DDC3256 - Texas Instruments

DDC3256 Current-Input Analog-To-Digital Converter

The DDC3256 is a 24-bit, 256-channel, current-input analog-to-digital (A/D) converter. It combines both, current-to-voltage conversion by current integration, and A/D conversion. Up to 256 individual low-level current output devices, such as photodiodes, can be directly connected to its inputs and digitized in parallel (simultaneously). For each of the 25.

Features

• Single-chip solution to directly measure 256 lowlevel currents simultaneously
• Adjustable full-scale charge range up to 320 pC
• Input current: 1 µA (maximum)
• Adjustable speed with integration times as low as 50 µs (20 KSPS per channel)
• Resolution: 24 bit
• Low power dissipation: 1.2 mW/channel
• Integral non-linearity: ±0.025% of reading ±1 ppm of full scale range (all channels active)
• Low noise: 0.26 fCrms at 320 pC FSR with 20 pF sensor capacitance
• No charge loss
• On-chip temperature sensor
• Serial LVDS output interface
• Single 1.85-V supply
• In-package bypass capacitors and .