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1402 参数 Datasheet PDF下载

1402图片预览
型号: 1402
PDF下载: 下载PDF文件 查看货源
内容描述: 串行12位, 2.2Msps采样ADC ,带有关断 [Serial 12-Bit, 2.2Msps Sampling ADC with Shutdown]
分类和应用:
文件页数/大小: 24 页 / 281 K
品牌: Linear [ Linear ]
 浏览型号1402的Datasheet PDF文件第10页浏览型号1402的Datasheet PDF文件第11页浏览型号1402的Datasheet PDF文件第12页浏览型号1402的Datasheet PDF文件第13页浏览型号1402的Datasheet PDF文件第15页浏览型号1402的Datasheet PDF文件第16页浏览型号1402的Datasheet PDF文件第17页浏览型号1402的Datasheet PDF文件第18页  
LTC1402  
U
W U U  
APPLICATIONS INFORMATION  
more than 0.25 inch long to the common reference. You  
may also choose to tie AGND2 (Pin 6) directly to a solid  
analog ground plane and eliminate all the 10µF capacitors  
at this pin. The external reference source needs to have  
enough output drive current for the 2kload at each ADC.  
Adjustment in Unipolar Mode with Pin 8 Held Low  
The code transitions occur midway between successive  
integer LSB values (i.e., FS + 0.5LSB, FS + 1.5LSB,  
FS + 2.5LSB,...FS – 2.5LSB, FS – 1.5LSB). The output at  
DOUT is binary with 1LSB = FS/4096 = 4.096V/4096 =  
1.0mV. In applications where absolute accuracy is impor-  
tant, offset and full-scale errors can be adjusted to zero.  
Offset error must be adjusted before full-scale error. In  
Figure 10b, zero offset is achieved by adjusting the offset  
FULL-SCALE AND OFFSET ADJUSTMENT  
Figure 9 shows the ideal input/output characteristics for  
the LTC1402 in bipolar mode and unipolar mode. Figure  
10a shows the components required for full-scale error  
adjustment. Figure 10b includes the components for off-  
set and full-scale adjustment.  
applied to the AIN input. For zero offset error apply  
0.5mV (i.e., 0.5LSB) to AIN+ and adjust the offset at the  
AINinput using R8 until the output code flickers between  
R1  
LTC1402  
+
51Ω  
3
4
A
A
011...111  
011...110  
011...101  
111...111  
111...110  
111...101  
IN  
IN  
ANALOG INPUT  
0V TO 4.096V  
OR ±2.048V  
R2  
39k  
R3  
51Ω  
S/H  
2.048V  
BANGAP  
REFERENCE  
5
V
REF  
REFERENCE  
AMP  
R4  
470k  
10µF  
64k  
64k  
100...010  
100...001  
100...000  
000...010  
000...001  
000...000  
7
6
GAIN  
R5  
500Ω  
AGND2  
(FS – 1LSB)  
FS – 1LSB  
INPUT VOLTAGE (V)  
1402 F010a  
1402 F09  
Figure 9. LTC1402 Transfer Characteristic  
Figure 10a. Full-Scale Adjustment Circuit with  
±10LSB Range  
Adjustment in Bipolar Mode with Pin 8 Held High  
5V  
The code transitions occur midway between successive  
integerLSBvalues(i.e., FS+0.5LSB, FS+1.5LSB, FS  
+2.5LSB,...FS2.5LSB, FS1.5LSB). TheoutputatDOUT  
is two’s complement binary with 1LSB = FS – (FS)/4096  
= 4.096V/4096 = 1.0mV. In applications where absolute  
accuracy is important, offset and full-scale errors can be  
adjusted to zero. Offset error must be adjusted before full-  
scale error. In Figure 10b, zero offset is achieved by  
R6  
R1  
LTC1402  
+
24k  
51Ω  
3
4
A
A
IN  
IN  
ANALOG INPUT  
0V TO 4.096V  
OR ±2.048V  
R2  
24k  
R3  
51Ω  
S/H  
5V  
R7  
7.5k  
2.048V  
BANGAP  
REFERENCE  
OFFSET  
ADJ  
R8  
10k  
5
V
REF  
REFERENCE  
AMP  
R4  
470k  
adjusting the offset applied to the AIN input. For zero  
10µF  
64k  
64k  
+
offset error, apply 0.5mV (i.e., 0.5LSB) to AIN and  
adjust the offset at the AINinput using R8 until the output  
code flickers between 0000 0000 0000 and 1111 1111  
1111. For full-scale adjustment in Figures 10a and 10b,  
7
6
GAIN  
FULL-SCALE  
R5  
ADJ 500Ω  
AGND2  
1402 F010b  
+
apply an input voltage of 2.0465V (FS – 1.5LSB) to AIN  
Figure 10b. Offset and Full-Scale Adjustment  
Circuits with ±10LSB Range  
and adjust R5 until the output code flickers between 0111  
1111 1110 and 0111 1111 1111.  
14  
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