參數(shù)資料
型號(hào): AD7804
廠商: Analog Devices, Inc.
英文描述: +3.3 V to +5 V Quad/Octal 10-Bit DACs
中文描述: 3.3伏至5伏四/八通道10位DAC
文件頁(yè)數(shù): 12/28頁(yè)
文件大?。?/td> 300K
代理商: AD7804
AD7804/AD7805/AD7808/AD7809
REV. A
–12–
determined by MX1 and MX0 in the channel control register as
shown in Table III. The internal V
DD
/2 reference is provided at
the COMP pin. This internal reference can be overdriven with
an external reference thus providing the facility for two external
references.
AD7804/AD7808 POWER-UP CONDITIONS
When power is applied to the device, the device will come up in
standby mode where all the linear circuitry excluding the refer-
ence are switched off. Figure 8 shows the relevant default val-
ues for the system control register. Since a write to the system
control register is required to remove the standby condition the
only bits for which default conditions are applicable are
PD
and
SSTBY. Figure 9 details the relevant default conditions for the
Channel Control Register.
PD
SSTBY
1
1
Figure 8. Default Conditions for System Control Register
on Power-Up
STBY
CLR
MX1
MX0
1
1
0
0
Figure 9. Default Conditions for Channel Control Register
on Power-Up
After power has been applied to the device the following proce-
dure should be followed to communicate and set up the device.
First, a write to the system control register is required to clear
the SSTBY bit and change the input coding scheme if required.
For example, to remove standby and set up offset binary input
coding 0060Hex should be written to the input register, if twos
complement coding is required 0020Hex should be written to
the input register. MD1 and MD0 are decoded in the input
register and this allows the data to be written to the system
control register.
Step two requires writing to the channel control register, which
allows individual control over each DAC in the package and
allows the V
BIAS
for the DAC to be selected as well as individual
DAC standby and clear functions. For example, if channel A is
to be configured for normal operation with internal reference
selected then 4110Hex should be written to the input register.
In the input register, the MD1 and MD0 bits are decoded in
association with the address bits to give access to the required
channel control register. The third and final step is to write data
to the selected DAC. To write half scale to channel A Main
DAC, 2200Hex should be written to the input register, the
MSB in the sixteen bit stream selects the Main DAC and the
next three bits address the DAC and the final 10 bits contain
the data. To write half scale to channel A Sub DAC, then A200
should be written to the input register. The flowchart in Figure
10 shows in graphic form the steps required in communicating
with the AD7804/AD7808.
WRITE TO SYSTEM
CONTROL REGISTER
WRITE TO CHANNEL
CONTROL REGISTER
SYSTEM
CONFIGURATION
CHANNEL
CONFIGURATION
DATA WRITE
N
N
N
N
Y
Y
Y
Y
ALL CHANNELS
CONFIGURED
DATA LOADING
COMPLETE
WRITE TO SELECTED
MAIN OR SUB DAC
DATA REGISTERS
CHANGE
CHANNEL
CONFIGURATION
CHANGE
SYSTEM
CONFIGURATION
END
POWER-UP
Figure 10. Flowchart for Controlling the DAC Following
Power-Up
AD7805/AD7809 INTERFACE SECTION
The AD7805 and AD7809 are parallel data input devices and
contain both control registers and data registers. The system
control register has global control over all DACs in the package
while the channel control register allows control over individual
DACs in the package. Two data registers are also available, one
for the 10-bit Main DAC and the second for the 8-bit Sub
DAC. In the parallel mode,
CS
and
WR
, in association with the
address pins, control the loading of data. Data is transferred
from the data register to the DAC register under the control of
the
LDAC
signal. Only data contained in the DAC register deter-
mines the analog output of any DAC. The timing diagram for
10-bit parallel loading is shown in Figure 2. The MODE pin on
the device determines whether writing is to the data registers or
to the control registers. When MODE is at a logic one, writing
is to the data registers. In the next write to the data registers a
bit in the channel control register determines whether the Main
DAC or the Sub DAC is addressed. This means that to address
either the Main or the Sub DAC the
Main
/Sub bit in the control
register has to be set appropriately before the data register write.
A logic zero on the mode pin enables writing to the control
register. Bit MD0 determines whether writing is to the system
control register or to the addressed channel control register.
