that1240 THAT Corporation, that1240 Datasheet - Page 3

• Manufacturer Part Number: that1240
• Description: Balanced Line Receiver Ics
• Manufacturer: THAT Corporation

THAT 1240 Series
Balanced Line Receiver ICs
The
performance opamps with integrated, laser-trimmed
resistors. These designs take full advantage of
THAT’s fully complementary dielectric isolation (DI)
process to deliver excellent performance with low
current consumption.
apply in many applications.
Resistor Trimming, Values, and CMRR
laser-trimmed, silicon-chromium (Si-Cr), thin-film,
integrated resistors to deliver the precise matching
required to achieve a 90 dB common mode rejection
Parameter
Small signal bandwidth
Output Gain Error
Output Voltage Swing
Output Offset Voltage
Output Short Circuit Current
Capacitive Load
The 1240-series devices rely upon proprietary,
THAT
1240-series
7
~
~
½v
½v
V
IN(CM)
IN(DIFF)
IN(DIFF)
Tel: [phone]; Fax: [phone]; Web: www.thatcorp.com
The devices are simple to
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; USA
ICs
Electrical Characteristics (con’t)
~
Symbol
G
BW
V
ER-OUT
V
V
I
C
In+
OFF
SC
In-
O+
O-
-3dB
L
consist
Copyright © 2008, THAT Corporation
Figure 2. THAT 1240 series test circuit
Theory of Operation
R
R
of
3
1
high
R
R
L
L
1243 (-3dB gain)
1246 (-6dB gain)
1243 (-3dB gain)
1246 (-6dB gain)
= 2kΩ; C
1240 (0dB gain)
1240 (0dB gain)
= 2kΩ; C
Page 3 of 8
b
a
V
V
Conditions
No signal
f = 1 kHz
R
R
R
CC
EE
L
L
L
= 2kΩ
= 2kΩ
= 0 Ω
L
L
= 300 pF
= 10 pF
ratio. Trimming is performed in two cycles, both
using dc inputs. First, gain is set by trimming the
R
pair (R
is trimmed (whichever needs to increase to meet the
required specification).
trimmed to within ±0.005 % of the R
the resistors themselves are on the order of 10 kΩ
(see Figure 1 for actual values, which change with the
specific part), an increase of as little as 0.6 Ω can
reduce the CMRR from over 90 dB to only 84 dB.
The better the starting CMRR, the more impact (in
dB) a given added resistance will have.
R
R
1
2
4
/R
2
To achieve 90 dB CMRR, the R
pair. Then, CMRR is set by trimming the other
3
/R
4
). Generally, only one resistor of each pair
Sense
Ref
Vout
V
-0.05
CC
Min
—
—
—
—
—
—
—
-7
—
—
-2.5
2,4
V
V
12.2
10.3
11.8
13.4
Typ
±25
R
8.6
EE
18
CC
—
—
0
L
+2
-2
Document 600035 Rev 04
V
+0.05
EE
Max
300
C
+7
—
—
—
—
—
—
—
—
+2.5
L
1
/R
2
3
/R
ratio. Since
4
ratio is
Units
MHz
MHz
MHz
MHz
MHz
MHz
mV
mA
dB
pF
V
V