- 您现在的位置：买卖IC网 > PDF目录17069 > DC1339A (Linear Technology)BOARD SAR ADC LTC2302 PDF资料下载
参数资料
| 型号： | DC1339A |
| 厂商： | Linear Technology |
| 文件页数： | 6/20页 |
| 文件大小： | 0K |
| 描述： | BOARD SAR ADC LTC2302 |
| 软件下载： | QuikEval System |
| 设计资源： | DC1339A Design File DC1339A Schematic |
| 标准包装： | 1 |
| 系列： | QuikEval™ |
| ADC 的数量： | 1 |
| 位数： | 12 |
| 采样率（每秒）： | 500k |
| 数据接口： | MICROWIRE?，串行，SPI? |
| 输入范围： | ±VREF/2 |
| 在以下条件下的电源（标准）： | 14mW @ 500kSPS |
| 已用 IC / 零件： | LTC2302 |
| 已供物品： | 板 |
| 相关产品： | LTC2302IDD#TRPBF-ND - IC ADC 12-BIT 1CH 500KSPS 10DFN LTC2302IDD#PBF-ND - IC ADC 12BIT 1CH 500KSPS 10-DFN LTC2302CDD#TRPBF-ND - IC ADC 12-BIT 1CH 500KSPS 10DFN LTC2302CDD#PBF-ND - IC ADC 12BIT 1CH 500KSPS 10-DFN |
LTC2302/LTC2306
14
23026fa
APPLICATIONS INFORMATION
Figure 2b. Analog Input Equivalent Circuit for
Large Filter Capacitances
Figure 2a. Analog Input Equivalent Circuit
chargingthesample-and-holdcapacitorsduringtheacquire
mode. In conversion mode, the analog inputs draw only
a small leakage current. If the source impedance of the
driving circuit is low, the ADC inputs can be driven directly.
Otherwise, more acquisition time should be allowed for a
source with higher impedance.
Reference
A low noise, stable reference is required to ensure full
performance. The LT1790 and LT6660 are adequate
for most applications. The LT6660 is available in 2.5V,
3V, 3.3V and 5V versions, and the LT1790 is available in
1.25V, 2.048V, 2.5V, 3V, 3.3V, 4.096V and 5V versions.
The exceptionally low input noise allows the input range to
be optimized for the application by changing the reference
voltage. The VREF input must be decoupled with a 10μF
capacitor in parallel with a 0.1μF capacitor, so verify that
the device providing the reference voltage is stable with
capacitive loads.
If the voltage reference is 5V and can supply 5mA, it can
be used for both VREF and VDD. VDD must be connected
to a clean analog supply, and a quiet 5V reference voltage
makes a convenient supply for this purpose.
Input Filtering
The noise and distortion of the input amplier and other
circuitry must be considered since they will add to the
ADC noise and distortion. Therefore, noisy input circuitry
should be ltered prior to the analog inputs to minimize
noise. A simple 1-pole RC lter is sufcient for many
applications.
The analog inputs of the LTC2302/LTC2306 can be modeled
as a 55pF capacitor (CIN) in series with a 100Ω resistor
(RON) as shown in Figure 2a. CIN gets switched to the
selected input once during each conversion. Large lter
RC time constants will slow the settling of the inputs. It
is important that the overall RC time constants be short
enough to allow the analog inputs to completely settle to
12-bit resolution within the acquisition time (tACQ) if DC
accuracy is important.
When using a lter with a large CFILTER value (e.g., 1μF),
the inputs do not completely settle and the capacitive input
switching currents are averaged into a net DC current
(IDC). In this case, the analog input can be modeled by
an equivalent resistance (REQ = 1/(fSMPL CIN)) in series
with an ideal voltage source (VREF/2) as shown in Figure
2b. The magnitude of the DC current is then approximately
IDC = (VIN – VREF/2)/REQ, which is roughly proportional
to VIN. To prevent large DC drops across the resistor
RFILTER, a lter with a small resistor and large capacitor
should be chosen. When running at the minimum cycle
time of 2μs, the input current equals 106μA at VIN = 5V,
which amounts to a full-scale error of 0.5LSB when using
a lter resistor (RFILTER) of 4.7Ω. Applications requiring
lower sample rates can tolerate a larger lter resistor for
the same amount of full-scale error.
CIN
55pF
RON
100Ω
RSOURCE
VIN
LTC2302
LTC2306
INPUT
(CH0, CH1
IN+, IN–)
C1
23026 F02a
REQ
1/(fSMPL CIN)
VREF/2
RFILTER
IDC
VIN
LTC2302
LTC2306
INPUT
(CH0, CH1
IN+, IN–)
CFILTER
23026 F02b
+
–
相关PDF资料 |
PDF描述 |
|---|---|
| EVAL-AD5821EBZ | BOARD EVALUATION FOR AD5821 |
| DC1067A-A | BOARD DELTA SIGMA ADC LTC2450 |
| 0210390933 | CABLE JUMPER 1MM .178M 23POS |
| PCMC135T-2R2MF | COIL 2.2 UH POWER CHOKE 20% SMD |
| AT-S-26-6/6/B-25-OE-R | MOD CORD SGL-ENDED 6-6 BLACK 25' |
相关代理商/技术参数 |
参数描述 |
|---|---|
| DC1342B | 制造商:Linear Technology 功能描述:DEV BOARD FOR LT3758AEMSE |
| DC1351A | 功能描述:EVAL BOARD FOR LTC4269-2 RoHS:是 类别:编程器，开发系统 >> 评估演示板和套件 系列:- 标准包装:1 系列:- 主要目的:数字电位器 嵌入式:- 已用 IC / 零件:AD5258 主要属性:- 次要属性:- 已供物品:板 相关产品:AD5258BRMZ1-ND - IC POT DGTL I2C1K 64P 10MSOPAD5258BRMZ10-ND - IC POT DGTL I2C 10K 64P 10MSOPAD5258BRMZ100-ND - IC POT DGTL I2C 100K 64P 10MSOPAD5258BRMZ50-ND - IC POT DGTL I2C 50K 64P 10MSOPAD5258BRMZ1-R7-ND - IC POT DGTL I2C 1K 64P 10MSOPAD5258BRMZ10-R7-ND - IC POT DGTL I2C 10K 64P 10MSOPAD5258BRMZ50-R7-ND - IC POT DGTL I2C 50K 64P 10MSOPAD5258BRMZ100-R7-ND - IC POT DGTL I2C 100K 64P 10MSOP |
| DC1354A-A | 制造商:Linear Technology 功能描述:DEMO BOARD FOR LT4256-1 制造商:Linear Technology 功能描述:EVAL BOARD, LT4256-1 HOT SWAP CONTROLLER |
| DC1354A-B | 制造商:Linear Technology 功能描述:DEMO BOARD FOR LT4256-2 制造商:Linear Technology 功能描述:EVAL BOARD, LT4256-2 HOT SWAP CONTROLLER |
| DC1355A | 制造商:Linear Technology 功能描述:DEMO BOARD FOR LTC4221 |
发布紧急采购，3分钟左右您将得到回复。