參數(shù)資料
型號(hào): AD7612
廠商: Analog Devices, Inc.
英文描述: 16-Bit, 750 kSPS, Unipolar/Bipolar Programmable Input PulSAR ADC
中文描述: 16位,750 kSPS的,單極/雙極可編程輸入PulSAR系列ADC的
文件頁數(shù): 22/32頁
文件大?。?/td> 587K
代理商: AD7612
AD7612
Internal Reference (REF = 5 V)
(PDREF = Low, PDBUF = Low)
To use the internal reference, the PDREF and PDBUF inputs
must be low. This enables the on-chip band gap reference, buffer,
and TEMP sensor resulting in a 5.00 V reference on the REF pin.
Rev. 0 | Page 22 of 32
The internal reference is temperature-compensated to 5.000 V
±35 mV. The reference is trimmed to provide a typical drift of
3 ppm/°C. This typical drift characteristic is shown in Figure 19.
External 2.5 V Reference and Internal Buffer (REF = 5 V)
(PDREF = High, PDBUF = Low)
To use an external reference 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 producing 5 V on the REF pin. The internal ref-
erence buffer is useful in multiconverter applications since a
buffer is typically required in these applications.
External 5 V Reference (PDREF = High, PDBUF = High)
To use an external reference directly on the REF pin, PDREF
and PDBUF should both be high. PDREF and PDBUF power
down the internal reference and the internal reference buffer,
respectively. For improved drift performance, an external ref-
erence such as the
ADR445
or
ADR435
is recommended.
Reference Decoupling
Whether using an internal or external reference, the AD7612
voltage reference input (REF) has a dynamic input impedance;
therefore, it should 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 capacitor connected to REF and
REFGND with minimum parasitic inductance. A 22 μF (X5R,
1206 size) ceramic chip capacitor (or 47 μF tantalum capacitor)
is appropriate when using either the internal reference or the
ADR445/ADR435 external reference.
The placement of the reference decoupling is also important to
the performance of the AD7612. The decoupling capacitor should
be mounted on the same side as the ADC right at the REF pin
with a thick PCB trace. The REFGND should also connect to
the reference decoupling capacitor with the shortest distance
and to the analog ground plane with several vias.
For applications that use multiple AD7612 or other PulSAR
devices, it is more effective to use the internal reference buffer
to buffer the external 2.5 V reference voltage.
The voltage reference temperature coefficient (TC) directly impacts
full scale; therefore, in applications where full-scale accuracy
matters, care must be taken with the TC. For instance, a
±15 ppm/°C TC of the reference changes full-scale by ±1 LSB/°C.
Temperature Sensor
The TEMP pin measures the temperature of the AD7612. To
improve the calibration accuracy over the temperature range, the
output of the TEMP pin is applied to one of the inputs of the
analog switch (such as
ADG779
), and the ADC itself is used to
measure its own temperature. This configuration is shown
in Figure 30.
ADG779
AD8021
C
C
ANALOG INPUT
(UNIPOLAR)
AD7612
IN+
TEMPERATURE
SENSOR
TEMP
0
Figure 30. Use of the Temperature Sensor
POWER SUPPLIES
The AD7612 uses five sets of power supply pins:
AVDD: analog 5 V core supply
VCC: analog high voltage positive supply
VEE: high voltage negative supply
DVDD: digital 5 V core supply
OVDD: digital input/output interface supply
Core Supplies
The AVDD and DVDD supply the AD7612 analog and digital
cores respectively. Sufficient decoupling of these supplies is
required consisting of at least a 10 μF capacitor and 100 nF on
each supply. The 100 nF capacitors should be placed as close as
possible to the AD7612. To reduce the number of supplies needed,
the DVDD can be supplied through a simple RC filter from the
analog supply, as shown in Figure 27.
High Voltage Supplies
The high voltage bipolar supplies, VCC and VEE are required
and must be at least 2 V larger than the maximum input, V
IN
.
For example, if using the bipolar 10 V range, the supplies should
be ±12 V minimum. Sufficient decoupling of these supplies is
also required consisting of at least a 10 μF capacitor and 100 nF
on each supply. For unipolar operation, the VEE supply can be
grounded with some slight THD performance degradation.
Digital Output Supply
The OVDD supplies the digital outputs and allows direct interface
with any logic working between 2.3 V and 5.25 V OVDD should
be set to the same level as the system interface. Sufficient decou-
pling is required consisting of at least a 10 μF capacitor and 100 nF
with the 100 nF placed as close as possible to the AD7612.
相關(guān)PDF資料
PDF描述
AD7612BCPZ 16-Bit, 750 kSPS, Unipolar/Bipolar Programmable Input PulSAR ADC
AD7612BCPZ-RL 16-Bit, 750 kSPS, Unipolar/Bipolar Programmable Input PulSAR ADC
AD7612BSTZ 16-Bit, 750 kSPS, Unipolar/Bipolar Programmable Input PulSAR ADC
AD7612BSTZ-RL 16-Bit, 750 kSPS, Unipolar/Bipolar Programmable Input PulSAR ADC
AD7622 16-Bit, 750 kSPS, Unipolar/Bipolar Programmable Input PulSAR ADC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD7612BCPZ 功能描述:IC ADC 16BIT 750KSPS SAR 48LFCSP 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® 其它有關(guān)文件:TSA1204 View All Specifications 標(biāo)準(zhǔn)包裝:1 系列:- 位數(shù):12 采樣率(每秒):20M 數(shù)據(jù)接口:并聯(lián) 轉(zhuǎn)換器數(shù)目:2 功率耗散(最大):155mW 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-TQFP 供應(yīng)商設(shè)備封裝:48-TQFP(7x7) 包裝:Digi-Reel® 輸入數(shù)目和類型:4 個(gè)單端,單極;2 個(gè)差分,單極 產(chǎn)品目錄頁面:1156 (CN2011-ZH PDF) 其它名稱:497-5435-6
AD7612BCPZ-RL 功能描述:IC ADC 16BIT 750KSPS SAR 48LFCSP 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:- 位數(shù):14 采樣率(每秒):83k 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):95mW 電壓電源:雙 ± 工作溫度:0°C ~ 70°C 安裝類型:通孔 封裝/外殼:28-DIP(0.600",15.24mm) 供應(yīng)商設(shè)備封裝:28-PDIP 包裝:管件 輸入數(shù)目和類型:1 個(gè)單端,雙極
AD7612BST 制造商:Analog Devices 功能描述:ADC 16BIT 750KSPS SAR 48-LQFP 制造商:Analog Devices 功能描述:ADC, 16BIT, 750KSPS, SAR, 48-LQFP
AD7612BSTZ 功能描述:IC ADC 16BIT 750KSPS SAR 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® 其它有關(guān)文件:TSA1204 View All Specifications 標(biāo)準(zhǔn)包裝:1 系列:- 位數(shù):12 采樣率(每秒):20M 數(shù)據(jù)接口:并聯(lián) 轉(zhuǎn)換器數(shù)目:2 功率耗散(最大):155mW 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-TQFP 供應(yīng)商設(shè)備封裝:48-TQFP(7x7) 包裝:Digi-Reel® 輸入數(shù)目和類型:4 個(gè)單端,單極;2 個(gè)差分,單極 產(chǎn)品目錄頁面:1156 (CN2011-ZH PDF) 其它名稱:497-5435-6
AD7612BSTZ-RL 功能描述:IC ADC 16BIT 750KSPS SAR 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:- 位數(shù):14 采樣率(每秒):83k 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):95mW 電壓電源:雙 ± 工作溫度:0°C ~ 70°C 安裝類型:通孔 封裝/外殼:28-DIP(0.600",15.24mm) 供應(yīng)商設(shè)備封裝:28-PDIP 包裝:管件 輸入數(shù)目和類型:1 個(gè)單端,雙極