参数资料
| 型号： | AD7840ARS |
| 厂商： | Analog Devices Inc |
| 文件页数： | 3/16页 |
| 文件大小： | 0K |
| 描述： | IC DAC 14BIT LOW POWER 5V 24SSOP |
| 产品培训模块： | Data Converter Fundamentals DAC Architectures |
| 标准包装： | 1 |
| 设置时间： | 2.5µs |
| 位数： | 14 |
| 数据接口： | 串行，并联 |
| 转换器数目： | 1 |
| 电压电源： | 双 ± |
| 功率耗散（最大）： | 100mW |
| 工作温度： | -25°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 24-SSOP（0.209"，5.30mm 宽） |
| 供应商设备封装： | 24-SSOP |
| 包装： | 管件 |
| 输出数目和类型： | 1 电压，双极 |
| 采样率（每秒）： | 400k |
AD7840
REV. B
–11–
AD7840–68000 Interface
An interface between the AD7840 and the 68000 microproces-
sor is shown in Figure 19. In this interface example, the LDAC
input is hardwired low. As a result the DAC latch and analog
output are updated on the rising edge of WR. A single move
instruction, therefore, loads the input latch and updates the output.
MOVE.W D0,$DAC
D0 = 68000 D0 Register
DAC = AD7840 Address
Figure 19. AD7840–MC68000 Parallel Interface
Serial Interfacing
Figures 20 to 23 show the AD7840 configured for serial inter-
facing with the CS input hardwired to –5 V. The parallel bus is
not activated during serial communication with the AD7840.
AD7840–ADSP-2101/ADSP-2102 Serial Interface
Figure 20 shows a serial interface between the AD7840 and the
ADSP-2101/ADSP-2102 DSP processor. Also included in the
interface is the AD7870, a 12-bit A/D converter. An interface
such as this is suitable for modem and other applications which
have a DAC and an ADC in serial communication with a
microprocessor.
The interface uses just one of the two serial ports of the
ADSP-2101/ADSP-2102. Conversion is initiated on the
AD7870 at a fixed sample rate (e.g., 9.6 kHz) which is provided
by a timer or clock recovery circuitry. While communication
takes place between the ADC and the ADSP-2101/ ADSP-2102,
the AD7870 SSTRB line is low. This SSTRB line is used to
provide a frame synchronization pulse for the AD7840 SYNC
and ADSP-2101/ADSP-2102 TFS lines. This means that com-
munication between the processor and the AD7840 can only
take place while the AD7870 is communicating with the processor.
This arrangement is desirable in systems such as modems where
the DAC and ADC communication should be synchronous.
The use of the AD7870 SCLK for the AD7840 SCLK and
ADSP-2101/ADSP-2102 SCLK means that only one serial port
of the processor is used. The serial clock for the AD7870 must
be set for continuous clock for correct operation of this interface.
Data from the ADSP-2101/ADSP-2102 is valid on the falling
edge of SCLK. The LDAC input of the AD7840 is permanently
low so the update of the DAC latch and analog output takes
place on the sixteenth falling edge of SCLK (with SYNC low).
The FORMAT pin of the AD7840 must be tied to +5 V and
the JUSTIFY pin tied to DGND for this interface to operate
correctly.
Figure 20. Complete DAC/ADC Serial Interface
AD7840–DSP56000 Serial Interface
A serial interface between the AD7840 and the DSP56000 is
shown in Figure 21. The DSP56000 is configured for normal
mode synchronous operation with gated clock. It is also set up
for a 16-bit word with SCK and SC2 as outputs and the FSL
control bit set to a 0. SCK is internally generated on the
DSP56000 and applied to the AD7840 SCLK input. Data from
the DSP56000 is valid on the falling edge of SCK. The SC2
output provides the framing pulse for valid data. This line must
be inverted before being applied to the SYNC input of the
AD7840.
The LDAC input of the AD7840 is connected to DGND so the
update of the DAC latch takes place on the sixteenth falling
edge of SCLK. As with the previous interface, the FORMAT
pin of the AD7840 must be tied to +5 V and the JUSTIFY pin
tied to DGND.
Figure 21. AD7840–DSP56000 Serial Interface
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相关代理商/技术参数 |
参数描述 |
|---|---|
| AD7840ARS-REEL | 功能描述:IC DAC 14BIT LOW POWER 5V 24SSOP 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:Data Converter Fundamentals DAC Architectures 标准包装:750 系列:- 设置时间:7µs 位数:16 数据接口:并联 转换器数目:1 电压电源:双 ± 功率耗散（最大）:100mW 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:28-LCC（J 形引线） 供应商设备封装:28-PLCC（11.51x11.51） 包装:带卷 (TR) 输出数目和类型:1 电压，单极；1 电压，双极 采样率（每秒）:143k |
| AD7840ARSZ | 功能描述:IC DAC 14BIT LOW POWER 5V 24SSOP RoHS:是 类别:集成电路 (IC) >> 数据采集 - 数模转换器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:50 系列:- 设置时间:4µs 位数:12 数据接口:串行 转换器数目:2 电压电源:单电源 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:8-TSSOP，8-MSOP（0.118"，3.00mm 宽） 供应商设备封装:8-uMAX 包装:管件 输出数目和类型:2 电压，单极 采样率（每秒）:* 产品目录页面:1398 (CN2011-ZH PDF) |
| AD7840ARSZ-REEL | 功能描述:IC DAC 14BIT LOW POWER 5V 24SSOP RoHS:是 类别:集成电路 (IC) >> 数据采集 - 数模转换器 系列:- 产品培训模块:Data Converter Fundamentals DAC Architectures 标准包装:750 系列:- 设置时间:7µs 位数:16 数据接口:并联 转换器数目:1 电压电源:双 ± 功率耗散（最大）:100mW 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:28-LCC（J 形引线） 供应商设备封装:28-PLCC（11.51x11.51） 包装:带卷 (TR) 输出数目和类型:1 电压，单极；1 电压，双极 采样率（每秒）:143k |
| AD7840BQ | 制造商:AD 制造商全称:Analog Devices 功能描述:LC2MOS Complete 14-Bit DAC |
| AD7840CQ | 制造商:未知厂家 制造商全称:未知厂家 功能描述:14-Bit Digital-to-Analog Converter |
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