ES5107

ES5107 CYRUSTEK | Alldatasheet

Document overview

• Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
• PDF pages: 20

Technical content

3 1/2 DIGIT A/D CONVERTER W/LED I、GENERL DESCRIPTION The ES5107 is a low power CMOS 3 1/2 digit A/D converter With LED display drivers. The single chip ES5107 provides all the necessary active devices which cont ain the internal clock. voltage reference. seven-segm ent decoders, LED display drivers. The improved internal zene r reference voltage circuit gives the analog common a small temperature coefficient of 60 ppm/℃ typically. The high accuracy characteristics of the ES5107 perform very low linearity error and rollover error. The high input impedance(>10 12Ω) and low input leakage current (1pA typical)give the ES5107 a good application in the field of high im pedance circuit measurement. The differential input and reference are suitable for measuring bridge transducer or ohms by using ratio-metric method. The dual slope conversion t echnique makes the ES5107 a good normal mode and common mode re jection ratio. With a suitable oscillator frequency. th e ES5107 has a high rejection of 50Hz, 60Hz and 400Hz line frequency noise. With a set of LED display a nd a few resistors and capacitors ES5107 can be built as a high perfo rmance panel meter. Existing ICL7107 based systems may be upgraded without changing external passive component values. II、FEATURES *Guaranteed zero reading with zero input. *Low input leakage current (1pA typical) *Internal Reference with low temperature drift (60ppm/℃ typical)

3 1/2 DIGIT A/D CONVERTER W/LED *Low noise(15µ Vp-p typical) *Direct LED display drive-no external components required *Differential input and voltage reference *Internal clock circuit III、APPLICATTONS *Digital panel meters *Digital multimeters *Thermometers *Capacitance meters *pH meters *Photometers

3 1/2 DIGIT A/D CONVERTER W/LED IV、PIN ASSIGNMENT

3 1/2 DIGIT A/D CONVERTER W/LED V、BLOCK DIAGRAM

3 1/2 DIGIT A/D CONVERTER W/LED VI、ABSOLUTE MAXIMUM RATINGS Characteristic Rating Supply Voltage V+ V - +6V -6V Analog Input Voltage(either input) V+ to V- Reference Input Voltage(either input) V+ to V- Clock Input GND to V+ Power Dissipation(plastic package) 800 mW Operating Temperatuer 0℃ to +70 ℃ Storage Temperature -65℃ to +160 ℃ Lead Temperature(Soldering, 10 sec) 270℃

3 1/2 DIGIT A/D CONVERTER W/LED VII、ELECTRICAL CHARACTERISTICS At V+ = +5V，V- = -5V，feocx = 48KHz，TA = 25℃ Characteristic Test Conditions Min Typ. Max Units Zero Input Reading V IN = OV Full Scale = 200mV -000.0 ±000.0 +000.0 Digital Reading Ratio-metric Reading V IN = VREF VREF = 100mV 999 999/1000 1000 Digital Reading Linearity Full Scale = 200mV or 2V -1 ±0.2 +1 Counts Rollover Error -VIN = +VIN ≅ 200mV -1 ±0.2 +1 Counts Common Mode Rejection Ratio VCM = ±1V,VIN = OV Full Scale = 200mV -5 0 - µV/V Noise (PK-PK Value not exceeded 95% of time) VIN = OV Full Scale = 200mV -1 5 - µVP-P Input Leakage Current VIN = OV - 1 10 pA Analog COMMON Voltage 25KΩ between Common and V+ 2.8 3.0 3.2 V Analog COMMON Temperature Coefficient 25KΩ between Common and V+ O℃≤T A≤70℃ -6 0 7 5 ppm/℃ Scale Factor Temperature Coefficient V IN = 199mV O℃≤TA≤70℃Ext. Ref. Oppm/℃ -6 0 7 5 ppm/℃ Zero Reading Drift VIN = OV O℃≤TA≤70℃ -0 . 2 1 µV/℃ Segment Sinking Current (except Pin 19) (include Pin 19) V+ = 5V Segment Voltage = 3V mA mA V+ Supply Current (not include LED current) V IN = OV - 0.5 0.65 mA V- Supply Current - 0.5 0.65 mA

3 1/2 DIGIT A/D CONVERTER W/LED

3 1/2 DIGIT A/D CONVERTER W/LED D、APPLICATION CIRCUITS A、Internal Reference:The analog COMMON voltage is used as reference voltage. Values here are for 2.0000V full-scale.

3 1/2 DIGIT A/D CONVERTER W/LED B、External Band-Gap Reference: A band-gap reference of 1.2V type is used to set up a high temperature stability voltage reference.

3 1/2 DIGIT A/D CONVERTER W/LED C、Zener Diode Reference: A low TC zener diode is used to set up the low temperature drift reference voltage.

3 1/2 DIGIT A/D CONVERTER W/LED D、Measuring Ratio-metric Values of Quad Load Cell.

3 1/2 DIGIT A/D CONVERTER W/LED X、PCB LAYOUT A、Board Back

3 1/2 DIGIT A/D CONVERTER W/LED B、Board Component Side.

