SLASFM1A June 2025 – December 2025 AFE10004-EP
PRODUCTION DATA
The DAC output buffer amplifiers are capable of rail-to-rail operation. The amplifier outputs are available at the DAC[0:3] and CLAMP[1:2] output pins. The buffer amplifiers are biased from the dedicated supply rails: VCC and VSS. The maximum DAC output voltage range is limited by these supplies.
The output amplifier is designed to drive capacitive loads as high as 15μF without oscillation. The output buffers are able to source 100mA and sink 20mA. The device implements short-circuit protection for momentary output shorts to ground and either supply. The sink short-circuit current is 40mA. The source short-circuit current is configurable to either 120mA (high-current mode) or 70mA (normal-current mode).
The high output current of the device gives good slewing characteristics even with large capacitive loads. To estimate the positive and negative slew rates for large capacitive loads, divide the source and sink short-circuit current values by the capacitor.
After start-up, the DAC output range is set automatically by the voltage present in the VSS and VCC pins. The DAC buffer amplifiers are automatically configured for positive voltage operation when VSS = 0V and 4.5V ≤ VCC ≤ 5.5V. Alternatively, the amplifiers are configured for negative voltage operation when VCC = 0V and 4.5V ≤ VSS ≤ 11V.
The device continuously monitors the buffer amplifier supplies to provide proper operation. In negative voltage operation, the valid VSS supply range is optimized through the VSSRANGE bit to distinguish between the wide VSS configuration (–11V ≤ VSS < –7V) and the narrow VSS configuration (–7V ≤ VSS ≤ –4.5V). The VSS range selection allows the device to detect supply failure conditions faster. The valid supply range for the device is determined at start-up. Table 6-2 shows the valid supply matrix.
| SUPPLY CONFIGURATION | SUPPLY | |
|---|---|---|
| VCC | VSS | |
| Invalid configuration | 0V ≤ VCC < 4.5V | –4.5V < VSS ≤ 0V |
| VCC configuration | 4.5V ≤ VCC ≤ 5.5V | VSS = 0V |
| Invalid configuration | 4.5V ≤ VCC ≤ 5.5V | VSS < 0V |
| Narrow VSS configuration | VCC = 0V | –7V ≤ VSS ≤ –4.5V |
| Invalid configuration | VCC > 0V | –7V ≤ VSS ≤ –4.5V |
| Wide VSS configuration | VCC = 0V | –11V ≤ VSS < –7V |
| Invalid configuration | VCC > 0V | –11V ≤ VSS < –7V |
During operation, if VCC or VSS fall to less than the specified threshold value associated to the supply configuration, or VDD drops to less than 4.5V, a reset event is generated and the DAC outputs enter the special VSS clamp mode. In VSS clamp mode, the DAC output pins are internally connected to the VSS pin.
The six DAC buffer amplifiers share the VCC and VSS supplies; therefore, all DACs are configured to the same output range.