Connections
Power
The USB interface runs on USB bus power, but the rest of the demo board
requires an external power supply. +/-15 V (m/-17V) supplies the
analog circuitry. +48V phantom power is input (not generated on the board) and
switched on and off via the on-board Phantom Power switch. Note that the ground
return for +48V phantom power is via the CHAS (chassis ground) connector. The
+5V input is regulated on board to 3.3V and supplies the digital logic.
Audio Input
The Neutrik combo connector accepts an XLR or ¼” TRS cable. Maximum input
signal level is +21dBu with +/-15V supplies, or +22dBu with +/-17V supplies.
The 1/4” TRS signal path includes a 20dB pad in order to support very high line
levels.
Audio Output
Separate XLR and ¼” TRS connectors are wired in parallel. Maximum output
signal level is +21dBu with +/-15V supplies, or +22dBu with +/-17V supplies.
The differential attenuator/output buffer (U3) adds a small amount of noise and
distortion to the signal and it is therefore recommended that test points TP1-TP3
be used to measure performance of the 1570/5171 ICs.
USB
A PC must be plugged into the demo board via USB in order to control parame-
ters in the 5171 (e.g. gain). Take care not to hot plug the demo board while the
GUI software is running as this will often crash the Windows drivers.
General Purpose Outputs (GPO)
The GPO3:0 pins are connected to header J12. J12 is conveniently located near
the prototyping area, so the user can easily connect optional circuitry to them.
Note that the GPO pins are also connected to LEDs, D1-D4, and pull up and pull
down resistors which set the 5171 device address during reset. Consideration
must be given to how any application circuitry that is added interacts with these
other functions.
Hardware Set-up
1. Connect a power supply to the V+, V-, +5V, +48V, CHAS and GND
connectors. Do not turn on power yet.
2. Plug in the audio input and output
3. Attach a USB cable to the demo board, but do not plug it into the PC yet
4. Turn on the power supply
5. Turn on phantom power to microphone (if appropriate)
6. Plug USB cable into PC. Windows should go through its procedure for discov-
ering the new USB peripheral and loading its driver.
Document 600134 Rev 02
Page 5 of 16
THAT 1570/5171-DEMO User’s Guide
THAT Corporation; 45 Sumner Street; Milford, MA 01757-1656; USA
Tel: +1 508 478 9200; Fax: +1 508 478 0990; Web: www.thatcorp.com
Copyright © 2009, THAT Corporation; All rights reserved.
