Manufacturer Part NumberDAC121C085
ManufacturerTexas Instruments
DAC121C085 datasheet

Specifications of DAC121C085

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

DAC121C085 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 ...

  • Page 2

    ... 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 ...

  • Page 3

    ... 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

    ... GND, input code range 48 to 4047. Boldface 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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    ... 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 REF Input Impedance LOGIC INPUT CHARACTERISTICS (SCL, SDA) V Input High Voltage IH V Input Low Voltage IL I ...

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    ... POWER REQUIREMENTS Supply Voltage Minimum V A Supply Voltage Maximum Normal -- V set to midscale. 2-wire interface quiet (SCL = SDA = V OUT I V DAC121C081 Supply Current ST_VA DAC121C085 Supply Current ST_VA Supply Current REF I ST_VREF (DAC121C085 only) Power Consumption & V for DAC121C085) ...

  • Page 8

    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 ...

  • Page 9

    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. ...

  • Page 10

    Note 6: Reflow temperature profiles are different for lead-free packages. Note 7: The inputs are protected as shown below. Input voltage magnitudes up to 5.5V, regardless of V example 3V, the digital input pins can be driven ...

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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 ...

  • Page 12

    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

    ... The DAC121C085 comes with an external reference supply pin (V ). For the DAC121C085 important that V REF kept as clean as possible. The Applications section describes a handful of ways to drive the reference appropriately. Refer to Section 2.1 for details. ...

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    SERIAL INTERFACE The I 2 C-compatible interface operates in all three speed modes. Standard mode (100kHz) and Fast mode (400kHz) are functionally the same and will be referred to as Standard- Fast mode in this document. High-Speed mode (3.4MHz) ...

  • Page 17

    ... Standard-Fast mode again before increasing the bus speed and switching to Hs-mode. ns16705 FIGURE 5. Beginning Hs-Mode Communication DAC121C085's on the 2-wire bus. When the bus is addressed by the broadcast address, all the DAC121C081's and DAC121C085's will respond and update synchronously. Fig- ure 6 and Figure 7 describe how the master device should ...

  • 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 ...

  • Page 19

    DAC REGISTER The DAC register, Figure 8, has sixteen bits. The first two bits are always zero. The next two bits determine the mode of operation (normal mode or one of three power-down modes). The final twelve bits of ...

  • Page 20

    ... Power Supply Rejection OUT Ratio (PSRR). Therefore necessary to provide a noise- free supply voltage to the reference. In order to use the full dynamic range of the DAC121C085, the supply pin (V V can be connected together and share the same supply REF voltage ...

  • Page 21

    LP3985 The LP3985 is a low noise, ultra low dropout voltage regulator with a 3% accuracy over temperature good choice for applications that do not require a precision reference for the DAC121C081. It comes in 3.0V, ...

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    DSP/MICROPROCESSOR INTERFACING Interfacing the DAC121C081 to microprocessors and DSPs is quite simple. The following guidelines are offered to simplify the design process. 2.3.1 Interfacing to the 2-wire Bus Figure 15 shows a microcontroller interfacing to the DAC121C081 via the ...

  • 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 ...

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    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’ ...