参数资料
型号: AD7995YRJZ-1RL
厂商: Analog Devices Inc
文件页数: 9/28页
文件大小: 0K
描述: IC ADC 10BIT 4CH I2C SOT23-8
产品变化通告: AD7991,5,9 Offset Error Change 17/Sept/2010
设计资源: Using AD8599 as an Ultralow Distortion Driver for the AD7995 (CN0044)
标准包装: 10,000
位数: 10
采样率(每秒): 1M
数据接口: I²C,串行
转换器数目: 1
功率耗散(最大): 4.68mW
电压电源: 单电源
工作温度: -40°C ~ 125°C
安装类型: 表面贴装
封装/外壳: SOT-23-8
供应商设备封装: SOT-23-8
包装: 带卷 (TR)
输入数目和类型: 4 个单端,单极
配用: EVAL-AD7995EBZ-ND - BOARD EVAL FOR AD7995
AD7991/AD7995/AD7999
Rev. B | Page 17 of 28
THEORY OF OPERATION
The AD7991/AD7995/AD7999 are low power, 12-/10-/8-bit,
single-supply, 4-channel ADCs. Each part can be operated from
a single 2.35 V to 5.5 V supply.
The AD7991/AD7995/AD7999 provide the user with a 4-channel
multiplexer, an on-chip track-and-hold, an ADC, and an I2C-
compatible serial interface, all housed in an 8-lead SOT-23 package
that offers the user considerable space-saving advantages over
alternative solutions.
The AD7991/AD7995/AD7999 normally remains in a power-
down state while not converting. Therefore, when supplies are
first applied, the part is in a power-down state. Power-up is initiated
prior to a conversion, and the device returns to the power-down
state upon completion of the conversion. This automatic power-
down feature allows the device to save power between conversions.
This means any read or write operations across the I2C interface
can occur while the device is in power-down.
CONVERTER OPERATION
The AD7991/AD7995/AD7999 are successive approximation
ADCs built around a capacitive DAC. Figure 18 and Figure 19
show simplified schematics of the ADC during its acquisition
and conversion phases, respectively. Figure 18 shows the ADC
during its acquisition phase: SW2 is closed, SW1 is in Position A,
the comparator is held in a balanced condition, and the sampling
capacitor acquires the signal on VIN. The source driving the
analog input needs to settle the analog input signal to within
one LSB in 0.6 μs, which is equivalent to the duration of the
power-up and acquisition time.
06
46
1-
0
20
CAPACITIVE
DAC
VIN
COMPARATOR
CONTROL
LOGIC
SW1
A
B
SW2
AGND
Figure 18. ADC Acquisition Phase
When the ADC starts a conversion, as shown in Figure 19, SW2
opens and SW1 moves to Position B, causing the comparator to
become unbalanced. The input is disconnected when the con-
version begins. The control logic and the capacitive DAC are used
to add and subtract fixed amounts of charge from the sampling
capacitor to bring the comparator back into a balanced condition.
When the comparator is rebalanced, the conversion is complete.
The control logic generates the ADC output code. Figure 20 shows
the ADC transfer function.
06
46
1-
02
1
VIN
COMPARATOR
CONTROL
LOGIC
SW1
A
B
SW2
AGND
CAPACITIVE
DAC
Figure 19. ADC Conversion Phase
ADC Transfer Function
The output coding of the AD7991/AD7995/AD7999 is straight
binary. The designed code transitions occur at successive integer
LSB values (that is, 1 LSB, 2 LSB, and so on). The LSB size for
the AD7991/AD7995/AD7999 is VREF/4096, VREF/1024, and
VREF/256, respectively. Figure 20 shows the ideal transfer
characteristics for the AD7991/AD7995/AD7999.
111 ... 111
111 ... 110
111 ... 000
A
D
C
CO
DE
AGND + 1 LSB
ANALOG INPUT
0V TO REFIN
AD7991 1 LSB = REFIN/4096
AD7995 1 LSB = REFIN/1024
AD7999 1 LSB = REFIN/256
+REFIN – 1 LSB
011 ... 111
000 ... 010
000 ... 001
000 ... 000
06
46
1-
02
2
Figure 20. AD7991/AD7995/AD7999 Transfer Characteristics
相关PDF资料
PDF描述
MS27467T9B98PALC CONN HSG PLUG 3POS STRGHT PINS
AD7995YRJZ-0RL IC ADC 10BIT 4CH I2C SOT23-8
MAX97220EETE+ IC LINE DVR/HEADPHONE AMP 16TQFN
AD7781CRZ-REEL IC ADC 20BIT 1CH LP SD 14SOIC
AD7781CRUZ-REEL IC ADC 20BIT 1CH LP SD 16TSSOP
相关代理商/技术参数
参数描述
AD7995YRMZ-0 功能描述:10 Bit Analog to Digital Converter 3, 4 Input 1 SAR 8-MSOP 制造商:analog devices inc. 系列:- 包装:散装 零件状态:上次购买时间 位数:10 采样率(每秒):140k 输入数:3,4 输入类型:单端 数据接口:I2C 配置:MUX-S/H-ADC 无线电 - S/H:ADC:1:1 A/D 转换器数:1 架构:SAR 参考类型:外部 电压 - 电源,模拟:2.7 V ~ 5.5 V 电压 - 电源,数字:2.7 V ~ 5.5 V 特性:- 工作温度:-40°C ~ 125°C 封装/外壳:8-TSSOP,8-MSOP(0.118",3.00mm 宽) 供应商器件封装:8-MSOP 标准包装:1
AD7997 制造商:AD 制造商全称:Analog Devices 功能描述:8-Channel, 10- and 12-Bit ADCs with I2CCompatible
AD7997BRU-0 功能描述:IC ADC 10BIT 8CHAN I2C 20TSSOP RoHS:否 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 标准包装:1,000 系列:- 位数:16 采样率(每秒):45k 数据接口:串行 转换器数目:2 功率耗散(最大):315mW 电压电源:模拟和数字 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:28-SOIC(0.295",7.50mm 宽) 供应商设备封装:28-SOIC W 包装:带卷 (TR) 输入数目和类型:2 个单端,单极
AD7997BRU-0REEL 功能描述:IC ADC 10BIT 8CHAN I2C 20TSSOP RoHS:否 类别:集成电路 (IC) >> 数据采集 - 模数转换器 系列:- 标准包装:2,500 系列:- 位数:16 采样率(每秒):15 数据接口:MICROWIRE?,串行,SPI? 转换器数目:1 功率耗散(最大):480µW 电压电源:单电源 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:38-WFQFN 裸露焊盘 供应商设备封装:38-QFN(5x7) 包装:带卷 (TR) 输入数目和类型:16 个单端,双极;8 个差分,双极 配用:DC1011A-C-ND - BOARD DELTA SIGMA ADC LTC2494
AD7997BRU-1 制造商:Analog Devices 功能描述:ADC Single SAR 188ksps 10-bit Serial 20-Pin TSSOP 制造商:Rochester Electronics LLC 功能描述:8-CHANNEL, 10-BIT ADC WITH 12C ITF I.C. - Bulk