Rainbow Electronics DS4432 User Manual

DS4432

Dual-Channel, I2C, 7-Bit Sink/Source

Current DAC

________________________________________________________________

Maxim Integrated Products

Rev 0; 12/08

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.

General Description

The DS4432 contains two I2C 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 I2C interface. The current DAC outputs power up in a high-impedance state.

Applications

Power-Supply Adjustment

Power-Supply Margining

Adjustable Current Sink or Source

Features

♦ 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

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

DC-DC

CONVERTER

OUT

SDA SCL

OUT0

OUT1

GND

FS0

FS1

4.7kΩ4.7kΩ

OUT0

FS0

FS1

DC-DC

CONVERTER

OUT

OUT1

DS4432

Typical Operating Circuit

Ordering Information

Denotes a lead(Pb)-free/RoHS-compliant package.

T&R = Tape and reel.

Pin Configuration

TOP VIEW

18V

SDA

2 7 OUT1SCL

DS4432

OUT0FS1 3 6

FS0GND 4 5

PART TEMP RANGE PIN-PACKAGE

DS4432U+ -40°C to +85°C 8 μSOP

DS4432U+T&R -40°C to +85°C 8 μSOP

SOP

DS4432

Dual-Channel, I2C, 7-Bit Sink/Source Current DAC

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

RECOMMENDED OPERATING CONDITIONS

(TA= -40°C to +85°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.

Voltage Range on VCC, 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

+ 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.

DC ELECTRICAL CHARACTERISTICS

(VCC= +2.7V to +5.5V, TA= -40°C to +85°C.)

OUTPUT CURRENT SOURCE CHARACTERISTICS

(VCC= +2.7V to +5.5V, TA= -40°C to +85°C.)

Supply Voltage VCC (Note 1) 2.7 5.5 V

Input Logic 1 (SDA, SCL) VIH 0.7 x VCC VCC + 0.3 V

Input Logic 0 (SDA, SCL) VIL -0.3 0.3 x VCC V

Ful l-Scale Re sistor Values R

PARAMETER S YMBOL CONDITIONS MIN TYP MAX UNITS

, R

FS0

(Note 2) 40 160 k

FS1

Supply Current ICC VCC = 5.5V (Note 3) 150 μA

Input Leakage (SDA, SCL) IIL VCC = 5.5V 1 μA

Output Leakage (SDA) IL 1 μA

Output Current Low (SDA) I

RFS Voltage V

I/O Capacitance C

PARAMETER S YMBOL CONDITIONS MIN TYP MAX UNITS

RFS

I/O

VOL = 0.4V 3

VOL = 0.6V 6

0.997 V

10 pF

Output Voltage for Sinking Current V

Output Voltage for Sourcing Current

Ful l-Scale Sink Output Current I

Ful l-Scale Source Output Current I

Output Current Ful l-Scale Accuracy

Output Current Temperature Coefficient

PARAMETER S YMBOL CONDITIONS MIN TYP MAX UNITS

OUT:SINK

OUT: SOU RCE

OUT:SINK

OUT: SOURC E

OUT:FS

OUT:TC

(Note 4) 0.5 3.5 V

(Note 4) 0

(Notes 1, 4) 50 200 μA

(Notes 1, 4) -200 -50 μA

+25°C, VCC = 3.3V; using 0.1% R resistor, V

(Note 5) ±130 ppm/°C

OUT0

= V

= 1.2V (Note 2)

OUT1

±5 %

0.75

DS4432

Dual-Channel, I2C, 7-Bit Sink/Source

Current DAC

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Note 1: All voltages with respect to ground. Currents entering the IC are specified positive, and currents exiting the IC are negative. Note 2: Input resistors (R

) must be between the specified values to ensure the device meets its accuracy and linearity specifications.

Note 3: Supply current specified with all outputs set to zero current setting. SDA and SCL are connected to V

. Excludes current

through R

resistors (I

RFS

). Total current including I

RFS

is ICC+ (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

C standard-mode timing.

Note 10: C

—total capacitance of one bus line in pF.

OUTPUT CURRENT SOURCE CHARACTERISTICS (continued)

(VCC= +2.7V to +5.5V, TA= -40°C to +85°C.)

AC ELECTRICAL CHARACTERISTICS

(VCC= +2.7V to +5.5V, TA= -40°C to +85°C.)

PARAMETER S YMBOL CONDITIONS MIN TYP MAX UNITS

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 INL (Notes 7, 8) -1 +1 LSB

ZERO

DNL (Notes 6, 7) -0.5 +0.5 LSB

DC source, V

DC sin k, V

DC source, VCC = 3.3V 0.08

DC sin k, V

-1 +1 μA

measured at 1.2V 0.41

OUT

measured at 1.2V 0.41

OUT

= 3.3V 0.14

%/V

SCL Clock Frequenc y f

Bus Free Time Between STOP and START Conditions

Hold Time (Repeated) START Condition

Low Period of SCL t

High Period of SCL t

Data Hold Time t

Data Setup Time t

START Setup Time t

SDA a nd SCL R i se Time tR (Note 10) 20 + 0.1CB 300 ns

SDA and SCL Fall Time tF (Note 10) 20 + 0.1CB 300 ns

STOP Setup Time t

SDA a nd SCL Capacit i ve Loading

PARAMETER S YMBOL CONDITIONS MIN TYP MAX UNITS

(Note 9) 0 400 kHz

SCL

1.3 μs

BUF

0.6 μs

HD: STA

1.3 μs

LOW

0.6 μs

HIGH

0 0.9 μs

HD:DAT

100 ns

SU:DAT

0.6 μs

SU:STA

0.6 μs

SU:STO

(Note 10) 400 pF

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