dc1333a-d DC1333A-D DC1333A-D LTC2640-HZ12 Demo Board | 12-Bit SPI DAC (4.096V ref, Reset to Zero-Scale) (requires DC2026) Demonstration circuit 1333A features the LTC2640, a 12-bit SPI DAC. This device establishes a new benchmark for size and integration of 12-bit DACs and onboard reference.