19-1098; Rev 2; 10/02
Low-Power, Quad, 12-Bit Voltage-Output DAC
with Serial Interface
__________________General Description
The MAX525 combines four low-power, voltage-output,
12-bit digital-to-analog converters (DACs) and four pre-
cision output amplifiers in a space-saving, 20-pin pack-
age. In addition to the four voltage outputs, each
amplifier’s negative input is also available to the user.
This facilitates specific gain configurations, remote
sensing, and high output drive capacity, making the
MAX525 ideal for industrial-process-control applica-
tions. Other features include software shutdown, hard-
ware shutdown lockout, an active-low reset which clears
all registers and DACs to zero, a user-programmable
logic output, and a serial-data output.
Each DAC has a double-buffered input organized as an
input register followed by a DAC register. A 16-bit serial
word loads data into each input/DAC register. The serial
interface is compatible with SPI™/QSPI™ and
MICROWIRE™. It allows the input and DAC registers to
be updated independently or simultaneously with a sin-
gle software command. The DAC registers can be
simultaneously updated through the 3-wire serial inter-
face. All logic inputs are TTL/CMOS-logic compatible.
______________________________Features
o
Four 12-Bit DACs with Configurable
Output Amplifiers
o
+5V Single-Supply Operation
o
Low Supply Current: 0.85mA Normal Operation
10µA Shutdown Mode
o
Available in 20-Pin SSOP
o
Power-On Reset Clears all Registers and
DACs to Zero
o
Capable of Recalling Last State Prior to Shutdown
o
SPI/QSPI and MICROWIRE Compatible
o
Simultaneous or Independent Control of DACs
through 3-Wire Serial Interface
o
User-Programmable Digital Output
MAX525
_________________Ordering Information
PART
MAX525ACPP
MAX525BCPP
MAX525ACAP
MAX525BCAP
TEMP RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
PIN-PACKAGE
20 Plastic DIP
20 Plastic DIP
20 SSOP
20 SSOP
INL
(LSB)
±1/2
±1
±1/2
±1
________________________Applications
Industrial Process Controls
Automatic Test Equipment
Digital Offset and Gain Adjustment
Motion Control
Remote Industrial Controls
Microprocessor-Controlled Systems
Ordering Information continued at end of data sheet.
Pin Configuration appears at end of data sheet.
_________________________________________________________________________Functional Diagram
DOUT CL
PDL
DECODE
CONTROL
INPUT
REGISTER A
DGND
AGND
V
DD
REFAB
FBA
MAX525
DAC
REGISTER A
OUTA
DAC A
FBB
OUTB
DAC B
FBC
OUTC
DAC C
FBD
OUTD
DAC D
16-BIT
SHIFT
REGISTER
INPUT
REGISTER B
DAC
REGISTER B
INPUT
REGISTER C
DAC
REGISTER C
SR
CONTROL
CS DIN SCLK
LOGIC
OUTPUT
UPO
INPUT
REGISTER D
DAC
REGISTER D
REFCD
SPI and QSPI are trademarks of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Low-Power, Quad, 12-Bit Voltage-Output DAC
with Serial Interface
MAX525
ABSOLUTE MAXIMUM RATINGS
V
DD
to AGND............................................................-0.3V to +6V
V
DD
to DGND ...........................................................-0.3V to +6V
AGND to DGND ..................................................................±0.3V
REFAB, REFCD to AGND ...........................-0.3V to (V
DD
+ 0.3V)
OUT_, FB_ to AGND...................................-0.3V to (V
DD
+ 0.3V)
Digital Inputs to DGND.............................................-0.3V to +6V
DOUT, UPO to DGND ................................-0.3V to (V
DD
+ 0.3V)
Continuous Current into Any Pin.......................................±20mA
Continuous Power Dissipation (T
A
= +70°C)
Plastic DIP (derate 8.00mW/°C above +70°C) .................640mW
SSOP (derate 8.00mW/°C above +70°C) ......................640mW
CERDIP (derate 11.11mW/°C above +70°C) .................889mW
Operating Temperature Ranges
MAX525_C_P ........................................................0°C to +70°C
MAX525_E_P .....................................................-40°C to +85°C
MAX525_MJP ..................................................-55°C to +125°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+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
= +5V ±10%, AGND = DGND = 0V, REFAB = REFCD = 2.5V, R
L
= 5kΩ, C
L
= 100pF, T
A
= T
MIN
to T
MAX
, unless otherwise
noted. Typical values are at T
A
= +25°C. Output buffer connected in unity-gain configuration (Figure 9).)