Bringing the
CLR
line low resets the DAC registers to one of
two known conditions depending on the coding scheme se-
lected. The hardware clear affects both the Main and Sub
DAC registers. With offset binary coding a clear sets the output
相關(guān)PDF資料
PDF描述
AD7804BN ECONOLINE: REC2.2-S_DRW(Z)/H* - 2.2W DIP Package- 1kVDC Isolation- Regulated Output- 4.5-9V, 9-18V, 18-36V, 36-72V Wide Input Range 2 : 1- UL94V-0 Package Material- Continuous Short Circiut Protection- Cost Effective- 100% Burned In- Efficiency to 84%
AD7804BR +3.3 V to +5 V Quad/Octal 10-Bit DACs
AD7805BN %2B3.3V to %2B5V Quad/Octal 10-Bit DACs
AD7805BR %2B3.3V to %2B5V Quad/Octal 10-Bit DACs
AD7805BRS +3.3 V to +5 V Quad/Octal 10-Bit DACs
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD7804BN 制造商:Analog Devices 功能描述:DAC 4-CH 10-bit 16-Pin PDIP Tube 制造商:Rochester Electronics LLC 功能描述:QUAD 10-BIT SERIAL DAC - Bulk
AD7804BNZ 功能描述:IC DAC 10BIT QUAD SERIAL 16DIP RoHS:是 類(lèi)別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:- 產(chǎn)品培訓(xùn)模塊:Data Converter Fundamentals DAC Architectures 標(biāo)準(zhǔn)包裝:750 系列:- 設(shè)置時(shí)間:7µs 位數(shù):16 數(shù)據(jù)接口:并聯(lián) 轉(zhuǎn)換器數(shù)目:1 電壓電源:雙 ± 功率耗散(最大):100mW 工作溫度:0°C ~ 70°C 安裝類(lèi)型:表面貼裝 封裝/外殼:28-LCC(J 形引線) 供應(yīng)商設(shè)備封裝:28-PLCC(11.51x11.51) 包裝:帶卷 (TR) 輸出數(shù)目和類(lèi)型:1 電壓,單極;1 電壓,雙極 采樣率(每秒):143k
AD7804BR 功能描述:IC DAC 10BIT 3.3V QUAD 16-SOIC RoHS:否 類(lèi)別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:- 產(chǎn)品培訓(xùn)模塊:Data Converter Fundamentals DAC Architectures 標(biāo)準(zhǔn)包裝:750 系列:- 設(shè)置時(shí)間:7µs 位數(shù):16 數(shù)據(jù)接口:并聯(lián) 轉(zhuǎn)換器數(shù)目:1 電壓電源:雙 ± 功率耗散(最大):100mW 工作溫度:0°C ~ 70°C 安裝類(lèi)型:表面貼裝 封裝/外殼:28-LCC(J 形引線) 供應(yīng)商設(shè)備封裝:28-PLCC(11.51x11.51) 包裝:帶卷 (TR) 輸出數(shù)目和類(lèi)型:1 電壓,單極;1 電壓,雙極 采樣率(每秒):143k
AD7804BR-REEL 功能描述:IC DAC 10BIT QUAD SRL 16-SOIC RoHS:否 類(lèi)別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:- 標(biāo)準(zhǔn)包裝:47 系列:- 設(shè)置時(shí)間:2µs 位數(shù):14 數(shù)據(jù)接口:并聯(lián) 轉(zhuǎn)換器數(shù)目:1 電壓電源:單電源 功率耗散(最大):55µW 工作溫度:-40°C ~ 85°C 安裝類(lèi)型:表面貼裝 封裝/外殼:28-SSOP(0.209",5.30mm 寬) 供應(yīng)商設(shè)備封裝:28-SSOP 包裝:管件 輸出數(shù)目和類(lèi)型:1 電流,單極;1 電流,雙極 采樣率(每秒):*
AD7804BRZ 功能描述:IC DAC 10BIT QUAD SRL 16-SOIC RoHS:是 類(lèi)別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 設(shè)置時(shí)間:4.5µs 位數(shù):12 數(shù)據(jù)接口:串行,SPI? 轉(zhuǎn)換器數(shù)目:1 電壓電源:單電源 功率耗散(最大):- 工作溫度:-40°C ~ 125°C 安裝類(lèi)型:表面貼裝 封裝/外殼:8-SOIC(0.154",3.90mm 寬) 供應(yīng)商設(shè)備封裝:8-SOICN 包裝:剪切帶 (CT) 輸出數(shù)目和類(lèi)型:1 電壓,單極;1 電壓,雙極 采樣率(每秒):* 其它名稱(chēng):MCP4921T-E/SNCTMCP4921T-E/SNRCTMCP4921T-E/SNRCT-ND