VIN" />
參數(shù)資料
型號: AD7870LPZ
廠商: Analog Devices Inc
文件頁數(shù): 4/28頁
文件大?。?/td> 0K
描述: IC ADC 12BIT SAMPLING 3V 28-PLCC
產(chǎn)品變化通告: Conversion Time Change
標準包裝: 1
位數(shù): 12
采樣率(每秒): 100k
數(shù)據(jù)接口: 串行,并聯(lián)
轉(zhuǎn)換器數(shù)目: 1
功率耗散(最大): 95mW
電壓電源: 雙 ±
工作溫度: 0°C ~ 70°C
安裝類型: 表面貼裝
封裝/外殼: 28-LCC(J 形引線)
供應(yīng)商設(shè)備封裝: 28-PLCC(11.51x11.51)
包裝: 管件
輸入數(shù)目和類型: 1 個單端,雙極
AD7870/AD7875/AD7876
Rev. C | Page 12 of 2
8
AD7876
TRACK-AND-HOLD
AMPLIFIER
TO INTERNAL
REFERENCE
2.1R
7R
VIN
REF OUT
AGND
TO INTERNAL
COMPARATOR
07
73
0-
00
9
3R
TO INTERNAL AGND
Figure 9. AD7876 Analog Input
Figure 10 shows the analog input for the AD7875. The input
range is 0 V to +5 V into an input resistance of typically 25 kΩ.
Once again, the designed code transitions occur midway
between successive integer LSB values. The output code is
straight binary with 1 LSB = FS/4096 = 5 V/4096 = 1.22 mV.
The ideal input/output transfer function is shown in Figure 12.
AD7875
TRACK-AND-HOLD
AMPLIFIER
TO INTERNAL AGND
3R
2R
VIN
AGND
TO INTERNAL
COMPARATOR
07
73
0-
01
0
Figure 10. AD7875 Analog Input
011…111
OUTPUT
CODE
AD7870 (AD7876)
011…110
100…001
100…000
0V
VIN – INPUT VOLTAGE
000…010
000…001
000…000
111…111
111…110
–FS
2
+FS – 1LSB
2
FS
1LSB =
FS = 6V (20V)
4096
07
73
0-
0
1
Figure 11. AD7870/AD7876 Transfer Function
OUTPUT
CODE
000…011
000…010
000…001
000…000
VIN – INPUT VOLTAGE
111…101
111…100
111…111
111…110
FS
1LSB =
FS = 5V
+FS – 1LSB
0V
4096
07
73
0-
0
12
Figure 12. AD7875 Transfer Function
OFFSET AND FULL-SCALE ADJUSTMENT—
AD7870
In most digital signal processing (DSP) applications, offset and
full-scale errors have little or no effect on system performance.
Offset error can always be eliminated in the analog domain
by ac coupling. Full-scale error effect is linear and does not
cause problems as long as the input signal is within the full
dynamic range of the ADC. Some applications will require
that the input signal span the full analog input dynamic range.
In such applications, offset and full-scale error have to be
adjusted to zero.
Where adjustment is required, offset error must be adjusted
before full-scale error. This is achieved by trimming the offset
of the op amp driving the analog input of the AD7870 while the
input voltage is 1/2 LSB below ground. The trim procedure is as
follows: apply a voltage of 0.73 mV(1/2 LSB) at V1 in Figure 13
and adjust the op amp offset voltage until the ADC output code
flickers between 1111 1111 1111 and 0000 0000 0000. Gain
error can be adjusted at either the first code transition (ADC
negative full-scale) or the last code transition (ADC positive full
scale). The trim procedures for both cases are as follows (see
相關(guān)PDF資料
PDF描述
IDT72841L25PF8 IC FIFO SYNC 4KX9 25NS 64QFP
LTC1337CG IC 3DVR/5RCVR 5V RS232 28-SSOP
VI-21Z-MX CONVERTER MOD DC/DC 2V 30W
LTC2145CUP-14#TRPBF IC ADC DUAL 14BIT 125MSPS 64-QFN
IDT72V805L15PF8 IC FIFO SYNC 256X18 15NS 128QFP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD7870LPZ1 制造商:AD 制造商全稱:Analog Devices 功能描述:LC2MOS Complete, 12-Bit, 100 kHz, Sampling ADCs
AD7870SE/883B 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog-to-Digital Converter, 12-Bit
AD7870SQ 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 12-Bit 100kHz Sampling RoHS:否 制造商:Analog Devices 通道數(shù)量: 結(jié)構(gòu): 轉(zhuǎn)換速率: 分辨率: 輸入類型: 信噪比: 接口類型: 工作電源電壓: 最大工作溫度: 安裝風(fēng)格: 封裝 / 箱體:
AD7870SQ/883B 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog-to-Digital Converter, 12-Bit
AD7870SQQ10 制造商:Analog Devices 功能描述: