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DAC5668/88/89 Hardware Description
Table 3. Input and Output Connections (continued)
REFERENCE
LABEL
CONNECTOR
DESCRIPTION
DESIGNATOR
TYPE
J19
OUTCLK1 Y4B
SMA
Optional CDCM7005 clock output.
J20
EXT_VCXO
SMA
External main clock input.
J21
DAC CLKOUT
SMA
CLKOUT output from DAC.
J22
EXT_REF_CLK
SMA
External reference clock input.
J23
RF_LO_IN
SMA
TRF3703 LO source input.
4.3
USB Interface
The DAC5668/88/89EVM contains a USB connector to interface to a USB 1.1 or later compliant USB port.
Programming of the CDCM7005 and DAC is accomplished through this port.
4.4
Power Management
The DAC5668/88/89EVM requires 1.8-V and 3.3-V supplies for normal operation. An additional 5-V supply
is required to power up the TRF3703 for RF measurements.
4.5
Input Data
The DAC5668/88/89EVM can accept 1.8-V or 3.3-V CMOS logic levels data inputs through the 34-pin
headers J2 and J7 per
and
. The board provides series dampening resistors to minimize
digital ringing and switching noise. The DAC logic level is selected through software.
Table 4. Input Data Connector J2 – Data A Bus
Pin
Description
Pin
Description
1
CMOS data bit 15 (MSB)
18
GND
2
GND
19
CMOS data bit 6
3
CMOS data bit 14
20
GND
4
GND
21
CMOS data bit 5
5
CMOS data bit 13
22
GND
6
GND
23
CMOS data bit 4
7
CMOS data bit 12
24
GND
8
GND
25
CMOS data bit 3
9
CMOS data bit 11
26
GND
10
GND
27
CMOS data bit 2
11
CMOS data bit 10
28
GND
12
GND
29
CMOS data bit 1
13
CMOS data bit 9
30
GND
14
GND
31
CMOS data bit 0 (LSB)
15
CMOS data bit 8
32
GND
16
GND
33
SYNC
17
CMOS data bit 7
34
GND
Table 5. Input Data Connector J7 – Data B Bus
Pin
Description
Pin
Description
1
CMOS data bit 0 (LSB)
18
GND
2
GND
19
CMOS data bit 9
3
CMOS data bit 1
20
GND
4
GND
21
CMOS data bit 10
5
CMOS data bit 2
22
GND
7
SLAU241A – June 2008 – Revised March 2010
DAC5668/88/89EVM
Copyright © 2008–2010, Texas Instruments Incorporated