AD7249 Analog Devices, AD7249 Datasheet

no-image

AD7249

Manufacturer Part Number
AD7249
Description
LC2MOS Dual 12-Bit Serial DACPORT
Manufacturer
Analog Devices
Datasheet

Specifications of AD7249

Resolution (bits)
12bit
Dac Update Rate
125kSPS
Dac Settling Time
7µs
Max Pos Supply (v)
+16.5V
Single-supply
Yes
Dac Type
Voltage Out
Dac Input Format
Ser

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
AD7249AR
Manufacturer:
ADI/亚德诺
Quantity:
20 000
Part Number:
AD7249ARZ
Manufacturer:
ADI/亚德诺
Quantity:
20 000
Part Number:
AD7249ARZ-REEL
Manufacturer:
ADI/亚德诺
Quantity:
20 000
Part Number:
AD7249BRZ
Manufacturer:
ADI/亚德诺
Quantity:
20 000
Part Number:
AD7249BRZ-REEL
Manufacturer:
VISHAY
Quantity:
2 000
Part Number:
AD7249SQ
Manufacturer:
SILICON
Quantity:
15 000
Part Number:
AD7249SQ
Manufacturer:
ADI/亚德诺
Quantity:
20 000
a
GENERAL DESCRIPTION
The AD7249 DACPORT contains a pair of 12-bit, voltage-
output, digital-to-analog converters with output amplifiers and
Zener voltage reference on a monolithic CMOS chip. No exter-
nal trims are required to achieve full specified performance.
The output amplifiers are capable of developing +10 V across a
2 kΩ load. The output voltage ranges with single supply opera-
tion are 0 V to +5 V or 0 V to +10 V, while an additional bipolar
± 5 V output range is available with dual supplies. The ranges
are selected using the internal gain resistor.
Interfacing to the AD7249 is serial, minimizing pin count and
allowing a small package size. Standard control signals allow
interfacing to most DSP processors and microcontrollers. The
data stream consists of 16 bits, DB15 to DB13 are don’t care
bits, the 13th bit (DB12) is used as the channel select bit and
the remaining 12 bits (DB11 to DB0) contain the data to update
the DAC. The 16-bit data word is clocked into the input register
on each falling SCLK edge.
The data format is natural binary in both unipolar ranges, while
either offset binary or twos complement format may be selected
in the bipolar range. A CLR function is provided which sets the
output to 0 V in both unipolar ranges and in the twos comple-
ment bipolar range, while with offset binary data format, the
output is set to –REFIN. This function is useful as a power-on
reset as it allows the outputs to be set to a known voltage level.
DACPORT is a registered trademark of Analog Devices, Inc.
The AD7249 features a serial interface which allows easy con-
nection to both microcomputers and 16-bit digital signal proces-
sors with serial ports. The serial data may be applied at rates up
to 2 MHz allowing a DAC update rate of 125 kHz.
The AD7249 is fabricated on linear compatible CMOS
(LC
aged in 16-lead DIP and 16-lead SOIC packages.
PRODUCT HIGHLIGHTS
1. Two complete 12-bit DACPORTs
2. Single or dual supply operation
3. Minimum 3-wire interface to most DSP processors
4. DAC update rate—125 kHz
REFOUT
The AD7249 contains two complete voltage output, 12-bit
DACs in both 16-lead DIP and SOIC packages.
2
REFIN
AGND
DGND
MOS), an advanced, mixed technology process. It is pack-
Dual 12-Bit Serial DACPORT
SCLK
FUNCTIONAL BLOCK DIAGRAM
SDIN
V
DD
INPUT SHIFT REGISTER
SYNC
BIN/COMP CLR
AD7249
12-BIT
DAC A
DAC B
12-BIT
V
SS
AD7249
A1
A2
2R
2R
2R
2R
LDAC
LC
2
MOS
R
V
R
V
OUTA
OUTB
OFSA
OFSB
®

Related parts for AD7249

AD7249 Summary of contents

Page 1

... +10 V, while an additional bipolar ± output range is available with dual supplies. The ranges are selected using the internal gain resistor. Interfacing to the AD7249 is serial, minimizing pin count and allowing a small package size. Standard control signals allow interfacing to most DSP processors and microcontrollers. The data stream consists of 16 bits, DB15 to DB13 are don’ ...

Page 2

... AD7249–SPECIFICATIONS + 100 pF to AGND. All specifications Parameter A Version STATIC PERFORMANCE Resolution 12 ± Relative Accuracy ± 0.9 3 Differential Nonlinearity ± Unipolar Offset Error ± Bipolar Zero Error ± Full-Scale Error ± 5 Full-Scale Temperature Coefficient ...

Page 3

... ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the AD7249 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high-energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality ...

Page 4

... REFOUT should be connected to REFIN. 12 REFIN Voltage Reference Input internally buffered before being applied to both DACs. The nominal reference voltage for specified operation of the AD7249 Output Offset Resistor for the amplifier of DAC connected to V OFSB AGND for the +10 V range and to REFIN for the – ...

Page 5

... Digital Feedthrough This is a measure of the voltage spike that appears on V result of feedthrough from the digital inputs on the AD7249 measured with LDAC held high. Relative Accuracy (Linearity) Relative Accuracy, or endpoint linearity measure of the ...

Page 6

... F External Reference In some applications, the user may require a system reference or some other external reference to drive the AD7249. References such as the AD586 provide an ideal external reference source (See Figure 10). The REFIN voltage is internally buffered by a unity gain amplifier before being applied to the D/A converter. ...

Page 7

... DIGITAL INTERFACE The AD7249 contains an input serial to parallel shift register and a DAC latch for both DAC A and DAC B. A simplified diagram of the input loading circuitry is shown in Figure 7. Serial data on the SDIN input is loaded to the input register under control of SYNC and SCLK. The SYNC input provides ...

Page 8

... Dual supplies may be used to improve settling time and give increased current sink capability for the amplifier. Figure 9 shows the connection diagram for unipolar operation of the AD7249. Table I shows the digital code vs. analog output for this configuration. input the two ...

Page 9

... Good printed circuit board layout is as important as the overall circuit design itself in achieving high speed converter perfor- mance. The AD7249 works on an LSB size of 2.44 mV for the unipolar range and the bipolar ± range, when using the unipolar range the LSB size is 1.22 mV. ...

Page 10

... The data transfer is initiated by TFS going low. Data from the ADSP-2101/ADSP-2102 is clocked into the AD7249 on the falling edge of SCLK. DB12 of the 16-bit serial data stream selects the DAC to be updated. Both DACs can be updated by holding LDAC high while performing two write cycles to the DAC ...

Page 11

... SBUF register is arranged correctly so that the don’t care bits are the first to be transmitted to the AD7249 and the last bit to be sent is the LSB of the word to be loaded to the AD7249. When data transmitted to the part, P3 ...

Page 12

... BSC 16 1 0.125 (3.17) 0.364 (9.246) MIN 0.344 (8.738) 0.02 (0.5) 0.016 (0.406 0.045 (1.15) 0.020 (0.50) SDIN V V SCLK OUTA OUTA AD7249* SYNC LDAC V V OUTB OUTB 0.195 (4.95) 0.115 (2.93) Cerdip (Q-16) 9 0.271 (6.89) 0.240 (6.09) 8 PIN 1 0.300 (7.62) REF 0.780 (19.81) 0.163 (4.14) 0.133 (3.378) 0.21 (5.33) 0.15 (3.81) 0.012 (0.305) ...

Related keywords