The TLC1550x and TLC1551 are data acquisition analog-to-digital converters (ADCs) using a 10-bit, switched-capacitor, successive-approximation network. A high-speed, 3-state parallel port directly interfaces to a digital signal processor (DSP) or microprocessor (P) system data bus. D0 through D9 are the digital output terminals with D0 being the least significant bit (LSB). Separate power terminals for the analog and digital portions minimize noise pickup in the supply leads. Additionally, the digital power is divided into two parts to separate the lower current logic from the higher current bus drivers. An external clock can be applied to CLKIN to override the internal system clock if desired.