参数资料
型号: AD7225BQ
厂商: Analog Devices Inc
文件页数: 2/24页
文件大小: 0K
描述: IC DAC 8BIT QUAD W/AMP 24-CDIP
产品培训模块: Data Converter Fundamentals
DAC Architectures
标准包装: 15
设置时间: 4µs
位数: 8
转换器数目: 4
电压电源: 双 ±
功率耗散(最大): 500mW
工作温度: -40°C ~ 85°C
安装类型: 通孔
封装/外壳: 24-CDIP(0.300",7.62mm)
供应商设备封装: 24-CDIP
包装: 管件
输出数目和类型: 4 电压,单极;4 电压,双极
采样率(每秒): 200k
AD7225
Rev. C | Page 10 of 24
INTERFACE LOGIC INFORMATION
The AD7225 contains two registers per DAC, an input register
and a DAC register. The A0 and A1 address lines select which
input register accepts data from the input port. When the WR
signal is low, the input latches of the selected DAC are transpa-
rent. The data is latched into the addressed input register on the
rising edge of
WR.
shows the addressing for the input
registers on the AD7225.
Table 5. AD7225 Addressing
A1
A0
Selected Input Register
Low
DAC A
Low
High
DAC B
High
Low
DAC C
High
DAC D
Only the data held in the DAC register determines the analog
output of the converter. The LDAC signal is common to all four
DACs and controls the transfer of information from the input
registers to the DAC registers. Data is latched into all four DAC
registers simultaneously on the rising edge of LDAC. The LDAC
signal is level triggered and therefore the DAC registers can be
made transparent by tying LDAC low (in this case, the outputs
of the converters respond to the data held in their respective
input latches). LDAC is an asynchronous signal and is indepen-
dent of WR. This is useful in many applications. However, in
systems where the asynchronous LDAC can occur during a
write cycle (or vice versa), care must be taken to ensure that
incorrect data is not latched through to the output. If LDAC is
activated prior to the rising edge of WR (or WR occurs during
LDAC), LDAC must stay low for t6or longer after WR
Table 6. Truth Table
goes high
to ensure correct data is latched through to the output. Table 6
shows the truth table for AD7225 operation. Figure 12 shows
the input control logic for the part; the write cycle timing
diagram is given in Figure 13.
WR
LDAC
Function
High
No operation. Device not selected.
Low
High
Input register of selected DAC transparent.
High
Input register of selected DAC latched.
High
Low
All four DAC registers Transparent (that is,
outputs respond to data held in respective
input registers). Input registers are latched.
High
All four DAC registers latched.
Low
DAC registers and selected input register
transparent output follows input data for
selected channel.
TO INPUT
LATCH A
TO INPUT
LATCH B
TO ALL
DAC LATCHES
TO INPUT
LATCH C
TO INPUT
LATCH D
LDAC
A0
A1
WR
00986-
012
Figure 12. Input Control Logic
ADDRESS
DATA IN
LDAC
WR
5V
0V
5V
0V
DATA
VALID
VINH
VINL
t2
t3
t1
t6
t5
t4
NOTES
1. ALL INPUT SIGNAL RISE AND FALL TIMES MEASURED FROM
10% TO 90% OF 5V.
tR = tF = 20ns OVER VDD RANGE.
2. TIMING MEASUREMENT REFERENCE LEVEL IS
3. IF LDAC IS ACTIVATED PRIOR TO THE RISING EDGE OF WR,
THEN IT MUST STAY LOW FOR
t6 OR LONGER AFTER WR
GOES HIGH.
VINH + VINL
2
00986-
013
Figure 13. Write Cycle Timing Diagram
相关PDF资料
PDF描述
AD7226BQ IC DAC 8BIT QUAD W/AMP 20-CDIP
AD7228CQ IC DAC 8BIT OCTAL W/AMP 24-CDIP
AD7233BNZ IC DAC 12BIT SRL W/AMP 8PDIP
AD7243BQ IC DAC 12BIT W/AMP W/REF 16-CDIP
AD7244AQ IC DAC 14BIT SRL W/REF 24-CDIP
相关代理商/技术参数
参数描述
AD7225BRS 功能描述:IC DAC 8BIT QUAD W/AMP 24-SSOP RoHS:否 类别:集成电路 (IC) >> 数据采集 - 数模转换器 系列:- 标准包装:2,400 系列:- 设置时间:- 位数:18 数据接口:串行 转换器数目:3 电压电源:模拟和数字 功率耗散(最大):- 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:36-TFBGA 供应商设备封装:36-TFBGA 包装:带卷 (TR) 输出数目和类型:* 采样率(每秒):*
AD7225BRS-REEL 功能描述:IC DAC 8BIT QUAD W/AMP 24-SSOP RoHS:否 类别:集成电路 (IC) >> 数据采集 - 数模转换器 系列:- 产品培训模块:LTC263x 12-, 10-, and 8-Bit VOUT DAC Family 特色产品:LTC2636 - Octal 12-/10-/8-Bit SPI VOUT DACs with 10ppm/°C Reference 标准包装:91 系列:- 设置时间:4µs 位数:10 数据接口:MICROWIRE?,串行,SPI? 转换器数目:8 电压电源:单电源 功率耗散(最大):2.7mW 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:14-WFDFN 裸露焊盘 供应商设备封装:14-DFN-EP(4x3) 包装:管件 输出数目和类型:8 电压,单极 采样率(每秒):*
AD7225BRSZ 功能描述:IC DAC 8BIT QUAD W/AMP 24SSOP RoHS:是 类别:集成电路 (IC) >> 数据采集 - 数模转换器 系列:- 标准包装:47 系列:- 设置时间:2µs 位数:14 数据接口:并联 转换器数目:1 电压电源:单电源 功率耗散(最大):55µW 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:28-SSOP(0.209",5.30mm 宽) 供应商设备封装:28-SSOP 包装:管件 输出数目和类型:1 电流,单极;1 电流,双极 采样率(每秒):*
AD7225CQ 制造商:Rochester Electronics LLC 功能描述:CMOS DAC IC - Bulk
AD7225CRS 功能描述:IC DAC 8BIT QUAD W/AMP 24-SSOP RoHS:否 类别:集成电路 (IC) >> 数据采集 - 数模转换器 系列:- 标准包装:47 系列:- 设置时间:2µs 位数:14 数据接口:并联 转换器数目:1 电压电源:单电源 功率耗散(最大):55µW 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:28-SSOP(0.209",5.30mm 宽) 供应商设备封装:28-SSOP 包装:管件 输出数目和类型:1 电流,单极;1 电流,双极 采样率(每秒):*