max5236eubt Maxim Integrated Products, Inc., max5236eubt Datasheet - Page 10

• Manufacturer Part Number: max5236eubt
• Description: Single-supply 3v/5v, Voltage-output, Dual, Precision 10-bit Dacs
• Manufacturer: Maxim Integrated Products, Inc.

The MAX5236/MAX5237 10-bit, voltage-output DACs
are
QSPI/MICROWIRE serial interface. The devices include
a 16-bit data-in/data-out shift register and have an input
consisting of an input register and a DAC register. In
addition, these devices employ precision trimmed inter-
nal resistors to produce a gain of 1.6384V/V, maximiz-
ing the output voltage swing, and a programmable
shutdown output impedance of 1kΩ or 200kΩ. The full-
scale output voltage is 4.092V for the MAX5237 and
2.046V for the MAX5236. These devices produce a
Single-Supply 3V/5V, Voltage-Output, Dual,
Precision 10-Bit DACs
(V
= 0.1µF ceramic || 2.2µF electrolytic, both DACs on, V
10
AC-COUPLED
DD
50mV/div
PIN
10
______________________________________________________________________________________
= +5V (MAX5237) V
1
2
3
4
5
6
7
8
9
2V/div
OUT_
easily
CS
NAME
configured
OUTA
OUTB
REFA
LDAC
SCLK
REFB
GND
MAJOR CARRY GLITCH
V
DIN
CS
DD
MAX5237
2µs/div
Detailed Description
DD
= +3V (MAX5236), R
DAC A Output
Reference for DAC A
Ground
Load DACs A and B
Chip Select Input
Shift Register Serial Clock Input
Serial Data Input
Positive Supply
Reference for DAC B
DAC B Output
with
Pin Description
MAX5236/7 toc28
FUNCTION
a
3-wire
Typical Operating Characteristics (continued)
L
2.25
2.00
1.75
1.50
1.25
1.00
0.75
0.50
0.25
= 5kΩ, C
0
OUT
0
= full scale, T
FULL-SCALE OUTPUT VOLTAGE
SPI/
0.25
vs. REFERENCE VOLTAGE
L
= 100pF, V
0.50
MAX5236
V
REF
weighted output voltage proportional to the digital input
code with an inverted rail-to-rail ladder network (Figure 3).
The reference inputs accept both AC and DC values
with a voltage range extending from 0.25V to 2.6V for
the MAX5237 and 0.25V to 1.5V for the MAX5236. For
proper operation do not exceed the input voltage
range limits. Determine the output voltage using the fol-
lowing equation:
where NB is the numeric value of the DACs binary input
code (0 to 1023), V
1.6384V/V is the gain of the internal output amplifier.
The code-dependent reference input impedance
ranges from a minimum of 28kΩ to several GΩ at code
0. The code-dependent reference input capacitance is
typically 23pF.
The output amplifiers have internal resistors that pro-
vide for a gain of 1.6384V/V. These trimmed resistors
minimize gain error. The output amplifiers have a typical
slew rate of 0.6V/µs and settle to 1/2LSB within 10µs
(typ) with a load of 5kΩ in parallel with 100pF. Use the
serial interface to set the shutdown output impedance
of the amplifiers to 1kΩ or 200kΩ.
A
(V)
0.75
= +25°C, unless otherwise noted.)
REF
V
= +1.25V (MAX5236), V
OUT
1.00
_ = (V
1.25
REF
REF
_ x NB / 1024) x 1.6384V/V
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
_ is the reference voltage, and
0
REF
FULL-SCALE OUTPUT VOLTAGE
0.5
vs. REFERENCE VOLTAGE
External Reference
= +2.5V (MAX5237), C
Output Amplifier
1.0
MAX5237
V
REF
(V)
1.5
2.0
REF
2.5