Manufacturer Part NumberDAC122S085
ManufacturerTexas Instruments
DAC122S085 datasheet

Specifications of DAC122S085

Resolution(bits)12Dac: Channels2
InterfaceSerial SPIOutput TypeVoltage
Output Range Max.(v Or Ma)5.5Settling Time(µs)8.5
Reference: TypeExtPower Consumption(typ)(mw)0.6
Pin/package10QFN, 10SON, 10VSSOP, 10WSON  
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DAC122S085 12-Bit Micro Power DUAL Digital-to-Analog Converter with
Rail-to-Rail Output
Literature Number: SNAS361D

DAC122S085 Summary of contents

  • Page 1

    ... DAC122S085 DAC122S085 12-Bit Micro Power DUAL Digital-to-Analog Converter with Rail-to-Rail Output Literature Number: SNAS361D ...

  • Page 2

    ... The DAC122S085 is a full-featured, general purpose DUAL 12-bit voltage-output digital-to-analog converter (DAC) that can operate from a single +2.7V to 5.5V supply and consumes 0 and 1 5V. The DAC122S085 is pack- aged in 10-lead LLP and MSOP packages. The 10-lead LLP package makes the DAC122S085 the smallest DUAL DAC in its class ...

  • Page 3

    ... Ordering Information Order Numbers DAC122S085CISD DAC122S085CISDX DAC122S085CIMM DAC122S085CIMMX DAC122S085EVAL Block Diagram www.national.com Temperature Range ≤ ≤ −40°C T +105°C A ≤ ≤ LLP Tape-and-Reel −40°C T +105°C A ≤ ≤ −40°C T +105°C A ≤ ≤ MSOP Tape-and-Reel −40°C T +105°C ...

  • Page 4

    Pin Descriptions LLP MSOP Symbol Pin No OUTA V 3 OUTB GND V 7 REFIN SYNC 10 SCLK PAD 11 (LLP only) Type Supply Power supply ...

  • Page 5

    Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage Voltage on any Input Pin Input Current at Any Pin (Note 3) Package Input Current ...

  • Page 6

    Symbol Parameter I Output Short Circuit Current (sink) OS Continuous Output I O Current (Note 10) C Maximum Load Capacitance Output Impedance OUT REFERENCE INPUT CHARACTERISTICS Input Range Minimum Input Range Maximum VREFIN Input Impedance LOGIC INPUT ...

  • Page 7

    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 4047. Boldface limits apply for T Symbol Parameter f SCLK Frequency SCLK ...

  • Page 8

    ... REFIN where V is the supply voltage for this product, and "n" is REF the DAC resolution in bits, which is 12 for the DAC122S085. MAXIMUM LOAD CAPACITANCE is the maximum capaci- tance that can be driven by the DAC with output stability maintained. MONOTONICITY is the condition of being monotonic, where the DAC has an output that never decreases when the input code increases ...

  • Page 9

    Transfer Characteristic Timing Diagrams www.national.com FIGURE 1. Input / Output Transfer Characteristic FIGURE 2. Serial Timing Diagram 8 20195205 20195206 ...

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    Typical Performance Characteristics 4047, unless otherwise stated INL 3.0V A DNL 3.0V A INL/DNL REFIN REF A SCLK 20195252 20195254 = 3.0V A 20195256 9 ...

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    INL/DNL SCLK INL/DNL vs Clock Duty Cycle at V INL/DNL vs Temperature at V www.national.com = 2.7V A 20195250 = 3.0V INL/DNL vs Clock Duty Cycle 20195224 = 3.0V INL/DNL vs Temperature at ...

  • Page 12

    Zero Code Error vs 20195230 Zero Code Error vs. f SCLK 20195234 Zero Code Error vs. Temperature 20195236 Zero Code Error vs. V Zero Code Error vs. Clock Duty Cycle Full-Scale Error vs REFIN 20195231 20195235 ...

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    Full-Scale Error vs. V Full-Scale Error vs. Clock Duty Cycle Supply Current vs. V www.national.com REFIN 20195232 Full-Scale Error vs. Temperature 20195238 Supply Current vs. Temperature A 20195244 12 Full-Scale Error vs. f SCLK 20195233 20195239 20195245 ...

  • Page 14

    Glitch Response 20195246 Power-On Reset 13 20195247 www.national.com ...

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    ... Functional Description 1.1 DAC SECTION The DAC122S085 is fabricated on a CMOS process with an architecture that consists of switches and resistor strings that are followed by an output buffer. The reference voltage is ex- ternally applied at V and is shared by all four DACs. REFIN For simplicity, a single resistor string is shown in Figure 3. ...

  • Page 16

    ... The DAC122S085 has four power-down modes, two of which are identical. In power-down mode, the supply current drops to 20 µ and 30 µA at 5V. The DAC122S085 is set in power-down mode by setting OP1 and OP0 to 11. Since this mode powers down both DACs, the first two bits of the shift register are used to select different output terminations for the DAC outputs ...

  • Page 17

    ... LM4050 Available with accuracy of 0.44%, the LM4050 shunt refer- ence is also a good choice as a reference for the DAC122S085 available in 4.096V and 5V versions and comes in a space-saving 3-pin SOT23. FIGURE 6. The LM4050 as a power supply The minimum resistor value in the circuit of Figure 6 must be chosen such that the maximum current through the LM4050 does not exceed its 15 mA rating ...

  • Page 18

    ... ESR values that may be too high at low tem- peratures. 2.2 BIPOLAR OPERATION The DAC122S085 is designed for single supply operation and thus has a unipolar output. However, a bipolar output may be obtained with the circuit in Figure 9. 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 19

    ... PC7 should be raised to end the write sequence. FIGURE 12. 68HC11 Interface 2.3.4 Microwire Interface Figure 13 shows an interface between a Microwire compatible device and the DAC122S085. Data is clocked out on the rising edges of the SK signal result, the SK of the Microwire device needs to be inverted before driving the SCLK of the DAC122S085. ...

  • Page 20

    ... Physical Dimensions inches (millimeters) unless otherwise noted 10-Lead MSOP Order Numbers DAC122S085CIMM NS Package Number MUB10A 10-Lead LLP Order Numbers DAC122S085CISD NS Package Number SDA10A 19 www.national.com ...

  • Page 21

    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 and Timing www.national.com/timing Data Converters www.national.com/adc Interface www.national.com/interface LVDS www.national.com/lvds Power Management www.national.com/power Switching Regulators www.national.com/switchers LDOs www.national.com/ldo ...

  • Page 22

    ... 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’ ...