參數(shù)資料
型號(hào): AD7669AR
廠商: ANALOG DEVICES INC
元件分類(lèi): 模擬信號(hào)調(diào)理
英文描述: LC2MOS Complete, 8-Bit Analog I/0 Systems
中文描述: SPECIALTY ANALOG CIRCUIT, PDSO28
封裝: SOIC-28
文件頁(yè)數(shù): 15/20頁(yè)
文件大小: 504K
代理商: AD7669AR
AD7569/AD7669
–15–
REV. B
an
RD
pulse for the AD7569/AD7669. This
RD
pulse accesses
data from the ADC and places the conversion result into a regis-
ter on the 74646. The rising edge of this pulse generates an in-
terrupt request to the processor. The conversion result is read
from the 74646 register by performing an I/O read to the
decoded address of the 74646. Writing data to the relevant
AD7569/AD7669 DAC involves an I/O write to the 74646,
which transfers the data to the data inputs of the AD7569/
AD7669. Data is latched into the selected DAC register on the
rising edge of
IOW
.
APPLYING THE AD7569/AD7669 DAC
An internal gain/offset network on the AD7569/AD7669 allows
several output voltage ranges. The part can produce unipolar
output ranges of 0 V to +1.25 V or 0 V to +2.5 V and bipolar
output ranges of –1.25 V to +1.25 V or –2.5 V to +2.5 V. Con-
nections for these various output ranges are outlined below.
UNIPOLAR (0 V to +1.25 V) CONFIGURATION
The first of the configurations provides an output voltage range
of 0 V to +1.25 V. This is achieved by tying the V
SS
and
RANGE inputs to AGND
DAC
(= 0 V). Figure 21 shows the con-
figuration of the AD7569 to achieve this output range. A similar
configuration of the AD7669 gives the same output range. The
table for output voltage versus the digital code in the DAC regis-
ter is shown in Table IV.
Figure 21. AD7569 Unipolar (0 V to +1.25 V) Operation
Table IV. Unipolar (0 V to +1.25 V) Code Table
DAC Register Contents
MSB
LSB
Analog Output, V
OUT
1111
1111
+V
REF
255
256
= +V
REF
/2
1000
0001
+V
REF
129
256
1000
0000
+V
REF
128
256
0111
1111
+V
REF
127
256
0000
0001
+V
REF
1
256
0000
0000
0 V
NOTE: 1 LSB = (V
REF
) (2
–8
) = V
REF
(1/256); V
REF
= +1.25 V Nominal
UNIPOLAR (0 V to +2.5 V) CONFIGURATION
The 0 V to +2.5 V output voltage range is achieved by tying V
SS
to AGND
DAC
(= 0 V) and the RANGE input to V
DD
. The table
for output voltage versus digital code is as in Table IV with
2.V
REF
replacing V
REF
. Note that for this range
1
LSB
=
2.
V
REF
(2
8
)
=
V
REF
1
128
BIPOLAR (–1.25 V to +1.25 V) CONFIGURATION
The first of the bipolar configurations is achieved by tying the
RANGE input to AGND
DAC
(= 0 V) and V
SS
to –5 V. The V
SS
voltage level at which the AD7569/AD7669 changes to bipolar
operation is approximately –1 V. When the part is configured
for bipolar outputs, the input coding becomes twos comple-
ment. The table for output voltage versus the digital code in the
DAC register is shown in Table V. Note as with the unipolar
configuration, a digital input code of all 0s produces an output
of 0 V. It should be noted, however, that a low pulse on the
RESET
line for the bipolar ranges sets the output voltage to
negative full scale.
