Manufacturer Part NumberDAC121C081
ManufacturerTexas Instruments
DAC121C081 datasheet

Specifications of DAC121C081

Resolution(bits)12Dac: Channels1
InterfaceSerial I2COutput TypeVoltage
Output Range Max.(v Or Ma)5.5Settling Time(µs)8.5
Reference: TypeSupplyPower Consumption(typ)(mw)0.38
Pin/package6SON, 6SOT, 6USON, 6WSON  
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DAC121C081/ DAC121C085 12-Bit Micro Power Digital-to-Analog Converter with
an I2C-Compatible Interface
Literature Number: SNAS395C

DAC121C081 Summary of contents

  • Page 1

    ... DAC121C081,DAC121C085 DAC121C081/ DAC121C085 12-Bit Micro Power Digital-to-Analog Converter with an I2C-Compatible Interface Literature Number: SNAS395C ...

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    ... Each DAC operates over the extended industrial temperature range of −40°C to +125°C. The DAC121C081 and DAC121C085 are each part of a fam- ily of pin compatible DACs that also provide 8 and 10 bit resolution. For 8-bit DACs see the DAC081C081 and DAC081C085 ...

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    ... Ordering Information Order Code DAC121C081CIMK DAC121C081CIMKX DAC121C081CISD DAC121C081CISDX DAC121C085CIMM DAC121C085CIMMX DAC121C08XEB Block Diagram www.national.com Temperature Range ≤ ≤ −40°C T +125°C A ≤ ≤ TSOT Tape-and-Reel −40°C T +125°C A ≤ ≤ −40°C T +125°C A ≤ ≤ LLP Tape-and-Reel −40°C T +125° ...

  • Page 4

    Pin Descriptions Symbol Type V Analog Output OUT V Supply A GND Ground Digital SDA Input/Output SCL Digital Input Digital Input, ADR0 three levels Digital Input, ADR1 three levels V Supply REF PAD Ground (LLP only) Package Pinouts V V ...

  • Page 5

    ... A REF 25°C, unless otherwise specified. A Conditions OUT OUT All ones Loaded to DAC register OUT DAC121C085 DAC121C081 200 µA A OUT 200 µA A OUT 200 µA A OUT 200 µA A OUT 0V, Input Code = FFFh. ...

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    Symbol Parameter Output Short Circuit Current SINK Continuous Output I O Current (Note 10) C Maximum Load Capacitance Output Impedance OUT REFERENCE INPUT CHARACTERISTICS- (DAC121C085 only) Input Range Minimum V Input Range Maximum ...

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    ... ST_VREF (DAC121C085 only) Power Consumption & V for DAC121C085) A REF Continuous Operation -- 2-wire interface actively addressing the DAC and writing to the DAC register. (output unloaded DAC121C081 Supply Current CO_VA DAC121C085 Supply Current CO_VA Supply Current REF I CO_VREF (DAC121C085 only) ...

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    A.C. and Timing Characteristics Values shown in this table are design targets and are subject to change before product release. The following specifications apply for V ≤ ≤ and all other limits are at T for MIN ...

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    Symbol Parameter t Rise time of SDA signal rDA t Fall time of SDA signal fDA t Rise time of SCL signal rCL Rise time of SCL signal after a t repeated start condition and after an rCL1 acknowledge bit. ...

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    ... This value is LSB = REF where V is the supply voltage for this product, and "n" is REF the DAC resolution in bits, which is 12 for the DAC121C081. 30004904 and V be well bypassed. A REF is expressed in pF units. b ...

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    Transfer Characteristic Timing Diagrams www.national.com FIGURE 1. Input / Output Transfer Characteristic FIGURE 2. Serial Timing Diagram 10 30004905 30004960 ...

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    Typical Performance Characteristics 4047, unless otherwise stated. INL INL/DNL vs Temperature at V INL/DNL REFIN REF A SCL 30004920 = 3.0V INL/DNL vs Temperature 30004922 = 3.0V A ...

