- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄373966 > AD9740ARU (ANALOG DEVICES INC) 10-Bit, 165 MSPS TxDAC D/A Converter PDF資料下載
參數(shù)資料
| 型號： | AD9740ARU |
| 廠商： | ANALOG DEVICES INC |
| 元件分類： | DAC |
| 英文描述： | 10-Bit, 165 MSPS TxDAC D/A Converter |
| 中文描述： | PARALLEL, WORD INPUT LOADING, 0.011 us SETTLING TIME, 10-BIT DAC, PDSO28 |
| 封裝： | MO-153AE, TSSOP-28 |
| 文件頁數(shù)： | 9/20頁 |
| 文件大?。?/td> | 743K |
| 代理商： | AD9740ARU |
REV. 0
AD9740
–9–
FUNCTIONAL DESCRIPTION
Figure 3 shows a simplified block diagram of the AD9740. The
AD9740 consists of a DAC, digital control logic, and full-scale
output current control. The DAC contains a PMOS current
source array capable of providing up to 20 mA of full-scale
current (I
OUTFS
). The array is divided into 31 equal currents
that make up the 5 most significant bits (MSBs). The next 4 bits,
or middle bits, consist of 15 equal current sources whose value
is 1/16th of an MSB current source. The remaining LSBs are
binary weighted fractions of the middle bits current sources.
Implementing the middle and lower bits with current sources,
instead of an R-2R ladder, enhances its dynamic performance for
multitone or low amplitude signals and helps maintain the DAC’s
high output impedance (i.e., >100 k
).
All of these current sources are switched to one or the other of
the two output nodes (i.e., IOUTA or IOUTB) via PMOS
differential current switches. The switches are based on the
architecture that was pioneered in the AD9764 family, with
further refinements to reduce distortion contributed by the
switching transient. This switch architecture also reduces vari-
ous timing errors and provides matching complementary drive
signals to the inputs of the differential current switches.
The analog and digital sections of the AD9740 have separate
power supply inputs (i.e., AVDD and DVDD) that can operate
independently over a 3.0 V to 3.6 V range. The digital section,
which is capable of operating up to a 165 MSPS clock rate,
consists of edge-triggered latches and segment decoding logic
circuitry. The analog section includes the PMOS current
sources, the associated differential switches, a 1.2 V band gap
voltage reference, and a reference control amplifier.
The DAC full-scale output current is regulated by the refer-
ence control amplifier and can be set from 2 mA to 20 mA via
an external resistor, R
SET
, connected to the full-scale adjust
(FSADJ) pin. The external resistor, in combination with both
the reference control amplifier and voltage reference, V
REFIO
,
sets the reference current I
REF
, which is replicated to the
segmented current sources with the proper scaling factor. The
full-scale current, I
OUTFS
, is 32 times I
REF
.
REFERENCE OPERATION
The AD9740 contains an internal 1.2 V band gap reference.
The internal reference can be disabled by raising REFLO to
AVDD. It can also be easily overridden by an external reference
with no effect on performance. REFIO serves as either an input
or output depending on whether the internal or an external
reference is used. To use the internal reference, simply decouple
the REFIO pin to ACOM with a 0.1
μ
F capacitor and connect
REFLO to ACOM via a resistance less than 5
. The internal
reference voltage will be present at REFIO. If the voltage at
REFIO is to be used anywhere else in the circuit, an external
buffer amplifier with an input bias current of less than 100 nA
should be used. An example of the use of the internal reference
is given in Figure 4.
150pF
+1.2V REF
AVDD
REFLO
CURRENT
SOURCE
ARRAY
3.3V
REFIO
FS ADJ
2k
0.1 F
AD9740
ADDITIONAL
LOAD
OPTIONAL
EXTERNAL
REF BUFFER
Figure 4. Internal Reference Configuration
An external reference can be applied to REFIO as shown in Figure 5.
The external reference may provide either a fixed reference voltage
to enhance accuracy and drift performance or a varying reference
voltage for gain control. Note that the 0.1
μ
F compensation capaci-
tor is not required since the internal reference is overridden, and
the relatively high input impedance of REFIO minimizes any
loading of the external reference.
