7106 UTC | Alldatasheet
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UNISONIC TECHNOLOGIES CO., LTD
7106 CMOS IC
w w w . u n i s o n i c . c o m . t w 1 of 18 Copyright © 2010 Unisonic Technologies Co., Ltd QW-R502-018.D 3 ½ DIGIT, LCD DISPLAY, A/D CONVERTERS DESCRIPTION The UTC 7106 is a high performance, low power, 3½ digits A/D converter. Incl uded are seven segment decoders, display drivers, a reference, and a clock. The UTC 7106 is designed to interface with a liquid crystal display (LCD) and includes a multiplexed backplane drive. The UTC 7106 bring together a combination of high accuracy, versatility, and true economy. It f eatures auto zero to less than 10μV, zero drift of less than 1 μV/°C, input bias current of 10pA (Max), and rollover error of less than one count. True differential inputs and reference are useful in all system, but give the designer an uncommon advantage when measuring load cells, strain gauges and other bridge type trans ducers. Finally, the true economy of single power supply operation, enables a high performance panel meter to be built with the addition of only 10 passive components and a display. FEATURES *Guaranteed Zero Reading for 0V Input On All Scales *True Polarity At Zero for Precise Null Detection *1pA Typical Input Current *True Differential Input And Reference, Direct Drive LCD Display *Low Noise-Less than 15μVp-p *On chip Clock and Reference *Low Power Dissipation-Typically Less than 10mW *No Additional Active Circuits Required *Enhanced Display Stability ORDERING INFORMATION Ordering Number Lead Free Plating Halogen Free Package Packing 7106L-D40-T 7106G-D40-T DIP-40 Tube 7106L-R40-R 7106G-R40-R SSOP-40 Tape Reel 7106L-R40-T 7106G-R40-T SSOP-40 Tube 7106L-QM1-Y 7106G-QM1-Y MQFP-44 Tray
UNISONIC TECHNOLOGIES CO., LTD 2 o f 1 8 www.unisonic.com.tw Q W - R 5 0 2 - 0 1 8 . D PIN CONFIGURATION DIP- 40/SSOP-40 (1000) AB4 POL(MINUS) OSC 1 OSC 2 OSC 3 TEST REF HI REF LO CREF + CREF - COMMON IN HI IN LO A-Z BUFF INT G2(10 s) BP (100 s), NC BP/GND POL AB4 A1 F1 G1 E1 D2 C2 B2 A2 F2 E2 D3 OSC 1 OSC 2 NC OSC 3 TEST NC NC 12 13 14 15 16 17 18 19 20 21 22 44 43 42 41 40 39 38 37 36 35 34 (1 s), (10 s), (100 s), MQFP - 44
UNISONIC TECHNOLOGIES CO., LTD 3 o f 1 8 www.unisonic.com.tw Q W - R 5 0 2 - 0 1 8 . D ABSOLUTE MAXIMUM RATINGS(Ta=25°C) PARAMETER SYMBOL RATINGS UNIT Supply Voltage (V+ ~ V-) V DD 15 V Analog Input Voltage (Either Input) (Note 1) V I,ANG V+ ~ V- V Reference Input Voltage (Either Input) V I,REF V+ ~ V- V Junction Temperature T J 150 °C Operating Temperature T OPR 0 ~ +70 °C Maximum Storage Temperature T STG -65 ~ +150 °C Note: 1. Input voltages may exceed the supply voltages provided the input current is limited to ±100μA. 2. Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum ratings are stress ratings only and functional device operation is not implied. THERMAL DATA PARAMETER SYMBOL RATINGS UNIT DIP-40 50 °C/W SSOP-40 70 °C/W Thermal Junction-to-Ambient MQFP-44 θJA 75 °C/W ELECTRICAL CHARACTERISTICS (Ta=25 , f℃ CLOCK=48kHz, measured by the circuit of Figure 1.) PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT SYSTEM PERFORMANCE Zero Input Reading R Z V IN=0.0V, Full Scale=200mV -000.0 ±000.0 +000.0 Digital