參數(shù)資料
型號(hào): AD7245AAP
廠商: ANALOG DEVICES INC
元件分類: DAC
英文描述: LC2MOS 12-Bit DACPORTs
中文描述: PARALLEL, WORD INPUT LOADING, 7 us SETTLING TIME, 12-BIT DAC, PQCC28
封裝: PLASTIC, LCC-28
文件頁(yè)數(shù): 9/16頁(yè)
文件大?。?/td> 306K
代理商: AD7245AAP
AD7245A/AD7248A
REV. A
–9–
T he data held in the DAC latch determines the analog output of
the converter. Data is latched into the DAC latch on the rising
edge of
LDAC
. T his
LDAC
signal is an asynchronous signal
and is independent of
WR
. T his is useful in many applications.
However, in systems where the asynchronous
LDAC
can occur
during a write cycle (or vice versa) care must be taken to ensure
that incorrect data is not latched through to the output. For ex-
ample, if
LDAC
goes LOW while
WR
is “LOW”, then the
LDAC
signal must stay LOW for t
7
or longer after
WR
goes
high to ensure correct data is latched through to the output.
T able I. AD7245A T ruth T able
CLR
LDAC WR
CS
Function
H
H
H
H
H
H
H
L
g
L
H
H
H
H
L
g
X
H
L
H
X
L
g
H
H
X
H
L
X
H
L
L
H
H
X
H
Both Latches are T ransparent
Both Latches are Latched
Both Latches are Latched
Input Latches T ransparent
Input Latches Latched
DAC Latches T ransparent
DAC Latches Latched
DAC Latches Loaded with all 0s
DAC Latches Latched with All
0s and Output Remains at
0 V or –5 V
Both Latches are T ransparent
and Output Follows Input Data
g
L
L
L
H = High State L = Low State X = Don’t Care
T he contents of the DAC latch are reset to all 0s by a low level
on the
CLR
line. With both latches transparent, the
CLR
line
functions like a zero override with the output brought to 0 V in
the unipolar mode and –5 V in the bipolar mode for the dura-
tion of the
CLR
pulse. If both latches are latched, a “LOW”
pulse on the
CLR
input latches all 0s into the DAC latch and
the output remains at 0 V (or –5 V) after the
CLR
line has re-
turned “HIGH.” T he
CLR
line can be used to ensure powerup
to 0 V on the AD7245A output in unipolar operation and is also
useful, when used as a zero override, in system calibration
cycles.
Figure 4 shows the input control logic for the AD7245A and the
write cycle timing for the part is shown in Figure 5.
Figure 4. AD7245A Input Control Logic
Figure 5. AD7245A Write Cycle Timing Diagram
INT E RFACE LOGIC INFORMAT ION—AD7248A
T he input loading structure on the AD7248A is configured for
interfacing to microprocessors with an 8-bit wide data bus. T he
part contains two 12-bit latches—an input latch and a DAC
latch. Only the data held in the DAC latch determines the ana-
log output from the converter. T he truth table for AD7248A
operation is shown in T able II, while the input control logic dia-
gram is shown in Figure 6.
Figure 6. AD7248A Input Control Logic
CSMSB
,
CSLSB
and
WR
control the loading of data from the
external data bus to the input latch. T he eight data inputs on
the AD7248A accept right justified data. T his data is loaded to
the input latch in two separate write operations.
CSLSB
and
WR
control the loading of the lower 8-bits into the 12-bit wide
latch. T he loading of the upper 4-bit nibble is controlled by
CSMSB
and
WR
. All control inputs are level triggered, and in-
put data for either the lower byte or upper 4-bit nibble is latched
into the input latches on the rising edge of
WR
(or either
CSMSB
or
CSLSB
). T he order in which the data is loaded to
the input latch (i.e., lower byte or upper 4-bit nibble first) is not
important.
T he
LDAC
input controls the transfer of 12-bit data from the
input latch to the DAC latch. T his
LDAC
signal is also level
triggered, and data is latched into the DAC latch on the rising
edge of
LDAC
. T he
LDAC
input is asynchronous and indepen-
dent of
WR
. T his is useful in many applications especially in
相關(guān)PDF資料
PDF描述
AD7245AAQ LC2MOS 12-Bit DACPORTs
AD7245AAR LC2MOS 12-Bit DACPORTs
AD7245ABN LC2MOS 12-Bit DACPORTs
AD7245ABR LC2MOS 12-Bit DACPORTs
AD7245ATE LC2MOS 12-Bit DACPORTs
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD7245AAP-REEL 制造商:Analog Devices 功能描述:DAC 1-CH R-2R 12-bit 28-Pin PLCC T/R 制造商:Rochester Electronics LLC 功能描述:PARALLEL,12-BIT DACPORT - Tape and Reel
AD7245AAPZ 功能描述:IC DAC 12BIT LC2MOS 28-PLCC RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:DACPORT® 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)目和類型:1 電壓,單極;1 電壓,雙極 采樣率(每秒):143k
AD7245AAPZ-REEL 功能描述:IC DAC 12BIT LC2MOS 28-PLCC RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:DACPORT® 標(biāo)準(zhǔn)包裝:2,400 系列:- 設(shè)置時(shí)間:- 位數(shù):18 數(shù)據(jù)接口:串行 轉(zhuǎn)換器數(shù)目:3 電壓電源:模擬和數(shù)字 功率耗散(最大):- 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:36-TFBGA 供應(yīng)商設(shè)備封裝:36-TFBGA 包裝:帶卷 (TR) 輸出數(shù)目和類型:* 采樣率(每秒):*
AD7245AAQ 功能描述:IC DAC 12BIT W/REF 24-CDIP RoHS:否 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:DACPORT® 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)目和類型:1 電壓,單極;1 電壓,雙極 采樣率(每秒):143k
AD7245AAR 功能描述:IC DAC 12BIT W/REF 24-SOIC RoHS:否 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:DACPORT® 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)目和類型:1 電壓,單極;1 電壓,雙極 采樣率(每秒):143k