AD7470:  10位、2.7 V至5.25 V、1.75 MSPS低功耗ADC

AD7470/AD7472分别是10位/12位高速、低功耗逐次逼近型ADC,工作电压为2.7 V至5.25 V单电源,12位AD7472的最高呑吐量可达1.5 MSPS,10位AD7470则可达1.75 MSPS。该器件内置一个低噪声、宽带宽采样/保持放大器,可处理20 MHz以上的输入频率。转换过程和数据采集过程均通过标准控制输入进行控制,可与微处理器或DSP轻松连接。输入信号在CONVST的下降沿进行采样,而转换同时在此处启动。转换开始时,BUSY电平升高,在CONVST 下降沿531.66 ns之后降低（AD7472的时钟频率为26 MHz）,表示转换完成。该器件不存在流水线延迟。转换结果通过标准CS和RD信号经高速并行接口进行存取。

AD7470/AD7472采用先进的设计技术,可在高呑吐量的情况下实现极低的功耗。当电源电压为3 V,呑吐量为1.5 MSPS时,AD7470的平均功耗通常仅为1.1 mA。当电源电压为5 V,呑吐量为1.75 MSPS时,平均功耗一般为1.6 mA。该器件还具有灵活的功耗/吞吐量管理功能。当采用3 V电源,呑吐量为500 kSPS时, AD7470的功耗可降至713 µA。采用5 V电源,呑吐量为500 kSPS时,功耗为944 µA。该器件同时支持自动休眠模式,这种模式下,器件唤醒,进入正常模式进行转换,转换结束时自动进入休眠模式。通过这种方式,可在较低呑吐量下实现极低的功耗。在这种模式下,AD7472可采用3 V电源,呑吐量为100 kSPS,平均功耗仅为124 µA。采用5 V电源,呑吐量为100 kSPS时,平均功耗为171 µA。该器件的模拟输入范围为0 V至REF IN。2.5 V外部基准电压通过REF IN引脚输入。转换速率取决于外部时钟。

The AD7470/AD7472 are 10-bit/12-bit high speed, low power, successive-approximation ADCs. The parts operate from a single 2.7 V to 5.25 V power supply and feature throughput rates up to 1.5 MSPS for the 12-bit AD7472 and up to 1.75 MSPS for the 10-bit AD7470. The parts contain a low-noise, wide bandwidth track/hold amplifier which can handle input frequencies in excess of 20 MHz.

The conversion process and data acquisition are controlled using standard control inputs, allowing easy interfacing to microprocessors or DSPs. The input signal is sampled on the falling edge of CONVST, and conversion is also initiated at this point. BUSY goes high at the start of conversion and goes low 531.66 ns after falling edge of CONVST (AD7472 with a clock frequency of 26 MHz) to indicate that the conversion is complete. There are no pipeline delays associated with the parts. The conversion result is accessed via standard CS and RD signals over a high speed parallel interface.

The AD7470/AD7472 use advanced design techniques to achieve very low power dissipation at high throughput rates. With 3 V supplies and 1.5 MSPS throughput rates, the AD7470 typically consumes, on average, just 1.1 mA. With 5 V supplies and 1.75 MSPS, the average current consumption is typically 1.6 mA. The part also offers flexible power/throughput rate management. Operating the AD7470 with 3 V supplies and 500 kSPS throughput reduces the current consumption to 713 μA. At 5 V supplies and 500 kSPS, the part consumes 944 μA.

It is also possible to operate the parts in an auto sleep mode, where the part wakes up to do a conversion and automatically enters sleep mode at the end of conversion. This method allows very low power dissipation numbers at lower throughput rates. In this mode, the AD7472 can be operated with 3 V supplies at 100 kSPS, and consume an average current of just 124 μA. At 5 V supplies and 100 kSPS, the average current consumption is 171 μA.

The analog input range for the part is 0 V to REF IN. The 2.5 V reference is applied externally to the REF IN pin. The conversion rate is determined by the externally-applied clock.

