- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄17109 > EVAL-ADUC7121QSPZ (Analog Devices Inc)BOARD EVALUATION FOR ADUC7121 PDF資料下載
參數(shù)資料
| 型號： | EVAL-ADUC7121QSPZ |
| 廠商： | Analog Devices Inc |
| 文件頁數(shù)： | 38/96頁 |
| 文件大?。?/td> | 0K |
| 描述： | BOARD EVALUATION FOR ADUC7121 |
| 設(shè)計(jì)資源： | ADUC7121 Gerber Files ADUC7121 Schematic |
| 標(biāo)準(zhǔn)包裝： | 1 |
| 系列： | MicroConverter® ADuC7xxx |
| 類型： | MCU |
| 適用于相關(guān)產(chǎn)品： | ADUC7121 |
| 所含物品： | 板，CD |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁當(dāng)前第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁第78頁第79頁第80頁第81頁第82頁第83頁第84頁第85頁第86頁第87頁第88頁第89頁第90頁第91頁第92頁第93頁第94頁第95頁第96頁
Data Sheet
ADuC7121
Rev. B | Page 43 of 96
Using the DACs
The on-chip DAC architecture consists of a resistor string DAC
followed by an output buffer amplifier. The functional equivalent
is shown in Figure 30.
Figure 30. DAC Structure
As shown in Figure 30, the reference source for each DAC is
user-selectable in software. It can be either AVDD, VREF, or
EXT_REF. In 0 V-to-AVDD mode, the DAC output transfer
function spans from 0 V to the voltage at the AVDD pin. In 0 V-
to-EXT_REF mode, the DAC output transfer function spans
from 0 V to the voltage at the VREF_2.5 pin. In 0 V-to-VREF mode,
the DAC output transfer function spans from 0 V to the internal
2.5 V reference, VREF.
The DAC output buffer amplifier features a true rail-to-rail
output stage implementation. This means that, when unloaded,
each output is capable of swinging to within less than 5 mV of
both AVDD and ground. Moreover, the linearity specification of the
DAC (when driving a 5 kΩ resistive load to ground) is guaranteed
through the full transfer function except for Code 0 to Code 100,
and, in 0 V-to-AVDD mode only, Code 3995 to Code 4095.
Linearity degradation near ground and AVDD is caused by satu-
ration of the output amplifier, and a general representation of its
effects (neglecting offset and gain error) is shown in Figure 31. The
dotted line in Figure 31 indicates the ideal transfer function, and
the solid line represents what the transfer function may look
like with endpoint nonlinearities due to saturation of the output
amplifier. Note that Figure 31 represents a transfer function in
0 V-to-AVDD mode only. In 0 V-to-VREF or 0 V-to-EXT_REF
modes (with VREF < AVDD or EXT_REF < AVDD), the lower
nonlinearity is similar. However, the upper portion of the
transfer function follows the ideal line right to the end (VREF in this
case, not AVDD), showing no signs of endpoint linearity errors.
Figure 31. Endpoint Nonlinearities Due to Amplifier Saturation
The endpoint nonlinearities conceptually illustrated in Figure 31
worsen as a function of output loading. The ADuC7121 data sheet
specifications assume a 5 kΩ resistive load to ground at the DAC
output. As the output is forced to source or sink more current,
the nonlinear regions at the top or bottom (respectively) of
Figure 31 become larger. With larger current demands, this can
significantly limit output voltage swing.
LDO (LOW DROPOUT REGULATOR)
The ADuC7121 contains an integrated LDO, which generates
the core supply voltage (DVDD) of approximately 2.6 V from
the IOVDD supply. As the LDO is driven from IOVDD, the
IOVDD supply voltage needs to be greater than 2.7 V.
An external compensation capacitor (CT) of 0.47 μF with low
ESR must be placed very close to each of the DVDD pins. This
capacitor also acts as a storage tank of charge, and supplies an
instantaneous charge required by the core, particularly at the
positive edge of the core clock (HCLK).
The DVDD voltage generated by the LDO is solely for providing
a supply for the ADuC7121. Therefore, users should not use a
DVDD pin as the power supply pin for any other chip. In
addition, it is recommended that the IOVDD has excellent
power supply decoupling to help improve line regulation
performance of the LDO.
The DVDD pin has no reverse battery, current limit, or thermal
shutdown protection; therefore, it is essential that users of the
ADuC7121 do not short this pin to ground at any time during
normal operation or during board manufacture.
CURRENT OUTPUT DACs (IDAC)
The ADuC7121 provides five current output digital-to-analog
converters (DACs). The current sources (five current DACs)
feature low noise and low drift high-side current output with
11-bit resolution. The five IDACs are as follows: IDAC0 with
250 mA full-scale (FS) output, IDAC1 with 200 mA FS output,
IDAC2 with 45 mA FS output, IDAC3 with 80 mA FS output,
and IDAC4 with 20 mA FS output.
