19-1206; Rev 0; 3/97
+2.5V to +5.5V, Low-Power, Single/Dual,
8-Bit Voltage-Output DACs in µMAX Package
_______________General Description
The MAX548A/MAX549A/MAX550A serial, 8-bit voltage-
output digital-to-analog converters (DACs) operate from
a single +2.5V to +5.5V supply. Their ±1LSB TUE spec-
ification is guaranteed over temperature. Operating cur-
rent (supply current plus reference current) is typically
75µA per DAC with V
DD
= 2.5V. In shutdown, the DAC
is disconnected from the reference, reducing current
drain to less than 1µA. The MAX548A/MAX549A allow
each DAC to be shut down independently.
The 10MHz, 3-wire serial interface is compatible with
SPI™/QSPI™ and Microwire™ interface standards.
Double-buffered inputs provide flexibility when updat-
ing the DACs; the input and DAC registers can be
updated individually or simultaneously.
The MAX548A is a dual DAC with an asynchronous
load input; it uses V
DD
as the reference input. The
MAX549A is a dual DAC with an external reference
input. The MAX550A is a single DAC with an external
reference input and an asynchronous load input.
The MAX548A/MAX549A/MAX550A’s low power con-
sumption and small µMAX and DIP packages make
these devices ideal for portable and battery-powered
applications.
____________________________Features
o
+2.5V to +5.5V Single-Supply Operation
o
±1LSB (max) TUE
o
Power-On Reset Clears All Registers to Zero
o
Low Operating Current:
150µA (MAX548A/MAX549A, V
REF
= +2.5V)
75µA (MAX550A, V
REF
= +2.5V)
o
1µA Shutdown Mode
o
10MHz, 3-Wire Serial Interface Compatible with
SPI/QSPI and Microwire
o
µMAX Package—50% Smaller than 8-Pin SO
o
Independent Shutdown of DACs
(MAX548A/MAX549A)
MAX548A/MAX549A/MAX550A
______________Ordering Information
PART
MAX548ACPA
MAX548ACUA
MAX548AC/D
MAX548AEPA
MAX548AEUA
TEMP. RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
†
8 Plastic DIP
8 µMAX
Dice*
8 Plastic DIP
8 µMAX
________________________Applications
Battery-Powered Systems
VCXO Control
Comparator-Level Settings
GaAs Amp Bias Control
Digital Gain and Offset Control
Ordering Information continued at end of data sheet.
*Dice
are specified at T
A
= +25°C, DC parameters only.
†
Contact factory for availability of 8-pin SO package.
_____________________Selector Guide
FEATURE
Number of DACs
DAC Reference
Asynchronous
Load DAC Input
µMAX Package
MAX548A
2
V
DD
√
√
MAX549A
2
External
—
√
MAX550A
1
External
√
√
_________________Pin Configurations
TOP VIEW
GND
1
OUTA
2
8
7
V
DD
OUTB
LDAC
SCLK
MAX548A
CS
3
DIN
4
6
5
DIP/µMAX
SPI and QSPI are trademarks of Motorola Inc.
Microwire is a trademark of National Semiconductor Corp.
Pin Configurations continued at end of data sheet.
