SZG-DAC-AD911X

The SZG-DAC-AD911X is a dual 125 MSPS DAC module featuring the Analog Devices AD9116 TxDAC®. The module is an excellent choice for communication signal paths and general waveform synthesis applications.

In the default configuration, the SMA outputs are ac-coupled through a transformer. With some resistor changes (performed by the end user), a buffered output stage may be selected instead.

Resources

SYZYGY Information

Compatibility Table

COMPATIBILITY PARAMETERSPECIFICATION
Port typeSYZYGY Standard
WidthSingle
5V supply requiredYes
Nominal 5V supply current200mA
Nominal 3.3V supply current10mA
VIO supply voltage1.8V to 3.3V
Nominal VIO supply current20mA
Total number of I/O17

DNA Data

This data is stored in the SYZYGY DNA microcontroller on the SZG-DAC-AD911X peripheral.

DNA PARAMETERDATA
Max 5V Load200 mA
Max 3.3V Load10 mA
Max VIO Load20 mA
IS_LVDSFalse
IS_DOUBLEWIDEFalse
VIO Min1.8V
VIO Max3.3V

Pinout

The source of the following pinout information is the SZG-DAC-AD911X schematic. This pinout follows the SYZYGY specification for STD ports.

  • Column PIN NUM (J1) lists the pin number on the SYZYGY specification’s Standard Samtec connector, this is reference designator J1 in the schematic.
  • Column SIGNAL NAME lists the SYZYGY specification’s name for this pin’s connection.
  • Column SCHEMATIC NET lists the net name found in the SZG-DAC-AD911X’s schematic for the connection.
PIN NUM (J1)SIGNAL NAMESCHEMATIC NETNOTE
5S0DB0
6S1DB1
7S2DB2
8S3DB3
9S4DB4
10S5DB5
11S6DB6
12S7DB7
13S8DB8
14S9DB9
15S10DB10
16S11DB11
17S12CS_B/PWRDN
18S13SCLK/CLKMD
19S14SDIO/FORMAT
20S15OPAMP_ENABLEAssert (1) to enable both DAC I and DAC Q outputs.
Deassert (0) to place both op-amps in power-down.
21S16RESET/PINMD
33P2C_CLKpDCLKIOOptional clock output (See schematics and DAC datasheet)
34C2P_CLKpCLKINInput clock to DAC through CLKIN level translator (U3)

Design

The design of the SZG-DAC-AD911X has been heavily influenced by the evaluation board designed and produced by Analog Devices. You might find it interesting to note that we sell the SZG-DAC-AD911X for significantly less than Analog Devices sell their eval board through Digi-Key (AD9116-DPG2-EBZ-ND).

Analog Devices AD911X

From the Analog Devices datasheet:

The AD9114/AD9115/AD9116/AD9117 are pin-compatible dual, 8-/10-/12-/14-bit, low power digital-to-analog converters (DACs) that provide a sample rate of 125 MSPS. These TxDAC® converters are optimized for the transmit signal path of communication systems. All the devices share the same interface, package, and pinout, providing an upward or downward component selection path based on performance, resolution, and cost.

The AD9114/AD9115/AD9116/AD9117 offer exceptional ac and dc performance and support update rates up to 125 MSPS.

The flexible power supply operating range of 1.8 V to 3.3 V and low power dissipation of the AD9114/AD9115/AD9116/AD9117 make them well suited for portable and low power applications.

Output Stage

By default, the SZG-DAC-AD911X is configured to provide single-ended, transformer-coupled outputs to SMA connectors J2 and J4. To use the buffered output stage instead, follow the instructions in the table below. Designators are labeled on the PCB silkscreen.

DesignatorsPart SizeValue
RemoveR25, R27, R74, and R7806030 Ohm
PlaceR7, R13, R53, and R60060310k Ohm
RemoveR28 and R7904020 Ohm
PlaceR9 and R59040215 Ohm

The bias networks for both output stages may be configured for specific applications. Refer to the additional documentation below.

Auxiliary Output

By default, the SZG-DAC-AD911X is configured to use the AD911X internal full-scale current adjust capability. In this configuration, the FSADJx/AUXx pins may be used as auxiliary DAC outputs. On the SZG-DAC-AD911X these outputs are provided on header J6. Refer to the documentation below for more information on using the auxiliary DAC outputs.

Clock Input

By default, the SZG-DAC-AD911X is configured to accept a single-ended CMOS clock over the C2P_CLKp connection from the carrier. In this configuration, the clock signal from the carrier is applied to the CLKIN and DCLKIO pins on the AD911x. If DCLKIO is configured as an output, remove R39 and place R34 — this connects DCLKIO to the P2C_CLKp pin for use on the carrier.

To apply an external clock source at J3, remove R39, R46, and R47. To apply the external clock to the DCLKIO pin, place R43. To connect the DCLKIO signal to the carrier at pin P2C_CLKp, place R34.

Additional Documentation