MAX5181BEEG MAXIM [Maxim Integrated Products], MAX5181BEEG Datasheet - Page 9

• Manufacturer Part Number: MAX5181BEEG
• Description: 10-Bit, 40MHz, Current/Voltage-Output DACs
• Manufacturer: MAXIM [Maxim Integrated Products]

reference output-current resistor (R
I
To disable the MAX5181/MAX5184’s internal reference,
connect REN to DV
reference may now be applied to drive the REFO pin to
set the full-scale output (Figure 3). Choose a reference
capable of supplying at least 150µA to drive the bias
circuit that generates the cascode current for the cur-
rent array. For improved accuracy and drift perfor-
mance, choose a fixed output voltage reference such
as the +1.2V, 25ppm/°C MAX6520 bandgap reference.
To enter the lower-power standby mode, connect digital
inputs PD and DACEN to DGND. In standby, both the
reference and the control amplifier are active with the
current array inactive. To exit this condition, DACEN
must be pulled high with PD held at DGND. The
MAX5181/MAX5184 typically require 50µs to wake up
and let both outputs and the reference settle.
For lowest power consumption, the MAX5181/MAX5184
provide a power-down mode in which the reference, con-
trol amplifier, and current array are inactive and the DAC
Figure 2. Setting IFS with the Internal +1.2V Reference and the Control Amplifier
REF
to 125µA and I
10-Bit, 40MHz, Current/Voltage-Output DACs
*COMPENSATION CAPACITOR (C
OPTIONAL EXTERNAL BUFFER
FOR HEAVIER LOADS
R
AGND
_______________________________________________________________________________________
SET
FS
MAX4040
DD
to 1mA.
. A temperature-stable, external
COMP
External Reference
= 100nF)
Shutdown Mode
SET
AGND
Standby Mode
C
COMP
= 9.6kΩ) sets
*
R
SET
REFO
REFR
I
REF
supply current is reduced to 1µA. To enter this mode,
connect PD to DV
PD to DGND and DACEN to DV
required for the parts to leave shutdown mode and settle
to their outputs’ values prior to shutdown. Table 1 lists the
power-down mode selection.
Figure 4 shows a detailed timing diagram for the
MAX5181/MAX5184. With each high transition of the
clock, the input latch is loaded with the digital value set
by bits D9 through D0. The content of the input latch is
then shifted to the DAC register, and the output up-
dates at the rising edge of the next clock.
The MAX5181 output is designed to supply full-scale
output currents of 1mA into 400Ω loads in parallel with
a capacitive load of 5pF. The MAX5184 features inte-
grated 400Ω resistors that restore the array current to
proportional, differential voltages of 400mV. These dif-
ferential output voltages can then be used to drive a
balun transformer or a low-distortion, high-speed oper-
ational amplifier to convert the differential voltage into a
single-ended voltage.
R
9.6k
SET
**
REFERENCE
REN
BANDGAP
+1.2V
**9.6kΩ REFERENCE CURRENT-SET RESISTOR
INTERNAL TO MAX5184 ONLY. USE EXTERNAL
R
SET
FOR MAX5181.
MAX5181
MAX5184
DD
DGND
. To return to active mode, connect
Timing Information
SOURCE ARRAY
CURRENT-
DD
. About 50µs are
I
Outputs
FS
9