AD7470 特点

• 额定电压(VDD)：2.7 V至5.25 V
• 1.75 MSPS（10位）
• 低功耗
  典型3.34 mW（1.5 MSPS,3 V电源
  典型7.97 mW（1.75 MSPS,5 V电源）
• 灵活的功耗/呑吐量管理
• 宽输入带宽：
  70 d典型信噪比B（500 kHz输入频率）
• 无流水线延迟
• 高速并行接口
• 休眠模式：50 nA（典型值）
• 24引脚SOIC和TSSOP封装
• Specified for VDD of 2.7 V to 5.25 V
• 1.75 MSPS (10-Bit)
• Low Power
  3.34 mW Typ at 1.5 MSPS with 3 V Supplies
  7.97 mW Typ at 1.75 MSPS with 5 V Supplies
• Flexible Power/Throughput Rate Management
• Wide Input Bandwidth
  70 dB Typ SNR at 500 kHz Input Frequency
• No Pipeline Delays
• High Speed Parallel Interface
• Sleep Mode: 50 nA Typ
• 24-Lead SOIC and TSSOP Packages

AD7470 技术指标

• Resolution (Bits): 10bit
• # Chan: 1
• Sample Rate: 1.75MSPS
• Interface: Par
• Analog Input Type: SE-Uni
• Ain Range: Uni (Vref)
• ADC Architecture: SAR
• Pkg Type: SOP

AD7470 亮点

1. 高呑吐量、低功耗。AD7470和AD7472可分别提供1.75 MSPS和1.5 MSPS的呑吐量,功耗仅为4 mW。
2. 灵活的功耗/呑吐量管理。转换速率由外部时钟决定,功耗随着转换速率的降低而下降。该器件还具有自动休眠模式,可在较低呑吐量下实现最高功效。
3. 无流水线延迟。该器件采用一个标准逐次逼近型ADC,通过CONVST输入和一次性转换控制可实现对采样时间的精确控制。

1. High Throughput with Low Power Consumption. The AD7470 offers 1.75 MSPS throughput and the AD7472 offers 1.5 MSPS throughput rates with 4 mW power consumption.
2. Flexible Power/Throughput Rate Management. The conversion rate is determined by an externally-applied clock allowing the power to be reduced as the conversion rate is reduced. The part also features an auto sleep mode to maximize power efficiency at lower throughput rates.
3. No Pipeline Delay. The part features a standard successive approximation ADC with accurate control of the sampling instant via a CONVST input and once off conversion control.

AD7470 建议配套产品

• Recommended Driver Amplifiers for the AD7470
  • For low noise, low distortion, wide bandwidth, we recommend the AD8021 or the ADA4899-1.
  • For low noise, low distortion, high slew rate, we recommend the AD8047.
  • For low noise, low distortion, low cost, we recommend the AD8051.
• Recommended 2.5V References for the AD7470
  • For low noise, high accuracy, we recommend the ADR421, ADR431 or the ADR441.
  • For low power, low cost, we recommend the ADR291 or the ADR3425.
• Recommended Power Solutions
  • For selecting voltage regulator products, use ADIsimPower.
  • For selecting supervisor products, use the Supervisor Parametric Search.

AD7470 功能框图

AD7470 芯片订购指南

产品型号	产品状态	封装	引脚	温度范围
AD7470ARU	量产	24 ld TSSOP	24	工业
AD7470ARU-REEL	量产	24 ld TSSOP	24	工业
AD7470ARU-REEL7	量产	24 ld TSSOP	24	工业
AD7470ARUZ	量产	24 ld TSSOP	24	工业
AD7470ARUZ-REEL	量产	24 ld TSSOP	24	工业
AD7470ARUZ-REEL7	量产	24 ld TSSOP	24	工业
EVAL-AD7470CB	量产	评估板	-	待定

AD7470 应用技术支持与电子电路设计开发资源下载

1. AD7470 数据手册DataSheet下载 .PDF
2. Analog Devices, Inc.ADI 美国模拟器件公司产品订购手册 .PDF
3. ADC模数转换器选型指南 . PDF