2.13.6 Analog Sigma-Delta Digital to Analog Converter (DAC)
(Ask a Question)Unless otherwise noted, sigma-delta DAC performance is specified at 25 °C with nominal power supply voltages, using the internal sigma-delta modulators with 16-bit inputs, HCLK = 100 MHz, modulator inputs updated at a 100 KHz rate, in voltage output mode with an external 160 pF capacitor to ground, after trimming and digital [pre-]compensation.
| Specification | Test Conditions | Min. | Typ. | Max. | Units |
|---|---|---|---|---|---|
| Resolution | 8 | — | 24 | Bits | |
| Output range | — | 0 to 2.56 | — | V | |
| Current output mode | — | 0 to 256 | — | µA | |
| Output Impedance | 6 | 10 | 12 | KΩ | |
| Current output mode | 10 | — | — | MΩ | |
| Output voltage compliance | Current output mode | — | 0–3.0 | — | V |
| –40ºC to +100ºC | 0–2.7 | — | 0–3.4 | V | |
| Gain error | Voltage output mode | — | 0.3 | ±2 | % |
| –40ºC to +100ºC | — | 0.3 | ±2 | % | |
| –55ºC to +125ºC | — | 0.3 | ±6 | % | |
| Current output mode | — | 0.3 | ±2 | % | |
| –40ºC to +100ºC | — | 0.3 | ±2 | % | |
| –55ºC to +125ºC | — | 0.3 | ±6 | % | |
| Output referred offset | DACBYTE0 = h’00 (8-bit) | — | 0.25 | ±1 | mV |
| –40ºC to +100ºC | — | 1 | ±2.5 | mV | |
| Current output mode | — | 0.3 | ±1 | µA | |
| –40ºC to +100ºC | — | 1 | ±2.5 | µA | |
| Integral non-linearity | RMS deviation from BFSL | — | 0.1 | 0.4 | % FS1 |
| Differential non-linearity | — | 0.05 | 0.4 | % FS1 | |
| Analog settling time | — | Refer to 2.13.6 Analog Sigma-Delta Digital to Analog Converter (DAC) | — | µs | |
| Power supply rejection ratio | DC, full scale output | 33 | 34 | dB | |
| Sigma-delta DAC power supply current requirements (not including VAREFx) | Input = 0, EN = 1 (operational mode) | — | — | — | |
| VCC33SDDx | 30 | 40 | µA | ||
| VCC15A | 3 | 5 | µA | ||
| Input = Half scale, EN = 1 (operational mode) | — | — | |||
| VCC33SDDx | — | 160 | 165 | µA | |
| VCC15A | — | 33 | 35 | µA | |
| Input = Full scale, EN = 1 (operational mode) | — | — | — | — | |
| VCC33SDDx | — | 280 | 285 | µA | |
| VCC15A | — | 70 | 75 | µA |
Note:
- FS is full-scale error, defined as the difference between the actual value that triggers the transition to full-scale and the ideal analog full-scale transition value. Full-scale error equals offset error plus gain error. Refer to the Analog-to-Digital Converter chapter of the SmartFusion Programmable Analog User’s Guide for more information.