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    INL/DNL vs V Zero Code Error vs. Temperature Full Scale Error vs. Temperature www.national.com A 30004926 30004928 30004929 12 Zero Code Error vs 30004927 Full Scale Error vs 30004936 Total Supply Current vs 30004930 ...

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    V Supply Current vs. V REF Total Supply Current vs. Temperature @ V Power-On Reset Total Supply Current vs. Temperature @ V A 30004931 = 5V A 30004933 30004935 30004932 5V Glitch Response 30004934 www.national.com ...

  • Page 15

    ... Functional Description 1.1 DAC SECTION The DAC121C081 is fabricated on a CMOS process with an architecture that consists of switches and resistor strings that are followed by an output buffer. For simplicity, a single resistor string is shown in Figure 3. This string consists of 4096 equal valued resistors with a switch at each junction of two resistors, plus a switch to ground ...

  • Page 16

    ... DAC121C081 ACKs the transfer by driving SDA low. Next, the lower eight data bits are sent by the master. The DAC121C081 then ACKs the transfer. At this point, the DAC master is writing data, the slave ACKs after every data byte is successfully received. When the master is reading data, the master ACKs after every data byte is received to let the slave know it wants to receive another data byte ...

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    ... Pin-compatible alternatives to the DAC121C081 options are available with additional address options. www.national.com address to the DAC121C081, and communication continues as shown above in the "Basic Operation" Diagram (see Figure 4). When the master generates a Repeated Start condition while in Hs-mode, the bus stays in Hs-mode awaiting the slave ad- dress from the master ...

  • Page 18

    Writing to the DAC Register To write to the DAC, the master addresses the part with the correct slave address (A6-A0) and writes a "zero" to the read/ write bit. If addressed correctly, the DAC returns an ACK to ...

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    ... The t outz bus. After the SCL bus is driven low by the I SDA bus will be held for a short time by the DAC121C081. This time is referred the relationship between the fall of SCL, at the 30% threshold, to the time when the DAC begins to transition the SDA bus. ...

  • Page 20

    ... Applications Information 2.1 USING REFERENCES AS POWER SUPPLIES While the simplicity of the DAC121C081 implies ease of use important to recognize that the path from the reference input (V for the DAC121C081 & V for the DAC121C085) A REF to V will have essentially zero Power Supply Rejection OUT Ratio (PSRR) ...

  • Page 21

    ... ESR values that may be too high at low tem- peratures. www.national.com 2.2 BIPOLAR OPERATION The DAC121C081 is designed for single supply operation and thus has a unipolar output. However, a bipolar output may be obtained with the circuit in Figure 14. This circuit will provide an output voltage range of ±5 Volts. A rail-to-rail amplifier should be used if the amplifier supplies are limited to ± ...

  • Page 22

    ... The separate ground planes must be connected in one place, preferably near the DAC121C081. Special care is required to guarantee that digital signals with fast edge rates do not pass over split ground planes. They must always have a continu- ous return path below their traces ...

  • Page 23

    ... Physical Dimensions www.national.com inches (millimeters) unless otherwise noted 6-Lead TSOT Order Numbers DAC121C081CIMK NS Package Number MK06A 6-Lead LLP Order Numbers DAC121C081CISD NS Package Number SDB06A 22 ...

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    MSOP Order Numbers DAC121C085CIMM NS Package Number MUA08A 23 www.national.com ...

  • Page 25

    For more National Semiconductor product information and proven design tools, visit the following Web sites at: Products Amplifiers www.national.com/amplifiers Audio www.national.com/audio Clock Conditioners www.national.com/timing Data Converters www.national.com/adc Displays www.national.com/displays Ethernet www.national.com/ethernet Interface www.national.com/interface LVDS www.national.com/lvds Power Management www.national.com/power Switching Regulators ...

  • Page 26

    ... Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’ ...