参数资料
型号: MX574AJCWI+
厂商: Maxim Integrated Products
文件页数: 4/18页
文件大小: 0K
描述: IC ADC 12BIT W/REF 28-SOIC
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 25
位数: 12
采样率(每秒): 40k
数据接口: 并联
转换器数目: 1
功率耗散(最大): 265mW
电压电源: 双 ±
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: 管件
输入数目和类型: 2 个单端,单极;2 个单端,双极
Maxim Integrated Products 12
MAX174/MX574A/MX674A
Industry-Standard, Complete 12-Bit ADCs
Figure 9. Power-Supply Bypassing
Power-Supply Bypassing
The MAX174/MX574A/MX674A power supplies must be
filtered, well regulated, and free from high-frequency
noise, or unstable output codes will result. Unless great
care is taken in filtering any switching spikes present in
the output, switching power supplies is not suggested for
applications requiring 12-bit resolution. Take note that a
few millivolts of noise converts to several error counts in
a 12-bit ADC.
All power-supply pins should use supply decoupling capac-
itors connected with short lead length to the pins, as shown
in Figure 9. The VCC and VEE pins should be decoupled
directly to AGND. A 4.7F tantalum type in parallel with a
0 1F disc ceramic type is a suitable decoupling.
Internal Reference
The MAX174/MX574A/MX674A have an internal buried
zener reference that provides a 10V, low-noise and low-
temperature drift output. An external reference voltage
can also be used for the ADC. When using ±15V sup-
plies, the internal reference can source up to 2mA in
addition to the BIPOFF and REFIN inputs over the entire
operating temperature range. With ±12V supplies, the
reference can drive the BIPOFF and REFIN inputs over
temperature, but it CANNOT drive an additional load.
Driving the Analog Input
The input leads to AGND and 10VIN or 20VIN should be
as short as possible to minimize noise pick up. If long
leads are needed, use shielded cables.
When using the 20VIN as the analog input, load capaci-
tance on the 10VIN pin must be minimized. Especially on
the faster MAX174, leave the 10VIN pin open to minimize
capacitance and to prevent linearity errors caused by
inadequate settling time.
The amplifier driving the analog input must have low
enough DC output impedance for low full-scale error.
Furthermore, low AC output impedance is also required
since the analog input current is modulated at the clock
rate during the conversion. The output impedance of an
amplifier is the open-loop output impedance divided by
the loop gain at the frequency of interest.
MX574A and MX674A—The approximate internal clock
rate is 600kHz and 1MHz, respectively, and amplifiers
like the MAX400 can be used to drive the input.
MAX174—The internal clock rate is 2MHz and faster
amplifiers like the OP-27, AD711, or OP-42 are required.
Track-and-Hold Interface
The analog input to the ADC must be stable to within
1/2 LSB during the entire conversion for specified 12-bit
accuracy. This limits the input signal bandwidth to a
couple of hertz for sinusoidal inputs even with the faster
MAX174. For higher bandwidth signals, a track-and-hold
amplifier should be used.
The STS output may be used to provide the Hold signal
to the track-and-hold amplifier. However, since the A/D’s
DAC is switched at approximately the same time as the
conversion is initiated, the switching transients at the out-
put of the T/H caused by the DAC switching may result in
code dependent errors. It is recommended that the Hold
signal to the T/H amplifier precede a conversion or be
coincident with the conversion start.
The first bit decision by the A/D is made approximately
1.5 clock cycles after the start of the conversion. This is
2.5s, 1.5s, and 0.8s for the MX574A, MX674A, and
MAX174, respectively. The T/H hold settling time must
be less than this time. For the MX574A and MX674A, the
AD585 sample-and-hold is recommended (Figure 10).
For the MAX174, a faster T/H amplifier, like the HA5320
or HA5330, should be used (Figure 11).
Input Configurations
The MAX174/MX574A/MX674A input range can be set
using pin strapping. Table 3 shows the possible input
ranges and ideal transition voltages. End-point errors can
be adjusted in all ranges.
VL
+5V
DIGITAL
GROUND
ANALOG
GROUND
+12V/15V
-12V/15V
VCC
VEE
DGND
RECOMMENDED
C1, C2, C4 – 0.1F CERAMIC
C4, C5, C6 – 4.7F
AGND
MAX174
MX574A
MX674A
C4
C1
C5
C2
C6
C3
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MX574AJCWI+ 功能描述:模数转换器 - ADC 12-Bit Precision 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
MX574AJCWI+T 功能描述:模数转换器 - ADC 12-Bit Precision 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
MX574AJCWI-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
MX574AJD 功能描述:模数转换器 - ADC 12-Bit Precision 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
MX574AJEPI 功能描述:模数转换器 - ADC Integrated Circuits (ICs) 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