参数资料
型号: MAX1293ACEG
厂商: MAXIM INTEGRATED PRODUCTS INC
元件分类: ADC
英文描述: 250ksps, +3V, 8-/4-Channel, 12-Bit ADCs with +2.5V Reference and Parallel Interface
中文描述: 4-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, PARALLEL ACCESS, PDSO24
封装: 0.150 INCH, QSOP-24
文件页数: 13/20页
文件大小: 224K
代理商: MAX1293ACEG
M
250ksps, +3V, 8-/4-Channel, 12-Bit ADCs
with +2.5V Reference and Parallel Interface
______________________________________________________________________________________
13
Selecting Clock Mode
The MAX1291/MAX1293 operate with either an internal
or an external clock. Control bits D6 and D7 select
either internal or external clock mode. The parts retain
the last requested clock mode if a power-down mode is
selected in the current input word. For both internal and
external clock mode, internal or external acquisition
can be used. At power-up, the MAX1291/MAX1293
enter the default external clock mode.
Internal Clock Mode
Select internal clock mode to release the μP from the
burden of running the SAR conversion clock. To select
this mode, bits D6 and D7 of the control byte must be
set to 1; the internal clock frequency is then selected,
resulting in a conversion time of 3.6μs. When using the
internal clock mode, tie the CLK pin either high or low
to prevent the pin from floating.
External Clock Mode
To select the external clock mode, bits D6 and D7 of
the control byte must be set to zero. Figure 6 shows the
clock and
WR
timing relationship for internal (Figure 6a)
and external (Figure 6b) acquisition modes with an
external clock. For proper operation, a 100kHz to
4.8MHz clock frequency with 30% to 70% duty cycle is
recommended. Operating the MAX1291/MAX1293 with
clock frequencies lower than 100kHz is not recom-
mended because it will cause a voltage droop across
the hold capacitor in the T/H stage that will result in
degraded performance.
Digital Interface
Input (control byte) and output data are multiplexed on
a three-state parallel interface. This parallel interface
(I/O) can easily be interfaced with standard μPs. The
signals
CS
,
WR,
and
RD
control the write and read
operations.
CS
represents the chip select signal, which
enables a μP to address the MAX1291/MAX1293 as an
I/O port. When high,
CS
disables the CLK
WR
and
RD
inputs and forces the interface into a high-impedance
(high-Z) state.
Input Format
The control byte is latched into the device on pins
D7–D0 during a write command. Table 2 shows the
control byte format.
Output Format
The output format for both the MAX1291/MAX1293 is
binary in unipolar mode and two’s complement in bipo-
lar mode. When reading the output data,
CS
and
RD
must be low. When HBEN = 0, the lower 8 bits are
read. With HBEN = 1, the upper 4 bits are available
and the output data bits D7–D4 are set either low in
unipolar mode or set to the value of the MSB in bipolar
mode (Table 5).
WR
CLK
CLK
WR
WR GOES HIGH WHEN CLK IS HIGH.
WR GOES HIGH WHEN CLK IS LOW.
t
CWS
t
CH
t
CL
t
CP
t
CWH
ACQUISITION STARTS
ACQUISITION STARTS
CONVERSION STARTS
CONVERSION STARTS
ACQUISITION ENDS
ACQUISITION ENDS
ACQMOD = "0"
ACQMOD = "0"
Figure 6a. External Clock and
WR
Timing (Internal Acquisition Mode)
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MAX1293ACEG+ 功能描述:模数转换器 - ADC 12-Bit 4Ch 250ksps 3.6V 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
MAX1293ACEG+T 功能描述:模数转换器 - ADC 12-Bit 4Ch 250ksps 3.6V 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
MAX1293ACEG-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
MAX1293AEEG 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
MAX1293AEEG+ 功能描述:模数转换器 - ADC 12-Bit 4Ch 250ksps 3.6V 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