参数资料
型号: MAX1249AEPE+
厂商: Maxim Integrated Products
文件页数: 8/24页
文件大小: 0K
描述: IC ADC 10BIT SERIAL 16-DIP
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 25
位数: 10
采样率(每秒): 133k
数据接口: MICROWIRE?,QSPI?,串行,SPI?
转换器数目: 1
功率耗散(最大): 842mW
电压电源: 单电源
工作温度: -40°C ~ 85°C
安装类型: 通孔
封装/外壳: 16-DIP(0.300",7.62mm)
供应商设备封装: 16-PDIP
包装: 管件
输入数目和类型: 4 个单端,单极;4 个单端,双极;2 个差分,单极;2 个差分,双极
MAX1248/MAX1249
+2.7V to +5.25V, Low-Power, 4-Channel,
Serial 10-Bit ADCs in QSOP-16
16
______________________________________________________________________________________
Software Power-Down
Software power-down is activated using bits PD1 and PD0
of the control byte. As shown in Table 5, PD1 and PD0
also specify the clock mode. When software shutdown is
asserted, the ADC operates in the last specified clock
mode until the conversion is complete. Then the ADC
powers down into a low quiescent-current state. In internal
clock mode, the interface remains active, and conversion
results may be clocked out after the MAX1248/MAX1249
enter a software power-down.
The first logical 1 on DIN is interpreted as a start bit
and powers up the MAX1248/MAX1249. Following the
start bit, the data input word or control byte also deter-
mines clock mode and power-down states. For exam-
ple, if the DIN word contains PD1 = 1, then the chip
remains powered up. If PD0 = PD1 = 0, a power-down
resumes after one conversion.
Hardware Power-Down
Pulling SHDN low places the converter in hardware
power-down (Table 6). Unlike software power-down
mode, the conversion is not completed; it stops coinci-
dentally with SHDN being brought low. SHDN also con-
trols the clock frequency in internal clock mode. Letting
SHDN float sets the internal clock frequency to 1.8MHz.
When returning to normal operation with SHDN floating,
there is a tRC delay of approximately 2M
x CL, where
CL is the capacitive loading on the SHDN pin. Pulling
SHDN high sets the internal clock frequency to 225kHz.
This feature eases the settling-time requirement for the
reference voltage. With an external reference, the
MAX1248/MAX1249 can be considered fully powered
up within 2s of actively pulling SHDN high.
Power-Down Sequencing
The MAX1248/MAX1249 auto power-down modes can
save considerable power when operating at less than
maximum sample rates. Figures 12, 13a, and 13b show
the average supply current as a function of the sampling
rate. The following discussion illustrates the various
power-down sequences.
Lowest Power at up to 500
Conversions/Channel/Second
The following examples illustrate two different power-
down sequences. Other combinations of clock rates,
compensation modes, and power-down modes may
give lowest power consumption in other applications.
Figure 13a depicts the MAX1248 power consumption
for one or eight channel conversions, utilizing full
power-down mode and internal-reference compensa-
tion. A 0.01F bypass capacitor at REFADJ forms an
RC filter with the internal 20k
reference resistor with a
0.2ms time constant. To achieve full 10-bit accuracy, 8
time constants or 1.6ms are required after power-up.
Waiting 1.6ms in FASTPD mode instead of in full power-
up can reduce the power consumption by a factor of 10
or more. This is achieved by using the sequence shown
in Figure 14.
Table 5. Software Power-Down and
Clock Mode
Table 6. Hardware Power-Down and
Internal Clock Frequency
S
SH
HD
DN
N
STATE
DEVICE
MODE
REFERENCE-
BUFFER
COMPENSATION
INTERNAL
CLOCK
FREQUENCY
1
Enabled
Internal
225kHz
Floating
Enabled
External
1.8MHz
0
Power-
Down
N/A
1000
10,000
0.1
100
10
1
CONVERSION RATE (Hz)
I DD
(
A)
1
100
10
1k
10k
1M
100k
VREF = VDD = 3.0V
RLOAD = ∞
CODE = 1010101000
1 CHANNEL
4 CHANNELS
Figure 12. Average Supply Current vs. Conversion Rate
with External Reference
PD1
PD0
DEVICE
0
Full Power-Down
0
1
Fast Power-Down
1
0
Internal Clock
1
External Clock
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MAX1249AEPE+ 功能描述:模数转换器 - ADC 10-Bit 4Ch 133ksps 5.25V 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
MAX1249AMJE 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
MAX1249BCEE 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
MAX1249BCEE+ 功能描述:模数转换器 - ADC 10-Bit 4Ch 133ksps 5.25V 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
MAX1249BCEE+T 功能描述:模数转换器 - ADC 10-Bit 4Ch 133ksps 5.25V 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