tc835 Microchip Technology Inc., tc835 Datasheet
tc835
Available stocks
Related parts for tc835
tc835 Summary of contents
Page 1
... PB3 Channel Selection © 2007 Microchip Technology Inc. General Description The TC835 is a low power, 4-1/2 digit (0.005% resolution), BCD analog-to-digital converter (ADC) that has been characterized for 200 kHz clock rate operation. The five conversions per second rate is nearly twice as fast as the ICL7135 or TC7135. The ...
Page 2
... REF CAP+ 6 TC835CKW –INPUT 7 +INPUT 64-Pin MQFP TC835CBU RUN/HOLD 30 DGND 29 POLARITY 28 CLK IN 27 BUSY 26 D1 (LSD) ...
Page 3
... Test circuit shown in Figure 6-7. 10: Specification related to clock frequency range over which the TC835 correctly performs its various functions. Increased errors result at higher operating frequencies. © 2007 Microchip Technology Inc. † Stresses above those listed under "Absolute Maximum Rat- ings" may cause permanent damage to the device. These are ...
Page 4
... Error of reading from best fit straight line 1.9959 Test circuit shown in Figure 6-7. 10: Specification related to clock frequency range over which the TC835 correctly performs its various functions. Increased errors result at higher operating frequencies. DS21478C-page 4 = +25° 200 kHz +5V -5V. A CLOCK Sym Min Typ Max ...
Page 5
... Over range output. A logic High indicates that the analog input exceeds the full scale input range. 28 UNDERRANGE Under range output. A logic High indicates that the analog input is less than 9% of the full scale input range. © 2007 Microchip Technology Inc. Table 2-1. Description TC835 DS21478C-page 5 ...
Page 6
... Integrate Time FIGURE 3-1: 3.2 Operational Theory The TC835 incorporates a system zero phase and integrator output voltage zero phase to the normal two phase dual slope measurement cycle. Reduced system errors, fewer calibration steps and a shorter overrange recovery time result. The TC835 measurement cycle contains four phases: ...
Page 7
... System Zero Phase. 3.2.2 ANALOG INPUT SIGNAL INTEGRATION The TC835 integrates the differential voltage between the +INPUT and -INPUT pins. The differential voltage must be within the device Common mode range (-1V from either supply rail, typically). The input signal polar- ity is determined at the end of this phase (see Figure 3-3) ...
Page 8
... ANALOG SECTION FUNCTIONAL DESCRIPTION 4.1 Differential Inputs The TC835 operates with differential voltages within the input amplifier Common mode range. The input amplifier Common mode range extends from 0.5V below the positive supply to 1V above the negative supply. Within this Common mode voltage range, an 86dB Common mode rejection ratio is typical ...
Page 9
... DIGITAL SECTION FUNCTIONAL DESCRIPTION The major digital subsystems within the TC835 are illustrated in Figure 5-1, with timing relationships shown in Figure 5-2. The multiplexed BCD output data can be displayed on LCD or LED. The digital section is best described through a discussion of the control sig- nals and data outputs. ...
Page 10
... Outputs. 5.1 RUN/HOLD Input When left open, this pin assumes a logic "1" level. With a RUN/HOLD = 1, the TC835 performs conversions continuously, with a new measurement cycle beginning every 40,002 clock pulses. When RUN/HOLD changes to a logic "0," the measure- ment cycle in progress will be completed, and data held and displayed as long as the logic " ...
Page 11
... The POLARITY bit is valid even for a zero reading. Signals less than the converter's LSB will have the signal polarity determined correctly. This is useful in null applications. © 2007 Microchip Technology Inc. TC835 5.7 Digit Drive Outputs Digit drive signals are positive going signals. The scan sequence ...
Page 12
... TC835 6.0 TYPICAL APPLICATIONS 6.1 Component Value Selection The integrating resistor is determined by the full-scale input voltage and the output current of the buffer used to charge the integrator capacitor. Both the buffer amplifier and the integrator have a class A output stage, with 100 µA of quiescent current µA drive current gives negligible linearity errors. Values of 5 µ ...
Page 13
... EQUATION 6-3: Clock Frequency (Hz) Reading 1/sec = 4000 6.3 Power Supplies and Grounds 6.3.1 POWER SUPPLIES The TC835 is designed to work from ±5V supplies. For single +5V operation, a ICL7135 can provide a –5V supply. 6.3.2 GROUNDING Systems should use separate digital and analog ground systems to avoid loss of accuracy. 6.4 High-Speed Operation ...
Page 14
... TC835 INT OUT 1 µF 0.33 µ BUFF OUT 100 kΩ TC835 22 F 200 kHz IN 100 kΩ +INPUT Analog 1 µF 9 Input –INPUT – 3 ANALOG COMMON REF V– 100 kΩ FIGURE 6-3: 4-1/2 Digit ADC Multiplexed Common Anode LED Display. ...
Page 15
... CLOCK REF 1 µF 8 BUSY C + REF 9 -INPUT (LSD +INPUT (MSD (LSB) (MSB TC835 10 9 150Ω MC14513 + Clock Input 120 kHz ...
Page 16
... In the event the full Microchip part number cannot be marked on one line, it will be carried over to the next line, thus limiting the number of available characters for customer-specific information. DS21478C-page 16 Example TC835CPI^^ 0741256 *h Example: M TC835CKW e ^^0741256 3 Example: M TC835CBU 0741256 © 2007 Microchip Technology Inc. ...
Page 17
... N NOTE © 2007 Microchip Technology Inc TC835 c DS21478C-page 17 ...
Page 18
... TC835 NOTE β DS21478C-page NOTE 2 φ α A2 © 2007 Microchip Technology Inc. ...
Page 19
... NOTE β © 2007 Microchip Technology Inc NOTE 2 A φ TC835 α A2 DS21478C-page 19 ...
Page 20
... TC835 DS21478C-page 20 © 2007 Microchip Technology Inc. ...
Page 21
... Updates package marking information for pb- free markings. 3. Updated package outline drawings and added landing pattern to applicable package outline drawing. Revision B (May 2002) The following is the list of modifications: 1. Undocumented changes Revision A (April 2002) • Original Release of this Document. © 2007 Microchip Technology Inc. TC835 DS21478C-page 21 ...
Page 22
... TC835 NOTES: DS21478C-page 22 © 2007 Microchip Technology Inc. ...
Page 23
... To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office PART NO. X /XX Device Temperature Package Range Device TC835: 4-1/2 Digit BCD A/D for PC Data Acq. Temperature Range C = 0°C to +70°C Package PI = Plastic DIP, (600 mil Body), 28-lead KW = Plastic Metric Quad Flatpack, (MQFP), 44-lead ...
Page 24
... TC835 NOTES: DS21478C-page 24 © 2007 Microchip Technology Inc. ...
Page 25
... Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights. © 2007 Microchip Technology Inc. Trademarks The Microchip name and logo, the Microchip logo, Accuron, dsPIC, K ...
Page 26
... Taiwan - Kaohsiung Tel: 886-7-536-4818 Fax: 886-7-536-4803 Taiwan - Taipei Tel: 886-2-2500-6610 Fax: 886-2-2508-0102 Thailand - Bangkok Tel: 66-2-694-1351 Fax: 66-2-694-1350 © 2007 Microchip Technology Inc. EUROPE Austria - Wels Tel: 43-7242-2244-39 Fax: 43-7242-2244-393 Denmark - Copenhagen Tel: 45-4450-2828 Fax: 45-4485-2829 France - Paris ...