PARAMETER
Resolution
Integral Nonlinearity
(Note 1)
Differential Nonlinearity
Offset Error
Offset-Error Tempco
Gain Error
Gain-Error Tempco
Power-Supply Rejection Ratio
Gain Error
Offset Error
Integral Nonlinearity
REFERENCE INPUT
Reference Input Range
Reference Input Resistance
Reference Current in Shutdown
V
REF
R
REF
Code-dependent, minimum at code 555 hex
0
8
0.01
±1
V
DD
- 1.4
V
kΩ
µA
INL
PSRR
GE
4.5V
≤
V
DD
≤
5.5V
MATCHING PERFORMANCE
(T
A
= +25°C)
-0.8
±1.0
±0.35
±2.0
±6.0
±1.0
LSB
mV
LSB
GE
(Note 1)
SYMBOL
N
INL
DNL
V
OS
6
-0.8
1
100
600
±2.0
MAX525A
MAX525B
Guaranteed monotonic
CONDITIONS
MIN
12
±0.25
±0.5
±1.0
±1.0
±6.0
TYP
MAX
UNITS
Bits
LSB
LSB
mV
ppm/°C
LSB
ppm/°C
µV/V
STATIC PERFORMANCE—ANALOG SECTION
2
_______________________________________________________________________________________
Low-Power, Quad, 12-Bit Voltage-Output DAC
with Serial Interface
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +5V ±10%, AGND = DGND = 0V, REFAB = REFCD = 2.5V, R
L
= 5kΩ, C
L
= 100pF, T
A
= T
MIN
to T
MAX
, unless otherwise
noted. Typical values are at T
A
= +25°C. Output buffer connected in unity-gain configuration (Figure 9).)
PARAMETER
Reference -3dB Bandwidth
Reference Feedthrough
Signal-to-Noise Plus
Distortion Ratio
DIGITAL INPUTS
Input High Voltage
Input Low Voltage
Input Leakage Current
Input Capacitance
DIGITAL OUTPUTS
Output High Voltage
Output Low Voltage
DYNAMIC PERFORMANCE
Voltage Output Slew Rate
Output Settling Time
Output Voltage Swing
Current into FB_
OUT_ Leakage Current
in Shutdown
Start-Up Time Exiting
Shutdown Mode
Digital Feedthrough
Digital Crosstalk
POWER SUPPLIES
Supply Voltage
Supply Current
Supply Current in Shutdown
Reference Current in Shutdown
V
DD
I
DD
(Note 3)
(Note 3)
4.5
0.85
10
0.01
5.5
0.98
20
±1
V
mA
µA
µA
CS
= V
DD
, DIN = 100kHz
R
L
=
∞
SR
To ±1/2LSB, V
STEP
= 2.5V
Rail-to-Rail
®
(Note 2)
0.6
12
0 to V
DD
0
0.01
15
5
5
0.1
±1
V/µs
µs
V
µA
µA
µs
nV-s
nV-s
V
OH
V
OL
I
SOURCE
= 2mA
I
SINK
= 2mA
V
DD
- 0.5
0.13
0.4
V
V
V
IH
V
IL
I
IN
C
IN
V
IN
= 0V or V
DD
0.01
8
2.4
0.8
±1.0
V
V
µA
pF
SINAD
SYMBOL
CONDITIONS
V
REF
= 0.67V
P-P
Input code = all 0s, V
REF
= 3.6V
P-P
at 1kHz
V
REF
= 1V
P-P
at 25kHz
MIN
TYP
650
-84
72
MAX
UNITS
kHz
dB
dB
MULTIPLYING-MODE PERFORMANCE
MAX525
Note 1:
Guaranteed from code 11 to code 4095 in unity-gain configuration.
Note 2:
Accuracy is better than 1.0LSB for V
OUT
= 6mV to V
DD
- 60mV, guaranteed by PSR test on end points.
Note 3:
R
L
=
∞,
digital inputs at DGND or V
DD
.
Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd.
