參數(shù)資料
型號: AD734
廠商: Analog Devices, Inc.
英文描述: 10 MHz, 4-Quadrant Multiplier/Divider(10MHz,四象限乘法器/除法器)
中文描述: 10兆赫,四象限乘法器/除法器(10MHz的,四象限乘法器/除法器)
文件頁數(shù): 8/12頁
文件大?。?/td> 283K
代理商: AD734
AD734
REV. B
–8–
(10V)
W =
(Z
2
– Z
1
) + S
S
OPTIONAL
SUMMING
INPUT
±
10V FS
Z INPUT
+10mV TO
+10V
D
1
2
3
4
5
6
7
10
8
9
11
13
12
14
W
ER
VN
VP
DD
Z1
Z2
X1
X2
U1
U2
U0
Y1
Y2
AD734
NC
NC
0.1μF
0.1μF
+15V
–15V
L
L
L
Figure 9. Connection for Square Rooting
Connections for Square-Rooting
T he AD734 may be used to generate an output proportional to
the square-root of an input using the connections shown in
Figure 9. Feedback is now via both the X and Y inputs, and is
always negative because of the reversed-polarity between these
two inputs. T he Z input must have the polarity shown, but
because it is applied to a differential port, either polarity of
input can be accepted with reversal of Z1 and Z2, if necessary.
T he diode D, which can be any small-signal type (lN4148 being
suitable) is included to prevent a latching condition which could
occur if the input momentarily was of the incorrect polarity of
the input, the output will be always negative.
Note that the loading on the output side of the diode will be
provided by the 25 k
of input resistance at X 1 and Y2, and by
the user’s load. In high speed applications it may be beneficial
to include further loading at the output (to 1 k
minimum) to
speed up response time. As in previous applications, a further
signal, shown here as S, may be summed to the output; if this
option is not used, this node should be connected to the load
ground.
DIVISION BY DIRE CT DE NOMINAT OR CONT ROL
T he AD734 may be used as an analog divider by directly vary-
ing the denominator voltage. In addition to providing much
higher accuracy and bandwidth, this mode also provides greater
flexibility, because all inputs remain available. Figure 10 shows
the connections for the general case of a three-input multiplier
divider, providing the function
(
U
1
U
2
where the X , Y, and Z signals may all be positive or negative,
but the difference U = U
1
– U
2
must be positive and in the
range +10 mV to +10 V. If a negative denominator voltage must
be used, simply ground the noninverting input of the op amp.
As previously noted, the X input must have a magnitude of less
than 1.25U.
W
=
X
1
X
2
(
)
Y
1
Y
2
)
(
)
+
Z
2,
(11)
2M
X – INPUT
Y – INPUT
U – INPUT
1
2
3
4
5
6
7
10
8
9
11
13
12
14
W
ER
VN
VP
DD
Z1
Z2
X1
X2
U1
U2
U0
Y1
Y2
AD734
NC
LOAD
GROUND
0.1μF
0.1μF
+15V
–15V
OPTIONAL
SUMMING INPUT
±
10V FS
W =(X
1
– X
2
)(Y
1
– Y
2
)
U
1
– U
2
+ Z
2
L
L
Z
U
1
U
2
Figure 10. Three-Variable Multiplier/Divider Using Direct
Denominator Control
T his connection scheme may also be viewed as a variable-gain
element, whose output, in response to a signal at the X input, is
controllable by both the Y input (for attenuation, using Y less
than U) and the U input (for amplification, using U less than
Y). T he ac performance is shown in Figure 11; for these results,
Y was maintained at a constant 10 V. At U = 10 V, the gain is
unity and the circuit bandwidth is a full 10 MHz. At U = 1 V,
the gain is 20 dB and the bandwidth is essentially unaltered. At
U = 100 mV, the gain is 40 dB and the bandwidth is 2 MHz.
Finally, at U = 10 mV, the gain is 60 dB and the bandwidth is
250 kHz, corresponding to a 250 MHz gain-bandwidth product.
70
60
50
40
30
20
10
0
G
10k
100k
1M
10M
FREQUENCY – Hz
U = 10mV
U = 100mV
U = 1V
U = 10V
Figure 11. Three-Variable Multiplier/Divider Performance
T he 2 M
resistor is included to improve the accuracy of the
gain for small denominator voltages. At high gains, the X input
offset voltage can cause a significant output offset voltage. T o
eliminate this problem, a low-pass feedback path can be used
from W to X 2; see Figure 13 for details.
Where a numerator of 10 V is needed, to implement a two-
quadrant divider with fixed scaling, the connections shown in
Figure 12 may be used. T he reference voltage output appearing
between Pin 9 (ER) and Pin 8 (VN) is amplified and buffered
by the second op amp, to impose 10 V across the Y1/Y2 input.
Note that Y2 is connected to the negative supply in this applica-
tion. T his is permissible because the common-mode voltage is
still high enough to meet the internal requirements. T he transfer
function is
W
=
10
V
X
1
X
2
U
1
U
2
+
Z
2
.
(12)
T he ac performance of this circuit remains as shown in Figure 11.
100k
SCALE
ADJUST
200k
10V
W =(X
1
– X
2
)
+ Z
2
U
1
– U
2
OP AMP = AD712 DUAL
2M
X – INPUT
U – INPUT
1
2
3
4
5
6
7
10
8
9
11
13
12
14
W
ER
VN
VP
DD
Z1
Z2
X1
X2
U1
U2
U0
Y1
Y2
AD734
L
LOAD
GROUND
0.1μF
0.1μF
+15V
–15V
OPTIONAL
SUMMING
INPUT
±
10V FS
L
Z
U
1
U
2
Figure 12. Two-Quadrant Divider with Fixed 10 V Scaling
相關PDF資料
PDF描述
AD73511 Low-Power CMOS Analog Front End with Flash based DSP Microcomputer(帶閃速DSP微計算機的單模擬前端)
AD7392 Parallel Input Micropower 10- and 12-Bit DACs(并行輸入微功耗12位D/A轉換器)
AD7395 +3 V, Dual, Serial Input 12-/10-Bit DACs
AD7395AN +3 V, Dual, Serial Input 12-/10-Bit DACs
AD7395AR +3 V, Dual, Serial Input 12-/10-Bit DACs
相關代理商/技術參數(shù)
參數(shù)描述
AD73411 制造商:AD 制造商全稱:Analog Devices 功能描述:Low-Power Analog Front End with DSP Microcomputer
AD73411BB-40 制造商:Analog Devices 功能描述:Audio Codec 1ADC / 1DAC 16-Bit 119-Pin BGA 制造商:Rochester Electronics LLC 功能描述:ANALOG FRONT-END PROCESSOR +DSP I.C. - Bulk
AD73411BB-80 制造商:Analog Devices 功能描述:Audio Codec 1ADC / 1DAC 16-Bit 119-Pin BGA 制造商:Rochester Electronics LLC 功能描述:ANALOG FRONT-END PROCESSOR +DSP I.C. - Bulk
AD7341JN 制造商:Rochester Electronics LLC 功能描述:- Bulk
AD7341JP 制造商:Rochester Electronics LLC 功能描述:- Bulk