Datasheet

MAX5522–MAX5525
Dual, Ultra-Low-Power,
10-Bit, Voltage-Output DACs
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Applications Information
1-Cell and 2-Cell Circuits
See Figure 3 for an illustration of how to power the
MAX5522–MAX5525 with either one lithium-ion battery
or two alkaline batteries. The low current consumption
of the devices make the MAX5522–MAX5525 ideal for
battery-powered applications.
Programmable Current Source
See the circuit in Figure 4 for an illustration of how to
configure the MAX5524/MAX5525 as a programmable
current source for driving an LED. The MAX5524/
MAX5525 drive a standard NPN transistor to program
the current source. The current source (I
LED
) is defined
in the equation in Figure 4.
REFIN
MAX5524
MAX6006
(1µA, 1.25V
SHUNT
REFERENCE)
GND
+1.25V
0.01µF
536kΩ
V
DD
DAC
VOUT
N
DAC
IS THE NUMERIC VALUE
OF THE DAC INPUT CODE.
V
OUT
(1.22mV / LSB)
1.8V ≤ V
ALKALINE
≤ 3.3V
2.2V ≤ V
LITHIUM
≤ 3.3V
V
OUT
=
V
REFIN
× N
DAC
1024
0.1µF
Figure 3. Portable Application Using Two Alkaline Cells or One Lithium Coin Cell
R
2N3904
N
DAC
IS THE NUMERIC VALUE
OF THE DAC INPUT CODE.
I
LED
REFIN
LED
1/2 MAX5524
V+
DAC
VOUT
I
LED
=
V
REFIN
× N
DAC
1024 × R
FB
Figure 4. Programmable Current Source Driving an LED
R
FB
N
DAC
IS THE NUMERIC VALUE
OF THE DAC INPUT CODE.
I
T
REFIN
1/2 MAX5524
DAC
VOUT
V
OUT
= V
BIAS
+ (I
T
× R)
V
OUT
V
BIAS
TRANSDUCER
V
BIAS
=
V
REFIN
× N
DAC
1024
Figure 5. Transimpedance Configuration for a Voltage-Biased
Current-Output Transducer