Date: Fri, 17 Sep 2010 14:11:59 -0400 From: Patrick Allison Subject: First pass at the digitizer schematic I sent off these schematics to Kael yesterday, so I figured I should probably send them off to you guys too: this is a first pass at the digitizer daughtercard (DDA) and the single-string version of the interface board (the ATRI board) schematics. Obviously this isn't finalized yet: I'm probably going to reorder the pins on the connectors to make the IRS route cleanly, but I think the components are mostly done on the DDA; on the ATRI board I still need to think more about what to do about the rubidium clock distribution. Things to note: The 'housekeeping' interface is different than what was used in ANITA and on the ICRR because I'm using I2C exclusively: I2C is a really nice 2-wire, moderate-speed (400 kbps) interface for communication between ICs (that's SDA/SCL which you see on the DDA's top level sheet). It saves a ton of pins and routing complexity. On the DDA, there are several I2C (housekeeping) peripherals: ADM1178: hot-swap controller (software power on and off, also current limit in case of faults), plus 12-bit voltage, current monitor for DDA AD5667: Dual 16-bit DAC for Vdly (sampling speed) and VadjN1 (Wilkinson ramp) control TMP102: Temperature sensor 24LC32A: EEPROM for board identification and maybe IRS calibration data Patrick