Datasheet

_________________________________________________________________ Maxim Integrated Products 9
Evaluates: MAX5723/MAX5724/
MAX5725A/MAX5725B
MAX5725A Evaluation Kit
Figure 6. Jumper Callouts
Detailed Description of Hardware
The MAX5725A EV kit provides a proven layout for the
MAX5725A IC. An on-board external 2.5V reference
(MAX6173), USB interface circuitry, and jumpers to
disconnect the on-board microcontroller are included on
the EV kit.
User-Supplied Power Supply
The EV kit is powered completely from the USB port by
default. To power the IC with a user-supplied power sup-
ply, move the shunt on jumper JU10 to the 2-3 position
and apply a 2.7V to 5.5V power supply at the VDD_EXT
and the nearest GND PCB pads on the EV kit.
The on-board external 2.5V voltage reference (U7) is
powered from the USB interface circuit when a shunt is
installed in the 1-2 position on jumper JU13. To use the
same external supply applied at the VDD_EXT PCB pad,
move the shunt to the 2-3 position on JU13.
User-Supplied Reference
The on-board voltage reference (U7) generates a voltage
reference of 2.5V. The user can apply an external voltage
reference by moving the shunt on jumper JU11 to the 2-3
position and applying 2V to VDD at the REF_EXT PCB
pad on the EV kit. If the internal reference is selected, the
REF pin becomes an output. In this case, JU11 should
be removed.
User-Supplied SPI
To evaluate the EV kit with a user-supplied SPI bus,
remove shunts from jumpers JU1–JU4. Apply the user-
supplied CS, SCLK, DIN, and DOUT signal to header
pins H1-1, H1-3, H1-5, and H1-7, respectively. Connect
the user-supplied SPI ground to header pins H1-2, H1-4,
H1-6, and H1-8.
User-Supplied IRQ, CLR, and LDAC
Remove the shunts from jumpers JU5 and JU6. Apply
the user-supplied IRQ, CLR, and LDAC to header pins
H1-11, H1-15, and H1-17, respectively. Connect the
user-supplied signal ground to header pins H1-12,
H1-16, H1-18.