Rev 0; 12/08
Dual-Channel, I
2
C, 7-Bit Sink/Source
Current DAC
General Description
The DS4432 contains two I
2
C programmable current
DACs that are each capable of sinking and sourcing
current up to 200µA. Each DAC output has 127 sink
and 127 source settings that are programmed using the
I
2
C interface. The current DAC outputs power up in a
high-impedance state.
♦
Two Current DACs
♦
Full-Scale Current 50µA to 200µA
♦
Full-Scale Range for Each DAC Determined by
External Resistors
♦
127 Settings Each for Sink and Source Modes
♦
I
2
C-Compatible Serial Interface
♦
Low Cost
♦
Small Package (8-Pin µSOP)
♦
-40°C to +85°C Temperature Range
♦
2.7V to 5.5V Operating Range
Features
DS4432
Applications
Power-Supply Adjustment
Power-Supply Margining
Adjustable Current Sink or Source
Pin Configuration
PART
Ordering Information
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 μSOP
8 μSOP
DS4432U+
DS4432U+T&R
TOP VIEW
SDA
SCL
FS1
GND
1
2
3
4
DS4432
+
8
7
6
5
V
CC
OUT1
OUT0
FS0
+Denotes
a lead(Pb)-free/RoHS-compliant package.
T&R = Tape and reel.
μSOP
Typical Operating Circuit
V
CC
V
OUT0
V
OUT1
4.7kΩ
4.7kΩ
SDA
SCL
DS4432
GND
OUT0
OUT1
R
0B
R
1B
V
CC
DC-DC
CONVERTER
FB
OUT
R
0A
DC-DC
CONVERTER
FB
OUT
R
1A
FS0
R
FS0
FS1
R
FS1
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
Dual-Channel, I
2
C, 7-Bit Sink/Source
Current DAC
DS4432
ABSOLUTE MAXIMUM RATINGS
Voltage Range on V
CC
, SDA, and SCL
Relative to Ground.............................................-0.5V to +6.0V
Voltage Range on FS0, FS1, OUT0, OUT1
Relative to Ground..................................-0.5V to (V
CC
+ 0.5V)
(Not to exceed 6.0V.)
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-55°C to +125°C
Soldering Temperature ...............................Refer to the IPC/JEDEC
J-STD-020 Specification.
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.
RECOMMENDED OPERATING CONDITIONS
(T
A
= -40°C to +85°C.)
PARAMETER
Supply Voltage
Input Logic 1 (SDA, SCL)
Input Logic 0 (SDA, SCL)
Full-Scale Resistor Values
SYMBOL
V
CC
V
IH
V
IL
R
FS0
, R
FS1
(Note 2)
(Note 1)
CONDITIONS
MIN
2.7
0.7 x V
CC
-0.3
40
TYP
MAX
5.5
V
CC
+ 0.3
0.3 x V
CC
160
UNITS
V
V
V
k
DC ELECTRICAL CHARACTERISTICS
(V
CC
= +2.7V to +5.5V, T
A
= -40°C to +85°C.)
PARAMETER
Supply Current
Input Leakage (SDA, SCL)
Output Leakage (SDA)
Output Current Low (SDA)
RFS Voltage
I/O Capacitance
SYMBOL
I
CC
I
IL
I
L
I
OL
V
RFS
C
I/O
V
OL
= 0.4V
V
OL
= 0.6V
3
6
0.997
10
V
CC
= 5.5V
CONDITIONS
V
CC
= 5.5V (Note 3)
MIN
TYP
MAX
150
1
1
UNITS
μA
μA
μA
mA
V
pF
OUTPUT CURRENT SOURCE CHARACTERISTICS
(V
CC
= +2.7V to +5.5V, TA = -40°C to +85°C.)
