參數(shù)資料
型號(hào)： EVAL-AD7451CBZ
廠商： Analog Devices Inc
文件頁(yè)數(shù)： 6/25頁(yè)
文件大?。?/td> 0K
描述： BOARD EVAL FOR AD7451
標(biāo)準(zhǔn)包裝： 1
ADC 的數(shù)量： 1
位數(shù)： 12
采樣率（每秒）： 1M
數(shù)據(jù)接口： SPI?、QSPI?、MICROWIRE? 和 DSP
輸入范圍： ±VREF
在以下條件下的電源（標(biāo)準(zhǔn)）： 9.25mW @ 1MSPS，5V
工作溫度： -40°C ~ 85°C
已用 IC / 零件： AD7451
已供物品： 板
AD7441/AD7451
Rev. D | Page 13 of 24
THEORY OF OPERATION
CIRCUIT INFORMATION
The AD7441/AD7451 are 10-/12-bit, high speed, low power,
single-supply, successive approximation, analog-to-digital con-
verters (ADCs) with a pseudo differential analog input. These
parts operate with a single 2.7 V to 5.25 V power supply and are
capable of throughput rates up to 1 MSPS when supplied with
an 18 MHz SCLK. The AD7441/AD7451 require an external
reference to be applied to the VREF pin.
The AD7441/AD7451 have a SAR ADC, an on-chip differential
track-and-hold amplifier, and a serial interface housed in either
an 8-lead SOT-23 or an MSOP package. The serial clock input
accesses data from the part and provides the clock source for
the SAR ADC. The AD7441/AD7451 feature a power-down
option for reduced power consumption between conversions.
The power-down feature is implemented across the standard
serial interface, as described in the Modes of Operation section.
CONVERTER OPERATION
The AD7441/AD7451 are SAR ADCs based around two
capacitive DACs. Figure 19 and Figure 20 show simplified
schematics of the ADC in the acquisition and conversion phase,
respectively. The ADC is comprised of control logic, an SAR,
and two capacitive DACs. In Figure 19 (acquisition phase), SW3
is closed, SW1 and SW2 are in Position A, the comparator is
held in a balanced condition, and the sampling capacitor arrays
acquire the differential signal on the input.
VIN+
VIN–
A
B
SW1
SW3
COMPARATOR
CONTROL
LOGIC
CAPACITIVE
DAC
CAPACITIVE
DAC
CS
VREF
SW2
B
A
03
15
3-
0
19
Figure 19. ADC Acquisition Phase
When the ADC starts a conversion (see Figure 20), SW3 opens
and SW1 and SW2 move to Position B, causing the comparator
to become unbalanced. Both inputs are disconnected once the
conversion begins. The control logic and the charge redistribu-
tion DACs are used to add and subtract fixed amounts of charge
from the sampling capacitor arrays to bring the comparator
back into a balanced condition. When the comparator is rebal-
anced, the conversion is complete. The control logic generates
the ADC output code. The output impedances of the sources
driving the VIN+ and VIN– pins must be matched; otherwise the
two inputs have different settling times, resulting in errors.
VIN+
VIN–
A
B
SW1
SW3
COMPARATOR
CONTROL
LOGIC
CAPACITIVE
DAC
CAPACITIVE
DAC
CS
VREF
SW2
B
A
03
15
3-
0
20
Figure 20. ADC Conversion Phase
ADC TRANSFER FUNCTION
The output coding for the AD7441/AD7451 is straight (natural)
binary. The designed code transitions occur at successive LSB
values (1 LSB, 2 LSB, and so on). The LSB size of the AD7451
is VREF/4096, and the LSB size of the AD7441 is VREF/1024. The
ideal transfer characteristic of the AD7441/AD7451 is shown in
000...000
0V
A
D
C
CO
DE
ANALOG INPUT
111...111
000...001
111...000
011...111
111...110
000...010
1LSB = VREF/4096 (AD7451)
1LSB = VREF/1024 (AD7441)
VREF – 1LSB
1LSB
03
15
3-
0
21
Figure 21. AD7441/AD7451 Ideal Transfer Characteristic
相關(guān)PDF資料
PDF描述
STD02W-T WIRE & CABLE MARKERS
STD09W-J WIRE & CABLE MARKERS
HKQ0603S0N8C-T INDUCTOR HI FREQ 0.8NH 0201
STD01W-G WIRE & CABLE MARKERS
EVAL-AD7949EDZ BOARD EVAL AD7949
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
EVAL-AD7451CBZ3 制造商:AD 制造商全稱:Analog Devices 功能描述:Pseudo Differential Input, 1 MSPS, 10-/12-Bit ADCs in an 8-Lead SOT-23
EVAL-AD7452CB 制造商:Analog Devices 功能描述:DEV TOOLS, DIFFERENTIAL INPUT, 555KSPS, 12BIT ADC IN AN 8-LE - Bulk
EVAL-AD7452CB3 制造商:AD 制造商全稱:Analog Devices 功能描述:Differential Input, 555 kSPS 12-Bit ADC in an 8-Lead SOT-23
EVAL-AD7453CB 制造商:Analog Devices 功能描述:DEV TOOLS, PSEUDO DIFFERENTIAL, 555 KSPS, 12-BIT A/D CNVRTR - Bulk
EVAL-AD7453CB2 制造商:AD 制造商全稱:Analog Devices 功能描述:Pseudo Differential, 555 kSPS, 12-Bit ADC in an 8-Lead SOT-23
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*