参数资料
型号: AD7873ARQZ-REEL7
厂商: Analog Devices Inc
文件页数: 16/29页
文件大小: 0K
描述: IC ADC 12BIT TOUCHSCREEN 16QSOP
标准包装: 1,000
类型: 电阻
触摸面板接口: 4 线
输入数/键: 1 TSC
分辨率(位): 12 b
评估套件: 可供
数据接口: 串行
数据速率/采样率 (SPS,BPS): 125k
电压基准: 外部,内部
电源电压: 2.2 V ~ 5.25 V
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 16-SSOP(0.154",3.90mm 宽)
供应商设备封装: 16-QSOP
包装: 带卷 (TR)
AD7873
Data Sheet
Rev. F | Page 22 of 28
16 Clocks per Cycle
The control bits for the next conversion can be overlapped with
the current conversion to allow for a conversion every 16 DCLK
cycles, as shown in Figure 38. This timing diagram also allows
the possibility of communication with other serial peripherals
between each byte (eight DCLKs) transfer between the
processor and the converter. However, the conversion must
complete within a short enough time frame to avoid capacitive
droop effects that could distort the conversion result. It should
also be noted that the AD7873 is fully powered while other
serial communications are taking place between byte transfers.
15 Clocks per Cycle
Figure 39 shows the fastest way to clock the AD7873. This
scheme does not work with most microcontrollers or DSPs
because they are not capable of generating a 15 clock cycle per
serial transfer. However, some DSPs allow the number of clocks
per cycle to be programmed. This method can also be used with
FPGAs (field programmable gate arrays) or ASICs (application
specific integrated circuits). As in the 16 clocks per cycle case,
the control bits for the next conversion are overlapped with the
current conversion to allow a conversion every 15 DCLK cycles
using 12 DCLKs to perform the conversion and 3 DCLKs to
acquire the analog input. This effectively increases the
throughput rate of the AD7873 beyond that used for the
specifications that are tested using 16 DCLKs per cycle, and
DCLK = 2 MHz.
8-Bit Conversion
The AD7873 can be set up to operate in an 8-bit mode rather
than a 12-bit mode by setting the MODE bit in the control
register to 1. This mode allows a faster throughput rate to be
achieved, assuming 8-bit resolution is sufficient. When using 8-bit
mode, a conversion is complete four clock cycles earlier than in
12-bit mode. This can be used with serial interfaces that provide
12 clock transfers, or two conversions can be completed with
three 8-clock transfers. The throughput rate increases by 25% as
a result of the shorter conversion cycle, but the conversion itself
can occur at a faster clock rate because the internal settling time
of the AD7873 is not as critical, because settling to eight bits is
all that is required. The clock rate can be as much as 50% faster.
The faster clock rate and fewer clock cycles combine to provide
double the conversion rate.
Figure 38. Conversion Timing, 16 DCLKs per Cycle, 8-Bit Bus Interface. No DCLK delay required with dedicated serial port.
Figure 39. Conversion Timing, 15 DCLKs per Cycle, Maximum Throughput Rate
DCLK
DIN
BUSY
DOUT
CS
1
S
11
10
9
8
7
6
5
4
3
2
1
0
11
10
9
1
8
CONTROL BITS
02164-
038
CS
DCLK
DIN
BUSY
DOUT
S
A2
PD1 PD0
A1
A0 MODE
SER/
DFR
MODE
SER/
DFR
1
11
10
9
8
7
6
5
4
3
2
1
0
11
10
9
8
7
6
5
4
15
1
15
1
S
A2
S
A2
A1
PD1 PD0
A0
02164-
039
相关PDF资料
PDF描述
VE-J5J-MX-F4 CONVERTER MOD DC/DC 36V 75W
VE-J5J-MX-F3 CONVERTER MOD DC/DC 36V 75W
MS27474E22B35S CONN RCPT 100POS JAM NUT W/SCKT
MS3452W14S-9SW CONN RCPT 2POS BOX MNT W/SCKT
D38999/24WJ61SB CONN RCPT 61POS JAM NUT W/SCKT
相关代理商/技术参数
参数描述
AD7873ARU 制造商:Analog Devices 功能描述:TOUCH SCREEN DIGITIZER 制造商:Rochester Electronics LLC 功能描述:12 BIT 16 LEAD TSSOP - Bulk
AD7873ARU-REEL 制造商:Analog Devices 功能描述:TOUCH SCREEN DIGITIZER 制造商:Rochester Electronics LLC 功能描述:12 BIT 16 LEAD TSSOP - Tape and Reel
AD7873ARU-REEL7 制造商:Analog Devices 功能描述:TOUCH SCREEN DIGITIZER 制造商:Rochester Electronics LLC 功能描述:12 BIT 16 LEAD TSSOP - Tape and Reel
AD7873ARUZ 功能描述:IC ADC 12BIT TOUCHSCREEN 16TSSOP RoHS:是 类别:集成电路 (IC) >> 数据采集 - 触摸屏控制器 系列:- 标准包装:96 系列:- 类型:- 触摸面板接口:- 输入数/键:- 分辨率(位):- 评估套件:* 数据接口:- 数据速率/采样率 (SPS,BPS):- 电压基准:- 电源电压:- 电流 - 电源:- 工作温度:- 安装类型:表面贴装 封装/外壳:16-TSSOP(0.173",4.40mm 宽) 供应商设备封装:16-TSSOP 包装:带卷 (TR)
AD7873ARUZ-REEL 功能描述:IC ADC 12BIT TOUCHSCREEN 16TSSOP RoHS:是 类别:集成电路 (IC) >> 数据采集 - 触摸屏控制器 系列:- 标准包装:96 系列:- 类型:- 触摸面板接口:- 输入数/键:- 分辨率(位):- 评估套件:* 数据接口:- 数据速率/采样率 (SPS,BPS):- 电压基准:- 电源电压:- 电流 - 电源:- 工作温度:- 安装类型:表面贴装 封装/外壳:16-TSSOP(0.173",4.40mm 宽) 供应商设备封装:16-TSSOP 包装:带卷 (TR)