09
49
2-
0
29
R
DAC0
VREF
AVDD
EXT_REF
09
49
2-
0
30
AVDD
AVDD – 100mV
100mV
0x00000000
0x0FFF0000
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| EVAL-ADUC7126QSPZ | BOARD EVALUATION FOR ADUC7126 |
| REC5-243.3SRWZ/H4/A | CONV DC/DC 5W 9-36VIN 3.3VOUT |
| EVAL-ADUC7023QSPZ | KIT DEV FOR ADUC7023 QUICK START |
| RPS-1K-6-250/2.0-9 | HEAT SHRINK SLEEVE |
| ECM30DCWH | CONN EDGECARD 60POS DIP .156 SLD |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| EVALADUC7121QSPZU1 | 制造商:Analog Devices 功能描述:QUICK START DEVELOPMENT SYSTEM - Boxed Product (Development Kits) |
| EVAL-ADUC7122QSPZ | 功能描述:BOARD EVALUATION FOR ADUC7122 RoHS:是 類別:編程器，開發(fā)系統(tǒng) >> 通用嵌入式開發(fā)板和套件（MCU、DSP、FPGA、CPLD等） 系列:MicroConverter® ADuC7xxx 標(biāo)準(zhǔn)包裝:1 系列:PICDEM™ 類型:MCU 適用于相關(guān)產(chǎn)品:PIC10F206，PIC16F690，PIC16F819 所含物品:板，線纜，元件，CD，PICkit 編程器 產(chǎn)品目錄頁面:659 (CN2011-ZH PDF) |
| EVAL-ADUC7124QSPZ | 功能描述:BOARD EVALUATION FOR ADUC7124 RoHS:是 類別:編程器，開發(fā)系統(tǒng) >> 通用嵌入式開發(fā)板和套件（MCU、DSP、FPGA、CPLD等） 系列:MicroConverter® ADuC7xxx 標(biāo)準(zhǔn)包裝:1 系列:PICDEM™ 類型:MCU 適用于相關(guān)產(chǎn)品:PIC10F206，PIC16F690，PIC16F819 所含物品:板，線纜，元件，CD，PICkit 編程器 產(chǎn)品目錄頁面:659 (CN2011-ZH PDF) |
| EVAL-ADUC7126QSPZ | 功能描述:BOARD EVALUATION FOR ADUC7126 RoHS:是 類別:編程器，開發(fā)系統(tǒng) >> 通用嵌入式開發(fā)板和套件（MCU、DSP、FPGA、CPLD等） 系列:MicroConverter® ADuC7xxx 標(biāo)準(zhǔn)包裝:1 系列:PICDEM™ 類型:MCU 適用于相關(guān)產(chǎn)品:PIC10F206，PIC16F690，PIC16F819 所含物品:板，線纜，元件，CD，PICkit 編程器 產(chǎn)品目錄頁面:659 (CN2011-ZH PDF) |
| EVAL-ADUC7128QSPZ | 功能描述:KIT DEV FOR ADUC7128 RoHS:是 類別:編程器，開發(fā)系統(tǒng) >> 通用嵌入式開發(fā)板和套件（MCU、DSP、FPGA、CPLD等） 系列:QuickStart™ PLUS 套件 產(chǎn)品培訓(xùn)模塊:Blackfin® Processor Core Architecture Overview Blackfin® Device Drivers Blackfin® Optimizations for Performance and Power Consumption Blackfin® System Services 特色產(chǎn)品:Blackfin? BF50x Series Processors 標(biāo)準(zhǔn)包裝:1 系列:Blackfin® 類型:DSP 適用于相關(guān)產(chǎn)品:ADSP-BF548 所含物品:板，軟件，4x4 鍵盤，光學(xué)撥輪，QVGA 觸摸屏 LCD 和 40G 硬盤 配用:ADZS-BFBLUET-EZEXT-ND - EZ-EXTENDER DAUGHTERBOARDADZS-BFLLCD-EZEXT-ND - BOARD EXT LANDSCAP LCD INTERFACE 相關(guān)產(chǎn)品:ADSP-BF542BBCZ-4A-ND - IC DSP 16BIT 400MHZ 400CSBGAADSP-BF544MBBCZ-5M-ND - IC DSP 16BIT 533MHZ MDDR 400CBGAADSP-BF542MBBCZ-5M-ND - IC DSP 16BIT 533MHZ MDDR 400CBGAADSP-BF542KBCZ-6A-ND - IC DSP 16BIT 600MHZ 400CSBGAADSP-BF547MBBCZ-5M-ND - IC DSP 16BIT 533MHZ MDDR 400CBGAADSP-BF548BBCZ-5A-ND - IC DSP 16BIT 533MHZ 400CSBGAADSP-BF547BBCZ-5A-ND - IC DSP 16BIT 533MHZ 400CSBGAADSP-BF544BBCZ-5A-ND - IC DSP 16BIT 533MHZ 400CSBGAADSP-BF542BBCZ-5A-ND - IC DSP 16BIT 533MHZ 400CSBGA |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。