参数资料
型号: AD7858BRZ-REEL
厂商: Analog Devices Inc
文件页数: 10/32页
文件大小: 0K
描述: IC ADC 12BIT 8CHAN SRL 24SOIC
标准包装: 1,000
位数: 12
采样率(每秒): 200k
数据接口: 8051,QSPI?,串行,SPI? µP
转换器数目: 2
功率耗散(最大): 33mW
电压电源: 模拟和数字
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 24-SOIC(0.295",7.50mm 宽)
供应商设备封装: 24-SOIC W
包装: 带卷 (TR)
输入数目和类型: 8 个单端,单极;4 个伪差分,单极
REV. B
–18–
AD7858/AD7858L
PERFORMANCE CURVES
Figure 18 shows a typical FFT plot for the AD7858 at 200 kHz
sample rate and 10 kHz input frequency.
FREQUENCY – kHz
0
–20
–120
0
100
20
SNR
dB
40
60
–40
–60
–80
80
–100
AVDD = DVDD = 3.3V
fSAMPLE = 200kHz
fIN = 10kHz
SNR = 72.04dB
THD = –88.43dB
Figure 18. FFT Plot
Figure 19 shows the SNR vs. Frequency for different supplies
and different external references.
INPUT FREQUENCY – kHz
74
73
0
100
20
S(N+D)
RATIO
dB
40
60
72
71
70
80
69
AVDD = DVDD WITH 2.5V REFERENCE
UNLESS STATED OTHERWISE
5.0V SUPPLIES, WITH 5V REFERENCE
5.0V SUPPLIES
5.0V SUPPLIES, L VERSION
3.3V SUPPLIES
Figure 19. SNR vs. Frequency
Figure 20 shows the Power Supply Rejection Ratio vs. Fre-
quency for the part. The Power Supply Rejection Ratio is de-
fined as the ratio of the power in adc output at frequency f to
the power of a full-scale sine wave.
PSRR (dB) = 10 log (Pf/Pfs)
Pf = Power at frequency f in adc output, Pfs = power of a
full-scale sine wave. Here a 100 mV peak-to-peak sine wave is
coupled onto the AVDD supply while the digital supply is left
unaltered. Both the 3.3 V and 5.0 V supply performances are
shown.
INPUT FREQUENCY – kHz
–78
–80
–90
0
100
20
PSRR
dB
40
60
–82
–84
–86
80
–88
AVDD = DVDD = 3.3V/5.0V,
100mVp-p SINE WAVE ON AVDD
3.3V
5.0V
Figure 20. PSRR vs. Frequency
POWER-DOWN OPTIONS
The AD7858 provides flexible power management to allow the
user to achieve the best power performance for a given through-
put rate. The power management options are selected by
programming the power management bits, PMGT1 and PMGT0,
in the control register and by use of the
SLEEP pin. Table VI
summarizes the power-down options that are available and how
they can be selected by using either software, hardware, or a
combination of both. The AD7858 can be fully or partially
powered down. When fully powered down, all the on-chip cir-
cuitry is powered down and IDD is 1
A typ. If a partial power-
down is selected, then all the on-chip circuitry except the reference
is powered down and IDD is 400
A typ. The choice of full or par-
tial power-down does not give any significant improvement in
throughput with a power-down between conversions. This is
discussed in the next section–Power-Up Times. However, a
partial power-down does allow the on-chip reference to be used
externally even though the rest of the AD7858 circuitry is pow-
ered down. It also allows the AD7858 to be powered up faster
after a long power-down period when using the on-chip refer-
ence (See Power-Up Times–Using On-Chip Reference).
When using the
SLEEP pin, the power management bits PMGT1
and PMGT0 should be set to zero (default status on power-up).
Bringing the
SLEEP pin logic high ensures normal operation,
and the part does not power down at any stage. This may be
necessary if the part is being used at high throughput rates when
it is not possible to power down between conversions. If the user
wishes to power down between conversions at lower throughput
rates (i.e. <100 kSPS for the AD7858) to achieve better power
performances, then the
SLEEP pin should be tied logic low.
If the power-down options are to be selected in software only,
then the
SLEEP pin should be tied logic high. By setting the
power management bits PMGT1 and PMGT0 as shown in
Table VI, a Full Power-Down, Full Power-Up, Full Power-
Down Between Conversions, and a Partial Power-Down Be-
tween Conversions can be selected.
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相关代理商/技术参数
参数描述
AD7858L 制造商:AD 制造商全称:Analog Devices 功能描述:3 V to 5 V Single Supply, 200 kSPS 8-Channel, 12-Bit Sampling ADC
AD7858LAN 制造商:Analog Devices 功能描述:
AD7858LAN3 制造商:AD 制造商全称:Analog Devices 功能描述:3 V to 5 V Single Supply, 200 kSPS 8-Channel, 12-Bit Sampling ADC
AD7858LANZ 功能描述:IC ADC 12BIT 8CHAN SRL 24DIP RoHS:是 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:12 采样率(每秒):300k 数据接口:并联 转换器数目:1 功率耗散(最大):75mW 电压电源:单电源 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:24-SOIC(0.295",7.50mm 宽) 供应商设备封装:24-SOIC 包装:带卷 (TR) 输入数目和类型:1 个单端,单极;1 个单端,双极