19-0403; Rev 0; 6/95
Dual, 8-Bit, Voltage-Output
Serial DAC in 8-Pin SO Package
_______________General Description
The MAX522 contains two 8-bit, buffered, voltage-output
digital-to-analog converters (DAC A and DAC B) in small
8-pin SO and DIP packages. DAC A’s buffer can source
and sink 5mA, and DAC B’s output can source and sink
500µA, both to within 0.5V of ground and V
DD
. The
MAX522 operates with a single +2.7V to +5.5V supply.
The device utilizes a 3-wire serial interface, which oper-
ates at clock rates up to 5MHz and is compatible with
SPI™, QSPI™, and Microwire™ interface standards.
The serial input shift register is 16 bits long and con-
sists of eight bits of DAC input data and eight bits for
DAC selection and shutdown control. DAC registers
can be loaded independently or in parallel at the posi-
tive edge of CS.
The MAX522’s ultra-low power consumption and small
8-pin SO package make it ideal for portable and bat-
tery-powered applications. Supply current is less than
1mA and drops below 1µA in shutdown mode. In addi-
tion, the reference input is disconnected from the REF
pin during shutdown, further reducing the system’s total
power consumption. The software format is compatible
with the MAX512/MAX513 triple 8-bit DACs.
____________________________Features
o
Operates from a Single +2.7V to +5.5V Supply
o
Dual Buffered Voltage Output
o
Low Power Consumption:
1mA Operating Current
<1µA Shutdown Current
o
Independently Programmable Shutdown Mode
o
5MHz, 3-Wire Serial Interface
o
SPI™, QSPI™, and Microwire™ Compatible
o
Space-Saving 8-Pin SO Package
MAX522
______________Ordering Information
PART
MAX522CPA
MAX522CSA
MAX522EPA
MAX522ESA
TEMP. RANGE
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 SO
8 Plastic DIP
8 SO
________________________Applications
Digital Gain and Offset Adjustment
Programmable Current Source
Programmable Voltage Source
Power-Amp Bias Control
VCO Tuning
________________Functional Diagram
0.22µF
8 DIN
SCLK
2
DAC
LATCH
A
DAC A
3 V
DD
7 REF
0.1µF
(OPTIONAL)
__________________Pin Configuration
TOP VIEW
OUTA
5
V
OUTA
0.1µF
16-BIT SHIFT REGISTER
CONTROL (8)
DATA (8)
OUTB
DAC
LATCH
B
DAC B
6
V
OUTB
0.01µF
CS 1
SCLK 2
V
DD
3
GND 4
8
DIN
REF
OUTB
OUTA
MAX522
7
6
5
CS
1
MAX522
DIP/SO
4 GND
SPI and QSPI are trademarks of Motorola Inc.
Microwire is a trademark of National Semiconductor Corp.
________________________________________________________________
Maxim Integrated Products
1
Call toll free 1-800-998-8800 for free samples or literature.
Dual, 8-Bit, Voltage-Output
Serial DAC in 8-Pin SO Package
MAX522
ABSOLUTE MAXIMUM RATINGS
V
DD
to GND ................................................................ -0.3V, +6V
Digital Inputs and Outputs to GND............... -0.3V, (V
DD
+ 0.3V)
REF ................................................................-0.3V, (V
DD
+ 0.3V)
OUTA, OUTB (Note 1)............................................................V
DD
Continuous Power Dissipation (T
A
= +70°C)
Plastic DIP (derate 9.09mW/°C above +70°C) ..............727mW
SO (derate 5.88mW/°C above +70°C) ...........................471mW
Operating Temperature Ranges
MAX522C_ A.......................................................0°C to +70°C
MAX522E_ A....................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +165°C
Lead Temperature (soldering, 10sec) .............................+300°C
Note 1:
The outputs may be shorted to V
DD
or GND if the package power dissipation is not exceeded. Typical short-circuit current to
GND is 50mA.
