參數(shù)資料
型號(hào): AD7621ACPZRL
廠商: Analog Devices Inc
文件頁數(shù): 7/32頁
文件大?。?/td> 0K
描述: IC ADC 16BIT 2MSPS DIFF 48LFCSP
標(biāo)準(zhǔn)包裝: 2,500
系列: PulSAR®
位數(shù): 16
采樣率(每秒): 2M
數(shù)據(jù)接口: 串行,并聯(lián)
轉(zhuǎn)換器數(shù)目: 1
功率耗散(最大): 86mW
電壓電源: 模擬和數(shù)字
工作溫度: -40°C ~ 85°C
安裝類型: 表面貼裝
封裝/外殼: 48-VFQFN 裸露焊盤,CSP
供應(yīng)商設(shè)備封裝: 48-LFCSP-VQ(7x7)
包裝: 帶卷 (TR)
輸入數(shù)目和類型: 1 個(gè)差分,雙極
AD7621
Rev. 0 | Page 15 of 32
THEORY OF OPERATION
04565-024
SW+
COMP
SW–
IN+
REF
REFGND
LSB
MSB
32,768C 16,384C
4C
2C
C
SWITCHES
CONTROL
LOGIC
BUSY
OUTPUT
CODE
CNVST
IN–
32,768C 16,384C
4C
2C
C
LSB
MSB
AGND
Figure 21. ADC Simplified Schematic
CIRCUIT INFORMATION
The AD7621 is a very fast, low power, single-supply, precise,
16-bit analog-to-digital converter (ADC) using successive
approximation architecture. The AD7621 features different
modes to optimize performances according to the applications.
In warp mode, the AD7621 is capable of converting 3,000,000
samples per second (3 MSPS).
The AD7621 provides the user with an on-chip track-and-hold,
successive approximation ADC that does not exhibit any
pipeline or latency, making it ideal for multiple multiplexed
channel applications.
The AD7621 can be operated from a single 2.5 V supply and
be interfaced to either 5 V, 3.3 V, or 2.5 V digital logic. It
is housed in 48-lead LQFP or tiny LFCSP packages that
combine space savings with flexibility, allowing the AD7621
to be configured as either a serial or parallel interface. The
AD7621 is pin-to-pin-compatible with, and a speed upgrade
of, the AD7677.
CONVERTER OPERATION
The AD7621 is a successive approximation analog-to-digital
converter (ADC) based on a charge redistribution DAC. Figure 21
shows the simplified schematic of the ADC. The capacitive
DAC consists of two identical arrays of 16 binary weighted
capacitors which are connected to the two comparator inputs.
During the acquisition phase, terminals of the array tied to the
comparator’s input are connected to AGND via SW+ and SW.
All independent switches are connected to the analog inputs.
Thus, the capacitor arrays are used as sampling capacitors and
acquire the analog signal on IN+ and IN inputs. A conversion
phase is initiated once the acquisition phase is complete and the
CNVST input goes low. When the conversion phase begins,
SW+ and SW are opened first. The two capacitor arrays are
then disconnected from the inputs and connected to the
REFGND input. Therefore, the differential voltage between the
inputs (IN+ and IN) captured at the end of the acquisition
phase is applied to the comparator inputs, causing the
comparator to become unbalanced. By switching each element
of the capacitor array between REFGND and REF, the
comparator input varies by binary weighted voltage steps
(VREF/2, VREF/4 through VREF/65536). The control logic toggles
these switches, starting with the MSB first, in order to bring the
comparator back into a balanced condition. After the
completion of this process, the control logic generates the ADC
output code and brings BUSY output low.
MODES OF OPERATION
The AD7621 features four modes of operation: wideband warp,
warp, normal, and impulse. Each of these modes is more
suitable to specific applications.
Wideband warp (WARP = high, IMPULSE = high) and warp
(WARP = high, IMPULSE = low) modes allow the fastest
conversion rate up to 3 MSPS. However, in these modes, the full
specified accuracy is guaranteed only when the time between
conversions does not exceed 1 ms. If the time between two
consecutive conversions is longer than 1 ms (after power up),
the first conversion result should be ignored. These modes
make the AD7621 ideal for applications where both high
accuracy and fast sample rate are required. Wideband warp
mode offers slightly improved linearity and THD over warp
mode.
Normal mode (WARP = low, IMPULSE = low) is the fastest
mode (2 MSPS) without any limitation on time between
conversions. This mode makes the AD7621 ideal for
asynchronous applications such as data acquisition systems,
where both high accuracy and fast sample rate are required.
Impulse mode (WARP = low, IMPULSE = high), the lowest
power dissipation mode, allows power saving between
conversions. The maximum throughput in this mode is
1.25 MSPS. In this mode, the ADC powers down circuits after
conversion making the AD7621 ideal for battery-powered
applications.
相關(guān)PDF資料
PDF描述
IDT72V211L10PF IC FIFO SYNC 512X9 10NS 32-TQFP
IDT72211L15PFI IC FIFO 512X9 SYNC 15NS 32-TQFP
MS3101F14S-6S CONN RCPT 6POS FREE HNG W/SCKT
MS3110F16-26P CONN RCPT 26POS WALL MNT W/PINS
IDT72211L15PFGI IC FIFO 512X9 SYNC 15NS 32-TQFP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD7621ACPZRL1 制造商:AD 制造商全稱:Analog Devices 功能描述:16-Bit, 2 LSB INL, 3 MSPS PulSAR?? ADC
AD7621AST 制造商:Analog Devices 功能描述:ADC Single SAR 3Msps 16-bit Parallel/Serial 48-Pin LQFP 制造商:Analog Devices 功能描述:IC 16-BIT ADC
AD7621ASTRL 制造商:Analog Devices 功能描述:ADC Single SAR 3Msps 16-bit Parallel/Serial 48-Pin LQFP T/R
AD7621ASTZ 功能描述:IC ADC 16BIT 2MSPS DIFF 48-LQFP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模數(shù)轉(zhuǎn)換器 系列:PulSAR® 標(biāo)準(zhǔn)包裝:1 系列:microPOWER™ 位數(shù):8 采樣率(每秒):1M 數(shù)據(jù)接口:串行,SPI? 轉(zhuǎn)換器數(shù)目:1 功率耗散(最大):- 電壓電源:模擬和數(shù)字 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:24-VFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:24-VQFN 裸露焊盤(4x4) 包裝:Digi-Reel® 輸入數(shù)目和類型:8 個(gè)單端,單極 產(chǎn)品目錄頁面:892 (CN2011-ZH PDF) 其它名稱:296-25851-6
AD7621ASTZ1 制造商:AD 制造商全稱:Analog Devices 功能描述:16-Bit, 2 LSB INL, 3 MSPS PulSAR?? ADC