Rainbow Electronics MAX5531 User Manual

General Description
The MAX5530/MAX5531 are single, 12-bit, ultra-low­power, voltage-output, digital-to-analog converters (DACs) offering Rail-to-Rail®buffered voltage outputs. The DACs operate from a 1.8V to 5.5V supply and con­sume less than 6µA, making them desirable for low­power and low-voltage applications. A shutdown mode reduces overall current, including the reference input current, to just 0.18µA. The MAX5530/MAX5531 use a 3-wire serial interface that is compatible with SPI™, QSPI™, and MICROWIRE™.
At power-up, the MAX5530/MAX5531 outputs are driven to zero scale, providing additional safety for applications that drive valves or for other transducers that must be off during power-up. The zero-scale outputs enable glitch­free power-up.
The MAX5530 accepts an external reference input. The MAX5531 contains an internal reference and provides an external reference output. Both devices have force­sense-configured output buffers.
The MAX5530/MAX5531 are available in a 4mm x 4mm x
0.8mm, 12-pin, thin QFN package and are guaranteed over the extended -40°C to +85°C temperature range.
For 10-bit compatible devices, refer to the MAX5520/ MAX5521 data sheet. For 8-bit compatible devices, refer to the MAX5510/MAX5511 data sheet.
Applications
Portable Battery-Powered Devices Instrumentation Automatic Trimming and Calibration in Factory
or Field Programmable Voltage and Current Sources Industrial Process Control and Remote
Industrial Devices Remote Data Conversion and Monitoring Chemical Sensor Cell Bias for Gas Monitors Programmable Liquid Crystal Display (LCD) Bias
Features
Ultra-Low 6µA Supply CurrentShutdown Mode Reduces Supply Current to
0.18µA (max)
Single +1.8V to +5.5V SupplySmall 4mm x 4mm x 0.8mm Thin QFN PackageFlexible Force-Sense-Configured Rail-to-Rail
Output Buffers
Internal Reference Sources 8mA of Current
(MAX5531)
Fast 16MHz 3-Wire SPI-/QSPI-/MICROWIRE-
Compatible Serial Interface
TTL- and CMOS-Compatible Digital Inputs with
Hysteresis
Glitch-Free Outputs During Power-Up
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit,
Voltage-Output DACs
________________________________________________________________ Maxim Integrated Products 1
12FB11
N.C.10OUT
45
N.C.6N.C.
1
2SCLK
3
9
8
7DIN
GND
V
DD
N.C.
MAX5530 MAX5531
CS
REFIN (MAX5530)
REFOUT(MAX5531)
THIN QFN
TOP VIEW
Pin Configuration
Ordering Information
Selector Guide
19-3063; Rev 0; 1/04
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.
PART REFERENCE TOP MARK
MAX5530ETC External AACS MAX5531ETC Internal AACT
Rail-to-Rail is a registered trademark of Nippon Motorola, Inc. SPI and QSPI are trademarks of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp
*EP = Exposed paddle (internally connected to GND).
PART TEMP RANGE PIN-PACKAGE
MAX5530ETC -40°C to +85°C 12 Thin QFN-EP* MAX5531ETC -40°C to +85°C 12 Thin QFN-EP*
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit, Voltage-Output DACs
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VDD= +1.8V to +5.5V, OUT unloaded, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at TA= +25°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.
VDDto GND..............................................................-0.3V to +6V
OUT to GND ...............................................-0.3V to (V
DD
+ 0.3V)
FB to GND ..................................................-0.3V to (V
DD
+ 0.3V)
SCLK, DIN,
CS to GND ..............................-0.3V to (V
DD
+ 0.3V)
REFIN, REFOUT to GND ............................-0.3V to (V
DD
+ 0.3V)
Continuous Power Dissipation (T
A
= +70°C)
Thin QFN (derate 16.9mW/°C above +70°C..............1349mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature..................................................... +150°C
Lead Temperature (soldering, 10s) .................................+300°C
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
STATIC ACCURACY (MAX5530 EXTERNAL REFERENCE)
Resolution N 12 Bits
VDD = 5V, V
REF
= 4.096V ±4 ±8
Integral Nonlinearity (Note 1) INL
V
DD
= 1.8V, V
REF
= 1.024V ±4 ±8
LSB
Guaranteed monotonic, V
DD
= 5V, V
REF
= 4.096V
±1
Differential Nonlinearity (Note 1) DNL
Guaranteed monotonic, V
DD
= 1.8V, V
REF
= 1.024V
±1
LSB
VDD = 5V, V
REF
= 4.096V ±1
Offset Error (Note 2) V
OS
VDD = 1.8V, V
REF
= 1.024V ±1
mV
Offset-Error Temperature Drift ±2
µV/°C
VDD = 5V, V
REF
= 4.096V ±2 ±4
Gain Error (Note 3) GE
V
DD
= 1.8V, V
REF
= 1.024V ±2 ±4
LSB
Gain-Error Temperature Coefficient
±4
ppm/°C
Power-Supply Rejection Ratio PSRR 1.8V VDD 5.5V 85 dB
STATIC ACCURACY (MAX5531 INTERNAL REFERENCE)
Resolution N 12 Bits
VDD = 5V, V
REF
= 3.9V ±4 ±8
Integral Nonlinearity (Note 1) INL
V
DD
= 1.8V, V
REF
= 1.2V ±4 ±8
LSB
Guaranteed monotonic, V
DD
= 5V, V
REF
= 3.9V
±1
Differential Nonlinearity (Note 1) DNL
Guaranteed monotonic, V
DD
= 1.8V, V
REF
= 1.2V
±1
LSB
VDD = 5V, V
REF
= 3.9V ±1
Offset Error (Note 2) V
OS
VDD = 1.8V, V
REF
= 1.2V ±1
mV
Offset-Error Temperature Drift ±2
µV/°C
VDD = 5V, V
REF
= 3.9V ±2 ±4
Gain Error (Note 3) GE
V
DD
= 1.8V, V
REF
= 1.2V ±2 ±4
LSB
Gain-Error Temperature Coefficient
±4
ppm/°C
±0.2
±0.2
±0.2
±0.2
±20 ±20
±20 ±20
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit,
Voltage-Output DACs
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VDD= +1.8V to +5.5V, OUT unloaded, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at TA= +25°C.)