_______________________________________________________________________________________
3
Low-Power, Quad, 12-Bit Voltage-Output DAC
with Serial Interface
MAX525
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +5V ±10%, AGND = DGND = 0V, REFAB = REFCD = 2.5V, R
L
= 5kΩ, C
L
= 100pF, T
A
= T
MIN
to T
MAX
, unless otherwise
noted. Typical values are at T
A
= +25°C. Output buffer connected in unity-gain configuration (Figure 9).)
PARAMETER
SCLK Clock Period
SCLK Pulse Width High
SCLK Pulse Width Low
CS
Fall to SCLK Rise Setup Time
SCLK Rise to
CS
Rise Hold Time
DIN Setup Time
DIN Hold Time
SCLK Rise to DOUT Valid
Propagation Delay
SCLK Fall to DOUT Valid
Propagation Delay
SCLK Rise to
CS
Fall Delay
CS
Rise to SCLK Rise Hold Time
CS
Pulse Width High
SYMBOL
t
CP
t
CH
t
CL
t
CSS
t
CSH
t
DS
t
DH
t
D01
t
D02
t
CS0
t
CS1
t
CSW
C
LOAD
= 200pF
C
LOAD
= 200pF
40
40
100
CONDITIONS
MIN
100
40
40
40
0
40
0
80
70
80
TYP
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
TIMING CHARACTERISTICS (Figure 6)
__________________________________________Typical Operating Characteristics
(V
DD
= +5V, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT
vs. TEMPERATURE
MAX525-02
INTEGRAL NONLINEARITY
vs. REFERENCE VOLTAGE
MAX525-01
REFERENCE VOLTAGE INPUT
FREQUENCY RESPONSE
0
REFAB SWEPT 0.67V
P-P
R
L
= 5kΩ
C
L
= 100pF
1000
950
900
SUPPLY CURRENT (µA)
850
800
750
700
650
600
550
0.3
0.2
0.1
0
INL (LSB)
-0.1
-0.2
-0.3
-0.4
-0.5
R
L
= 5kΩ
-4
RELATIVE OUTPUT (dB)
-8
-12
-16
CODE = FFF HEX
-20
0
500k
1M
1.5M
2M
2.5M
3M
FREQUENCY (Hz)
0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0 4.4
REFERENCE VOLTAGE (V)
500
-55 -40 -20
0
20
40
60
80 100 120
TEMPERATURE (°C)
4
_______________________________________________________________________________________
MAX525-03
Low-Power, Quad, 12-Bit Voltage-Output DAC
with Serial Interface
____________________________Typical Operating Characteristics (continued)
(V
DD
= +5V, T
A
= +25°C, unless otherwise noted.)
MAX525
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX525-04
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY
MAX525-05
OUTPUT FFT PLOT
V
REF
= 1kHz, 0.006V TO 3.6V
R
L
= 5kΩ
C
L
= 100pF
MAX525-10
1000
950
SUPPLY CURRENT (µA)
900
850
800
750
700
650
600
4.0
4.2
4.4
4.6
4.8
5.0
5.2
5.4
CODE = FFF HEX
0.50
0.45
0.40
THD + NOISE (%)
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
DAC CODE = ALL 1s
REFAB = 1V
P-P
R
L
= 5kΩ
C
L
= 100pF
0
SIGNAL AMPLITUDE (dB)
10
100
-20
-40
-60
-80
5.6
1
-100
0.5
1.6
2.7
3.8
4.9
6.0
SUPPLY VOLTAGE (V)
FREQUENCY (kHz)
FREQUENCY (kHz)
FULL-SCALE ERROR
vs. LOAD
MAX525-09
REFERENCE FEEDTHROUGH
AT 1kHz
REFAB INPUT SIGNAL
SIGNAL AMPLITUDE (dB)
-20
V
REF
= 3.6V
P-P
AT 1kHz
R
L
= 5kΩ
C
L
= 100pF
MAX525-11
0
0
FULL-SCALE ERROR (LSB)
-1
-2
-40
-3
-60
OUTA FEEDTHROUGH
-4
-80
-5
0.01
0.1
1
LOAD (kΩ)
10
100
-100
0.5
1.2
1.9
2.6
3.3
4.0
FREQUENCY (kHz)
_______________________________________________________________________________________
5
DSP 与 ARM 处理器
