Datasheet

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3 Digital Interface
4 Power Supplies
Digital Interface
The ADS7845EVM is designed to easily interface with multiple control platforms. Samtec part numbers
SSW-110-22-F-D-VS-K and TSM-110-01-T-DV-P provide a convenient 10-pin, dual-row, header/socket
combination at J2. This header/socket provides access to the digital control and serial data pins of the
TSC. Consult Samtec at www.samtec.com or call 1-800-SAMTEC-9 for a variety of mating connector
options.
Table 2. Digital Interface Pinout
Pin Number Signal Description
J2.1 Unused
J2.2 BUSY TSC busy flag
J2.3 SCLK Serial clock
J2.4 DGND Digital ground
J2.5 SCLKR Serial clock return (for DSP host systems)
J2.6 Unused
J2.7 SS Slave select - Active low signal, enables data transfer. Frame sync on DSP host systems.
J2.8 Unused
J2.9 FSR Frame sync return (for DSP host systems)
J2.10 DGND Digital ground
J2.11 MOSI Serial data input to TSC from host
J2.12 Unused
J2.13 MISO Serial data output from TSC to host
J2.14 Unused
J2.15 PENIRQ Pen interrupt output from TSC
J2.16 SCL I
2
C bus serial clock
J2.17 Unused
J2.18 DGND Digital ground
J2.19 Unused
J2.20 SDA I
2
C bus data line
J3 provides connection to the common power bus for the ADS7845EVM. Power is supplied on the pins
listed in Table 3 .
Table 3. Power Supply Pinout
Signal Pin Number Signal
Unused 1 2 Unused
+5VA 3 4 Unused
DGND 5 6 AGND
Unused 7 8 +VD1
+3.3VD 9 10 Unused
When power is supplied to J3, JMP4 allows for one of three different DC voltages to be used as the power
supply of the ADS7845. See the schematic and printed circuit board silkscreen for details.
The ADS7845EVM-PDK motherboard (the USB-MODEVM Interface Board) supplies power to J3 of the
ADS7845EVM. Power for the motherboard is supplied either through its USB connection or on terminal
blocks on the board.
SBAU122 – March 2006 ADS7845EVM and ADS7845EVM-PDK 3
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