Reading Ratio metric Reading R R V IN=VREF, VREF=100mV 999 999/1000 1000 Digital Reading Rollover Error E R -VIN=+VIN 200mV≒ Difference in Reading for Equal Positive and Negative Inputs Near Full Scale ±0.2 ±1 Counts Linearity L Full Scale=200mV or Full Scale=2V Maximum Devi- ation from Best Straight Line Fit (Note 2) ±0.2 ±1 Counts Common Mode Rejection Ratio CMRR VCM=1V,VIN=0V, Full Scale=200mV(Note 2) 50 μV/V Noise V N VIN=0V,Full Scale=200mV (Peak-To-Peak Value Not Exceeded 95% of Time) 15 μV Leakage Current Input IL V IN=0(Note 2) 1 10 pA Zero Reading Drift D ZR V IN=0, 0℃ ~ 70℃ (Note 2) 0.2 1 μV/°C Scale Factor Temperature Coefficient ΦT,S VIN=199mV, 0℃ ~ 70℃, (Ext.Ref.0ppm/℃) (Note 2) 1 5 ppm/°C End Power Supply Character V+ Supply Current IEP V IN=0 1.0 1.8 mA COMMON Pin Analog Common Voltage VCOM 25kΩ Between Common and Positive Supply (With Respect to +Supply) 2.7 3.05 3.3 V Temperature Coefficient of Analog Common ΦT,A 25kΩ Between Common and Positive Supply (With Respect to +Supply) 80 ppm/°C
UNISONIC TECHNOLOGIES CO., LTD 4 o f 1 8 www.unisonic.com.tw Q W - R 5 0 2 - 0 1 8 . D ELECTRICAL CHARACTERISTICS(Cont.) PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT DISPLAY DRIVER Peak-To-Peak Segment Drive Voltage Peak-To-Peak Backplane Drive Voltage V D,PP V+ ~ V-=9V(Note 1) 4 5.5 6 V Note: 1. Back plane drive is in phase with segment drive fo r”off”segment,180 degrees out of phase for ”on” segment . Frequency is 20 times conversion rate. Average DC component is less than 50mV. 2. Not tested, guaranteed by design.
UNISONIC TECHNOLOGIES CO., LTD 5 o f 1 8 www.unisonic.com.tw Q W - R 5 0 2 - 0 1 8 . D TYPICAL APPLICATIONS AND TEST CIRCUIT (LCD DISPLAY COMPONENTS SELECTED FOR 200mV FULL SCALE) 20 21 40V+ AB4 POL OSC 1 OSC 2 OSC 3 TEST REF HI REF LO C REF+ CREF - COM IN HI IN LO A-Z BUFF INT BP UTC 7106 DISPLAY R3 C4 R4 C1 IN + - C2 R2 C3 DISPLAY C1=0.1μF C2=0.47μF C3=0.22μF C4=100pF C5=0.02μF R1=24kΩ R2=47kΩ R3=91kΩ R4=1kΩ R5=1MΩ + -
UNISONIC TECHNOLOGIES CO., LTD 6 o f 1 8 www.unisonic.com.tw Q W - R 5 0 2 - 0 1 8 . D DESIGN INFORMATION SUMMARY SHEET *OSCILLATOR FREQUENCY fosc=0.45/RC COSC>50pF, ROSC>50kΩ fOSC (Typ)=48kHz *OSCILLATOR PERIOD tOSC=RC/0.45 *INTEGRATION CLOCK FREQUENCY fCLOCK=fOSC/4 *INTEGRATION PERIOD tINT=1000×(4/fOSC) *60/50Hz REJECTION CRITERION tINT/t60Hz or tINT/t50Hz=Integer *OPTIMUM INTEGRATION CURRENT IINT=4μA *FULL SCALE ANALOG INPUT VOLTAGE VINFS (Typ)=200mV or 2V *INTEGRATE ESISTOR R INT= VINFS/ IINT *INTEGRATE CAPACITOR CINT=(tINT)(IINT)/ VINT *INTEGRATOR OUTPUT VOLTAGE SWING VINT=(tINT)(IINT)/ CINT *VINT MAXIMUM SWING (V- + 0.5V)<VINT<(V+ - 0.5V), VINT (Typ)=2V *DISPLAY COUNT COUNT=1000×V IN/VREF *CONVERSION CYCLE tCYC=tCLOCK×4000 tCYC=tOSC×16,000 When fOSC=48kHz, tCYC=333ms *COMMON MODE INPUT VOLTAGE (V- + 1V)<VIN<(V+ - 0.5V) *AUTO-ZERO CAPACITOR 0.01μF<CAZ<1μF *REFERENCE CAPACITOR 0.1μF<CREF<1μF *VCOM Biased between Vi and V- COM V+ ≒ - 2.8V Regulation lost when V+ to V- < 6.8V≒ If VCOM is externally pulled down to (V+ to V-)/2, the VCOM circuit will turn off. *POWER SUPPLY: SINGLE 9V V+ - V- =9V V GND V+ ≒ - 4.5V Digital supply is generated by internal parts. *DISPLAY: LCD Type: Direct drive with digital logic supply amplitude.
UNISONIC TECHNOLOGIES CO., LTD 7 o f 1 8 www.unisonic.com.tw Q W - R 5 0 2 - 0 1 8 . D TYPICAL INTEGRATOR AMPLIFIER OUTPUT WAVEFORM (INT PIN) DE-INTEGRATE PHASE 0 - 1999 COUNTS SIGNAL INTEGRATE PHASE FIXED
1000 COUNTS
(COUNTS) 2999-1000 TOTAL CONVERSION TIME=4000 × tCLOCK=16,000 × tosc DETAILED DESCRIPTION ANALOG SECTION Figure 1 shows the Analog Section for the UTC 7106. Each measurement cycle is divided into three phases. They are(1) auto-zero(A-Z), (2)signal integrate (INT)and (3)de-integrate(DE). AUTO-ZERO PHASE During auto-zero three things happen. First, input high and low are disconnected from the pins and internally shorted to analog COMMON. Second, the reference capacitor is charged to the reference voltage. Third, a feedback loop is closed around the system to charge the auto-zero capacitor C AZ to compensate for offset voltages in the buffer amplifier, integrator, and comparator. Since the comparator is included in the loop, the A-Z accuracy is limited only by the noise of the system. In any case, the offset referred to the input is less than 10μV. SIGNAL INTEGRATE PHASE During signal integrate, the auto-zero loop is opened, the internal short is removed, and the internal input high and low are connected to the external pins . The converter then integrates the differential voltage between IN HI and IN LO for a fixed time. This differential voltage can be within a wide common mode range: up to 1V from either supply. if, on the other hand, the input signal has no return with resp ect to the converter power supply, IN LO can be tied to analog COMMON to establish the correct common mode volt age. At the end of this phas e, the polarity of the integrated signal is determined. DE-INTEGRATE PHASE The final phase is de-integrate, or re ference integrate. Input low is inte rnally connected to analog COMMON and input high is connected across the previously charged refer ence capacitor. Circuitry within the chip ensures that the capacitor will be connected with the correct polarity to cause the integrator output to return to zero. The time required for the output to return to zero is proportional to the input signal. Specifically the digital reading displayed is: DISPLAY COUNT=1000( V IN/ VREF ). DIFFERENTIAL INPUT The input can accept differential voltages anywhere with in the common mode range of the input amplifier, or specifically from 0.5V below the posit ive supply to 1V above the negative suppl y. In this range, the system has a CMRR of 86dB typical. However, care must be exercised to assure the integrator output does not saturate. A worst case condition would be a large positive common mode volt age with a near full scale negative differential input voltage. The negative input signal drives the integrator positive when most of its swing has been used up by the positive common mode voltage. For these critical applications t he integrator output swing can be reduced to less than the recommended 2V full scale swing with little loss of accuracy. The integrator output can swing to within 0.3V of either supply without loss of linearity.
