- 您现在的位置：买卖IC网 > PDF目录382545 > SPT7861SCT (FAIRCHILD SEMICONDUCTOR CORP) 10-BIT, 40 MSPS, 160 mW A/D CONVERTER PDF资料下载
参数资料
| 型号： | SPT7861SCT |
| 厂商： | FAIRCHILD SEMICONDUCTOR CORP |
| 元件分类： | ADC |
| 英文描述： | 10-BIT, 40 MSPS, 160 mW A/D CONVERTER |
| 中文描述： | 1-CH 10-BIT SUCCESSIVE APPROXIMATION ADC, PARALLEL ACCESS, PQFP32 |
| 封装： | 7 MM, TQFP-32 |
| 文件页数： | 7/11页 |
| 文件大小： | 87K |
| 代理商： | SPT7861SCT |
7
6/25/01
SPT7861
Table II
–
Clock Cycles
Clock
1
2
3
4
5-15
16
Operation
Reference zero sampling
Auto-zero comparison
Auto-calibrate comparison
Input sample
11-bit SAR conversion
Data transfer
The 16-phase clock, which is derived from the input clock,
synchronizes these events. The timing signals for adjacent
ADC sections are shifted by one clock cycle so that the
analog input is sampled on every cycle of the input clock
by exactly one ADC section. After 16 clock periods, the
timing cycle repeats. The latency from analog input
sample to the corresponding digital output is 12 clock
cycles.
Since only 16 comparators are used, a huge power
savings is realized.
The auto-zero operation is done using a closed loop
system that uses multiple samples of the comparator
’
s
response to a reference zero.
The auto-calibrate operation, which calibrates the gain
of the MSB reference and the LSB reference, is also
done with a closed loop system. Multiple samples of the
gain error are integrated to produce a calibration volt-
age for each ADC section.
Capacitive displacement currents, which can induce
sampling error, are minimized since only one compara-
tor samples the input during a clock cycle.
The total input capacitance is very low since sections of
the converter that are not sampling the signal are iso-
lated from the input by transmission gates.
VOLTAGE REFERENCE
The SPT7861 requires the use of a single external voltage
reference for driving the high side of the reference ladder.
It must be within the range of 3 V to 5 V. The lower side of
the ladder is typically tied to AGND (0.0 V), but can be run
up to 2.0 V with a second reference. The analog input volt-
age range will track the total voltage difference measured
between the ladder sense lines, V
RHS
and V
RLS
.
Force and sense taps are provided to ensure accurate
and stable setting of the upper and lower ladder sense line
voltages across part-to-part and temperature variations.
By using the configuration shown in figure 3, offset and
gain errors of less than ±2 LSB can be obtained.
In cases where wider variations in offset and gain can be
tolerated, V
REF
can be tied directly to V
RHF
, and AGND can
be tied directly to V
RLF
as shown in figure 4. Decouple
force and sense lines to AGND with a .01 μF capacitor
(chip cap preferred) to minimize high-frequency noise in-
jection. If this simplified configuration is used, the following
considerations should be taken into account.
The reference ladder circuit shown in figure 4 is a simpli-
fied representation of the actual reference ladder with
force and sense taps shown. Due to the actual internal
structure of the ladder, the voltage drop from V
RHF
to V
RHS
is not equivalent to the voltage drop from V
RLF
to V
RLS
.
Figure 3
–
Ladder Force/Sense Circuit
5*
&
&
'*
8
B
"" @ ; +=+<
8
B
Figure 4
–
Reference Ladder
#
#
94+
"" @ ; +=+<
/>@0
&
/5*0
+=+
&
/+=+2$0
/84=.0
83=+
"
%
2$
.+
相关PDF资料 |
PDF描述 |
|---|---|
| SPT7863SCS | 10-BIT, 40 MSPS, 160 mW A/D CONVERTER |
| SPT7863SCT | 10-BIT, 40 MSPS, 160 mW A/D CONVERTER |
| SPT7863 | 10-BIT, 40 MSPS, 160 mW A/D CONVERTER |
| SPT7871 | 10-BIT, 100 MSPS TTL A/D CONVERTER |
| SPT7871SCU | 10-BIT, 100 MSPS TTL A/D CONVERTER |
相关代理商/技术参数 |
参数描述 |
|---|---|
| SPT7861SCT_Q | 功能描述:模数转换器 - ADC 10-BIT A/D CONVERTER 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 |
| SPT7861SCTX | 功能描述:视频模拟/数字化转换器集成电路 10BIT 40MSPS SaR aDC RoHS:否 制造商:Texas Instruments 输入信号类型:Differential 转换器数量:1 ADC 输入端数量:4 转换速率:3 Gbps 分辨率:8 bit 结构: 输入电压:3.3 V 接口类型:SPI 信噪比: 电压参考: 电源电压-最大:3.45 V 电源电压-最小:3.15 V 最大功率耗散: 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:TCSP-48 封装:Reel |
| SPT7862 | 制造商:CADEKA 制造商全称:CADEKA 功能描述:10-BIT, 40 MSPS, DUAL-CHANNEL A/D CONVERTER |
| SPT7862SIT | 制造商:CADEKA 制造商全称:CADEKA 功能描述:10-BIT, 40 MSPS, DUAL-CHANNEL A/D CONVERTER |
| SPT7863 | 制造商:FAIRCHILD 制造商全称:Fairchild Semiconductor 功能描述:10-BIT, 40 MSPS, 160 mW A/D CONVERTER |
发布紧急采购，3分钟左右您将得到回复。