Table V. Bipolar (–1.25 V to +1.25 V) Code Table
DAC Register Contents
MSB
LSB
Analog Output, V
OUT
0111
1111
+V
REF
127
128
0000
0001
+V
REF
1
128
0000
0000
0 V
1111
1111
–V
REF
1
128
= –V
REF
1000
0001
–V
REF
127
128
1000
0000
–V
REF
128
128
NOTE: 1 LSB = (V
REF
)(2
–7
) = V
REF
(1/128)
BIPOLAR (–2.5 V to +2.5 V) CONFIGURATION
The –2.5 V to +2.5 V bipolar output range is achieved by tying
the RANGE input to V
DD
and the V
SS
input to –5 V. Once
again, the input coding is 2s complement. The table for output
voltage versus digital code is as in Table V with 2.V
REF
replacing
V
REF
. Note that for this range
1
LSB
=
4.
V
REF
(2
8
)
=
V
REF
1
64
相關(guān)PDF資料
PDF描述
AD7569 Complete, 8-Bit Analog I/0 Systems(完備的8位模擬I/O系統(tǒng))
AD7669 Complete, 8-Bit Analog I/0 Systems(完備的8位模擬I/O系統(tǒng))
AD7569AQ LC2MOS Complete, 8-Bit Analog I/0 Systems
AD7569BN LC2MOS Complete, 8-Bit Analog I/0 Systems
AD7569BQ LC2MOS Complete, 8-Bit Analog I/0 Systems
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD7669AR-REEL 制造商:Analog Devices 功能描述:
AD7669ARZ 功能描述:IC I/O PORT 8BIT ANALOG 28SOIC RoHS:是 類(lèi)別:集成電路 (IC) >> 接口 - 專(zhuān)用 系列:LC²MOS 特色產(chǎn)品:NXP - I2C Interface 標(biāo)準(zhǔn)包裝:1 系列:- 應(yīng)用:2 通道 I²C 多路復(fù)用器 接口:I²C,SM 總線 電源電壓:2.3 V ~ 5.5 V 封裝/外殼:16-TSSOP(0.173",4.40mm 寬) 供應(yīng)商設(shè)備封裝:16-TSSOP 包裝:剪切帶 (CT) 安裝類(lèi)型:表面貼裝 產(chǎn)品目錄頁(yè)面:825 (CN2011-ZH PDF) 其它名稱(chēng):568-1854-1
AD7669ARZ-REEL 功能描述:IC I/O PORT 8BIT ANALOG 28SOIC RoHS:是 類(lèi)別:集成電路 (IC) >> 接口 - 專(zhuān)用 系列:LC²MOS 特色產(chǎn)品:NXP - I2C Interface 標(biāo)準(zhǔn)包裝:1 系列:- 應(yīng)用:2 通道 I²C 多路復(fù)用器 接口:I²C,SM 總線 電源電壓:2.3 V ~ 5.5 V 封裝/外殼:16-TSSOP(0.173",4.40mm 寬) 供應(yīng)商設(shè)備封裝:16-TSSOP 包裝:剪切帶 (CT) 安裝類(lèi)型:表面貼裝 產(chǎn)品目錄頁(yè)面:825 (CN2011-ZH PDF) 其它名稱(chēng):568-1854-1
AD7669JN 制造商:Analog Devices 功能描述:Data Acquisition System Single ADC Dual DAC 8-Bit 28-Pin PDIP W 制造商:Rochester Electronics LLC 功能描述:COMPLETE 8 BIT I/O SYSTEM - Bulk
AD7669JNZ 功能描述:IC I/O PORT 8BIT ANLG 28DIP RoHS:是 類(lèi)別:集成電路 (IC) >> 接口 - 專(zhuān)用 系列:LC²MOS 特色產(chǎn)品:NXP - I2C Interface 標(biāo)準(zhǔn)包裝:1 系列:- 應(yīng)用:2 通道 I²C 多路復(fù)用器 接口:I²C,SM 總線 電源電壓:2.3 V ~ 5.5 V 封裝/外殼:16-TSSOP(0.173",4.40mm 寬) 供應(yīng)商設(shè)備封裝:16-TSSOP 包裝:剪切帶 (CT) 安裝類(lèi)型:表面貼裝 產(chǎn)品目錄頁(yè)面:825 (CN2011-ZH PDF) 其它名稱(chēng):568-1854-1