Rainbow Electronics MAX5444 - Manual (Page 10)

MAX5441–MAX5444
+3V/+5V, Serial-Input,
Voltage-Output, 16-Bit DACs
10 ______________________________________________________________________________________
Unipolar Configuration
Figure 2a shows the MAX5441–MAX5444 configured for
unipolar operation with an external op amp. The op amp
is set for unity gain, and Table 1 lists the codes for this
circuit. The bipolar MAX5442/MAX5444 can also be
used in unipolar configuration by connecting RFB and
INV to REF. This allows the DAC to power-up to mid-
scale.
Bipolar Configuration
Figure 2b shows the MAX5442/MAX5444 configured for
bipolar operation with an external op amp. The op amp
is set for unity gain with an offset of -1/2V
REF . Table 2
lists the offset binary codes for this circuit.
Power-Supply Bypassing and
Ground Management
Bypass V DD with a 0.1µF ceramic capacitor connected
between V DD and GND. Mount the capacitor with short
leads close to the device (less than 0.25 inches).
Table 1. Unipolar Code Table
Table 2. Bipolar Code Table
0 0000 0000 0000 0000
V REF ✕ (1 / 65,536) 0000 0000 0000 0001
V REF ✕ (32,768 / 65,536) = 1/2V REF 1000 0000 0000 0000
V REF ✕ (65,535 / 65,536) 1111 1111 1111 1111
ANALOG OUTPUT, V OUT
MSB LSB
DAC LATCH CONTENTS
-V REF ✕ (32,768 / 32,768) = -V REF 0000 0000 0000 0000
-V REF ✕ (1 / 32,768) 0111 1111 1111 1111
0 1000 0000 0000 0000
+V REF ✕ (1 / 32,768) 1000 0000 0000 0001
+V REF ✕ (32,767 / 32,768) 1111 1111 1111 1111
ANALOG OUTPUT, V OUT
MSB LSB
DAC LATCH CONTENTS