PARAMETER
CONDITIONS
UNITS
Power-Supply Rejection Ratio PSRR 1.8V VDD 5.5V 85 dB
REFERENCE INPUT (MAX5530)
Reference-Input Voltage Range V
REFIN
0
V
Normal operation 4.1 M
Reference-Input Impedance R
REFIN
In shutdown 2.5 G
REFERENCE OUTPUT (MAX5531)
No external load, VDD = 1.8V No external load, VDD = 2.5V No external load, VDD = 3V
Initial Accuracy
No external load, VDD = 5V
V
Output-Voltage Temperature Coefficient
TA = -40°C to +85°C (Note 4) 12 30
ppm/°C
Line Regulation V
REFOUT
< VDD - 200mV (Note 5) 2 200 µV/V
0 I
REFOUT
1mA, sourcing, VDD = 1.8V,
V
REF
= 1.2V
0.3 2
0 I
REFOUT
8mA, sourcing, VDD = 5V,
V
REF
= 3.9V
0.3 2
Load Regulation
-150µA ≤ I
REFOUT
0, sinking 0.2
µV/µA
0.1Hz to 10Hz, V
REFOUT
= 3.9V
10Hz to 10kHz, V
REFOUT
= 3.9V
0.1Hz to 10Hz, V
REFOUT
= 1.2V 50
Output Noise Voltage
10Hz to 10kHz, V
REFOUT
= 1.2V
µV
P-P
VDD = 5V 30
Short-Circuit Current (Note 6)
V
DD
= 1.8V 14
mA
Capacitive Load Stability Range
(Note 7)
nF
Thermal Hysteresis (Note 8)
ppm
REFOUT unloaded, VDD = 5V 5.4
Reference Power-Up Time (from Shutdown)
REFOUT unloaded, V
DD
= 1.8V 4.4
ms
Long-Term Stability
ppm/
1khrs
DAC OUTPUT (OUT)
Capacitive Driving Capability C
L
pF
VDD = 5V, V
OUT
set to full scale, OUT
shorted to GND, source current
65
VDD = 5V, V
OUT
set to 0V, OUT shorted to
V
DD
, sink current
65
VDD = 1.8V, V
OUT
set to full scale, OUT
shorted to GND, source current
14
Short-Circuit Current (Note 6)
V
DD
= 1.8V, V
OUT
set to 0V, OUT shorted to
V
DD
, sink current
14
mA
SYMBOL
V
V
REFOUT
TEMPCO
MIN TYP MAX
1.197 1.214 1.231
1.913 1.940 1.967
2.391 2.425 2.459
3.828 3.885 3.941
150 600
450
0 to 10
200
200
1000
V
DD
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit, Voltage-Output DACs
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(VDD= +1.8V to +5.5V, OUT unloaded, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at TA= +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V
DD
= 5V 3
Coming out of shutdown (MAX5530)
3.8
DAC Power-Up Time
Coming out of standby (MAX5531)
V
DD
= 1.8V
to 5.5V
0.4
ms
Output Power-Up Glitch CL = 100pF 10 mV FB_ Input Current 10 pA
DIGITAL INPUTS (SCLK, DIN, CS)
4.5V VDD 5.5V 2.4
2.7V < VDD 3.6V 2.0Input High Voltage V
IH
1.8V VDD 2.7V 0.7 x V
D D
V
4.5V VDD 5.5V 0.8
2.7V < VDD 3.6V 0.6Input Low Voltage V
IL
1.8V VDD 2.7V
V
Input Leakage Current I
IN
(Note 9)
µA
Input Capacitance C
IN
10 pF
DYNAMIC PERFORMANCE
Voltage-Output Slew Rate SR Positive and negative (Note 10) 10
V/ms
Voltage-Output Settling Time
0.1 to 0.9 of full scale to within 0.5 LSB (Note 10)
µs
VDD = 5V 80
0.1Hz to 10Hz 55
VDD = 5V
Output Noise Voltage
10Hz to 10kHz
µV
P-P
POWER REQUIREMENTS
Supply Voltage Range V
DD
1.8 5.5 V VDD = 5V 2.6 4 VDD = 3V 2.6 4MAX5530
3.6 5 VDD = 5V 5.3 7.0 VDD = 3V 4.8 7.0
Supply Current (Note 9) I
DD
MAX5531
5.4 7.0
µA
VDD = 5V 3.3 4.5 VDD = 3V 2.8 4.0Standby Supply Current I
DDSD
(Note 9)
2.4 3.5
µA
Shutdown Supply Current I
DDPD
(Note 9)
µA
V
= 1.8V
DD
VDD = 1.8V
VDD = 1.8V 476
VDD = 1.8V
VDD = 1.8V
VDD = 1.8V
0.3 x V
±0.05 ±0.5
660
620
0.05 0.25
DD