________________________________________________________________
Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
+2.5V to +5.5V, Low-Power, Single/Dual,
8-Bit Voltage-Output DACs in µMAX Package
MAX548A/MAX549A/MAX550A
ABSOLUTE MAXIMUM RATINGS
V
DD
, SCLK, DIN,
CS, LDAC,
OUT_ to GND ...............-0.3V to 6V
REF to GND ................................................-0.3V to (V
DD
+ 0.3V)
Maximum Current (any pin) .............................................±50mA
Continuous Power Dissipation (T
A
= +70°C)
Plastic DIP (derate 9.09mW/°C above +70°C) .............727mW
µMAX (derate 4.10mW/°C above +70°C) .....................330mW
Operating Temperature Ranges
MAX5_ _AC_ A.....................................................0°C to +70°C
MAX5_ _AE_ A ..................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10sec) .............................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
DD
= +2.5V to +5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
STATIC PERFORMANCE
Resolution
Differential Nonlinearity
Total Unadjusted Error
Zero-Code Error
Full-Scale Error
REFERENCE INPUT
Reference Input
Voltage Range
Reference Input Resistance
DAC Code = 55 Hex (Note 2)
Reference Input Current
DAC Code = 55 Hex (Note 3)
DAC OUTPUT
DAC Output Voltage Swing
DAC Output Resistance
DAC Output Resistance
Matching
DIGITAL INPUTS
Input High Voltage
Input Low Voltage
Input Current
Input Capacitance (Note 4)
V
IH
V
IL
I
IN
C
IN
V
IN
= 0V or V
DD
0.7V
DD
0.3V
DD
±1
10
V
V
µA
pF
R
OUT
∆R
OUT
/
R
OUT
MAX548A/MAX549A
MAX548A
MAX549A/MAX550A
0
0
33.3
±0.2
V
DD
V
REF
V
kΩ
%
V
REF
R
REF
MAX549A/MAX550A for specified
performance
MAX549A
MAX550A
MAX549A
I
REF
MAX550A
V
DD
= V
REF
= 5.5V
V
DD
= V
REF
= 2.5V
V
DD
= V
REF
= 5.5V
V
DD
= V
REF
= 2.5V
2.5
16.7
33.3
330
150
165
75
550
250
275
125
µA
V
DD
V
kΩ
N
DNL
TUE
ZCE
FSE
Guaranteed
monotonic
MAX5_ _AEUA (Note 1)
All others
MAX5_ _AEUA (Note 1)
All others
8
±0.9
±0.9
±1
±1
±1
±1
Bits
LSB
LSB
LSB
LSB
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
+2.5V to +5.5V, Low-Power, Single/Dual,
8-Bit Voltage-Output DACs in µMAX Package
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +2.5V to +5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C)
PARAMETER
DYNAMIC PERFORMANCE
Digital Feedthrough and
Crosstalk
Voltage-Output Settling Time
Voltage-Output Slew Rate
Wake-Up Time at Power-Up
POWER SUPPLIES
Supply Voltage Range
Supply Current (MAX548A)
Supply Current
(MAX549A/MAX550A)
Shutdown Current
V
DD
I
DD
Outputs unloaded, all inputs = GND or V
DD
Outputs unloaded,
all inputs = GND or
V
DD
(Note 5)
V
DD
= 5.5V
V
DD
= 2.5V
2.5
330
150
0.3
0.3
5.5
550
µA
250
10
µA
µA
V
CS
= high, all digital inputs from 0V to V
DD
To ±1/2LSB, C
L
= 20pF
C
L
= 20pF
C
L
= 20pF
V
DD
= 2.5V
V
DD
= 5.5V
50
4
1.4
3.1
4
nV-sec
µs
V/µs
µs
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX548A/MAX549A/MAX550A
I
DD
Outputs unloaded, all inputs = GND or V
DD
;
V
DD
= 5.5V
Shutdown mode
TIMING CHARACTERISTICS
(V
DD
= +2.5V to +5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Digital inputs switching from 0V to V
DD
.) (Figure 3) (Note 4)
PARAMETER
SCLK Pulse Width High
SCLK Pulse Width Low
DIN to SCLK High Setup
DIN to SCLK High Hold
CS
Low to SCLK High Setup
CS
High to SCLK High Setup
SCLK High to CS Low Hold
Delay, SCLK High to
CS
High
CS
Pulse Width High
SCLK Period
LDAC
Pulse Width Low
CS High to
LDAC
Low
V
DD
High to
CS
Low
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
SYMBOL
t
CH
t
CL
t
DS
t
DH
t
CSS0
t
CSS1
t
CSH0
t
CSH1
t
CSW
t
CP
t
LDAC
t
CSLD
MAX548A/MAX550A only
MAX548A/MAX550A only
V
DD
= 2.5V
V
DD
= 5.5V
V
DD
= 2.5V
V
DD
= 5.5V
CONDITIONS
MIN
40
40
30
0
10
30
30
10
10
20
40
80
50
50
5
TYP
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
µs
Cold temperature specifications (to -40°C) guaranteed by design using six sigma design limits.
Worst-case input resistance at REF occurs at DAC code 55 hex.
Worst-case reference input current occurs at DAC code 55 hex.
Guaranteed by design. Not production tested.
I
DD
measured with DACs loaded with worst-case DAC code 55 hex.
