Electronic Components Datasheet Search
  English  ▼
ALLDATASHEET.NET

X  

AD7541AKR Datasheet(PDF) 4 Page - Analog Devices

Part # AD7541AKR
Description  CMOS 12-Bit Monolithic Multiplying 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

AD7541AKR Datasheet(HTML) 4 Page - Analog Devices

  AD7541AKR Datasheet HTML 1Page - Analog Devices AD7541AKR Datasheet HTML 2Page - Analog Devices AD7541AKR Datasheet HTML 3Page - Analog Devices AD7541AKR Datasheet HTML 4Page - Analog Devices AD7541AKR Datasheet HTML 5Page - Analog Devices AD7541AKR Datasheet HTML 6Page - Analog Devices AD7541AKR Datasheet HTML 7Page - Analog Devices AD7541AKR Datasheet HTML 8Page - Analog Devices  
Zoom Inzoom in Zoom Outzoom out
 4 / 8 page
background image
AD7541A
–4–
REV. B
GENERAL CIRCUIT INFORMATION
The simplified D/A circuit is shown in Figure 1. An inverted
R-2R ladder structure is used—that is, the binarily weighted
currents are switched between the OUT1 and OUT2 bus lines,
thus maintaining a constant current in each ladder leg indepen-
dent of the switch state.
10k
10k
10k
20k
20k
20k
20k
20k
S1
S2
S3
S12
VREF
OUT2
OUT1
RFEEDBACK
BIT 12 (LSB)
BIT 3
BIT 2
BIT 1 (MSB)
DIGITAL INPUTS (DTL/TTL/CMOS COMPATIBLE)
LOGIC: A SWITCH IS CLOSED TO IOUT1 FOR
ITS DIGITAL INPUT IN A "HIGH" STATE.
10k
Figure 1. Functional Diagram (Inputs HIGH)
The input resistance at VREF (Figure 1) is always equal to RLDR
(RLDR is the R/2R ladder characteristic resistance and is equal to
value “R”). Since RIN at the VREF pin is constant, the reference
terminal can be driven by a reference voltage or a reference
current, ac or dc, of positive or negative polarity. (If a current
source is used, a low temperature coefficient external RFB is
recommended to define scale factor.)
EQUIVALENT CIRCUIT ANALYSIS
The equivalent circuits for all digital inputs LOW and all digital
inputs HIGH are shown in Figures 2 and 3. In Figure 2 with all
digital inputs LOW, the reference current is switched to OUT2.
The current source ILEAKAGE is composed of surface and junc-
tion leakages to the substrate, while the I/4096 current source
represents a constant 1-bit current drain through the termina-
tion resistor on the R-2R ladder. The ON capacitance of the
output N-channel switch is 200 pF, as shown on the OUT2
terminal. The OFF switch capacitance is 70 pF, as shown on
the OUT1 terminal. Analysis of the circuit for all digital inputs
HIGH, as shown in Figure 3 is similar to Figure 2; however, the
ON switches are now on terminal OUT1, hence the 200 pF at
that terminal.
ILEAKAGE
70pF
R
ILEAKAGE
200pF
I/4096
IREF
R
15k
VREF
RFB
OUT1
OUT2
Figure 2. DAC Equivalent Circuit All Digital Inputs LOW
ILEAKAGE
70pF
R
ILEAKAGE
200pF
I/4096
IREF
R
15k
VREF
RFB
OUT2
OUT1
Figure 3. DAC Equivalent Circuit All Digital Inputs HIGH
APPLICATIONS
UNIPOLAR BINARY OPERATION
(2-QUADRANT MULTIPLICATION)
Figure 4 shows the analog circuit connections required for uni-
polar binary (2-quadrant multiplication) operation. With a dc
reference voltage or current (positive or negative polarity) ap-
plied at Pin 17, the circuit is a unipolar D/A converter. With an
ac reference voltage or current, the circuit provides 2-quadrant
multiplication (digitally controlled attenuation). The input/
output relationship is shown in Table II.
R1 provides full-scale trim capability [i.e., load the DAC register
to 1111 1111 1111, adjust R1 for VOUT = –VREF (4095/4096)].
Alternatively, Full Scale can be adjusted by omitting R1 and R2
and trimming the reference voltage magnitude.
C1 phase compensation (10 pF to 25 pF) may be required for
stability when using high speed amplifiers. (C1 is used to cancel
the pole formed by the DAC internal feedback resistance and
output capacitance at OUT1).
Amplifier A1 should be selected or trimmed to provide VOS
10% of the voltage resolution at VOUT. Additionally, the ampli-
fier should exhibit a bias current which is low over the tempera-
ture range of interest (bias current causes output offset at VOUT
equal to IB times the DAC feedback resistance, nominally 11 k
Ω).
The AD544L is a high speed implanted FET input op amp with
low factory-trimmed VOS.
18
16
1
2
3
17
AD7541A
VDD
RFB
VDD
VREF
PINS 4–15
DGND
OUT1
OUT2
R1
*
VIN
BIT 1 – BIT 12
DIGITAL
GROUND
ANALOG
COMMON
R2
*
C1
33pF
AD544L
(SEE TEXT)
VOUT
*REFER TO TABLE 1
Figure 4. Unipolar Binary Operation
Table I. Recommended Trim Resistor Values vs. Grades
Trim
Resistor
JN/AQ/SD
KN/BQ/TD
R1
100
100
R2
47
33
Table II. Unipolar Binary Code Table for Circuit of Figure 4
Binary Number in DAC
MSB
LSB
Analog Output, VOUT
1 1 1 1
1 1 1 1
1 1 1 1
–VIN
4095
4096