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit,
Voltage-Output DACs
_______________________________________________________________________________________ 5
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
TIMING CHARACTERISTICS (VDD = 4.5V TO 5.5V)
Serial Clock Frequency f
SCLK
0
MHz
DIN to SCLK Rise Setup Time t
DS
15 ns
DIN to SCLK Rise Hold Time t
DH
0ns
SCLK Pulse-Width High t
CH
24 ns
SCLK Pulse-Width Low t
CL
24 ns
CS Pulse-Width High t
CSW
100 ns
SCLK Rise to CS Rise Hold Time
t
CSH
0ns
CS Fall to SCLK Rise Setup Time
t
CSS
20 ns
SCLK Fall to CS Fall Setup t
CSO
0ns
CS Rise to SCK Rise Hold Time t
CS1
20 ns
TIMING CHARACTERISTICS
(VDD= +4.5V to +5.5V, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at TA= +25°C.)
TIMING CHARACTERISTICS
(VDD= +1.8V to +5.5V, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at TA= +25°C.)
Note 1: Linearity is tested within codes 96 to 4080. Note 2: Offset is tested at code 96. Note 3: Gain is tested at code 4095. FB is connected to OUT. Note 4: Guaranteed by design. Not production tested. Note 5: V
DD
must be a minimum of 1.8V.
Note 6: Outputs can be shorted to V
DD
or GND indefinitely, provided that the package power dissipation is not exceeded.
Note 7: Optimal noise performance is at 2nF load capacitance. Note 8: Thermal hysteresis is defined as the change in the initial +25°C output voltage after cycling the device from T
MAX
to T
MIN
.
Note 9: All digital inputs at V
DD
or GND.
Note 10: Load = 10kin parallel with 100pF, V
DD
= 5V, V
REF
= 4.096V (MAX5530) or V
REF
= 3.9V (MAX5531).
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
TIMING CHARACTERISTICS (VDD = 1.8V TO 5.5V)
Serial Clock Frequency f
SCLK
010
MHz
DIN to SCLK Rise Setup Time t
DS
24 ns
DIN to SCLK Rise Hold Time t
DH
0 ns
SCLK Pulse-Width High t
CH
40 ns
SCLK Pulse-Width Low t
CL
40 ns
CS Pulse-Width High t
CSW
ns
SCLK Rise to CS Rise Hold Time
t
CSH
0 ns
CS Fall to SCLK Rise Setup Time
t
CSS
30 ns
SCLK Fall to CS Fall Setup t
CSO
0 ns
CS Rise to SCK Rise Hold Time t
CS1
30 ns
16.7
150
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit, Voltage-Output DACs
6 _______________________________________________________________________________________
Typical Operating Characteristics
(V
DD
= 5.0V, V
REF
= 4.096V (MAX5530), V
REF
= 3.9V (MAX5531), TA = +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
(MAX5531)
MAX5530 toc01
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (µA)
5.55.04.0 4.52.5 3.0 3.52.0
1
2
3
4
5
6
7
8
9
10
0
1.5 6.0
SUPPLY CURRENT vs. TEMPERATURE
(MAX5531)
MAX5530 toc02
TEMPERATURE (°C)
SUPPLY CURRENT (µA)
603510-15
1
2
3
4
5
6
7
8
9
10
0
-40 85
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE (MAX5531)
MAX5530 toc03
TEMPERATURE (°C)
SHUTDOWN SUPPLY CURRENT (nA)
603510-15
1
10
100
1000
0.1
-40 85
STANDBY SUPPLY CURRENT
vs. TEMPERATURE (MAX5531)
MAX5530 toc04
TEMPERATURE (°C)
STANDBY SUPPLY CURRENT (µA)
603510-15
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0
-40 85
V
REF
= 3.9V
V
REF
= 2.4V
V
REF
= 1.9V
V
REF
= 1.2V
SUPPLY CURRENT
vs. CLOCK FREQUENCY
MAX5530 toc05
FREQUENCY (kHz)
SUPPLY CURRENT (µA)
1000010001001010.1
10
100
1000
1
0.01 100000
CS = LOGIC LOW CODE = 0
VDD = 5V
VDD = 1.8V
SUPPLY CURRENT
vs. LOGIC INPUT VOLTAGE
MAX5530 toc06
LOGIC INPUT VOLTAGE (V)
SUPPLY CURRENT (mA)
4.54.03.0 3.51.0 1.5 2.0 2.50.5
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0
0 5.0
ALL DIGITAL INPUTS SHORTED TOGETHER
INL vs. INPUT CODE (V
DD
= V
REF
= 1.8V)
MAX5530 toc07
DIGITAL INPUT CODE
INL (LSB)
4000350030002500200015001000500
-4
-3
-2
-1
0
1
2
-5 0 4500
INL vs. INPUT CODE
(V
DD
= V
REF
= 5V)
MAX5530 toc08
DIGITAL INPUT CODE
INL (LSB)
4000350030002500200015001000500
-4
-3
-2
-1
0
1
2
-5 04500
DNL vs. INPUT CODE
(V
DD
= V
REF
= 1.8V)
MAX5530 toc09
DIGITAL INPUT CODE
DNL (LSB)
4000350030002500200015001000500
-0.05
0
0.05
0.10
0.15
0.20
0.25
-0.10 04500
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit,
Voltage-Output DACs
_______________________________________________________________________________________ 7
DNL vs. INPUT CODE
(V
DD
= V
REF
= 5V)
MAX5530 toc10
DIGITAL INPUT CODE
DNL (LSB)
4000350030002500200015001000500
-0.10
-0.05
0
0.05
0.10
0.15
0.20
-0.15
04500
OFFSET VOLTAGE
vs. TEMPERATURE
MAX5530 toc11
TEMPERATURE (°C)
OFFSET VOLTAGE (mV)
603510-15
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1.0
-1.0
-40 85
VDD = 5V V
REF
= 3.9V
GAIN-ERROR CHANGE
vs. TEMPERATURE
MAX5530 toc12
TEMPERATURE (°C)
GAIN-ERROR CHANGE (LSB)
603510-15
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
-0.5
-40 85
VDD = 5V V
REF
= 3.9V
DIGITAL FEEDTHROUGH RESPONSE
MAX5530 toc13
20µs/div
CS 5V/div
SCLK 5V/div
DIN 5V/div
OUT 50mV/div
ZERO SCALE
DAC OUTPUT LOAD REGULATION
vs. OUTPUT CURRENT
MAX5530 toc14
DAC OUTPUT CURRENT (µA)
DAC OUTPUT VOLTAGE (V)
8006004002000-200-400-600-800
0.6042
0.6044
0.6046
0.6048
0.6050
0.6040
-1000 1000
VDD = 1.8V DAC CODE = MIDSCALE V
REF
= 1.2V
DAC OUTPUT VOLTAGE
vs. OUTPUT SOURCE CURRENT
MAX5530 toc16
OUTPUT SOURCE CURRENT (mA)
OUTPUT VOLTAGE (V)
1010.10.01
1
2
3
4
5
0
0.001 100
V
REF
= V
DD
CODE = MIDSCALE
V
DD
= 5V
V
DD
= 3V
V
DD
= 1.8V
DAC OUTPUT VOLTAGE
vs. OUTPUT SINK CURRENT
MAX5530 toc17
OUTPUT SINK CURRENT (mA)
DAC OUTPUT VOLTAGE (V)
1010.10.01
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0
0.001 100
V
REF
= V
DD
CODE = MIDSCALE
VDD = 5V
VDD = 3V
VDD = 1.8V
OUTPUT LARGE-SIGNAL STEP RESPONSE
(V
DD
= 1.8V, V
REF
= 1.2V)
MAX5530 toc18
100µs/div
V
OUT
200mV/div
Typical Operating Characteristics (continued)
(V
DD
= 5.0V, V
REF
= 4.096V (MAX5530), V
REF
= 3.9V (MAX5531), TA = +25°C, unless otherwise noted.)
DAC OUTPUT LOAD REGULATION
vs. OUTPUT CURRENT
MAX5530 toc15
DAC OUTPUT CURRENT (mA)
DAC OUTPUT VOLTAGE (V)
86-8 -6 -4 0 2-2 4
1.9405
1.9410
1.9415
1.9420
1.9425
1.9430
1.9435
1.9440
1.9400
-10 10
VDD = 5.0V DAC CODE = MIDSCALE V
REF
= 3.9V
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit, Voltage-Output DACs
8 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(V
DD
= 5.0V, V
REF
= 4.096V (MAX5530), V
REF
= 3.9V (MAX5531), TA = +25°C, unless otherwise noted.)
OUTPUT LARGE-SIGNAL STEP RESPONSE
(V
DD
= 5V, V
REF
= 3.9V)
MAX5530 toc19
200µs/div
V
OUT
500mV/div
OUTPUT MINIMUM SERIES RESISTANCE
vs. LOAD CAPACITANCE
MAX5530 toc20
CAPACITANCE (µF)
MINIMUM SERIES RESISTANCE (Ω)
1010.10.010.001
100
200
300
400
500
600
0
0.0001 100
FOR NO OVERSHOOT
MAJOR CARRY OUTPUT VOLTAGE GLITCH
(CODE 7FFh TO 800h)
(V
DD
= 5V, V
REF
= 3.9V)
MAX5530 toc22
100µs/div
V
OUT
AC-COUPLED 5mV/div
REFERENCE OUTPUT VOLTAGE
vs. TEMPERATURE
MAX5530 toc23
TEMPERATURE (°C)
REFERENCE OUTPUT VOLTAGE (V)
6035-15 10
3.905
3.910
3.915
3.920
3.925
3.930
3.935
3.940
3.900
-40 85
VDD = 5V
REFERENCE OUTPUT VOLTAGE
vs. REFERENCE OUTPUT CURRENT
MAX5530 toc24
REFERENCE OUTPUT CURRENT (µA)
REFERENCE OUTPUT VOLTAGE (V)
7500550035001500
1.215
1.216
1.217
1.218
1.219
1.220
1.214
-500
VDD = 1.8V
REFERENCE OUTPUT VOLTAGE
vs. REFERENCE OUTPUT CURRENT
MAX5530 toc25
REFERENCE OUTPUT CURRENT (µA)
REFERENCE OUTPUT VOLTAGE (V)
14,50012,0009500700045002000
3.89
3.90
3.91
3.92
3.88
-500
VDD = 5V
REFERENCE OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
MAX5530 toc26
SUPPLY VOLTAGE (V)
REFERENCE OUTPUT VOLTAGE (V)
5.55.04.0 4.52.5 3.0 3.52.0
1.21732
1.21734
1.21736
1.21738
1.21740
1.21742
1.21744
1.21746
1.21748
1.21750
1.21730
1.5 6.0
NO LOAD
POWER-UP OUTPUT VOLTAGE GLITCH
MAX5530 toc21
20ms/div
V
OUT
10mV/div
V
DD
2V/div
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit,
Voltage-Output DACs
_______________________________________________________________________________________ 9
REFERENCE LINE-TRANSIENT RESPONSE
(V
REF
= 3.9V)
MAX5530 toc28
100µs/div
5.5V
V
DD
4.5V
V
REF
500mV/div
3.9V
REFERENCE LOAD TRANSIENT
(V
DD
= 1.8V)
MAX5530 toc29
200µs/div
REFOUT SOURCE CURRENT
0.5mA/div
V
REFOUT
500mV/div
REFERENCE LOAD TRANSIENT
(V
DD
= 5V)
MAX5530 toc30
200µs/div
REFOUT SOURCE CURRENT
0.5mA/div
V
REFOUT
500mV/div
3.9V
REFERENCE LOAD TRANSIENT
(V
DD
= 1.8V)
MAX5530 toc31
200µs/div
REFOUT SINK CURRENT 50µA/div
V
REFOUT
500mV/div
REFERENCE LOAD TRANSIENT
(V
DD
= 5V)
MAX5530 toc32
200µs/div
REFOUT SINK CURRENT 100µA/div
V
REFOUT
500mV/div
3.9V
Typical Operating Characteristics (continued)
(V
DD
= 5.0V, V
REF
= 4.096V (MAX5530), V
REF
= 3.9V (MAX5531), TA = +25°C, unless otherwise noted.)
REFERENCE LINE-TRANSIENT RESPONSE
(V
REF
= 1.2V)
MAX5530 toc27
100µs/div
2.8V
V
DD
1.8V
V
REF
500mV/div
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit, Voltage-Output DACs
10 ______________________________________________________________________________________
REFERENCE PSRR
vs. FREQUENCY
MAX5530 toc33
FREQUENCY (kHz)
POWER-SUPPLY REJECTION RATIO (dB)
100100.1 1
10
20
30
40
50
60
70
80
0
0.01 1000
VDD = 1.8V
REFERENCE PSRR
vs. FREQUENCY
MAX5530 toc34
FREQUENCY (kHz)
POWER-SUPPLY REJECTION RATIO (dB)
100100.1 1
10
20
30
40
50
60
70
80
0
0.01 1000
VDD = 5V
REFERENCE OUTPUT NOISE
(0.1Hz TO 10Hz) (V
DD
= 1.8V, V
REF
= 1.2V)
MAX5530 toc35
1s/div
100µV/div
REFERENCE OUTPUT NOISE
(0.1Hz TO 10Hz) (V
DD
= 5V, V
REF
= 3.9V)
MAX5530 toc36
1s/div
100µV/div
Typical Operating Characteristics (continued)
(V
DD
= 5.0V, V
REF
= 4.096V (MAX5530), V
REF
= 3.9V (MAX5531), TA = +25°C, unless otherwise noted.)
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit,
Voltage-Output DACs
______________________________________________________________________________________ 11
12-BIT DAC
DAC
REGISTER
OUT
REFIN
GND
MAX5530
INPUT
REGISTER
POWER-
DOWN
CONTROL
CONTROL
LOGIC
AND
SHIFT
REGISTER
FB
SCLK
V
DD
DIN
CS
Pin Description
MAX5530 Functional Diagram
PIN
MAX5530
NAME FUNCTION
11CS Active-Low Digital-Input Chip Select 22SCLK Serial-Interface Clock 33DIN Serial-Interface Data Input 4—REFIN Reference Input
—4REFOUT Reference Output
5, 6, 7, 11
N.C. No Connection. Leave N.C. inputs unconnected (floating) or connected to GND.
88V
DD
Power Input. Connect VDD to a 1.8V to 5.5V power supply. Bypass VDD to GND with a 0.1µF capacitor.
99GND Ground 10 10 OUT Analog Voltage Output 12 12 FB Feedback Input
EP EP
Exposed
Paddle
Exposed Paddle. Connect EP to GND.
MAX5531
5, 6, 7, 11
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit, Voltage-Output DACs
12 ______________________________________________________________________________________
Detailed Description
The MAX5530/MAX5531 single, 12-bit, ultra-low-power, voltage-output DACs offer Rail-to-Rail buffered voltage outputs. The DACs operate from a 1.8V to 5.5V supply and require only 6µA (max) supply current. These devices feature a shutdown mode that reduces overall current, including the reference input current, to just
0.18µA. The MAX5531 includes an internal reference that saves additional board space and can source up to 8mA, making it functional as a system reference. The 16MHz, 3-wire serial interface is compatible with SPI, QSPI, and MICROWIRE protocols. When VDDis applied, all DAC outputs are driven to zero scale with virtually no output glitch. The MAX5530/MAX5531 out­put buffers are configured in force sense allowing users to externally set voltage gains on the output (an output amplifier inverting input is available). These devices come in a 4mm x 4mm thin QFN package.
Digital Interface
The MAX5530/MAX5531 use a 3-wire serial interface compatible with SPI, QSPI, and MICROWIRE protocols (Figures 1 and 2).
The MAX5530/MAX5531 include a single, 16-bit, input shift register. Data loads into the shift register through the serial interface. CS must remain low until all 16 bits are clocked in. Data loads MSB first, D11–D0. The 16 bits consist of 4 control bits (C3–C0) and 12 data bits (D11–D0) (see Table 1). The control bits C3–C0 control the MAX5530/MAX5531, as outlined in Table 2.
Each DAC channel includes two registers: an input reg­ister and a DAC register. The input register holds input data. The DAC register contains the data updated to the DAC output.
The double-buffered register configuration allows any of the following:
• Loading the input registers without updating the DAC registers
• Updating the DAC registers from the input registers
• Updating all the input and DAC registers simultaneously
12-BIT DAC
2-BIT
PROGRAMMABLE
REFERENCE
DAC
REGISTER
OUT
REF BUF
GND
MAX5531
REFOUT
INPUT
REGISTER
POWER-
DOWN
CONTROL
CONTROL
LOGIC
AND
SHIFT
REGISTER
FB
SCLK
V
DD
DIN
CS
MAX5531 Functional Diagram
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit,
Voltage-Output DACs
______________________________________________________________________________________ 13
t
CSW
t
CSS
t
CS0
t
DH
t
CL
t
CS1
t
CSH
t
CH
t
DS
SCLK
DIN
CS
C2
C1 D0
C3
Figure 1. Timing Diagram
Figure 2. Register Loading Diagram
CONTROL DATA BITS
MSB
LSB
C3
D0
Table 1. Serial Write Data Format
C2 C1 C0 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1
CS
16151413121110987654321SCLK
C3 C2 C1 C0 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0DIN
CONTROL BITS DATA BITS
COMMAND EXECUTED
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit, Voltage-Output DACs
14 ______________________________________________________________________________________
CONTROL BITS INPUT DATA
C3 C2 C1 C0 D11–D0
FUNCTION
0000
No operation; command is ignored.
000112-bit data
Load input register from shift register; DAC register unchanged;
DAC output unchanged. 0010 — Command reserved; do not use. 0011 — Command reserved; do not use.
0100 — Command reserved; do not use. 0101 — Command reserved; do not use. 0110 — Command reserved; do not use. 0111 — Command reserved; do not use.
100012-bit data
Load DAC register from input register; DAC output updated;
MAX5530 enters normal operation if in shutdown; MAX5531 enters
normal operation if in standby or shutdown.
100112-bit data
Load input register and DAC register from shift register; DAC output
updated; MAX5530 enters normal operation if in shutdown;
MAX5531 enters normal operation if in standby or shutdown. 1010 — Command reserved; do not use.
1011 — Command reserved; do not use.
1100
D11, D10,
XXXXXXXXXX
MAX5530 enters shutdown; MAX5531 enters standby*. For the
MAX5531, D11 and D10 configure the internal reference voltage
(Table 3).
1101
D11, D10,
XXXXXXXXXX
MAX5530/MAX5531 enter normal operation; DAC output reflects
existing contents of DAC register. For the MAX5531, D11 and D10
configure the internal reference voltage (Table 3).
1110
D11, D10,
XXXXXXXXXX
MAX5530/MAX5531 enter shutdown; DAC output set to high
impedance. For the MAX5531, D11 and D10 configure the internal
reference voltage (Table 3).
111112-bit data
Load input register and DAC register from shift register; DAC output
updated; MAX5530 enters normal operation if in shutdown;
MAX5531 enters normal operation if in standby or shutdown.
Table 2. Serial-Interface Programming Commands
X = Don’t care. *Standby mode can be entered from normal operation only. It is not possible to enter standby mode from shutdown.
XXXXXXXXXXXX
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit,
Voltage-Output DACs
______________________________________________________________________________________ 15
Power Modes
The MAX5530/MAX5531 feature two power modes to conserve power during idle periods. In normal opera­tion, the device is fully operational. In shutdown mode, the device is completely powered down, including the internal voltage reference in the MAX5531. The MAX5531 also offers a standby mode where all circuitry is powered down except the internal voltage reference. Standby mode keeps the reference powered up while the remaining circuitry is shut down, allowing it to be used as a system reference. Standby mode also helps reduce the wake-up delay by not requiring the refer­ence to power up when returning to normal operation.
Shutdown Mode
The MAX5530/MAX5531 feature a software-program­mable shutdown mode that reduces the typical supply current and the reference input current to 0.18µA (max). Writing an input control word with control bits C[3:0] = 1110 places the device in shutdown mode (Table 2). In shutdown, the MAX5530 reference input and DAC output buffers go high impedance. Placing the MAX5531 into shutdown turns off the internal refer­ence, and the DAC output buffers go high impedance. The serial interface remains active for all devices.
Table 2 shows several commands that bring the MAX5530/MAX5531 back to normal operation. The power-up time from shutdown is required before the DAC outputs are valid.
Note: For the MAX5531, standby mode cannot be entered directly from shutdown mode. The device must be brought into normal operation before entering stand­by mode.
Standby Mode (MAX5531 Only)
The MAX5531 features a software-programmable standby mode that reduces the typical supply current to 6µA. Standby mode powers down all circuitry except the internal voltage reference. Place the device in standby mode by writing an input control word with control bits C[3:0] = 1100 (Table 2). The internal refer­ence and serial interface remain active while the DAC output buffers go high impedance. If the MAX5531 is coming out of standby, the power-up time from standby is required before the DAC outputs are valid.
For the MAX5531, standby mode cannot be entered directly from shutdown mode. The device must be brought into normal operation before entering standby mode. To enter standby from shutdown, issue the com­mand to return to normal operation, followed immedi­ately by the command to go into standby.
Table 2 shows several commands that bring the MAX5531 back to normal operation. When transitioning from standby mode to normal operation, only the DAC power-up time is required before the DAC outputs are valid.
Reference Input
The MAX5530 accepts a reference with a voltage range extending from 0 to VDD. The output voltage (V
OUT
) is represented by a digitally programmable voltage source as:
V
OUT
= (V
REF
x N / 4096) x gain
where N is the numeric value of the DAC’s binary input code (0 to 4095), V
REF
is the reference voltage and gain is the externally set voltage gain for the MAX5530/ MAX5531.
In shutdown mode, the reference input enters a high­impedance state with an input impedance of 2.5G(typ).
Reference Output
The MAX5531 internal voltage reference is software configurable to one of four voltages. Upon power-up, the default reference voltage is 1.214V. Configure the reference voltage using the D11 and D10 data bits (Table 3) when the control bits are as follows C[3:0] = 1100, 1101, or 1110 (Table 2). VDDmust be kept at a minimum of 200mV above V
REF
for proper operation.
D11 D10 REFERENCE VOLTAGE (V)
00 1.214 01 1.940 10 2.425 11 3.885
Table 3. Reference Output Voltage Programming
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit, Voltage-Output DACs
16 ______________________________________________________________________________________
Applications Information
1-Cell and 2-Cell Circuit
See Figure 3 for an illustration of how to power the MAX5530/MAX5531 with either one lithium-ion battery or two alkaline batteries. The low current consumption of the devices makes the MAX5530/MAX5531 ideal for battery-powered applications.
Programmable Current Source
See the circuit in Figure 4 for an illustration of how to configure the MAX5530 as a programmable current source for driving an LED. The MAX5530 drives a stan­dard NPN transistor to program the current source. The current source (I
LED
) is defined in the equation in
Figure 4.
Voltage Biasing a Current-Output
Transducer
See the circuit in Figure 5 for an illustration of how to con­figure the MAX5530 to bias a current output transducer. In Figure 5, the output voltage of the MAX5530 is a func­tion of the voltage drop across the transducer added to the voltage drop across the feedback resistor R.
Self-Biased Two-Electrode
Potentiostat Application
See the circuit in Figure 6 for an illustration of how to use the MAX5531 to bias a two-electrode potentiostat on the input of an ADC.
Unipolar Output
Figure 7 shows the MAX5530 in a unipolar output con­figuration with unity gain. Table 4 lists the unipolar out­put codes.
Bipolar Output
The MAX5530 output can be configured for bipolar operation, as shown in Figure 8. The output voltage is given by the following equation:
V
OUT
= V
REF
x [(NA- 2048) / 2048]
where NArepresents the numeric value of the DAC’s binary input code. Table 5 shows digital codes (offset binary) and the corresponding output voltage for the circuit in Figure 4.
Configurable Output Gain
The MAX5530/MAX5531 have a force-sense output, which provides a connection directly to the inverting ter­minal of the output op amp, yielding the most flexibility. The advantage of the force-sense output is that specific gains can be set externally for a given application. The gain error for the MAX5530/MAX5531 is specified in a unity-gain configuration (op-amp output and inverting ter­minals connected), and additional gain error results from external resistor tolerances. Another advantage of the force-sense DAC is that it allows many useful circuits to be created with only a few simple external components.
An example of a custom fixed gain using the force-sense output of the MAX5530/MAX5531 is shown in Figure 9. In this example, R1 and R2 set the gain for V
OUT
.
V
OUT
=[(V
REFIN
x NA) / 4096] x [1 + (R2 / R1)]
where NArepresents the numeric value of the DAC input code.
REFIN
MAX5530
MAX6006
(1µA, 1.25V
SHUNT
REFERENCE)
GND
+1.25V
0.01µF
536k
V
DD
DAC
VOUT
N
DAC
IS THE NUMERIC VALUE
OF THE DAC INPUT CODE.
V
OUT
(0.30mV / LSB)
1.8V V
ALKALINE
3.3V
2.2V V
LITHIUM
3.3V
V
OUT
=
V
REFIN
× N
DAC
4096
0.1µF
Figure 3. Portable Application Using Two Alkaline Cells or One Lithium Coin Cell
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit,
Voltage-Output DACs
______________________________________________________________________________________ 17
R
2N3904
N
DAC
IS THE NUMERIC VALUE OF THE DAC INPUT CODE.
I
LED
REFIN
LED
MAX5530
V+
DAC
VOUT
I
LED
=
V
REFIN
× N
DAC
4096 × R
FB
Figure 4. Programmable Current Source Driving an LED
DAC
BAND
GAP
TO ADC
OUT
REFOUT
MAX5531
TO ADC
TO ADC
FB
WE
SENSOR
CE
I
F
R
F
C
L
REF
Figure 6. Self-Biased Two-Electrode Potentiostat Application
R
FB
N
DAC
IS THE NUMERIC VALUE
OF THE DAC INPUT CODE.
I
T
REFIN
MAX5530
VOUT
V
OUT
= V
BIAS
+ (IT × R)
V
OUT
V
BIAS
TRANSDUCER
V
BIAS
=
V
REFIN
× N
DAC
4096
DAC
Figure 5. Transimpedance Configuration for a Voltage-Biased Current-Output Transducer
NA IS THE DAC INPUT CODE (0 TO 4095 DECIMAL).
REFIN
MAX5530
OUT
FB
V
OUT
=
V
REFIN
× N
A
4096
DAC
Figure 7. Unipolar Output Circuit
DAC CONTENTS
MSB
ANALOG OUTPUT
+V
REF
(4095/4096)
+V
REF
(2049/4096)
+V
REF
(2048/4096) = +V
REF
/ 2
+V
REF
(2047/4096)
+V
REF
(1/4096) 0V
Table 4. Unipolar Code Table (Gain = +1)
DAC CONTENTS
MSB
ANALOG OUTPUT
+V
REF
(2047/2048)
+V
REF
(1/2048) 0V
-V
REF
(1/2048)
-V
REF
(2047/2048)
-V
REF
(2048/2048) = -V
REF
Table 5. Bipolar Code Table (Gain = +1)
LSB
1111 1111 1100 1000 0000 0001 1000 0000 0000 0111 1111 1111 0000 0001 0001 0000 0000 0000
LSB
1111 1111 1111 1000 0000 0001 1000 0000 0000 0111 1111 1111 0000 0000 0001 0000 0000 0000
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit, Voltage-Output DACs
18 ______________________________________________________________________________________
Power Supply and Bypassing
Considerations
Bypass the power supply with a 0.1µF capacitor to GND. Minimize lengths to reduce lead inductance. If noise becomes an issue, use shielding and/or ferrite beads to increase isolation. For the thin QFN package, connect the exposed paddle to ground.
Layout Considerations
Digital and AC transient signals coupling to GND can create noise at the output. Use proper grounding tech­niques, such as a multilayer board with a low-inductance ground plane. Wire-wrapped boards and sockets are not recommended. For optimum system performance, use printed circuit (PC) boards. Good PC board ground lay­out minimizes crosstalk between DAC outputs, reference inputs, and digital inputs. Reduce crosstalk by keeping analog lines away from digital lines.
Figure 8. Bipolar Output Circuit
Figure 9. Separate Force-Sense Outputs Create Unity and Greater-than-Unity DAC Gains Using the Same Reference
REFIN
MAX5530
OUT
V
OUT
FB
V+
10k 10k
V-
DAC
Figure 10. Software-Configurable Output Gain
H
L
FB
W
N
DAC
IS THE NUMERIC VALUE OF THE DAC INPUT CODE.
N
POT
IS THE NUMERIC VALUE OF THE POT INPUT CODE.
REFIN
MAX5530
MAX5401
SOT-POT
100k
VOUT
5PPM/°C
RATIOMETRIC
TEMPCO
1.8V ≤ V
DD
5.5V
V
OUT
V
OUT
=
V
REFIN
× N
DAC
4096
(
1 +
255 - N
POT
)
255
SCLK
DIN
CS2
CS1
DAC
Chip Information
TRANSISTOR COUNT: 10,688 PROCESS: BiCMOS
MAX5530
REFIN
DAC
OUT
FB
V
OUT
R2
R1
MAX5530/MAX5531
Ultra-Low-Power, 12-Bit,
Voltage-Output DACs
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 19
© 2004 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages
.)
24L QFN THIN.EPS
PACKAGE OUTLINE 12,16,20,24L QFN THIN, 4x4x0.8 mm
21-0139
1
B
2
PACKAGE OUTLINE 12,16,20,24L QFN THIN, 4x4x0.8 mm
21-0139
2
B
2
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