KADO505 3 3/4-DIGIT 4000-COUNT A/D CONVERTER 3 3/4-DIGIT 4000-COUNT A/D CONVERTER The KADOS505 is a CMOS low-power dual-slope analog-to-digital converter for di- 48-QFP-1010D gital multi-meter with 3 3/4-digit numeric triplex LCD driver, auto-ranging frequency counter, and single 9V battery operation. (t is ideal for low power manual-range (except auto-ranging frequency) DMM appli- cations with the 4000 counts full-scale. The KADO505 provides many user functions such as Data Hold/Peak Hold/Low Battery Detection/Continuity Check (Beeper)/Auto-ranging Frequency/Serial Data Output. The built-in temperature-stable CMOS bandgap voltage reference is eco- nomical of saving the external reference. The KADO505 is designed to interface with a liquid crystal display (LCD) and inclu- des a seven-segment decoder, LCD driver, backplane driver, and decimal point driver. Besides, it provides one annunciator pin for unit display on LCD. The frequency counter is auto-ranging from 4KHz to 4MHz over four decade ra- nges with one annunciator, which is useful in measuring the normal sinewave including the rectangual wave frequency ranging from 74mV,.,. to 3 V,.p of input level without connecting the external input attenuation circuit. FEATURES * Triplex LCD display polarity, data hold, peak hold, low-battery, KHz, MHz 3 dicimal points O.L for input overrange * One annunciator pin for unit display on LCD * On-chip CMOS bandgap voltage reference * Auto-ranging frequency counter (from 4KHz to 46MHz) * Zero reading for zero Input * Rollover error:less than ftcount * Low power operation: below 3.36mW In voltage mode, below 12mW In frequency mode * Serial data output * Data hold/Peak hold * Low battery detection (typ Vpo=6.8V) * Continuity check:beeper output below 400 counts * Single 9V battery power supply * Package type:48QFP TYPICAL APPLICATIONS * Digital Multimeter, Digital Pane! Meter, Digital Thermometer, Digital Capacitance Meter * Digital Clamp Meter ORDERING INFORMATION Device Supply Voltage Package | Temperature Range KADOS05 QV 48 QFP | oc ~ +50C ea ELECTRONICSKADO505 3 3/4-DIGIT 4000-COUNT A/D CONVERTER BLOCK DIAGRAM ffoos >& o ssh DO oO 8 og z << oO TSH i : 2% 3 g 8 zo6 5 hratim = = s W BANDGAP BIAS | VIN-+ 4 ib 4 VIN rom = oses - LEVEL SHIFTER _ FREQ iy | osc osc2 V/F SEL 43 _ | oser TEST [Counter = CONTROL LOGIC [oS 32/40KHz SEL FUNCTION y BUZZER 1) BEEP Pa j 13sec TIME =i IL 4000 COUNTER SERIAL 21) SDATA DP1 DECIMAL POINT OUTPUT CK Dp? DRIVER (8) ST { TRIPLEX LCD DRIVER | 1 2) 3K 4M 5 WENT KE WS 1 Tet 2 1 a@eaee Pe xyrperereeerre agnmaoa agag 838 88RB888 5992 PIN CONFIGURATION 48 QFP < ae arr FF OO SSORF ODE OS TEG1 ikRERRRE ) HOO Le LL VIN- CI? 3 4 0 2928 27 26 23 T--osc3 ACOM C14 23-1 082 VIN+ CT 224_LJ0SC1 FREQCIC 214-1) SDATA V/F SEL 4 oICICK TEST CI TNC Vop (7 ef) ST 32/40KHz SEL CI 17[- BEEP OH CT 16/1] ANNU PH CI 15f-0-1SpP12 DPI C447 C) 14-1 sop11 DP2 (717 1 Mi 2 34 5 678940 Sf soPt0 OOO OU CUO UO OOO OGOGUUCO Eeeahe regres DOM DBBBBRRBR (Top View) ELECTRONICSKADO505 3 3/4-DIGIT 4000-COUNT A/D CONVERTER PIN DESCRIPTION Pin No. Symbol Vo Description 1 BP1 oO Backplane 1 of LCD 2 BP2 Oo Backplane 2 of LCD 3 BP3 oO Backplane 3 of LCD 4 SDP1 oO Segment display (Hz/K/M) | 5 SDP2 Oo Segment display ( /cO/b0) ; 6 SDP3 O Segment display (dO/g0/a0) | 7 SDP4 oO Segment display (e0/foAL J ) 8 SDP5 Oo Segment display (dp1/c1/b1) 9g SDP6 Oo Segment display (d1/g1/a1) 10 SDP7 oO Segment display (e1/f1/DH) 1 SDP8 Oo Segment display (dp2/c2/b2) 12 SDP9 oO Segment display (d2/g2/a2) 13 SDP10 oO Segment display (e2/f2/PH) 14 SDP11 Oo Segment display (dp3/c3/b3) 15 SDP12 oO Segment display (= /e3/a3,d3,g3) 16 ANNU Oo annunciator pin (square-wave output for another segment display) 17 BEEP oO Beep frequency output (fosc/16) 18 ST Oo Serial output enable 19 NC No connection 20 CK Oo Clock of serial output 21 SDATA oO Serial data output 22 Osc! l External oscillator connection. 