Linearity degradation near ground and AV
參數(shù)資料
型號: EVAL-ADUC7024QSZ
廠商: Analog Devices Inc
文件頁數(shù): 58/104頁
文件大小: 0K
描述: KIT DEV QUICK START ADUC7024
產(chǎn)品培訓(xùn)模塊: ARM7 Applications & Tools
Intro to ARM7 Core & Microconverters
設(shè)計資源: ADUC7024 Dev System Schematic/Brd Outline
7024 Gerber Files
標(biāo)準(zhǔn)包裝: 1
系列: QuickStart™ 套件
類型: MCU
適用于相關(guān)產(chǎn)品: ADuC7024
所含物品: 評估板、電源、纜線、軟件和說明文檔
Data Sheet
ADuC7019/20/21/22/24/25/26/27/28/29
Rev. F | Page 57 of 104
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 illustrated in Figure 64.
The dotted line in Figure 64 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 64 represents a transfer function
in 0-to-AVDD mode only. In 0-to-VREF or 0-to-DACREF mode
(with VREF < AVDD or DACREF < 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.
0
495
5-
02
4
AVDD
AVDD – 100mV
100mV
0x00000000
0x0FFF0000
Figure 64. Endpoint Nonlinearities Due to Amplifier Saturation
The endpoint nonlinearities conceptually illustrated in
Figure 64 get worse as a function of output loading. Most
of the ADuC7019/20/21/22/24/25/26/27/28/29 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 64 become larger. With larger current demands, this
can significantly limit output voltage swing.
POWER SUPPLY MONITOR
The power supply monitor regulates the IOVDD supply on the
ADuC7019/20/21/22/24/25/26/27/28/29. It indicates when the
IOVDD supply pin drops below one of two supply trip points.
The monitor function is controlled via the PSMCON register.
If enabled in the IRQEN or FIQEN register, the monitor
interrupts the core using the PSMI bit in the PSMCON MMR.
This bit is immediately cleared after CMP goes high.
This monitor function allows the user to save working registers
to avoid possible data loss due to low supply or brown-out
conditions. It also ensures that normal code execution does
not resume until a safe supply level is established.
Table 53. PSMCON Register
Name
Address
Default Value
Access
PSMCON
0xFFFF0440
0x0008
R/W
Table 54. PSMCON MMR Bit Descriptions
Bit
Name
Description
3
CMP
Comparator bit. This is a read-only bit that
directly reflects the state of the comparator.
Read 1 indicates that the IOVDD supply is above
its selected trip point or that the PSM is in
power-down mode. Read 0 indicates that the
IOVDD supply is below its selected trip point. This
bit should be set before leaving the interrupt
service routine.
2
TP
Trip point selection bit. 0 = 2.79 V, 1 = 3.07 V.
1
PSMEN
Power supply monitor enable bit. Set to 1 to
enable the power supply monitor circuit. Cleared
to 0 to disable the power supply monitor circuit.
0
PSMI
Power supply monitor interrupt bit. This bit is set
high by the MicroConverter after CMP goes low,
indicating low I/O supply. The PSMI bit can be
used to interrupt the processor. After CMP
returns high, the PSMI bit can be cleared by
writing a 1 to this location. A 0 write has no
effect. There is no timeout delay; PSMI can be
immediately cleared after CMP goes high.
COMPARATOR
The ADuC7019/20/21/22/24/25/26/27/28/29 integrate voltage
comparators. The positive input is multiplexed with ADC2, and
the negative input has two options: ADC3 and DAC0. The output
of the comparator can be configured to generate a system inter-
rupt, be routed directly to the programmable logic array, start
an ADC conversion, or be on an external pin, CMPOUT, as
shown in Figure 65.
04
95
5-
02
5
MUX
IRQ
MUX
DAC0
ADC2/CMP0
ADC3/CMP1
P0.0/CMPOUT
Figure 65. Comparator
Note that because the ADuC7022, ADuC7025, and ADu7027
parts do not support a DAC0 output, it is not possible to use
DAC0 as a comparator input on these parts.
Hysteresis
Figure 66 shows how the input offset voltage and hysteresis
terms are defined.
04
95
5-
0
63
CMPOUT
CMP0
VH
VOS
Figure 66. Comparator Hysteresis Transfer Function
相關(guān)PDF資料
PDF描述
EVAL-ADUC845QSZ KIT DEV FOR ADUC845 QUICK START
HCM15DRXS CONN EDGECARD 30POS DIP .156 SLD
EVAL-ADUC832QSZ KIT DEV FOR ADUC832 QUICK START
HBM15DRXS CONN EDGECARD 30POS DIP .156 SLD
PCX1H270MCL1GS CAP ALUM 27UF 50V 20% SMD
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
EVAL-ADUC7026QS 制造商:Analog Devices 功能描述:MICROCONTROLLER, PRECISION ANALOG,MULTI-CHANNEL 12-BIT ADC - Bulk 制造商:Analog Devices 功能描述:EVALUATION KIT
EVAL-ADUC7026QSP 制造商:Analog Devices 功能描述:Evaluation Board For Precision Analog Microcontroller, 12-Bit Analog I/O, ARM7TDMI MCU 制造商:Analog Devices 功能描述:QUICK START DEVELOPMENT SYSTEM - Bulk 制造商:Analog Devices 功能描述:EVALUATION KIT
EVAL-ADUC7026QSPZ 功能描述:KIT DEV ADUC7026/7027 QUICK PLUS 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
EVAL-ADUC7026QS-U1 制造商:Analog Devices 功能描述:QUICK START DEVL SYST EVAL BOARD I.C. - Bulk
EVAL-ADUC7026QSZ 功能描述:KIT DEV FOR ADUC7026/7027 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™ 套件 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)