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CROSSTALK

OUTPUT VOLTAGE STABILITY

SETTLING TIME AND OUTPUT GLITCH PERFORMANCE

DAC5574

SLAS407 – DECEMBER 2003

The DAC5574 architecture uses separate resistor strings for each DAC channel in order to achieve ultra-low

crosstalk performance. DC crosstalk seen at one channel during a full-scale change on the neighboring channel

is typically less than 0.0025 LSBs. The ac crosstalk measured (for a full-scale, 1 kHz sine wave output generated

at one channel, and measured at the remaining output channel) is typically under –100 dB.

The DAC5574 exhibits excellent temperature stability of

±3 ppm/°C typical output voltage drift over the specified

temperature range of the device. This enables the output voltage of each channel to stay within a

±25 µV window

for a

±1°C ambient temperature change. Combined with good dc noise performance and true 8-bit differential

linearity, the DAC5574 becomes a perfect choice for closed-loop control applications.

Settling time to within the 8-bit accurate range of the DAC5574 is achievable within 6 µs for a full-scale code

change at the input. Worst case settling times between consecutive code changes is typically less than 2 µs. The

high-speed serial interface of the DAC5574 is designed in order to support up to 188 kSPS update rate. For

full-scale output swings, the output stage of each DAC5574 channel typically exhibits less than 100 mV of

overshoot and undershoot when driving a 200 pF capacitive load. Code-to-code change glitches are extremely

low (~10 µV) given that the code-to-code transition does not cross an Nx16 code boundary. Due to internal

segmentation of the DAC5574, code-to-code glitches occur at each crossing of an Nx16 code boundary. These

glitches can approach 100 mVs for N = 15, but settle out within ~2 µs. Sufficient bypass capacitance is required

to ensure 10 µs settling under capacitive loading. To observe the settling performance under resistive load

conditions, the power supply (hence DAC5574 reference supply) must settle quicker than the DAC5574.

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