参数资料
型号: MAX110BEAP
厂商: MAXIM INTEGRATED PRODUCTS INC
元件分类: ADC
英文描述: Low-Cost, 2-Channel, 【14-Bit Serial ADCs
中文描述: 2-CH 14-BIT DELTA-SIGMA ADC, SERIAL ACCESS, PDSO20
封装: 5.30 MM, 0.65 MM PITCH, SSOP-20
文件页数: 20/24页
文件大小: 411K
代理商: MAX110BEAP
M
Low-Cost, 2-Channel, ±14-Bit S erial ADCs
20
______________________________________________________________________________________
Capacitive Loading Effects of XCLK in
Internal RC-Oscillator Mode
When using the internal RC oscillator, capacitive load-
ing effects on the XCLK pin must be minimized. Stray
capacitance causes the V
DD
power consumption to
increase by an amount p =
1
2
CV
2
f, where C = stray
capacitance, V is the supply voltage, and f is the fre-
quency of the internal RC oscillator.
External Referenc e
The reference inputs to the ADC are high impedance,
allowing both an external voltage reference and ratio-
metric applications without loading effects. The fully dif-
ferential analog signal and reference inputs are
advantageous for performing ratiometric conversions
(Figures 11 and 12). For example, when measuring
load cells, the bridge excitation and the ADC reference
input both share the same voltage source. As the exci-
tation changes with temperature or voltage, the output
of the load cell will change. But since the differential
reference voltage also changes, the conversion results
remain constant, all else remaining equal.
Weigh S c ale Applic ation
The fully differential analog signal and reference inputs
make the MAX111 easy to interface to transducers with
differential outputs, such as the load cell in Figure 11.
Because the ADC input is differential, the load cell only
requires differential gain, eliminating the need for the
difference amplifier (differential to single-ended con-
verter) of the standard three op-amp instrumentation-
amplifier realization.
The 30mV full-scale bridge output is amplified to 2V
full-scale and applied to the MAX111 channel-one
input. The reference voltage to the ADC is created by a
voltage divider connected to the +5V rail. The same 5V
provides excitation for the bridge; therefore, as the
excitation voltage varies, the reference voltage to the
ADC also varies, providing an ADC output that does
not depend on the supply voltage.
The two 121k
resistors connected to the +5V supplies
shift the common-mode voltage from 2.5V (5V/2) to
1.5V to ensure linearity. Match these two resistors to
avoid introducing differential offset, or trim the resistor
mismatch with a potentiometer. In practice, the scale is
“zeroed” or “tared” by storing the average of several
conversions in a memory location while the scale is
+5V
30mV
FULL-SCALE
121k
2k
121k
49.9k
1k
22k
10k
1k
1k
1/2 MAX492
+5V
1/2 MAX492
1μF
1μF
REF+
REF-
IN1+
IN1-
AGND
CS
DIN
DOUT
SCLK
49.9k
V
DD
+5V
0.1μF
MAX111
+5V
+5V
GND
Figure 11. Weigh Scale Application
相关PDF资料
PDF描述
MAX110BEPE Low-Cost, 2-Channel, 【14-Bit Serial ADCs
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相关代理商/技术参数
参数描述
MAX110BEAP-T 功能描述:模数转换器 - ADC RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32
MAX110BEPE 功能描述:模数转换器 - ADC RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32
MAX110BEPE+ 功能描述:模数转换器 - ADC 2Ch +/-14Bit Serial RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32
MAX110BEWE 功能描述:模数转换器 - ADC RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32
MAX110BEWE+ 功能描述:模数转换器 - ADC 2Ch +/-14Bit Serial RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32