max5188beeit Maxim Integrated Products, Inc., max5188beeit Datasheet - Page 9

• Manufacturer Part Number: max5188beeit
• Description: Dual, 8-bit, 40mhz, Current/voltage, Alternate-phase Output Dacs
• Manufacturer: Maxim Integrated Products, Inc.

To disable the MAX5188/MAX5191’s internal reference,
connect REN to DV
reference may now be applied to drive the REFO pin
(Figure 3) to set the full-scale output. Choose a refer-
ence that can supply 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 digi-
tal 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
Figure 2. Setting I
Table 1. Power-Down Mode Selection
X = Don’t care
(POWER-DOWN SELECT)
*COMPENSATION CAPACITOR (C
PD
0
0
1
OPTIONAL EXTERNAL BUFFER
FOR HEAVIER LOADS
FS
AGND
with the Internal +1.2V Reference and Control Amplifier
MAX4040
_______________________________________________________________________________________
DD
I
REF
. A temperature-stable external
=
V
R
REF
SET
COMP
Dual, 8-Bit, 40MHz, Current/Voltage,
(DAC ENABLE)
External Reference
= 100nF)
DACEN
AGND
0
1
X
C
Standby Mode
COMP
*
R
SET
Alternate-Phase Output DACs
REFO
REFR
POWER-DOWN
I
Shutdown
REF
Wake-Up
Standby
MODE
R
SET
9.6k
must be pulled high with PD held at DGND. The
MAX5188/MAX5191 typically require 50µs to wake up
and allow both the outputs and the reference to settle.
For lowest power consumption, the MAX5188/MAX5191
provide a power-down mode in which the reference,
control amplifier, and current array are inactive and the
DAC’s supply current is reduced to 1µA. To enter this
mode, connect PD to DV
connect PD to DGND and DACEN to DV
are required for the devices to leave shutdown mode
and settle their outputs to the values prior to shutdown.
Table 1 lists the power-down mode selection.
**
REN
REFERENCE
BANDGAP
+1.2V
**9.6kΩ REFERENCE CURRENT SET RESISTOR
INTERNAL TO MAX5191 ONLY. USE EXTERNAL
R
SET
FOR MAX5188.
MAX5188
MAX5191
MAX5188
MAX5191
MAX5188
MAX5191
Last state prior to standby mode
DGND
OUTPUT STATE
DD
. To return to active mode,
SOURCE ARRAY
CURRENT-
Shutdown Mode
High-Z
High-Z
DD
AGND
AGND
. About 50µs
I
FS
9