Datasheet

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General Description

The DS4412 contains two I

C adjustable-current DACs

that are each capable of sinking or sourcing current. Each

output has 15 sink and 15 source settings that are pro-

grammed by I

C interface. The full-scale range and step

size of each output is determined by an external resistor

that can adjust the output current over a 4:1 range.

The output pins, OUT0 and OUT1, 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 500µA to 2mA

♦ Full-Scale Range for Each DAC Determined by

External Resistors

♦ 15 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 Operation

DS4412

Dual-Channel, I

C Adjustable

Sink/Source Current DAC

DC-DC

CONVERTER

OUT

SDA

SCL

OUT0

OUT1

GND

FS0

FS1

4.7kΩ4.7kΩ

OUT0

FS0

FS1

DC-DC

CONVERTER

OUT

OUT1

DS4412

Typical Operating Circuit

Ordering Information

Rev 1; 10/08

________________________________________________________________

Maxim Integrated Products

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.

Denotes a lead-free/RoHS-compliant package.

T&R = Tape and reel.

PART TEMP RANGE PIN-PACKAGE

DS4412U+ -40°C to +85°C 8 μSOP

DS4412U+T&R -40°C to +85°C 8 μSOP

OUT1

OUT0

FS0GND

FS1

SCL

SDA

SOP

TOP VIEW

DS4412

Pin Configuration

Summary of content (10 pages)

PAGE 1
Rev 1; 10/08 Dual-Channel, I2C Adjustable Sink/Source Current DAC The DS4412 contains two I2C adjustable-current DACs that are each capable of sinking or sourcing current. Each output has 15 sink and 15 source settings that are programmed by I2C interface. The full-scale range and step size of each output is determined by an external resistor that can adjust the output current over a 4:1 range. The output pins, OUT0 and OUT1, power-up in a highimpedance state.
PAGE 2
DS4412 Dual-Channel, I2C Adjustable Sink/Source Current DAC ABSOLUTE MAXIMUM RATINGS Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range .............................-55°C to +125°C Soldering Temperature .....................................Refer to IPC/JEDEC J-STD-020 Specification Voltage Range on VCC, SDA, and SCL Relative to Ground.............................................-0.5V to +6.0V Voltage Range on OUT0, OUT1 Relative to Ground ................-0.
PAGE 3
Dual-Channel, I2C Adjustable Sink/Source Current DAC DS4412 OUTPUT CURRENT CHARACTERISTICS (continued) (VCC = +2.7V to +5.5V, TA = -40°C to +85°C.) PARAMETER SYMBOL CONDITIONS MIN TYP Output-Current Variation due to Power-Supply Change DC source +0.36 DC sink +0.12 Output-Current Variation due to Output Voltage Change DC source, V OUT measured at 1.2V DC sink, VOUT measured at 1.2V -0.02 Output Leakage Current at Zero Current Setting UNITS %/V %/V +0.
PAGE 4
Dual-Channel, I2C Adjustable Sink/Source Current DAC DS4412 Pin Description NAME PIN FUNCTION SDA 1 I2C Serial Data. Input/output for I2C data. SCL 2 I2C Serial Clock. Input for I2C clock. FS1 3 FS0 5 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. GND 4 Ground OUT0 6 OUT1 7 Current Outputs.
PAGE 5
Dual-Channel, I2C Adjustable Sink/Source Current DAC DIFFERENTIAL LINEARITY DS4412 toc07 RANGE FOR THE 0.5mA TO 2.0mA CURRENT SOURCE AND SINK RANGE 0.7500 1.0 0.6 0.5000 0.4 0.2500 0.2 DNL (LSB) INL (LSB) RANGE FOR THE 0.5mA TO 2.0mA CURRENT SOURCE AND SINK RANGE 0.8 DS4412 toc08 INTEGRAL LINEARITY 1.0000 0.0000 0 -0.2 -0.2500 -0.4 -0.5000 -0.6 -0.7500 -0.8 -1.0000 -1.
PAGE 6
DS4412 Dual-Channel, I2C Adjustable Sink/Source Current DAC Detailed Description The DS4412 contains two I 2 C adjustable-current sources that are each capable of sinking and sourcing current. Each output, OUT0 and OUT1, has 15 sink and 15 source settings that are programmed through the I2C interface. The full-scale ranges and corresponding step sizes of the outputs are determined by external resistors, connected to pins FS0 and FS1, which can adjust the output currents over a 4:1 range.
PAGE 7
Dual-Channel, I2C Adjustable Sink/Source Current DAC I2C Slave Address The DS4412’s slave address is 90h. I2C Definitions The following terminology is commonly used to describe I2C data transfers: Master Device: The master device controls the slave devices on the bus. The master device generates SCL clock pulses and START and STOP conditions. Slave Devices: Slave devices send and receive data at the master’s request.
PAGE 8
DS4412 Dual-Channel, I2C Adjustable Sink/Source Current DAC TYPICAL I2C WRITE TRANSACTION MSB START 1 LSB 0 0 1 0 0 0 R/W MSB SLAVE ACK b7 READ/ WRITE SLAVE ADDRESS LSB b6 b5 b4 b3 b2 b1 b0 MSB SLAVE ACK b7 LSB b6 REGISTER/MEMORY ADDRESS b5 b4 b3 b2 b1 b0 SLAVE ACK STOP DATA EXAMPLE I2C TRANSACTIONS 90h A) SINGLE BYTE WRITE -WRITE RESISTOR F9h TO 00h 90h B) SINGLE BYTE READ -READ RESISTOR F8h F9h START 1 0 0 1 0 0 0 0 SLAVE 1 1 1 1 1 0 0 1 ACK SLAVE 0 0 0 0 0 0 0 0 ACK
PAGE 9
Dual-Channel, I2C Adjustable Sink/Source Current DAC Where: IR0B = Example Calculation for an Adjustable Power Supply In this example, the Typical Operating Circuit is used as a base to create Figure 3, a 2.0V voltage supply with ±20% margin. The adjustable power supply has a DC-DC converter output voltage, VOUT, of 2.0V and a DC-DC converter feedback voltage, VFB, of 0.8V. To determine the relationship of R0A and R0B, we start with the equation: VFB = R 0B × VOUT R 0 A + R 0B Substituting VFB = 0.
PAGE 10
DS4412 Dual-Channel, I2C Adjustable Sink/Source Current DAC Revision History REVISION NUMBER REVISION DATE 0 9/07 1 10/08 DESCRIPTION PAGES CHANGED Initial release. — Added the I/O capacitance (CI/O) parameter to the DC Electrical Characteristics table. 2 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.