參數(shù)資料
型號(hào): AD7651ASTZ
廠商: Analog Devices Inc
文件頁(yè)數(shù): 10/28頁(yè)
文件大小: 0K
描述: IC ADC 16BIT 100KSPS 48-LQFP
標(biāo)準(zhǔn)包裝: 1
系列: PulSAR®
位數(shù): 16
采樣率(每秒): 100k
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): 45mW
電壓電源: 模擬和數(shù)字
工作溫度: -40°C ~ 85°C
安裝類(lèi)型: 表面貼裝
封裝/外殼: 48-LQFP
供應(yīng)商設(shè)備封裝: 48-LQFP(7x7)
包裝: 托盤(pán)
輸入數(shù)目和類(lèi)型: 2 個(gè)偽差分,單極
產(chǎn)品目錄頁(yè)面: 778 (CN2011-ZH PDF)
配用: EVAL-AD7651CBZ-ND - BOARD EVALUATION FOR AD7651
AD7651
Voltage Reference Input
The AD7651 allows the choice of either a very low temperature
drift internal voltage reference or an external 2.5 V reference.
For applications that use multiple AD7651s, it is more effective
to use the internal buffer to buffer the reference voltage.
Unlike many ADCs with internal references, the internal
reference of the AD7651 provides excellent performance and
can be used in almost all applications.
Care should be taken with the voltage reference’s temperature
coefficient, which directly affects the full-scale accuracy if this
parameter matters. For instance, a ±15 ppm/°C temperature
coefficient of the reference changes full scale by ±1 LSB/°C.
To use the internal reference along with the internal buffer,
PDREF and PDBUF should both be LOW. This will produce a
1.207 V voltage on REFBUFIN which, amplified by the buffer,
will result in a 2.5 V reference on the REF pin.
Note that VREF can be increased to AVDD – 1.85 V. Since the
input range is defined in terms of VREF, this would essentially
increase the range to 0 V to 3 V with an AVDD above 4.85 V.
The AD780 can be selected with a 3 V reference voltage.
The output impedance of REFBUFIN is 11 k (minimum) when
the internal reference is enabled.
It is useful to decouple
REFBUFIN with a 100 nF ceramic capacitor. Thus, the 100 nF
capacitor provides an RC filter for noise reduction.
The TEMP pin, which measures the temperature of the AD7651,
can be used as shown in
. The output of TEMP pin is
applied to one of the inputs of the analog switch (e.g., ADG779),
and the ADC itself is used to measure its own temperature. This
configuration is very useful for improving the calibration
accuracy over the temperature range.
Figure 24. Temperature Sensor Connection Diagram
To use an external reference along with the internal buffer,
PDREF should be HIGH and PDBUF should be LOW. This
powers down the internal reference and allows the 2.5 V
reference to be applied to REFBUFIN.
ADG779
AD8021
CC
02964-0-024
ANALOG INPUT
(UNIPOLAR)
AD7651
IN
TEMPERATURE
SENSOR
TEMP
To use an external reference directly on REF pin, PDREF and
PDBUF should both be HIGH.
PDREF and PDBUF respectively power down the internal
reference and the internal reference buffer. Note that the PDREF
and PDBUF input current should never exceed 20 mA. This
could eventually occur when input voltage is above AVDD (for
instance at power up). In this case, a 100 series resistor is
recommended.
Power Supply
The AD7651 uses three power supply pins: an analog 5 V supply
AVDD, a digital 5 V core supply DVDD, and a digital input/
output interface supply OVDD. OVDD allows direct interface
with any logic between 2.7 V and DVDD + 0.3 V. To reduce the
supplies needed, the digital core (DVDD) can be supplied
through a simple RC filter from the analog supply, as shown in
. The AD7651 is independent of power supply
sequencing once OVDD does not exceed DVDD by more than
0.3 V, and is thus free of supply voltage induced latch-up.
The internal reference is temperature compensated to 2.5 V ±
20 mV. The reference is trimmed to provide a typical drift of 7
. This typical drift characteristic is shown in
For improved drift performance, an external reference such as
the AD780 can be used.
The AD7651 voltage reference input REF has a dynamic input
impedance; it should therefore be driven by a low impedance
source with efficient decoupling between the REF and REFGND
inputs. This decoupling depends on the choice of the voltage
reference but usually consists of a low ESR tantalum capacitor
connected to REF and REFGND with minimum parasitic
inductance. A 10 F (X5R, 1206 size) ceramic chip capacitor (or
47 F tantalum capacitor) is appropriate when using either the
internal reference or one of these recommended reference
voltages:
The low noise, low temperature drift ADR421 and AD780
The low power ADR291
The low cost AD1582
Rev. 0 | Page 18 of 28
相關(guān)PDF資料
PDF描述
VI-2WM-IX-B1 CONVERTER MOD DC/DC 10V 75W
LTC1402CGN#PBF IC ADC 12BIT 2.2MSPS SHDN 16SSOP
VE-2N2-IX-B1 CONVERTER MOD DC/DC 15V 75W
VE-26Y-IV-B1 CONVERTER MOD DC/DC 3.3V 99W
CS5532-BSZ IC ADC 24BIT 2CH W/LNA 20SSOP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD7651ASTZ 制造商:Analog Devices 功能描述:16BIT SAR ADC REF 7651 LQFP48
AD7651ASTZRL 功能描述:IC ADC 16BIT UNIPOLAR 48LFCSP RoHS:是 類(lèi)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:1,000 系列:- 位數(shù):12 采樣率(每秒):300k 數(shù)據(jù)接口:并聯(lián) 轉(zhuǎn)換器數(shù)目:1 功率耗散(最大):75mW 電壓電源:單電源 工作溫度:0°C ~ 70°C 安裝類(lèi)型:表面貼裝 封裝/外殼:24-SOIC(0.295",7.50mm 寬) 供應(yīng)商設(shè)備封裝:24-SOIC 包裝:帶卷 (TR) 輸入數(shù)目和類(lèi)型:1 個(gè)單端,單極;1 個(gè)單端,雙極
AD7652 制造商:AD 制造商全稱(chēng):Analog Devices 功能描述:16-Bit 1 MSPS SAR Unipolar ADC with Ref
AD7652ACP 制造商:Analog Devices 功能描述:ADC Single SAR 500ksps 16-bit Parallel/Serial 48-Pin LFCSP EP 制造商:Rochester Electronics LLC 功能描述:16-BIT 500KSPS SAR UNIPOLAR ADC W/ REF - Bulk 制造商:Analog Devices 功能描述:16BIT SAR ADC REF 7652 LFSCP-48
AD7652ACPRL 制造商:Analog Devices 功能描述:ADC Single SAR 500ksps 16-bit Parallel/Serial 48-Pin LFCSP EP T/R