Electronic Components Datasheet Search
  English  ▼

Delete All
ON OFF
ALLDATASHEET.COM

X  

Preview PDF Download HTML

AD7937 Datasheet(PDF) 5 Page - Analog Devices

Part No. AD7937
Description  LC2MOS 84 Loading Dual 12-Bit DAC
Download  8 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  AD [Analog Devices]
Direct Link  http://www.analog.com
Logo AD - Analog Devices

AD7937 Datasheet(HTML) 5 Page - Analog Devices

  AD7937 Datasheet HTML 1Page - Analog Devices AD7937 Datasheet HTML 2Page - Analog Devices AD7937 Datasheet HTML 3Page - Analog Devices AD7937 Datasheet HTML 4Page - Analog Devices AD7937 Datasheet HTML 5Page - Analog Devices AD7937 Datasheet HTML 6Page - Analog Devices AD7937 Datasheet HTML 7Page - Analog Devices AD7937 Datasheet HTML 8Page - Analog Devices  
Zoom Inzoom in Zoom Outzoom out
 5 / 8 page
background image
AD7937
–5–
REV. 0
UNIPOLAR BINARY OPERATION
(2-QUADRANT MULTIPLICATION)
Figure 4 shows the circuit diagram for unipolar binary operation.
With an ac input, the circuit performs 2-quadrant multiplication.
The code table for Figure 4 is given in Table II.
Operational amplifiers A1 and A2 can be in a single package
(AD644, AD712) or separate packages (AD544, AD711,
AD OP27). Capacitors C1 and C2 provide phase compensation
to help prevent overshoot and ringing when high-speed op amps
are used.
For zero offset adjustment, the appropriate DAC register is loaded
with all 0s and amplifier offset adjusted so that VOUTA or VOUTB
is 0 V. Full-scale trimming is accomplished by loading the DAC
register with all 1s and adjusting R1 (R3) so that VOUTA (VOUTB)
= –VIN (4095/4096). For high temperature operation, resistors
and potentiometers should have a low Temperature Coefficient.
In many applications, because of the excellent Gain T.C. and Gain
Error specifications of the AD7937, Gain Error trimming is not
necessary. In fixed reference applications, full scale can also be
adjusted by omitting R1, R2, R3, R4 and trimming the reference
voltage magnitude.
IOUTA
AGNDA
DAC A
RFBA
C1
33pF
R2
47
A1
R1
100
VDD VINA
IOUTB
AGNDB
RFBB
C2
33pF
R4
47
A2
1/2
AD712
1/2
AD712
VOUTA
VOUTB
DAC B
VINB
R3
100
DGND
DATA
INPUT
AD7937*
DB7
DB0
CONTROL CIRCUITRY
OMITTED FOR CLARITY
*
Figure 4. Unipolar Binary Operation
Table II. Unipolar Binary Code Table for
Circuit of Figure 4
Binary Number in
DAC Register
Analog Output,
MSB
LSB
VOUTA or VOUTB
1111 1111 1111
−V
IN
4095
4096


1000 0000 0000
−V
IN
2048
4096


=− 1
2 V IN
0000 0000 0001
−V
IN
1
4096


0000 0000 0000
0 V
BIPOLAR OPERATION
(4-QUADRANT MULTIPLICATION)
The recommended circuit diagram for bipolar operation is shown
in Figure 5. Offset binary coding is used.
With the appropriate DAC register loaded to 1000 0000 0000,
adjust R1 (R3) so that VOUTA (VOUTB) = 0 V. Alternatively, R1,
R2 (R3, R4) may be omitted and the ratios of R6, R7 (R9, R10)
varied for VOUTA (VOUTB) = 0 V. Full-scale trimming can be
accomplished by adjusting the amplitude of VIN or by varying the
value of R5 (R8).
If R1, R2 (R3, R4) are not used, then resistors R5, R6, R7 (R8,
R9, R10) should be ratio matched to 0.01% to ensure gain error
performance to the data sheet specification. When operating over a
wide temperature range, it is important that the resistors be of
the same type so that their temperature coefficients match.
The code table for Figure 5 is given in Table III.
IOUTA
AGNDA
DAC A
RFBA
C1
33pF
R2
47
A1
R1
100
VDD VINA
IOUTB
AGNDB
RFBB
C2
33pF
R4
47
A3
VOUTA
DAC B
VINB
R3
100
DGND
DATA
INPUT
AD7937*
DB7
DB0
CONTROL CIRCUITRY
OMITTED FOR CLARITY
*
R6
20k
R7
10k
R5
20k
R10
20k
A2
1/2
AD712
VOUTB
R8
20k
A4
R9
10k
1/2
AD712
1/2
AD712
1/2
AD712
Figure 5. Bipolar Operation (Offset Binary Coding)
Table III. Bipolar Code Table for Offset Binary
Circuit of Figure 5
Binary Number in
DAC Register
Analog Output,
MSB
LSB
VOUTA or VOUTB
1111 1111 1111
+V
IN
2047
2048


1000 0000 0001
+V
IN
1
2048


1000 0000 0000
0 V
0111 1111 1111
−V
IN
1
2048


0000 0000 0000
−V
IN
2048
2048


=−V
IN


Html Pages

1  2  3  4  5  6  7  8 


Datasheet Download

Go To PDF Page

Related Electronics Part Number

Part No.DescriptionHtml ViewManufacturer
AD7537 LC2MOS 8+4 Loading Dual 12-Bit DAC 1  2  3  4  5  More Analog Devices
AD7547 LC2MOS PARALLEL LOADING DUAL 12-BIT DAC 1  2  3  4  5  More Analog Devices
AD7549 LC2MOS DUAL 12-BIT uP-COMPATIBLE DAC 1  2  3  4  5  More Analog Devices
AD7249 LC2MOS Dual 12-Bit Serial DACPORT 1  2  3  4  5  More Analog Devices
MAX5104 Low-Power Dual Voltage-Output 12-Bit DAC with Serial Interface 1  2  3  4  5  More Maxim Integrated Products
MAX7537 CMOS Parallel Loading Dual 12-Bit multiplying D/A COnverters 1  2  3  4  5  More Maxim Integrated Products
WM2638 Dual 12-Bit Serial Input Voltage Output DAC with Internal reference 1  2  3  4  5  More Wolfson Microelectronics plc
AD7548 LC2MOS 8-BIT uP COMPATIBLE 12-BIT DAC 1  2  3  4  5  More Analog Devices
LTC1448 Dual 12-Bit Rail-to-Rail Micropower DAC 1  2  3  4  5  More Linear Technology
MX7537 CMOS Parallel Loading Dual 12-Bit Multiplying D/A Converters 1  2  3  4  5  More Maxim Integrated Products

Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ] 

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Link Exchange   |   Manufacturer List
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn