CNT7 ABCIRCUITS | Alldatasheet

Document overview

  • Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
  • PDF pages: 7

Technical content

Features

  • Counter drives two seven s egment non multiplexed displays .
  • Up or down counter.
  • Mechanical or electronic inp uts.
  • Few external parts required.
  • Low power consumption 5 mA typical.
  • Supply voltage 3.3 to 5.25 volts.
  • On chip input pull up resistors.
  • Output polarity select .
  • TTL and CMOS compatible.
  • Part is in full production.
  • SOIC and DIP 28 Pin Package.
  • ROHS Complian t
  • Low EMI

Applications

  • Data Displays
  • Large display control
  • Numeric Displays
  • Controls

Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 Part Number CNT7 Copyright © 2014 ABCircuits. Revised September 2014 Page 2 of 7 Example Circuit LEFT COMMON ANODE DISPLAYVCC VCC CLEAR COUNT CNT7 214 SEGRA NC SEGRC SEGRE SEGRG NC CLK SEGLF SEGLD SEGLB CB SEGRF SEGRB VSS SEGLE SEGRD SEGLA SEGLG VDD SEGLCNC DEB CLR- NC UP SW- NC POL VCC RIGHT COMMON ANODE DISPLAY A B C D E F G G F E D C B A COM A B C D E F G G F E D C B A COM Connection Diagram CNT7 5 24 SEGRA NC SEGRC SEGRE SEGRG NC CLK SEGLF SEGLD SEGLB CB SEGRF SEGRB VSS SEGLE SEGRD SEGLA SEGLG VDD SEGLC NC DEB CLR- NC UP SW- NC POL Pin Description Pin # Description Pin # Description

1 DEB 28 VDD

2 CLR- 27 POL

3 CLK 26 NC

4 NC 25 SW-

5 NC 24 UP

6 SEGLF 23 SEGLG

7 SEGLD 22 SEGLE

8 SEGLB 21 SEGLC

9 NC 20 SEGLA

10 CB 19 NC

11 SEGRF 18 SEGRG

12 SEGRD 17 SEGRE

13 SEGRB 16 SEGRC

14 VSS 15 SEGRA

Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 Part Number CNT7 Copyright © 2014 ABCircuits. Revised September 2014 Page 3 of 7 POL Polarity input. If this pin is open or high, the “on” segments will have a high level on the SEG outputs of the chip. If this pin is low or grounded “on” segments will output as a low on the SEG pins. This pin is read once at power up and has a built in pull up resistor. UP This input signal determines count direction, up or down. If this input is open or high, the counter will count up. If this input is grounded or low, the counter will count down. This input is read once at power up and has a built in pull up resistor. CLR- This input clears the counters when low. If the counter is in the up mode, the counter clears to 00. If the counter is in the down mode, the counter clears to 99. CLR is a software derived function, and as such requires 1 mS of minimum input pulse width. This input has a built in pull up resistor. SW- SW- and DEB form an optional switch de -bounce circuit. This input would be tied to a switch to ground. An internal pull up resistor is provided. DEB This is the inverted output of the switch de -bounce circuit, which may be tied directly to the CLK input if your design uses a mechanical switch. De -bounce time is about 37 mS, limiting input speed to about 13 clocks per second. The output is push pull. CLK This is the input to the two hardware decade counters. On the positive edge of this input, the counter increments the counters in UP mode; or decrements the counters in down mode . This input does not have a pull up resistor . Maximum clock frequency is 12 MHz. CB This is the counters carry/borrow output. This signal ties to the clock of the next IC in the chain . The output is push pull. SEGRA, SEGRB, SEGRC, SEGRD, SEGRE, SEGRF, SEGRG SEGLA, SEGLB, SEGLC, SEGLD, SEGLE, SEGLF, SEGLG SEGR is the right hand of the two displays. SEGL is the left hand of the two displays If the POL pin is open or hi, this SEG outputs will be high when a segment is on. If the POL pin is low or grounded, the SEG outputs will be low when a segment is on. These are the seven segment outputs to each individual display An external driver or current limiting resistor is required for each segment. If you are using only a resistor, it must be sized to limit source current to 5 mA maximum per pin or sink current to 9 mA per pin. See also the segment table, and the ASCII to seven segment translation table. VSS Connect to system ground .

Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 Part Number CNT7 Copyright © 2014 ABCircuits. Revised September 2014 Page 4 of 7 VDD Connect to supply voltage of 3.3 to 5 volts. A .1 uF decoupling capacitor to ground is recommended. NOTES: Make no connection to the NC pins . Pins 9 and 19 must be left unconnected . Segment Identification Table Seven Segment Translation Table

Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 Part Number CNT7 Copyright © 2014 ABCircuits. Revised September 2014 Page 5 of 7 Using Drivers For Brighter Displays CLEAR LEFT COMMON ANODE DISPLAY A B C D E F G G F E D C B A COM ULN2804 17IN1 IN2 IN3 IN4 IN5 IN6 IN7 IN8 COM OUT8 OUT7 OUT6 OUT5 OUT4 OUT3GND OUT1 OUT2 VCC ULN2804 17IN1 IN2 IN3 IN4 IN5 IN6 IN7 IN8 COMOUT8 OUT7 OUT6 OUT5 OUT4 OUT3 GND OUT1 OUT2 VCC VCC VCC CNT7 214 SEGRA NC SEGRC SEGRE SEGRG NC CLK SEGLF SEGLD SEGLB CB SEGRF SEGRB VSS SEGLE SEGRD SEGLA SEGLG VDD SEGLCNC DEB CLR- NC UP SW- NC POL RIGHT COMMON ANODE DISPLAY A B C D E F G G F E D C B A COM COUNT VCC Counter Expansion Example DISPLAY IN DISPLAY IN DISPLAY IN DISPLAY EXPANSION EXAMPLE CNT7

3 SEGR

Symbol Description Min Typical Max Units Notes Tstg Storage Temperature -55 25 +100 ºC Ta Operating Temperature -40 +85 ºC Vdd Vdd - Vss Voltage -0.5 +6.0 V Vio Input Voltage Vss - 0.5 Vdd +0.5 V Imio Maximum current into any pin -25 +50 mA ESD Electrostatic Discharge Voltage 2000 V Human Body Model ESD LU Latch up current 200 mA

Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 Part Number CNT7 Copyright © 2014 ABCircuits. Revised September 2014 Page 6 of 7 Symbol Description Min Typical Max Units Notes Vdd Supply Voltage 3.3 5.25 V Idd Supply Current 5 8 mA Note 1 Voh High Output Level Vdd - 1.0 V Note 2 Vol Low Output Voltage 0.75 V Note 3 Vih Input High Level 2.1 V Vil Input Low Level 0.8 V Ioh High Level Source Current 10 mA Note 2 Iol Low Level Sink Current 25 mA Note 3 Cio Capacitive load 3.5 10 pF Iil Input leakage 1 nA Rpu Pull Up Resistors On Inputs 4 5.6 8 k? Note 1: Vdd=5VDC, all inputs and outputs open Note 2 Ioh=10 mA max per pin, 80 mA maximum all pins combined Note 3 Iol=25 mA max per pin 150 mA maximum all pins combined Theory Of Operation The CNT7 IC is a custom programmed microprocessor designed t o monitor a hardware counter and display the results. Clear, output polarity and up/down modes are provided as internal software functions. A separate input debouncing function and input/ output pins are provided to minimize additional components.

Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 Part Number CNT7 Copyright © 2014 ABCircuits. Revised September 2014 Page 7 of 7 Physical Dimensions SOIC-28 Physical Dimensions 28 Pin Dip Package (-DIP Suffix) Close but not quite? Our products are software based, we can modify existing parts to fit your needs at a minimal cost or create new parts designed to your specifications. Em ail us and we can make a chip for you! For the latest version of this spec sheet, visit www.abcircuits.com Design Services Available We can quickly turn your idea into a chip, a pc board, or a finished product. Contact us with your needs and specifications.