1 0 0 0
0 0 0 0
0 0 0 0
–VIN
2048
4096


= –1/2 VIN
0 0 0 0
0 0 0 0
0 0 0 1
–VIN
1
4096


0 0 0 0
0 0 0 0
0 0 0 0
0 Volts


Similar Part No. - AD7541AKR

ManufacturerPart #DatasheetDescription
logo
Analog Devices
AD7541AKR AD-AD7541AKR Datasheet
227Kb / 8P
   CMOS 12-Bit Monolithic Multiplying DAC
REV. B
AD7541AKR AD-AD7541AKR Datasheet
230Kb / 8P
   CMOS 12-Bit Monolithic Multiplying DAC
REV. B
AD7541AKR AD-AD7541AKR Datasheet
299Kb / 14P
   CMOS, 12-Bit, Monolithic Multiplying DAC
AD7541AKRZ AD-AD7541AKRZ Datasheet
230Kb / 8P
   CMOS 12-Bit Monolithic Multiplying DAC
REV. B
AD7541AKRZ AD-AD7541AKRZ Datasheet
299Kb / 14P
   CMOS, 12-Bit, Monolithic Multiplying DAC
More results

Similar Description - AD7541AKR

ManufacturerPart #DatasheetDescription
logo
Analog Devices
AD7541A AD-AD7541A Datasheet
227Kb / 8P
   CMOS 12-Bit Monolithic Multiplying DAC
REV. B
AD7541A AD-AD7541A_17 Datasheet
299Kb / 14P
   CMOS, 12-Bit, Monolithic Multiplying DAC
5962-89481022A AD-5962-89481022A Datasheet
230Kb / 8P
   CMOS 12-Bit Monolithic Multiplying DAC
REV. B
AD7541AKRZ AD-AD7541AKRZ Datasheet
230Kb / 8P
   CMOS 12-Bit Monolithic Multiplying DAC
REV. B
AD7541AKNZ AD-AD7541AKNZ Datasheet
230Kb / 8P
   CMOS 12-Bit Monolithic Multiplying DAC
REV. B
AD7541A AD-AD7541A_15 Datasheet
230Kb / 8P
   12-Bit Monolithic Multiplying DAC
REV. B
logo
Sipex Corporation
HS7541A SIPEX-HS7541A Datasheet
110Kb / 7P
   12-Bit CMOS Multiplying DAC
logo
Analog Devices
AD7545 AD-AD7545_17 Datasheet
229Kb / 9P
   CMOS 12-Bit Buffered Multiplying DAC
logo
Intersil Corporation
AD7545 INTERSIL-AD7545 Datasheet
111Kb / 7P
   12-Bit, Buffered, Multiplying CMOS DAC
August 1997
AD7545 INTERSIL-AD7545_01 Datasheet
271Kb / 8P
   12-Bit, Buffered, Multiplying CMOS DAC
More results


Html Pages

1 2 3 4 5 6 7 8


Datasheet Download

Go To PDF Page


Link URL




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

About Alldatasheet   |   Advertisement   |   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
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com