MAX5154BCEE+ Maxim Integrated Products, MAX5154BCEE+ Datasheet - Page 13

• Manufacturer Part Number: MAX5154BCEE+
• Description: IC DAC 12BIT DUAL LP SER 16-QSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX5154BCEE+

• Settling Time: 15µs
• Number Of Bits: 12
• Data Interface: Serial
• Number Of Converters: 2
• Voltage Supply Source: Single Supply
• Power Dissipation (max): 667mW
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 16-QSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The serial-data output, DOUT, is the internal shift regis-
ter’s output. DOUT allows for daisy chaining of devices
and data readback. The MAX5154/MAX5155 can be
programmed to shift data out of DOUT on SCLK’s
falling edge (Mode 0) or on the rising edge (Mode 1).
Mode 0 provides a lag of 16 clock cycles, which main-
tains compatibility with SPI/QSPI and Microwire inter-
faces. In Mode 1, the output data lags 15.5 clock
cycles. On power-up, the device defaults to Mode 0.
UPO allows an external device to be controlled through
the serial interface (Table 1), thereby reducing the
number of microcontroller I/O pins required. On power-
up, UPO is low.
The power-down lockout pin (PDL) disables software
shutdown when low. When in shutdown, transitioning
PDL from high to low wakes up the part with the output
set to the state prior to shutdown. PDL can also be
used to asynchronously wake up the device.
Any number of MAX5154/MAX5155s can be daisy
chained by connecting the DOUT pin of one device to
the DIN pin of the following device in the chain (Figure 7).
Since the MAX5154/MAX5155’s DOUT pin has an inter-
nal active pull-up, the DOUT sink/source capability
determines the time required to discharge/charge a
capacitive load. Refer to the digital output V
specifications in the Electrical Characteristics .
Figure 8 shows an alternate method of connecting sev-
eral MAX5154/MAX5155s. In this configuration, the
data bus is common to all devices; data is not shifted
through a daisy chain. More I/O lines are required in
this configuration because a dedicated chip-select
input (CS) is required for each IC.
Figure 9 shows the MAX5154/MAX5155 configured for
unipolar, rail-to-rail operation with a gain of +2V/V. The
MAX5154 can produce a 0V to 4.096V output with
2.048V reference (Figure 9), while the MAX5155 can
produce a range of 0V to 2.5V with a 1.25V reference.
Table 2 lists the unipolar output codes. An offset to the
output can be achieved by connecting a voltage to
OS_, as shown in Figure 10. By applying V
the output values will range between 1V and (1V +
V
__________Applications Information
REF
x 2).
Low-Power, Dual, 12-Bit Voltage-Output DACs
User-Programmable Logic Output (UPO)
______________________________________________________________________________________
Power-Down Lockout Input (P P D D L L )
Daisy Chaining Devices
Unipolar Output
Serial-Data Output
OH
OS
and V
_ = -1V,
OL
Figure 9. Unipolar Output Circuit (Rail-to-Rail)
Figure 10. Setting OS_ for Output Offset
Table 2. Unipolar Code Table (Gain = +2)
Note: ( ) are for the sub bit.
MSB
1 1 1 1 1 1 1 1 11 1 1 ( 0 )
1 0 0 0 0 0 0 0 00 0 1 ( 0 )
1 0 0 0 0 0 0 0 00 0 0 ( 0 )
0 1 1 1 1 1 1 1 11 1 1 ( 0 )
0 0 0 0 0 0 0 0 0 0 0 1 ( 0 )
0 0 0 0 0 0 0 0 00 0 0 ( 0 )
with Serial Interface
DAC CONTENTS
GAIN = +2V/V
REF_
REF_
DAC _
MAX5154
MAX5155
DAC_
MAX5154
MAX5155
LSB
AGND
AGND
+5V/+3V
V
DD
+5V/+3V
+V
V
DD
REF
ANALOG OUTPUT
+V
+V
+V
+V
DGND
R
R
REF
REF
REF
REF
2048
4096
DGND
R
R
OS_
4095
4096
2049
4096
4096
2047
4096
0V
OS_
1
OUT_
x 2
OUT_
V
x
x 2
x 2
x 2
OS
2
V
REF
13