MAX5548ETE+T Maxim Integrated Products, MAX5548ETE+T Datasheet - Page 8

• Manufacturer Part Number: MAX5548ETE+T
• Description: IC DAC 8BIT DUAL 30MA 16-TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX5548ETE+T

• Settling Time: 30µs
• Number Of Bits: 8
• Data Interface: Serial
• Number Of Converters: 2
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power Dissipation (max): -

The MAX5548 8-bit, dual current-steering DAC (see the
Functional Diagram) operates with DAC update rates
up to 10Msps in SPI mode and 400ksps in I
The converter consists of a 16-bit shift register and
input DAC registers, followed by a current-steering
array. The current-steering array generates full-scale
currents up to 30mA per DAC. An integrated +1.25V
bandgap reference, control amplifier, and an external
resistor determine each data converter’s full-scale
output range.
The MAX5548 provides an internal +1.25V bandgap ref-
erence or accepts an external reference voltage source
between +0.5V and +1.5V. REFIN serves as the input for
an external low-impedance reference source. Leave
REFIN unconnected in internal reference mode. Internal
or external reference mode is software selectable
through the SPI/I
Dual, 8-Bit, Programmable, 30mA
High-Output-Current DAC
8
6, 13, 15
8, 16
_______________________________________________________________________________________
PIN
10
11
12
14
—
1
2
3
4
5
7
9
Reference Architecture and Operation
SCLK/SCL
DOUT/A1
DIN/SDA
FSADJB
FSADJA
SPI/I2C
NAME
CS/A0
REFIN
OUTB
OUTA
GND
N.C.
V
EP
2
DD
C serial interface.
Detailed Description
Serial Clock Input. Connect SCL to V
Serial Data Input. Connect SDA to V
Chip-Select Input in SPI Mode/Address Select 0 in I
V
SPI/I2C Select Input. Connect SPI/I2C to V
I
Serial Data Output in SPI Mode/Address Select 1 in I
other devices or to read back in SPI mode. The digital data is clocked out on SCLK’s falling edge.
Connect A1 to V
No Connection. Leave unconnected or connect to GND.
Reference Input. Drive REFIN with an external reference source between +0.5V and +1.5V. Leave REFIN
unconnected in internal reference mode. Bypass REFIN with a 0.1µF capacitor to GND as close to the
device as possible.
Ground
DACB Output. OUTB provides up to 30mA of output current.
D AC B Ful l - S cal e Ad j ust Inp ut. For m axi m um ful l - scal e outp ut cur r ent, connect a 20kΩ r esi stor b etw een
FS AD JB and G N D . For m i ni m um ful l - scal e cur r ent, connect a 40kΩ r esi stor b etw een FS AD JB and G N D .
D AC A Ful l - S cal e Ad j ust Inp ut. For m axi m um ful l - scal e outp ut cur r ent, connect a 20kΩ r esi stor b etw een
FS AD JA and G N D . For m i ni m um ful l - scal e cur r ent, connect a 40kΩ r esi stor b etw een FS AD JA and G N D .
DACA Output. OUTA provides up to 30mA of output current.
Power-Supply Input. Connect V
capacitor as close to the device as possible.
Exposed Pad. Connect to GND. Do not use as a substitute ground connection.
2
DD
C mode.
or GND to set the device address in I
DD
Architecture
or GND to set the device address in I
2
C mode.
DD
to a +2.7 to +5.25V power supply. Bypass V
DD
DD
through a 2.4kΩ resistor in I
through a 2.4kΩ resistor in I
2
The MAX5548’s reference circuit
control amplifier to regulate the full-scale current (I
for the current outputs of the DAC. This device has a
software-selectable full-scale current range (see the
command summary in Table 4). After selecting a cur-
rent range, an external resistor (R
scale current. See Table 1 for a matrix of I
R
During startup, when the power is first applied, the
MAX5548 defaults to the external reference mode, and
to the 1mA–2mA full-scale current-range mode.
The 8-bit DAC data is decoded as offset binary, MSB
first, with 1 LSB = I
responding current as shown in Table 2.
The MAX5548 features a pin-selectable SPI/I
interface. Connect SPI/I2C to GND to select I
or connect SPI/I2C to V
DD
C mode.
FSADJ
to select SPI mode, or connect SPI/I2C to GND to select
FUNCTION
2
selections.
C Mode. CS is an active-low input. Connect A0 to
2
C Mode. Use DOUT to daisy chain the MAX5548 to
2
C mode.
FS
2
/ 256, and converted into the cor-
2
C mode.
C mode.
DD
to select SPI mode. SDA
Serial Interface
Pin Description
DD
(Figure 1) employs a
FSADJ
to GND with a 0.1µF
_) sets the full-
DAC Data
2
2
C mode,
C serial
FS
and
FS
)