3 1/2 DIGIT A/D CONVERTER W/LED XI、NOTES FOR APPLICATION A、Analog COMMON The COMMON pin is used to set the common-mode voltage for the system in which the input signals ar e floating with respect to the power supply of the ES5107. In all most of th e applications, IN LO, REF LO and COMMON Pins are tied to the same poi nt, so that the common mode voltage can be removed from the reference system and the converter. In some applications, IN LO may not at the same point with COMMON and thus a common mode voltage exists in the system the high CMRR(86dB typical )of the ES5107 can take care of this co mmon mode voltage. Nevertheless, it should be care to prevent the output of the integrator from saturation. The COMMON pin is also used as a vol tage reference. It sets a voltage, which is around 2.9 volts more negati ve than the positive supply. The COMMON voltage of ES5107 has a 0.001%/% voltage coefficient and a low output impedance of 15Ω typical. The analog COMMON is tied internally to an N channel FET capable of sinking 30mA. This FET will hold the COMMON voltage at 2.9 volts when an external load attempt to pull th e COMMON voltage toward the positive supply. The source current of COMMON is only 10 µA, so it is easy to pull COMMON voltage to a more negative voltage with respect to the positive supply.

3 1/2 DIGIT A/D CONVERTER W/LED When the total supply voltage is large enough to cause the zener to regulate(>7V), the COMMON voltage will have a low temperature coefficient typically less than 60 ppm/℃ This voltage can be used to gene rate the ES5107 reference voltage and an external voltage reference will be unnecessary in most cases. B、Reference Voltage For a 1000 counts reading. the input signal must be equal to the reference voltage. So for a 2000 counts full scale reading, it requires the input signal be twice the reference voltage. Thus for the 200.0mV and 2.000V full scale, the reference voltage should equal 100.0mV and 1.000V In some applications the full-sca le input voltage may be other than 200mV or 2V but 600mV, for example. The reference voltage should be set to 300mV and the input signal can be used directly without being divided. The differential reference can be used during the measurement of resistor by the ratio-metric method a nd when a digital reading of zero is desired for VIN ≠0.A compensating offset voltage can be applied between COMMON and IN LO and the voltage of being measured is connected bet ween COMMON and IN HI. C、System Timing The oscillator frequency is divided by four prior to clocking the internal decade counters. The signal integrate takes a fixed 1000 counts time period which is equal to 4000 clock pulses.

3 1/2 DIGIT A/D CONVERTER W/LED To make a maximum rejection of lin e frequency (60 HZ or 50HZ) noise pickcup, the signal integrate period should be a multiple of the line frequency period. For 60Hz noise rejection, oscill ator frequencies of 120KHz, 80Khz, 60KHz, 48KHz, 40KHz etc. should be selected. For 50Hz rejection, oscillator frequencies of 100KKz , 40KHz, etc. would be suitable. For all ranges of frequency Rosc should be 100K Ω Cosc is selected from the approximate equation f=0.45/RC For 48KHz clock (3 readings/second), Cosc = 100pF. D、Integrating Resistor The input buffer amplifier and integrat or both have a class A output stage with 100 µA of quiescent current and can supply 20 µA drive currents with negligible linearity errors. The integrati ng resistor should be chosen to remain in the output stage linear drive region. It s hould be noticed that the integrating resistor should not be so large such that the leakage currents of printed circuit board will induce errors. For a 200mV fu ll-scale the recommended integrating resistor value is 47KΩ and for 2V full scale is 470KΩ. E、Integrating Capacitor The integrating capacitor s hould be selected to maximize integrator output voltage swing without causing output saturation. If the analog COMMON is used as voltage reference a ±2V full-scale integrator out put swing is satisfactory For 3 readings/second)48Khz clock)a 0.22µF value of CINT is suggested. When different oscillator frequencies are used

3 1/2 DIGIT A/D CONVERTER W/LED CINT must be changed in inverse pr oportion to maintain the nominal ±2V integrator swing. The integrating capacitor s hould have low dielectric absorption to minimize roll-over error. An inexpensive polypropylene capacitor will work well. F、Auto-Zero Capacitor The auto-zero capacitor size has some influence on system noise. A 0.47 µF capacitor is recommended for 200mV full scale where noise is very important. A 0.047µF capacitor is adequate for 2V full scale applications. A mylar type dielectric capacitor is adequate. G、Reference Voltage Capacitor When IN LO is tied to analog COMMON, a 0.1 µF capacitor is adequate to be the reference capacitor. If a large common mode voltage exists and the application require a 200mV fu ll scale a larger value is required to prevent roll over error A1.0µF capacitor will hold the roll-over error to 0.5 count. H、Test The TEST pin is tied to the internal negative logic supply through a 500 Ω resistor. When TEST is pulled high all segm ents will be turned on and the display should read -1888.

3 1/2 DIGIT A/D CONVERTER W/LED XII、PHYSICAL DIMENSION

3 1/2 DIGIT A/D CONVERTER W/LED ㆒、ES5170Q PIN CONFIGURATION

3 1/2 DIGIT A/D CONVERTER W/LED ㆓、ES5107Q-PACKAGE