_______________________________________________________________________________________
3
+2.5V to +5.5V, Low-Power, Single/Dual,
8-Bit Voltage-Output DACs in µMAX Package
MAX548A/MAX549A/MAX550A
__________________________________________Typical Operating Characteristics
(V
DD
= V
REF
= 2.5V, R
L
= 1MΩ, C
L
= 15pF, T
A
= +25°C, unless otherwise noted.)
OPERATING CURRENT PER DAC
vs. TEMPERATURE
MAX548A-550A TOC-01
SHUTDOWN CURRENT
vs. TEMPERATURE
200
SHUTDOWN CURRENT (nA)
160
120
40
36
32
28
V
DD
= V
REF
= 2.5V
-60
-20
20
TEMPERATURE (°C)
60
100
V
DD
= V
REF
= 5.0V
MAX548A-550A TOC-02
240
150.2
OPERATING CURRENT PER DAC (µA)
149.8
149.4
75.4
75.0
V
DD
= V
REF
= 2.5V
74.6
-60
-20
20
TEMPERATURE (°C)
60
V
DD
= V
REF
= 5.0V
100
MAX549A/MAX550A
REFERENCE SMALL-SIGNAL
FREQUENCY RESPONSE
MAX548A-550A TOC-03
MAX549A/MAX550A
REFERENCE AC FEEDTHROUGH
vs. FREQUENCY
MAX548A-550A TOC-04
10
0
RELATIVE OUTPUT (dB)
-10
-20
-30
-40
-50
1k
V
DD
= 2.5V
V
REF
= 100mVp-p SINE WAVE
0
-20
RELATIVE OUTPUT (dB)
V
DD
= 5V
V
REF
= 2Vp-p SINE WAVE
-40
-60
-80
DAC CODE = FF hex
10k
100k
FREQUENCY (Hz)
1M
10M
V
REF
= 1Vp-p SINE WAVE
DAC CODE = 00 hex
-100
10
100
1k
10k
100k
1M
FREQUENCY (Hz)
DIGITAL FEEDTHROUGH
MAX548A-550A TOC-05
SETTLING TIME (FALLING)
DAC CODE FF hex to 00 hex
MAX548A-550A TOC-06
SCLK, 5V/div
OUT, 1V/div
OUT, 50mV/div
CS, 5V/div
200ns/div
2µs/div
4
_______________________________________________________________________________________
+2.5V to +5.5V, Low-Power, Single/Dual,
8-Bit Voltage-Output DACs in µMAX Package
_____________________________Typical Operating Characteristics (continued)
(V
DD
= V
REF
= 2.5V, R
L
= 1MΩ, C
L
= 15pF, T
A
= +25°C, unless otherwise noted.)
MAX548A/MAX549A/MAX550A
OUTPUT GLITCH FILTERING
MAX548A-550A TOC-07
SETTLING TIME (RISING)
DAC CODE 00 hex to FF hex
MAX548A-550A TOC-08
CODE = 00 hex
OUT, 50mV/div, C
L
= 0pF
OUT, 50mV/div, C
L
= 100pF
OUT, 50mV/div, C
L
= 220pF
OUT, 50mV/div, C
L
= 1000pF
CS, 5V/div
OUT, 1V/div
CS, 5V/div
5µs/div
2µs/div
______________________________________________________________Pin Description
PIN
MAX548A
1
2
—
3
MAX549A
1
2
—
3
MAX550A
1
—
2
3
NAME
GND
OUTA
OUT
CS
Ground
DAC A Output Voltage
DAC Output Voltage
Chip-Select Input. A logic low on
CS
enables serial data to be
clocked into the input shift register. Programming commands are
executed at
CS’s
rising edge.
Serial-Data Input. Data is clocked into the 16-bit input shift register on
SCLK’s rising edge.
Serial-Clock Input. Data is clocked in on SCLK’s rising edge.
Load DAC Input. After
CS
goes high and if programmed by the
control word, a falling edge on
LDAC
updates the DAC latch(es).
Connect
LDAC
to V
DD
if unused.
DAC B Output Voltage
External Reference Voltage Input for DAC(s)
Positive Power Supply (+2.5V to +5.5V)
FUNCTION
4
5
4
5
4
5
DIN
SCLK
LDAC
6
—
6
7
—
8
6
7
8
—
7
8
OUTB
REF
V
DD
_______________________________________________________________________________________
5