150pF
+1.2V REF
AVDD
REFLO
CURRENT
SOURCE
ARRAY
REFIO
FS ADJ
R
SET
AD9740
EXTERNAL
REF
I
REF
=
V
REFIO
/R
SET
AVDD
REFERENCE
CONTROL
AMPLIFIER
V
REFIO
3.3V
Figure 5. External Reference Configuration
DIGITAL DATA INPUTS (DB9–DB0)
150pF
+1.20V REF
AVDD
ACOM
REFLO
PMOS
CURRENT SOURCE
ARRAY
3.3V
SEGMENTED SWITCHES
FOR DB9–DB1
LSB
SWITCH
REFIO
FS ADJ
DVDD
DCOM
CLOCK
3.3V
R
SET
2k
0.1 F
IOUTA
IOUTB
AD9740
SLEEP
LATCHES
I
REF
V
REFIO
CLOCK
IOUTB
IOUTA
R
LOAD
50
V
OUTB
V
OUTA
R
LOAD
50
V
DIFF
= V
OUTA
– V
OUTB
MODE
Figure 3. Simplified Block Diagram
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| AD9742 | 12-Bit, 165 MSPS TxDAC D/A Converter |
| AD9742-EB | 12-Bit, 165 MSPS TxDAC D/A Converter |
| AD9742AR | 12-Bit, 165 MSPS TxDAC D/A Converter |
| AD9742ARU | 12-Bit, 165 MSPS TxDAC D/A Converter |
| AD9744ARURL7 | 14-Bit, 165 MSPS TxDAC D/A Converter |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| AD9740ARURL7 | 功能描述:IC DAC 10BIT 210MSPS 28-TSSOP RoHS:否 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:TxDAC® 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)目和類型:1 電流，單極；1 電流，雙極 采樣率（每秒）:* |
| AD9740ARUZ | 功能描述:IC DAC 10BIT 210MSPS 28-TSSOP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:TxDAC® 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:50 系列:- 設(shè)置時(shí)間:4µs 位數(shù):12 數(shù)據(jù)接口:串行 轉(zhuǎn)換器數(shù)目:2 電壓電源:單電源 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:8-TSSOP，8-MSOP（0.118"，3.00mm 寬） 供應(yīng)商設(shè)備封裝:8-uMAX 包裝:管件 輸出數(shù)目和類型:2 電壓，單極 采樣率（每秒）:* 產(chǎn)品目錄頁面:1398 (CN2011-ZH PDF) |
| AD9740ARUZ1 | 制造商:AD 制造商全稱:Analog Devices 功能描述:10-Bit, 210 MSPS TxDAC D/A Converter |
| AD9740ARUZRL7 | 功能描述:IC DAC 10BIT 210MSPS 28-TSSOP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:TxDAC® 產(chǎn)品培訓(xùn)模塊:LTC263x 12-, 10-, and 8-Bit VOUT DAC Family 特色產(chǎn)品:LTC2636 - Octal 12-/10-/8-Bit SPI VOUT DACs with 10ppm/°C Reference 標(biāo)準(zhǔn)包裝:91 系列:- 設(shè)置時(shí)間:4µs 位數(shù):10 數(shù)據(jù)接口:MICROWIRE?，串行，SPI? 轉(zhuǎn)換器數(shù)目:8 電壓電源:單電源 功率耗散（最大）:2.7mW 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:14-WFDFN 裸露焊盤 供應(yīng)商設(shè)備封裝:14-DFN-EP（4x3） 包裝:管件 輸出數(shù)目和類型:8 電壓，單極 采樣率（每秒）:* |
| AD9740ARZ | 功能描述:IC DAC 10BIT 210MSPS 28-SOIC RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 數(shù)模轉(zhuǎn)換器 系列:TxDAC® 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)目和類型:1 電壓，單極；1 電壓，雙極 采樣率（每秒）:* 其它名稱:MCP4921T-E/SNCTMCP4921T-E/SNRCTMCP4921T-E/SNRCT-ND |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。