[参考译文] TAD5212：90kHz 带宽模式+ 768kHz FS +线性插值不如预期平坦

https://e2e.ti.com/support/audio-group/audio/f/audio-forum/1557372/tad5212-90khz-bandwidth-mode-768khz-fs-linear-interpolation-is-not-as-flat-as-it-should-be

工具/软件：

我正在对频率响应进行测试、结果并不像数据表中规定的那样平坦。

我的采样速率为 744kHz、我使用线性相位内插滤波器。

根据数据表、即–0.2dB @ 0.15xFS = 111kHz。

我的测量值约为–0.6dB @ 90kHz。

测试方法：从 DSP 向 DAC 馈送 16 位 I2S、从而生成正弦波。

想知道我的预期、测试方法或用于初始化 DAC 的设置（包括在下面）是否有问题。

    // SW reset
    data = 0x00;
    i2c_write_reg(kDacBus, kDacAddress, 0x00, &data, 1);
    data = 0x01;
    i2c_write_reg(kDacBus, kDacAddress, 0x01, &data, 1);
    std::this_thread::sleep_for(std::chrono::milliseconds(2));
    data = 0x00;
    i2c_write_reg(kDacBus, kDacAddress, 0x00, &data, 1);
    // Bring out of sleep mode
    data = 0x09;
    i2c_write_reg(kDacBus, kDacAddress, 0x02, &data, 1);
    std::this_thread::sleep_for(std::chrono::milliseconds(2));
    // Disable GPIO1
    data = 0;
    i2c_write_reg(kDacBus, kDacAddress, 0x0a, &data, 1);
    // Primary ASI: I2S, 16 bit data
    data = 0x40;
    i2c_write_reg(kDacBus, kDacAddress, 0x1a, &data, 1);
    // Primary ASI RX Channel 2: I2S right slot 0
    data = 0x30;
    i2c_write_reg(kDacBus, kDacAddress, 0x29, &data, 1);
    // DAC demod rate override
    data = (1 << 4);
    i2c_write_reg(kDacBus, kDacAddress, 0x4f, &data, 1);
    // DAC: wide bandwidth
    data = 0xe1;
    i2c_write_reg(kDacBus, kDacAddress, 0x65, &data, 1);  // Channel 1p
    i2c_write_reg(kDacBus, kDacAddress, 0x6c, &data, 1);  // Channel 2p
    data = 0xe0;
    i2c_write_reg(kDacBus, kDacAddress, 0x66, &data, 1);  // Channel 1m
    i2c_write_reg(kDacBus, kDacAddress, 0x6d, &data, 1);  // Channel 2m
    // Disable DAC biquads
    data = (1 << 4);
    i2c_write_reg(kDacBus, kDacAddress, 0x73, &data, 1);
    // Disable inputs, enable outputs
    data = 0x0c;
    i2c_write_reg(kDacBus, kDacAddress, 0x76, &data, 1);
    // Power up DAC
    data = 0x40;
    i2c_write_reg(kDacBus, kDacAddress, 0x78, &data, 1);