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
= +2.7V to +5.5V, REF = V
DD
, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
STATIC PERFORMANCE
Resolution
Differential Nonlinearity
Integral Nonlinearity
Total Unadjusted Error
Zero-Code Temperature
Coefficient
Power-Supply Rejection Ratio
REFERENCE INPUTS
Reference Input Voltage Range
Reference Input Capacitance
Reference Input Resistance
Reference Input Resistance
(shutdown mode)
DAC OUTPUTS
Output Voltage Range
Capacitive Load at OUT_
Output Resistance
DIGITAL INPUTS
Input High Voltage
Input Low Voltage
Input Current
Input Capacitance
V
IH
V
IL
I
IN
C
IN
V
IN
= 0V or V
DD
(Notes 4, 5)
0.1
(0.7)(V
DD
)
(0.3)(V
DD
)
±10
10
V
V
µA
pF
DAC A
DAC B
DAC A
DAC B
0
0.1
0.01
50
500
REF
V
µF
Ω
R
REF
(Note 3)
8
2
GND
25
V
DD
V
pF
kΩ
MΩ
PSRR
4.5V
≤
V
DD
≤
5.5V, REF = 4.096V
2.7V
≤
V
DD
≤
3.6V, REF = 2.4V
N
DNL
INL
TUE
Guaranteed monotonic
(Note 2)
(Note 2)
±1
100
0.01
0.015
8
±1
±1.5
Bits
LSB
LSB
LSB
µV/°C
%/%
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
Dual, 8-Bit, Voltage-Output
Serial DAC in 8-Pin SO Package
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +2.7V to +5.5V, REF = V
DD
, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
DYNAMIC PERFORMANCE
Voltage-Output Slew Rate
Voltage-Output Settling Time
Digital Feedthrough
and Crosstalk
POWER SUPPLIES
Supply Voltage Range
Supply Current
Shutdown Supply Current
V
DD
I
DD
All inputs = 0V
V
DD
= 5.5V
V
DD
= 5.5V
V
DD
= 3.6V
2.7
1.3
0.9
0.1
5.5
2.8
2.5
V
mA
µA
SR
C
L
= 0.1µF (DAC A), C
L
= 0.01µF (DAC B)
To ±
1
⁄
2
LSB
All 0s to all 1s
C
L
= 0.1µF (DAC A)
C
L
= 0.01µF (DAC B)
0.1
70
70
10
V/µs
µs
nV-s
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX522
TIMING CHARACTERISTICS
(Note 4)
(V
DD
= +2.7V to +5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
PARAMETER
SERIAL INTERFACE TIMING
––
—
CS Fall to SCLK Rise Setup Time
––
—
SCLK Rise to CS Rise Setup Time
DIN to SCLK Rise Setup Time
DIN to SCLK Rise Hold Time
SCLK Pulse Width High
SCLK Pulse Width Low
––
—
CS Pulse Width High
SYMBOL
t
CSS
t
CSH
t
DS
t
DH
t
CH
t
CL
t
CSPWH
CONDITIONS
MIN
150
150
50
50
100
100
200
TYP
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
Note 2:
Reduced digital code range (code 24 through code 232) is due to swing limitations of the output amplifiers. See
Typical
Operating Characteristics.
Note 3:
Reference input resistance is code dependent. The lowest input resistance occurs at code 55hex. Refer to the
Reference
Input
section in the
Detailed Description.
Note 4:
Guaranteed by design. Not production tested.
Note 5:
Input capacitance is code dependent. The highest capacitance occurs at code 00hex.
_______________________________________________________________________________________
3
Dual, 8-Bit, Voltage-Output
Serial DAC in 8-Pin SO Package
MAX522
__________________________________________Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
OUTPUT VOLTAGE vs.
OUTPUT SOURCE CURRENT (V
DD
= 3V)
MAX522 TOC-01
OUTPUT VOLTAGE vs.
OUTPUT SOURCE CURRENT (V
DD
= 5V)
MAX522 TOC-02
OUTPUT VOLTAGE vs.