23 OSC2 Vo A cryatal between pins 22 and 23 is available. 24 OSC3 VO Pins 22,23,24 make up the oscillator. The pin 22 is connected to the junction of a resistor and acapacitor. The resistor is tied to pin 23 and the capacitor is tied to pin 24. 25 D GNO oO Digital ground (3 volts below Vpp) 26 Vss Negative supply voltage 27 NC No connection. This pin should be open in normal operation. 28 Cint vo Integrating capacitor connection 29 Roewt ' VO Deintegrating resistor connection 30 Rint | vO Integrating resistor connection 31 Caz ; oO Auto zero capacitor connection 32 Crer Vo Reference capacitor negative connection 33 Crer + VO Reference capacitor positive connection 34 VaerOUT ; oO Reference voltage output 35 VrerIN + | | Reference voltage positive input 36 VrerlN ~ | | Reference voltage negative input 37 VIN I Analog negative input 38 A COM L oO Analog circuit common ground regerence (3 volts below Vpo) 39 ELECTRONICSKADOS505 3 3/4-DIGIT 4000-COUNT A/D CONVERTER PIN DESCRIPTION | Pin No. Symbol vo Description 39 VIN l Analog positive input 40 FREQ I Frequency input 41 V/F SEL I Voltage or frequency mode selection (when floating ; voltage mode, when L : frequency mode} 42 TEST t Test mode enable (When floating : function selection is possible, when "L: test mode) 43 Voo I Supply voltage 44 32/40KHz SEL I 32.768KHz or 40KHz crysta! oscillator selection (floating for 32.768KHz, connect to D GND for 40KHz crystal) 45 DH | Data hold (Data hold on/off is possible at every toggle.) : Test control pin 1 for test mode 46 | PH 1 Peak hold (Peak Hold on/off is possible at every toggle.) Test control pin 2 for test mode 47 DP1 | Becimal point controt pin 1 48 DP2 | Decimal point control pin 2 a 40KADO505 3 3/4-DIGIT 4000-COUNT A/D CONVERTER ABSOLUTE MAXIMUM RATINGS (note 1 & 2) Characteristics Symbol Value Unit Supply Voltage Vpo 03 to +100 Vv Analog Input Voltage AVin -0.3 to Von +0.3 Vv Digital Input Voltage DViw D GND 03 to Vpp +0.3 Vv Beeper Output Current lacer 1to +1 mA ; LCD Output Current lico 0.1 to +01 mA | Analog Output Current Alour ~3to +3 mA | Digital Output Current Dlour 1to +1 mA | Operating Temperature Range Torr 0 to +50 C |; Storage Temperature Range Tst 40 to +125 C } Power Dissipation Po 12 mw ESD Susceptibility (Note 3) Vesp + 1,500 Vv (Test Condition : Vss =OV) Note 1:ABSOLUTE MAXIMUM RATINGS are those values beyond which the device may be damaged permanently. Normal operation is not guaranteed at or above these extermes. Note 2:All voltages are measured with respect to the Vss voltage level unless otherwise specified. Note 3:100pF discharged through a 1.5kQ resistor (Human body model). RECOMMENDED OPERATING CONDITIONS | Characteristics Symbol Min Typ Max Unit | Supply Voltage | Me 78 so | 86 ' Oscillation Frequency fosc 32.768 or 40 KHz Digital Input H Voltage - Voi Vo-05 | | | Digital Input L Voltage Vi D GND+0.5 | Reference Input Vottagettose=92.768KH2) | ACOM+ 327.68 mV Reference Input Voltage(fosc = 40KHz) ACOM + 400.00 LCD-On Drive Voltage =Ssss<CSsss Mico: | GND | LCD-Off Drive Voltage Vico-oFr . | DGND+05 Operating Temperature Range Torr 0 +50 ELECTRONICS 41KADO505 3 3/4-DIGIT 4000-COUNT A/D CONVERTER ELECTRICAL CHARACTERISTICS (Converter Specifications:Vop =9V, Vss=OV, Ta= 25C, VaerIN= 327.68MV:fosc = 32.768KHz or VrerlIN= 400MV:fosc = 40 KHz, unless otherwise specified.) Characteristics Symbol Test Conditions Min Typ Max Unit Supply Current Ibo At voltage mode, Viw=OmV 120 240 500 pA Reference Voltage Output VaerOUT 10 1.28 1.4 Vv Temperature Coefficient Tempco 100 ppm/C of Reference Voltage Voltages above A COM Reference Vottage Power PSRR - 1200 +1200 ppm/V Supply Rejection Ratio D GND Voltage D GND 27 3.0 3.3 Vv voltages below Vpo A COM Voltage A COM 27 3.0 3.3 Vv Digital Input H Current lin Vin=Voo 1.0 pA Digital Input L Current Ie Vin=DGND 10 pA Input Leakage Current lea in=ACOM 10 1 +10 pA Beep Out Frequency facee fosc/16 Hz Voltage Mode Error ERR-V at voltage 400mV range -2 0 +2 counts Frequency Mode Error ERR-FRE at frequency mode 4 0 +4 | counts Continuity Check Vaiue cc at voltage mode 399 | counts Vin = 399 counts ! Low Battery Detection : Veat voltages above Vss 6.2 6.8 78 v | Voltage Serial Output Clock voltage mode fosc/4 ; | fsck ~ Hz . Frequency frequency mode fosc/2 iL - | SDATA Output H Voltage Vsox 0.5mA sourcing 2.5 y | SDATA Output L Voltage 1 Vso. 0.5mA sinking 0.5 | LCD Output H Voltage Vion 0.1mA sourcing 25; V LCD Output L Voltage Viot 0.1mA sinking | 0.5 | Beep Output H Voitage Veou 0.5mA sourcing 25 v | Beep Output L Voltage Veou 0.5mA sinking 0.5 | Annunciator Frequency fanny ' fosc/768 Hz 1 Note 4:Specifications are subject to change without notice. a ELECTRONICSKADO505 3 3/4-DIGIT 4000-COUNT A/D CONVERTER FUNCTIONAL DESCRIPTION 1. Analog Section Fig. 1. shows the Block Diagram of the Analog Section for the KADO505. Voltage measurement cycle is divided into three phases which are (1) Auto-zero{A-Z), (2) Signal integration(INT) and (3) Deintegration(DE). Crer Veer Vrer Veer IN+ OUT IN- TO DIGITAL SECTION COMPARATOR Fig. 1. Analog Section of KADOSO5 Dual-slope Conversion (negative input) Cint je) Time Rint Caz Vin O07 fA, Auto-zero (AZ) Vout VrerlN Oo0 Lage? DEINT, Roeint Input integration (INT) AZ A COM A COM Deintegration (DE) lt Fig. 2. Waveform and Block Diagram of Dual-slope A/D Converter (negative Input) Teble 1. Conversion Time Time Conversion time A-Z iNT DE fosc (A-Z+ INT + DE) 100ms 100ms 244.14ms 32.768KHz 444.14ms (1638counts) (1638counts) (4000counts)} 100ms 100ms 200ms 40KHz 400ms (2000counts) (2000counts) (4000counts) | en ELECTRONICSKADO505 3 3/4-DIGIT 4000-COUNT A/D CONVERTER (1) Auto-zero phase During auto-zero three things happen. First input high and low are disconnected from the pins and internally shorted to analog COM. 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 Caz 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 limitted only by the noise of the system. In any case, the offset referred to the input is less than 10yV. (2) 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 VIN+ and VIN fora fixed time. This differential voltage can be within a wide common mode range. If, on the other hand, the input signal has no return with respect to the converter power supply, VIN- can be tied to analog COM to establish the correct common mode voltage. At the end of this phase, the polarity of the integrated signal is determined. (3) De-integrate phase The final phase is de-integrate, or reference integrate. input low is internally connected to analog COM and input high is connected across the previously charged reference capacitor. The 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. Specially, in the case of fosc= 40KHz, Rint = 200k, Roewt = 400K2, Cinr = 0. 1uF, the digital reading displayed is Vin VaecrIN 4000 ( ) 2. Differential Input Differential voltages within the common-mode range of the input amplifier can be accepted by the input. Care must be exer- cised to ensure the integrator output does not saturate. For the large negative input signal, the integrator swing can be reduced to !ess than the full-scale swing with littte loss of accuracy. 3. Differential Reference the reference voltage can be generated anywhere within the power supply voltage 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 capacitance 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 deintegrate a negative input signal. This diference in reference for positive or negative input voltage will give a roll-over error. However, by selecting the reference capacitor such that it is large enough in comparison to the stray capacitance, this error can be held to less than 0.5 count worst case. 4. Analog Common (A COM) this pin is included primarily to set the common mode voltage for battery operation or for any system where the input signals are floating with respect to the power supply. the COMMON pin sets a voltage that is approximately 3.0 volts more negative than the positive supply. The on-chip CMOS bandgap voltage reference can be used without degradation in performance, as shown in Fig 3. In the case of using an external reference with good temperature coefficient, the temperature stability may be improved, as shown in Fig. 4. 44 ELECTRONICSKADOS505 3 3/4-DIGIT 4000-COUNT A/D CONVERTER Analog COMMON is also used as the input low return during auto-zero and de-integrate. If VIN- is different from analog COMMON, a common mode voltage exists in the system and is taken care of by the excellent CMRR of the converter. However, in some applications VIN- will be set at a fixed known voltage (power supply common for Instance). in this applica- tion, analog COMMON should be tied to the same point, thus removing the common mode voltage from the converter. The same holds true for the reference voltage. If reference can be conveniently tied to the analog COMMON, It should be since this removes the common mode voltage from the reference system. Vop Vop Vop Voo KADO505 KADOS5S05 6.8kN 1.28V VrerOUT VaerIN + 1.2V Reference VecelN + VaeriN 4 VaerIN A COM A COM Fig. 3. Using an On-chip Reference Fig. 4. Using an External Reference 5. Digital Section The digital section for the KADO505 is illustrated in Fig 5. The backplane(BP) frequency is the clock frequency divided by 768.For two and half readings/second this is a 52Hz square wave with a nominal amplitude of 3 volts. The segments are driven at the same frequency and amplitude. When a segment driver is in phase with the backplane signal the segment is OFF, but an out of phase segment drive signal causes the segment to be ON or visible. In all cases negligible DC voltage exists across the segments. The polarity indication is ON for negative analog inputs. If VIN+ and VINare reversed this indicator would be reversed giving a ON for positive analog inputs. Bo D-H wn no BE on A MH BP1,2,3 To Switch Drivers From Comparator Output Segment Output D GND Fig. 5. Digital Section of KADO505 45 ELECTRONICSKADO505 3 3/4-DIGIT 4000-COUNT A/D CONVERTER 6. System Timing The clocking circuit for the KADO505 shown in Fig 6. Three clocking methods can be used: 1. An R-C oscillator using all three pins. 2. An external oscillator connected to pin 22 3. A crystal between pins 22 and 23. The oscillator frequency is divided by two before it clocks the decade counters. It is then further divided to form the three convert-cycle phases, namely: signal integrate (2000counts), reference de-integrate (0 to 4000counts) and auto-zero (2000 counts). For 2.5 readings/second, an oscillator frequency of 40KHz would be used. The signal integration cycle should be a multiple of GOHz to achieve maximum rejection of 6OKHz pickup. Oscillator frequencies of 32.76KHz, 40KHz, 48KHz, 60KHz, 80KHz, 120KHz, 240KHz, etc. should be selected. For 50Hz rejection, oscillator frequencies of 40KHz, 50KHz, 667/3KHz, 100KHz, 200KHz, etc. would be suitable. Note that 40KHz (2.5 readings/second) will reject both 50 and 60Hz (also 400 and 440Hz). Fig. 6. Clock Circuits 7. Component Value Selection (1) Reference Capacitor For most applications, a 0.1uF capacitor is suitable. However, a larger value is needed to prevent roll-over error where a large common mode voltage exists (i.e. the VacriN- pin is not at analog common) and a 400mvV scale is used. {2) Auto-zero Capacitor the noise of the system is severely influenced by the auto-zero capacitor. For the all scale including 400mV scale, a 0.1F is adequate. (3) integrating Capacitor The integrating capacitor must be selected to ensure that the integrator will not saturate (at approximately 1V from positive supply). A nominal + 2V full-scale integrator swing is acceptable for the KADO505 when VIN-is connected to the analog common. The normal value for Cir is 0.1yF for either 32KHz or 40KHz clock. these values should be changed in inverse proportion to maintain the same output swing if different oscillator frequencies are used. The integrating capacitor must have a low dielectric absorption to minimize roll-over errors. Polypropylene capacitors give good performance for this application. (4) Integrating Resistor Both the integrator and the buffer amplifier are designed to have a class A output stages. They can supply 8yA drive currents with negligible non-linearity. The integrating resistor{Riw1) should have a large value enough to remain in the amplifier linear drive region over the entire input voltage range, but not so large that leakage currents on the printed circuits board induce undesirable errors. For 40KHz oscillation frequency, 200kN is recommended and 163.8kM for 32.768KHz. a ELECTRONICSKADO505 3 3/4-DIGIT 4000-COUNT A/D CONVERTER (5) De-integrating Resistor For alt ranges of oscillation frequency a 400kQ resistor is recommended for 2V full scale swing of integrator output. The de-integrating path is different way from that of the integrating. (6) Oscillator Components A 200k2. oscillation resistor (Rosc) is recommended for all ranges of frequency and the oscillation capacitor (Cosc) is selec- ted from the following equation: f= 045 osc = Rose Gos Cosc For 32.768KHz clock (2.3 readings/second), Cosc=68pF and for 40KHz clock (2.5 readings/second), Cosc = S6pF. (7) Reference Voltage Reaint Rie VaerIN = Vin tint toe where Veer IN:Reference input voltage (827.68mV for fosc=32.768KHz and 400mV for fosc =40KHz) Vin:Analog input voltage (400mvV to +400mvV) toe:De-integrating time tur:integrating time Riwintegrating resistor Roont:De-integrating resistor The resistors between the buffer amplifier and the integrator are two different values in which one is a integrating resistor and another is a de-integrating resistor. In some applications where the analog-to-digital converter is applied to a transducer, there will exist a scale factor other than unity between the analog input voltage and the desired digital reading. For example, ina thermometer system, the designer seems like to have a full scale reading when the transducer output voltage is 0.644V. The designer should apply the input voltage directly and adjust Vrer IN=0.644V. In this instance, suitable values for integra- ting resistor, de-integrating resistor, and capacitor would be 200kM, 400kN and 0.1uF. This can give a slightly quieter sys- tem and eliminate a extra divider network on the input. Another advantage is that the differential reference can be used when a digital reading of zero is desired for Viv *s. zero volts. This is a common event in temperature and weighing systems. By connecting the voltage transducer between VIN+ and A COM, and the variable (or fixed) offset voltage between VIN- and A COM, the offset reading can be conveniently generated. 8. Frequency Measurement In addition to serving as an analog-to-digital converter, the KADO505 internal counter can also have a auto-ranging freque- ncy counter function ranges from 4.000KHz to 4.000MHz. In the frequency measurement mode, periodic waveforms (pul- ses) at the FREQ input will be counted through the hysteresis comparator and displayed on the LCD. Under Peak Hold on, KADOS05 hold/dispiay the larger value of inputs compared with the perevious hold-on value up to OL in which range can not be changed to the next high step. The steps of range are as follows: up to 4.000kHz => OL => 40.00KHz => OL => 400.0KHz => OL => 4.000MHz => OL 47 ELECTRONICSKADOS505 3 3/4-DIGIT 4000-COUNT A/D CONVERTER 9. Function Selection The functions can be selected by using the four pins; V/F SEL(pin 41), TEST(pin 42), DHi(pin 45), PH(pin 46) Table 2. Function Selection (when TEST pin is floating) Pin Name Conditions Function Remark floating voltage mode V/F SEL (41) floating = internal pull-up to Vop low frequency mode DH (45) first toggle data hold on low =D GND level second toggle | data hold off high =Vpo level 1 first toggle : ak hold on PH (48) ogg) pe second toggle i peak hold off (1) Voltage Mode With external circult applications ac/dc voltage/current test, resistance test, diode test, continuity check etc. modes are available. (2) Peak Hold Peak Hold means to hold/display the absolutely larger value in the same polarity inputs in the voltage or frequency measure- ment mode compared with the previous hold-on value. Peak Hold in the first toggle allows the KADO505 to hold the highest A/D conversion readout, and the next toggle allows the KADO505 to hold off the previous readout. Under Peak Hold on, if the input is over 3999 counts, Over Load(OL) is displayed and if the next time the input goes down under over-load, the largest value in the previous measured values up to 3999 counts is displayed. During Peak Hold on if the states of DP1, DP2, V/F SEL are changed from low to high or high to low, the peak Hold function tums off. Under Peak Hold on, the beeper turns on whenever the input is below 400 counts irrespective of the display value. (3) Data Hoid In the V/F measurement mode, data Hold in the first toggle allows the KADO505 to hold the A/D conversion readout or frequency counter readout, and the next toggle allows the KADO505 to hold off the previous readout. During Data Hold on if the states of DP1, DP2, V/F SEL are changed from low to high or high to low, the Data Hold function turns off. Under Data Hold on in the voltage mode, the beeper turns on whenever the hold-readout is below 400 counts. Data Hold and Peak Hold can be used in the same time. 10. Decimal Point Table 3, Decimal Point Selection (When voltage mode) Conditions Position of LCD Display OP2 (Pin 48) DP1 (Pin 47) Decima! Point Oo ., 0 . _.. NA . 3999) 0 1 dpt (decimal point 1) 399.9 1 QO dp2 (decimal point 2) 39.99 1 1 dp3 (decimal! point 3) 3.999 *N/A:Not applicable <= ELECTRONICSKADOS05 3 3/4-DIGIT 4000-COUNT A/D CONVERTER 11. Serial Data Output ST J L 1 2 3 4 5 25 2 27 CK {} SDATA (Da XTX De X DX X ea X Dea X Cex DarX Ds) Table 4. CK Output Value Mode CK Remark Voltage mode fose/4 fosc =32.768 or 40KHz Frequency mode fosc/2 (1) Serial data output format De | Om Dor Obu Dis Dorz | Dor: | Das Dai Des | Deo | Dos | Doz | Dos Dio | Oss | Drs Deo | Des | Des Doo | a ELECTRONICSKADOS505 33/4-DIGIT 4000-COUNT A/D CONVERTER Table 5. Serial Data Output Symbol Data output Data Value Remark Dor 0 in range (O L display) 1 over range Dp 0 positive (voltage mode), MHz (frequency mode) (Polarity, KHz, MHz display) 1 negative (voltage mode), KHz (frequency mode) Don a 0 | Peak Holdoff : | (Data Hold) : 1 : ~ | Peak Holdon a Dow Data Hold off oT (Data Hold) 1 Data Hold on Dis 0 good battery (Low Battery) 1 low battery 00 not applicable Dopz, Dorr 01 dp1 (decimal point 1) (Decimal Point) 10 dp2 (decimal point 2) a 11 dp3 (decimal point 3) =sidt|tti<iis*s*Y _ 00 Fo OO Dar, Dao a 0 1 | - 1 _ _ (Thousands) 10 2 11 3 0000 QO 0001 1 - 0010 2 | Dxs, Dxz, Dx1, Dxo : 00 14 a 3 _ oO (Hundereds for X=B, 0100 | | 4 OO Tens for X=C, _ 01 o1 5 - : | Unities for X=D) 0110 6 __| 0111 7 1000 8 1001 9 - Z ELECTRONICS 50KADO505 3 3/4-DIGIT 4000-COUNT A/D CONVERTER 12. Liquid Crystal Display weaee +3V (Vpn) conse +2V eI es ---- DGNO | ue -Voo SEG ON | eo Csi DGND | . DGNO + % (Veg: OGND} SEG OFF f J | | TT L__i oo BEND . DGND 4 (Vg9- OGND) * feo = (lose / 128) / 6 = loge / 768 Fig 7. Triplex LCD Drive Waveform ar . ELECTRONICSKADO505 3 3/4-DIGIT 4000-COUNT A/D CONVERTER A aa ual e] lf C bebe het + MiKo _ q ' a | ym A Ea Cas oOCe > Oca OO MKHz Ip. Ip: Fig 8. LCD Display Tabie 6. Triplex LCD Segment Assignments KADO505 Pin No. LCD Pad No. BP1 BP2 BP3 1 27 BPI fl 26 BP2 ee ee er _ BP3 4 24 Hz K2 M2 5 13 cO bo 6 42 do go a0 7 "1 20 10 iF 8 10 dpt ct bi poe oe pe : 10 8 et A D-H _ Wo 7 | dp2sti(<dtt**~** bo wp..CUd a | "go a2 13 5 @2 2 P-H 14 4 dp3 c3 b3 15 7 3 pol( =) e3 a3, d3, g3 14 >) spe IS | 22 Eee ne. rs om po 17 a u- nn 18 poy SO 19 KI 7 20 M1 24 a 22 C J ~ pe to-go po _ 1 ee jo - 1 DC - eg 52KADO505 3 3/4-DIGIT 4000-COUNT A/D CONVERTER TYPICAL APPLICATION Fe 4OMOHM Al +e vi $00.0my tv] - RS 4M0HM =a v2 000v hw? + _J ava $F cox ae 7 . v3 4000v FP swe z _ > j Bis 2 Ra soKOHM rt 90K va 400 Ov eH TO Po 2,0 , | PARALLEL PORT * R2 4KOHM a v5 a000v 1 2 * 2 Ry 4000 OHea al R ow = 3 ta| Coss g g x RIN TEMP a . ELECTRONICS