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PGA460: pga460回波数据有疑惑。

Part Number: PGA460
Other Parts Discussed in Thread: MSP430F149, , , MSP-EXP430F5529LP


         大家好,我在做一个超声回波测试的工作。使用的是pga460芯片,使用串口通信。在官网买的开发板调试没有任何问题。当自己做板子和调试的时候,使用msp430f149作为控制mcu,使用aclk校准的dco 2M作为主时钟,串口时钟由主时钟分频提供。


55 09 1C DA 55 0A 1C 32 A7 55 0A 1B C0 1A 55 0A 21 3F 95 55 09 1C DA 55 0A 1E 1E B9 55 0A 22 1C B7 55 0A 20 1C B9 55 0A 1A FC DE 55 0A 19 FF DC 55 0A 18 FF DD 55 0A 17 FF DE 55 0A 16 8A 55 55 0A 15 88 58 55 0A 14 71 70 55 0A 6E 07 80 55 0A 6D CE B9 55 0A 6C 8B FD 55 0A 6B 0B 7F 55 0A 6A FF 8B 55 0A 69 FF 8C 55 0A 68 FF 8D 55 0A 67 FF 8E 55 0A 66 FF 8F 55 0A 65 FF 90 55 0A 64 73 1E 55 0A 63 01 91 55 0A 62 A8 EA 55 0A 61 EC A7 55 0A 60 FF 95 55 0A 5F FF 96 55 09 4C AA 55 09 4D A9 55 09 1F D7 55 0A 40 80 35 55 00 01 FE 55 07 F8 55 0A 40 00 B5


41 30 6E A1 C0 D7 EE FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF F6 E2 C8 AF 8E 6F 5B 57 6B 83 9B AB AC B1 BA C5 CE CF C8 C5 C4 BD B6 B4 9F 81 7A 77 64 66 65 61 64 6A 6F 77 77 75 69 5A 5A 58 58 53 48 39 34 34 31 2F 31 30 27 24 27 29 28 27 2E 2E 23 26 2D 3A 39 33 29 21 1D 20 20 22 21 1E 23 22 25 25 21 27 30 3F 41 3D 41 49 4F E3


  • 您好,


  • 您好,




    1、任何数字通信都应远离模拟接收器引脚。 IO , TXD , RXD 和 SCLK 引脚应布线在 PCB 的另一侧,远离模拟信号。 当 IO 针脚参考高电压 VPWR 并以高速波特率运行时,对连接器或主控制器的连线应尽可能直接。 这是首先要检查的事情,因为您的问题似乎受到数字通信线路的影响。

    2、分隔接地类型以减少 AFE 输入处的噪音。 特别是换能器传感器地,驱动部分和返回路径电路在连接到主接地之前应具有单独的接地。 通过铁氧体磁珠分离传感器和主接地是最佳做法,但不是必须的;用铜皮或 0 Ω电阻 连接也是可以接受的。

    3、模拟引脚 INP 和 INN对噪音比较敏感 ,因此应尽可能短地直接连接到传感器。 确保INN电容器靠近引脚,以缩短接地线的长度。

    4、AVDD , IOREG 和 VPWR 引脚的去耦电容器应尽可能靠近引脚

    此外,为了帮助验证主板布局或任何其他可能与硬件相关的东西是否有问题,您是否能够断开板子上的微控制器与 PGA460 的连接,并尝试以下操作:

    测试 1 :将微控制器连接到 BoostXL-PGA460 板。 使用您的微控制器触发 BoostXL-PGA460 板上的 PGA460 读数。 测试的时候,看是否能够看到噪音问题消失了? 请注意,在 BoostXL-PGA460 板上,您需要驱动 COM_PD 信号低和 COM_SEL 信号高 (这两个信号都位于电路板的 BoosterPack 接头上) ,以便板载 mux 能够启用 UART 通信。

    测试 2 :将 MSP-EXP430F5529LP 连接到您板子上的 PGA460 通信线上。 使用LaunchPad 触发您电路板上 PGA460 的读数。 看是否仍然看到与以前相同的噪音问题?


    Can you provide the schematic? 

    Also, can you verify that the following layout recommendations have been followed:

    • Any digital communication should be routed away from the analog receiver pins. The IO, TXD, RXD, and SCLK pins should be routed on the opposite side of the PCB, away from of the analog signals. When the IO pin is referenced to a high-voltage VPWR, and operating at a high-speed baud rate, the trace to the connector or master should be as direct as possible. This is the first thing I would check since the customer’s issue seems to be affected by the digital communication lines. 
    • Separate the grounding types to reduce noise at the AFE input. In particular, the transducer sensor ground, supporting driver, and return-path circuitry should have a separate ground before being connected to the main ground. Separating the sensor and main grounds through a ferrite bead is best practice, but not required; a copper-trace or 0-Ω short is also acceptable when bridging grounds.
    • The analog return path pins, INP and INN, are most susceptible to noise and therefore should be routed as short and directly to the transducer as possible. Ensure the INN capacitor is close to the pin to reduce the length of the ground wire.
    • The decoupling capacitors for the AVDD, IOREG, and VPWR pins should be placed as close to the pins as possible

    Additionally, to help verify if there could be something with the board layout or anything else potentially hardware related, are they able to disconnect their microcontroller from the PGA460 on their board and try the following:

    • Test 1: Connect their microcontroller to the BoostXL-PGA460 board. Use their microcontroller to trigger readings on the PGA460 of the BoostXL-PGA460 board.  If they do this, do they see the noise issues disappear?  On the BoostXL-PGA460 board, please note that you would need to drive the COM_PD signal low and COM_SEL signal high (both signals are located on the board’s BoosterPack headers) so that the on-board mux could enable UART communication. 
    • Test 2: Connect the MSP-EXP430F5529LP to the PGA460 communication lines on their board. Use the LaunchPad to trigger a reading on the PGA460 on their board. If they do this, do they still see the same noise issues as before?