OUTPUT SINK CURRENT
800
OUTPUT VOLTAGE (mV)
700
600
500
400
300
200
100
DAC B
REF = V
DD
= 3V
CODE = ALL 1s
MAX522 TOC-03
3.5
3.0
OUTPUT VOLTAGE (V)
2.5
2.0
1.5
1.0
0.5
REF = V
DD
= 3V
CODE = ALL 1s
0.1
1
10
DAC B
DAC A
5.2
5.0
OUTPUT VOLTAGE (V)
4.8
4.6
4.4
4.2
4.0
REF = V
DD
= 5V
CODE = ALL 1s
0.1
1
10
DAC B
DAC A
900
DAC A
0
0.0001 0.001 0.01
100
3.8
0.0001 0.001 0.01
100
0
0.0001 0.001 0.01
0.1
1
10
100
OUTPUT SOURCE CURRENT (mA)
OUTPUT SOURCE CURRENT (mA)
OUTPUT SINK CURRENT (mA)
TOTAL UNADJUSTED ERROR
vs. DIGITAL CODE
MAX522 TOC-04
POSITIVE SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX522 TOC-05
POSITIVE SUPPLY CURRENT
vs. TEMPERATURE
MAX522 TOC-06
0
DAC A LOADED WITH 5mA
-5
-10
TUE (LSB)
-15
-20
-25
-30
REF = V
DD
= 3V
-35
0
32
64
96
128
DAC B LOADED WITH 0.5mA
1.5
1.4
1.3
1.2
I
DD
(mA)
REF = V
DD
ALL LOGIC INPUTS GROUNDED
1.370
1.365
1.360
I
DD
(mA)
1.355
1.350
1.345
1.340
REF = V
DD
= 5V
ALL LOGIC INPUTS = 5V
ALL DACs SET TO ALL 1s
-60 -40 -20 0
1.1
1.0
0.9
0.8
0.7
0.6
160 192 224 255
0.5
2.5
3.0
3.5
4.0
V
DD
(V)
4.5
5.0
5.5
20 40 60 80 100 120 140
DIGITAL CODE
TEMPERATURE (°C)
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX522 TOC-07
REFERENCE FEEDTHROUGH
vs. FREQUENCY
MAX522 TOC-08
REFERENCE LARGE-SIGNAL
FREQUENCY RESPONSE
MAX522 TOC-09
4.5
SHUTDOWN SUPPLY CURRENT (µA)
4.0
3.5
3.0
2.5
2.0
1.5
1.0
REF = V
DD
= 5V
ALL LOGIC INPUTS = 5V
ALL DACs SET TO ALL 1s
0
-20
FEEDTHROUGH (dB)
-40
-60
-80
DAC A, B
V
DD
= 3V
V
REF
= 0V TO 2.9V SINE WAVE
NO LOAD
CODE = ALL 0s
5
0
RELATIVE OUTPUT (dB)
-5
-10
-15
-20
V
DD
= 3V
V
REF
= 0V TO V
DD
SINE WAVE
0.01
0.1
1
10
100
-100
0.5
0
-60 -40 -20 0
20 40 60 80 100 120 140
TEMPERATURE (°C)
-120
0.01
0.1
1
10
100
1000
FREQUENCY (kHz)
-25
0.001
1000
FREQUENCY (kHz)
4
_______________________________________________________________________________________
Dual, 8-Bit, Voltage-Output
Serial DAC in 8-Pin SO Package
____________________________Typical Operating Characteristics (continued)
(T
A
= +25°C, unless otherwise noted.)
MAX522
REFERENCE SMALL-SIGNAL
FREQUENCY RESPONSE
0
RELATIVE OUTPUT (dB)
MAX522 TOC-10
DAC A
-20
DAC B
-40
-60
-80
V
DD
= 3V
V
REF
= 1.5V DC WITH ±40mV
P-P
SINE WAVE SUPERIMPOSED
0.1k
1k
10k
100k
1M
10M
FREQUENCY (Hz)
LINE-TRANSIENT RESPONSE (OUTA)
CLOCK FEEDTHROUGH (OUTA)
A
3.14V
A
2.86V
B
B
20µs/div
REF = 2.56V, NO LOAD, CODE = ALL 1s
A : V
DD,
100mV/div
B : OUTA, 500µV/div
CS = HIGH
1µs/div
A: SCLK, 333kHz, 0V TO 2.9V, 2V/div
B: OUTA, 2mV/div
_______________________________________________________________________________________
5
电机驱动控制（Motor Control）
