+
Gnd
Dual Layout Option
Input Protection
In-
The THAT 1246 is a conventional balanced
When a THAT 1200 series IC is installed, capaci-
Figure 7 shows the internal overvoltage protection
While the internal protection circuitry shown is
THAT1206
or THAT1246
In+
Vee
Ref
In-
Vcc
Vee
THAT Corporation; 45 Sumner Street; Milford, Massachusetts 01757-1656; USA
DIP version
Tel: [phone]; Fax: [phone]; Web: www.thatcorp.com
CM out or N/C
Vcc
CM in or Sense
Vout
Connect
for
THAT1246
Addi-
+
Cb
tionally, proper ESD handling precautions must be
observed until the IC is properly affixed to the PCB.
mended approach to protecting the 1200 series from
ESD damage.
12V Zener diodes permits the maximum allowable
input signal to reach the IC's input pins, but directs
high-energy ESD impulses to the rails. So long as the
supply rails are adequately decoupled, most ESD
events will be diminished to harmless levels.
Figure 6. Dual PCB layout for THAT 1206 and THAT 1246
Vee
Gnd
In-
In+
THAT 1200
THAT 1203
THAT 1206
Diodes D1-D6 in figures 3 and 4 show our recom-
Figure 7. Internal input protection circuitry (see text)
Part No.
THAT1206
IN+
THAT1246
IN-
In+
Table 3. Input resistance values
Ref
In-
Vee
Surface mount versions
This arrangement of 1N4148s and
Sense
Vout
Vcc
Vee
R
R
N/C
Vcc
Vee
Vcc
Vee
Vcc
InGenius Balanced Line Receiver
500W
7kW
7kW
R
CM in
CM Out
Vcc
Vout
Preliminary Information
R'
R'
Connect
for
THAT1246
CM IN
23.5kW
17kW
17kW
R’
+
Cb