PARAMETER
Output Voltage for Sinking Current
Output Voltage for Sourcing
Current
Full-Scale Sink Output Current
Output Current Full-Scale
Accuracy
Output Current Temperature
Coefficient
SYMBOL
V
OUT:SINK
(Note 4)
CONDITIONS
MIN
0.5
0
50
-200
TYP
MAX
3.5
V
CC
-
0.75
200
-50
±5
±130
UNITS
V
V
μA
μA
%
ppm/°C
V
OUT:SOURCE
(Note 4)
I
OUT:SINK
(Notes 1, 4)
+25°C, V
CC
= 3.3V; using 0.1% R
FS
resistor, V
OUT0
= V
OUT1
= 1.2V (Note 2)
(Note 5)
Full-Scale Source Output Current I
OUT:SOURCE
(Notes 1, 4)
I
OUT:FS
I
OUT:TC
2
_______________________________________________________________________________________
Dual-Channel, I
2
C, 7-Bit Sink/Source
Current DAC
OUTPUT CURRENT SOURCE CHARACTERISTICS (continued)
(V
CC
= +2.7V to +5.5V, TA = -40°C to +85°C.)
PARAMETER
Output Current Variation Due to
Power-Supply Change
Output Current Variation Due to
Output-Voltage Change
Output Leakage Current at Zero
Current Setting
Output Current Differential
Linearity
Output Current Integral Linearity
I
ZERO
DNL
INL
(Notes 6, 7)
(Notes 7, 8)
SYMBOL
CONDITIONS
DC source, V
OUT
measured at 1.2V
DC sink, V
OUT
measured at 1.2V
DC source, V
CC
= 3.3V
DC sink, V
CC
= 3.3V
-1
-0.5
-1
MIN
TYP
0.41
0.41
0.08
0.14
+1
+0.5
+1
MAX
UNITS
%/V
%/V
μA
LSB
LSB
DS4432
AC ELECTRICAL CHARACTERISTICS
(V
CC
= +2.7V to +5.5V, T
A
= -40°C to +85°C.)
PARAMETER
SCL Clock Frequency
Bus Free Time Between STOP
and START Conditions
Hold Time (Repeated) START
Condition
Low Period of SCL
High Period of SCL
Data Hold Time
Data Setup Time
START Setup Time
SDA and SCL Rise Time
SDA and SCL Fall Time
STOP Setup Time
SDA and SCL Capacitive
Loading
SYMBOL
f
SCL
t
BUF
t
HD:STA
t
LOW
t
HIGH
t
HD:DAT
t
SU:DAT
t
SU:STA
t
R
t
F
t
SU:STO
C
B
(Note 10)
(Note 10)
(Note 10)
(Note 9)
CONDITIONS
MIN
0
1.3
0.6
1.3
0.6
0
100
0.6
20 + 0.1C
B
20 + 0.1C
B
0.6
400
300
300
0.9
TYP
MAX
400
UNITS
kHz
μs
μs
μs
μs
μs
ns
μs
ns
ns
μs
pF
Note 1:
Note 2:
Note 3:
All voltages with respect to ground. Currents entering the IC are specified positive, and currents exiting the IC are negative.
Input resistors (R
FS
) must be between the specified values to ensure the device meets its accuracy and linearity specifications.
Supply current specified with all outputs set to zero current setting. SDA and SCL are connected to V
CC
. Excludes current
through R
FS
resistors (I
RFS
). Total current including I
RFS
is I
CC
+ (2 x I
RFS
).
Note 4:
The output voltage range must be satisfied to ensure the device meets its accuracy and linearity specifications.
Note 5:
Temperature drift excludes drift caused by external resistor.
Note 6:
Differential linearity is defined as the difference between the expected incremental current increase with respect to position
and the actual increase. The expected incremental increase is the full-scale range divided by 127.
Note 7:
Guaranteed by design.
Note 8:
Integral linearity is defined as the difference between the expected value as a function of the setting and the actual value.
The expected value is a straight line between the zero and the full-scale values proportional to the setting.
Note 9:
Timing shown is for fast-mode (400kHz) operation. This device is also backward compatible with I
2
C standard-mode timing.
Note 10:
C
B
—total capacitance of one bus line in pF.
_______________________________________________________________________________________
3
Dual-Channel, I
2
C, 7-Bit Sink/Source
Current DAC
DS4432
Pin Description
NAME
SDA
SCL
FS1
FS0
GND
OUT0
OUT1
V
CC
PIN
1
2
3
5
4
6
7
8
I
2
C Serial Data. Input/output for I
2
C data.
I
2
C Serial Clock. Input for I
2
C clock.
Full-Scale Calibration Inputs. A resistor to ground on these pins determines the full-scale current
for each output. FS0 controls OUT0; FS1 controls OUT1.
Ground
Current Outputs. Sinks or sources the current determined by the register settings and the
resistance connected to FS0 and FS1.
Power Supply
FUNCTION
Typical Operating Characteristics
(Applies to OUT0 and OUT1. V
CC
= 2.7V to 5.0V, SDA = SCL = V
CC
, T
A
= +25°C, and no loads on OUT0, OUT1, FS0, or FS1, unless
otherwise noted.)
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
DS4432 toc01
SUPPLY CURRENT
vs. TEMPERATURE
DS4432 toc02
VOLTCO (SOURCE)
40kΩ LOAD ON FS0 AND FS1.
DS4432 toc03
150
125
SUPPLY CURRENT (μA)
100
75
50
25
0
2.5
DOES NOT INCLUDE CURRENT DRAWN BY
RESISTORS CONNECTED TO FS0 OR FS1.
150
125
SUPPLY CURRENT (μA)
100
75
DOES NOT INCLUDE CURRENT DRAWN BY
RESISTORS CONNECTED TO FS0 OR FS1.
-150
-175
I
OUT
(μA)
80
V
CC
= 5.5V
V
CC
= 2.7V
V
CC
= 3.3V
-200
50
25
0
-225
-250
-40
-20
0
20
40
60
0
1
2
V
OUT
(V)
3
4
5
TEMPERATURE (°C)
3.0
3.5
4.0
4.5
5.0
5.5
SUPPLY VOLTAGE (V)
VOLTCO (SINK)
DS4432 toc04
TEMPERATURE COEFFICIENT
vs. SETTING (SOURCE)
DS4432 toc05
TEMPERATURE COEFFICIENT
vs. SETTING (SINK)
TEMPERATURE COEFFICIENT (°C/ppm)
550
450
350
250
150
50
-50
-150
-250
0
25
50
75
100
125
+25°C TO +85°C
+25°C TO -40°C
RANGE FOR THE 50μA TO 200μA CURRENT
SINK RANGE.
DS4432 toc06
250
300
TEMPERATURE COEFFICIENT (°C/ppm)
250
200
150
100
50
0
-50
40kΩ LOAD ON FS0 AND FS1.
RANGE FOR THE 50μA TO 200μA CURRENT
SOURCE RANGE.
650
225
I
OUT
(μA)
200
+25°C TO -40°C
175
+25°C TO +85°C
0
25
50
75
100
125
150
0
0.5
1.0
1.5
2.0
V
OUT
(V)
2.5
3.0
3.5
4.0
SETTING (DEC)
SETTING (DEC)
4
_______________________________________________________________________________________
Dual-Channel, I
2
C, 7-Bit Sink/Source
Current DAC
Typical Operating Characteristics (continued)
(Applies to OUT0 and OUT1. V
CC
= 2.7V to 5.0V, SDA = SCL = V
CC
, T
A
= +25°C, and no loads on OUT0, OUT1, FS0, or FS1, unless
otherwise noted.)
INTEGRAL LINEARITY
DS4432 toc07
DS4432
DIFFERENTIAL LINEARITY
0.8
0.6
0.4
DNL (LSB)
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
RANGE FOR THE 50μA TO 200μA CURRENT
SOURCE AND SINK RANGE.
DS4432 toc08
1.0
0.8
0.6
0.4
INL (LSB)
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
0
1.0
RANGE FOR THE 50μA TO 200μA CURRENT
SOURCE AND SINK RANGE.
25
50
75
100
125
0
25
50
75
100
125
SETTING (DEC)
SETTING (DEC)
Block Diagram
SDA SCL
V
CC
I
2
C-COMPATIBLE
SERIAL INTERFACE
DS4432
V
CC
F8h
SOURCE OR
SINK MODE
GND
CURRENT
DAC0
F9h
127 POSITIONS
EACH FOR SINK
AND SOURCE
MODE
CURRENT
DAC1
FS0
R
FS0
OUT0
FS1
R
FS1
OUT1
_______________________________________________________________________________________
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