UNISONIC TECHNOLOGIES CO., LTD 8 o f 1 8 www.unisonic.com.tw Q W - R 5 0 2 - 0 1 8 . D DETAILED DESCRIPTION(Cont.) DIFFERENTIAL REFERENCE The reference voltage can be generated any where within the power supply volt age of the converter. The main source of common mode error is a roll-over voltage caused by the reference capacitor losing or gaining charge to stray capacity on its nodes. If there is a large common mode voltage, the reference capacitor can gain charge (increase voltage) when called up to de-integrate a positive signal but lose charge (decrease voltage) when called up to de-integrate a negative input signal. This difference in refe rence for positive or negative input voltage will give a roll-over error. However, by selecting the reference capacito r such that it is large enou gh in comparison to the stray capacitance, this error can be held to less than 0.5 count worst case. (See Component Value Selection)
coefficient (0.001%/V), low output impedance ( 15≒ Ω), and a temperature coefficient typically less than 80ppm/℃. reference can easily be added, as shown in Figure 2. analog COMMON, it should be since this removes the common mode voltage from the reference system. Figure 2. Using an External Reference
UNISONIC TECHNOLOGIES CO., LTD 1 0 o f 1 8 www.unisonic.com.tw Q W - R 5 0 2 - 0 1 8 . D DETAILED DESCRIPTION(Cont.) TEST The TEST pin serves two function. On the UTC 7106 it is coupled to the internally generated digital supply through a 500 Ω resistor. Thus it can be used as the negative supply for externally g enerated segment drivers such as decimal points or any other presentation the user may wa nt to include on the LCD display. Figures 3 and 4 show such an application. No more than a 1mA load should be applied. The second function is a “lamp test”. When TEST is pulled high (to V+) all segments will be turned on and the display should read ”1888”. The TEST pin will sink about 15mA under these conditions. CAUTION: In the lamp test mode, the segments have a constant DC voltage (no square-wave) . This may burn the LCD display if maintained for extended periods.
when ON. In all cases negligible DC voltage exists across the segments. Figure 5. Digital Section
- Figure 6A. An external oscillator connected to pin 40.
- Figure 6B. An R-C oscillator using all three pins.
voltage. For three readings/second, an oscillator frequency of 48kHz would be used. 40kHz (2.5 readings/second) will reject both 50Hz and 60Hz (also 400Hz and 440Hz). Figure 6. Clock Circuits placed on the PC board. For 2V full scale, 470kΩ is near optimum and similarly a 47kΩ for a 200mV scale. frequencies are used, these values should be changed in inverse proportion to maintain the same output swing. undetectable errors at reasonable cost. speed of recovery from overload and is adequate for noise on this scale.
UNISONIC TECHNOLOGIES CO., LTD 1 3 o f 1 8 www.unisonic.com.tw Q W - R 5 0 2 - 0 1 8 . D DETAILED DESCRIPTION(Cont.) Reference Capacitor A 0.1μF capacitor gives good results in most applications. However, where a large common mode voltage exists (i.e.,the REF LO pin is not at analog COMMON)and a 200mV scale is used, a larger value is required to prevent roll-ovre error. Generally 1μF will hold the roll-over error to 0.5 count in this instance. Oscillator Components For all ranges of frequency a 91kΩ resistor is recommended and the capacitor is selected from the equation: f= 0.45/RC For 48kHz Clock (3 Readings/sec), C=100pF. Reference Voltage The analog input required to generate full scale output (2000 counts) is: V IN=2VREF.Thus, for the 200mV and 2V scale, VREF should equal 100mV and 1V, respectively. However, in many applications where the A/D is connected to a transducer, there will exist a scale fa ctor other than unity between the input voltage and the digital reading. For instance, in a weighing system, the designer might like to have a full scale reading when the voltage from the transducer is 0.662V. Instead of dividing the input down to 200mV, the designer should use the input voltage directly and select V REF=0.341V. Suitable values for integrating resistor and capacitor would be 120k Ω and 0.22 μF. This makes the system slightly quieter and also avoids a divider network on the input.
UNISONIC TECHNOLOGIES CO., LTD 1 4 o f 1 8 www.unisonic.com.tw Q W - R 5 0 2 - 0 1 8 . D TYPICAL APPLICATIONS The UTC 7106 may be used in a wide variety of configurations. The circuits which follow show some of the possibilities, and serve to illustrate the exceptional versatility of these A/D converters.
UNISONIC TECHNOLOGIES CO., LTD 1 5 o f 1 8 www.unisonic.com.tw Q W - R 5 0 2 - 0 1 8 . D TYPICAL APPLICATIONS(Cont.)
UNISONIC TECHNOLOGIES CO., LTD 1 6 o f 1 8 www.unisonic.com.tw Q W - R 5 0 2 - 0 1 8 . D TYPICAL APPLICATIONS(Cont.)
Figure 10. Circuit for Developing Underrange and Overrange from UTC 7106
Test is used as a common-mode reference level to ensure compatiblity with most op amps. Figure 11. AC to DC Converter with UTC 7106 and reliable and may be changed without notice.