Electronic Components Datasheet Search |
|
TC7136ACPL Datasheet(PDF) 8 Page - TelCom Semiconductor, Inc |
|
TC7136ACPL Datasheet(HTML) 8 Page - TelCom Semiconductor, Inc |
8 / 12 page 3-254 TELCOM SEMICONDUCTOR, INC. TC7136 TC7136A LOW POWER, 3-1/2 DIGIT ANALOG-TO-DIGITAL CONVERTERS Figure 4. Conversion Timing During Normal Operation System Timing The oscillator frequency is divided by 4 prior to clocking the internal decade counters. The four-phase measure- ment cycle takes a total of 4000 counts, or 16,000 clock Figure 5. Conversion Timing During Overrange Operation DIGITAL SECTION The TC7136/A contains all the segment drivers neces- sary to directly drive a 3-1/2 digit LCD. An LCD backplane driver is included. The backplane frequency is the external clock frequency divided by 800. For three conversions per second the backplane frequency is 60 Hz with a 5V nominal amplitude. When a segment driver is in-phase with the backplane signal, the segment is OFF. An out-of-phase segment drive signal causes the segment to be ON, or visible. This AC drive configuration results in negligible DC voltage across each LCD segment, ensuring long LCD life. The polarity segment driver is ON for negative analog inputs. If VIN + and V IN – are reversed, this indicator would reverse. On the TC7136/A, when the TEST pin is pulled to V+, all segments are turned ON. The display reads –1888. During this mode the LCD segments have a constant DC voltage impressed. DO NOT LEAVE THE DISPLAY IN THIS MODE FOR MORE THAN SEVERAL MINUTES. LCDS MAY BE DESTROYED IF OPERATED WITH DC LEVELS FOR EXTENDED PERIODS. The display font and segment drive assignment are shown in Figure 6. pulses. The 4000-count cycle is independent of input signal magnitude. Each phase of the measurement cycle has the following length: (1) Auto-zero phase: 3000 to 2900 counts (1200 to 11,600 clock pulses) (2) Signal integrate: 1000 counts (4000 clock pulses) This time period is fixed. The integration period is: tSI = 4000 , where fOSC is the externally-set clock frequency. (3) Reference integrate: 0 to 2000 counts (4) Zero integrator: 11 to 640 counts The TC7136 is a drop-in replacement for the TC7126 and ICL7126. The TC7136A offers a greatly-improved inter- nal reference temperature coefficient. Minor component value changes are required to upgrade existing designs and improve the noise performance. COMPONENT VALUE SELECTION Auto-Zero Capacitor (CAZ) The CAZ capacitor size has some influence on system noise. A 0.47 µF capacitor is recommended for 200 mV full- scale applications where 1 LSB is 100 µV. A 0.1 µF capacitor is adequate for 2V full-scale applications. A Mylar-type dielectric capacitor is adequate. Reference Voltage Capacitor (CREF) The reference voltage, used to ramp the integrator Figure 6. Display FONT and Segment Assignment 1 fOSC INT DENT ZI AZ 4000 910–2900 1–2000 1000 11–140 AZ 4000 ZI DEINT INT 1000 2001–2090 31–640 300–910 DISPLAY FONT 1000's 100's 10's 1's |
Similar Part No. - TC7136ACPL |
|
Similar Description - TC7136ACPL |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |