Difference between revisions of "OPTOFAST"

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Line 48: Line 48:
 
* Common VCC in option
 
* Common VCC in option
 
* Install transistor Q1
 
* Install transistor Q1
−
* R1 = 150
 
−
** LED current is 3.5V/150 Ohms = 23 mA
 
−
** CTR = .20, 4.7 mA
 
−
* R2 = Do not populate
 
−
* R3 = 10K
 
−
** Base drive ~ (Vin - 0.7V)/R3
 
−
** At 5V drive this is 4.3V/R3
 
−
*** Using R3=10K at 5V this is 0.43mA Ib
 
−
*** HFE (MMBT3904) = 100 min
 
−
*** That is potentially 43 mA (in the switching range of the transistor)
 
−
**** Collector resistor and LED voltage drop are current limiter
 
−
** At 3.3V drive this is (3.3-0.7)/10K = .26mA Ib
 
−
*** HFE = 100 min
 
−
*** That is 26 mA (in the switching range of the transistor)
 
 
* H1 do not short
 
* H1 do not short
 +
 +
{| class="wikitable"
 +
! VCC(In)
 +
! 5.00
 +
! 3.30
 +
! V
 +
|-
 +
| R1
 +
| 180.00
 +
| 100.00
 +
| Ohms
 +
|-
 +
| Vf LED
 +
| 1.30
 +
| 1.30
 +
| V
 +
|-
 +
| V LED
 +
| 3.70
 +
| 2.00
 +
| V
 +
|-
 +
| Icc
 +
| 20.56
 +
| 20.00
 +
| mA
 +
|-
 +
| CTR
 +
| 0.20
 +
| 0.20
 +
| A/A
 +
|-
 +
| Iout
 +
| 4.11
 +
| 4.00
 +
| mA
 +
|-
 +
|}
  
 
=== Direct Drive - Special Option ===
 
=== Direct Drive - Special Option ===
Line 80: Line 104:
 
=== Standard Output ===
 
=== Standard Output ===
  
−
* R17 = 1.2K
+
* R17 = 2.2K
−
** 5V/1.2K = 4.1mA of output transistor B-E current
+
** 5V/2.2K = 2mA of output transistor B-E current
−
** Leaves 4.7-4.1 mA = 600 uA of output low current
+
** Leaves 4-2 mA = 2 mA of output low current
 +
 
 +
{| class="wikitable"
 +
! VCC(In)
 +
! 5.00
 +
! 3.30
 +
! V
 +
|-
 +
| Iout
 +
| 4.11
 +
| 4.00
 +
| mA
 +
|-
 +
| VCC (Out)
 +
| 5.00
 +
| 3.30
 +
| V
 +
|-
 +
| R17 (COLL)
 +
| 2200.00
 +
| 2200.00
 +
| Ohms
 +
|-
 +
| I COL
 +
| 2.27
 +
| 1.50
 +
| mA
 +
|-
 +
| Iol
 +
| 1.84
 +
| 2.50
 +
| mA
 +
|-
 +
| Ioh
 +
| 2.27
 +
| 1.50
 +
| mA
 +
|-
 +
|}
  
 
=== Open Collector Output - Special Option ===
 
=== Open Collector Output - Special Option ===
Line 148: Line 210:
  
 
=== Test Results===
 
=== Test Results===
−
* Channel Fast/Slow TransBuff/Direct Input Rise/Fall Time(uS)
+
{| class="wikitable"
−
1 Slow Transistor Buffer Fall 28.6
+
! Channel
−
1 Slow Transistor Buffer Rise 1.8
+
! Fast/Slow
−
2 Fast Transistor Buffer Fall 6.68
+
! TransBuff/Direct
−
2 Fast Transistor Buffer Rise 3.6
+
! Input Rise/Fall
−
3 Slow Direct Input Fall 1.84
+
! Time(uS)
−
3 Slow Direct Input Rise 27.4
+
|-
−
4 Fast Direct Input Fall 4.24
+
| 1
−
4 Fast Direct Input Rise 5.28
+
| Slow
−
</pre>
+
| Transistor Buffer
 +
| Fall
 +
| 28.6
 +
|-
 +
| 1
 +
| Slow
 +
| Transistor Buffer
 +
| Rise
 +
| 1.8
 +
|-
 +
| 2
 +
| Fast
 +
| Transistor Buffer
 +
| Fall
 +
| 6.68
 +
|-
 +
| 2
 +
| Fast
 +
| Transistor Buffer
 +
| Rise
 +
| 3.6
 +
|-
 +
| 3
 +
| Slow
 +
| Direct Input
 +
| Fall
 +
| 1.84
 +
|-
 +
| 3
 +
| Slow
 +
| Direct Input
 +
| Rise
 +
| 27.4
 +
|-
 +
| 4
 +
| Fast
 +
| Direct Input
 +
| Fall
 +
| 4.24
 +
|-
 +
| 4
 +
| Fast
 +
| Direct Input
 +
| Rise
 +
| 5.28
 +
|-
 +
|}
  
 
=== Ch1-Slow-NPNBuffer-InFall ===
 
=== Ch1-Slow-NPNBuffer-InFall ===
Line 178: Line 286:
  
 
=== Ch2-Fast-NPNBuffer-InRise ===
 
=== Ch2-Fast-NPNBuffer-InRise ===
 +
 +
* 3.6uS
  
 
[[File:Ch2-Fast-NPNBuffer-InRise.png]]
 
[[File:Ch2-Fast-NPNBuffer-InRise.png]]
  
 
=== Ch3-Slow-Direct-InFall ===
 
=== Ch3-Slow-Direct-InFall ===
 +
 +
* 1.84uS
  
 
[[File:Ch3-Slow-Direct-InFall.png]]
 
[[File:Ch3-Slow-Direct-InFall.png]]
  
 
=== Ch3-Slow-Direct-InRise ===
 
=== Ch3-Slow-Direct-InRise ===
 +
 +
* 27.4uS
  
 
[[File:Ch3-Slow-Direct-InRise.png]]
 
[[File:Ch3-Slow-Direct-InRise.png]]
  
 
=== Ch4-Fast-Direct-InFall ===
 
=== Ch4-Fast-Direct-InFall ===
 +
 +
* 4.24uS
  
 
[[File:Ch4-Fast-Direct-InFall.png]]]
 
[[File:Ch4-Fast-Direct-InFall.png]]]
  
 
=== Ch4-Fast-Direct-InRise ===
 
=== Ch4-Fast-Direct-InRise ===
 +
 +
* 5.28uS
  
 
[[File:Ch4-Fast-Direct-InRise.png]]
 
[[File:Ch4-Fast-Direct-InRise.png]]

Latest revision as of 20:55, 29 March 2023

Tindie-mediums.png

2017-01-28T19 42 37.589Z-OPTOFAST-P668-720px-act.jpg

OPTOFAST - 4 Channel Optocoupler Card

See our other Optocoupler cards

  • OPTOFAST-2 - Speed improved 4 channel optocoupler card - Suggested replacement for this card
  • OPTOSMALL - Four channel optocoupler card
  • OPTOOUT8-I2C - Eight channel optocoupler card - I2C interface
  • OPTOUSB - Optically coupled USB to FTDI interface
  • OPTOFASTBI - Two Optos in Two Directions

Features

  • Opto-Isolator card
  • 4-Channels
  • 4N25 Optoisolators
  • Input /Output isolation
  • Transistor driver for Opto LED reduces required drive from 10 mA to under 500 uA
  • Input channels share their own common VCC/Ground
  • Output channels share their own common Vcc/Ground
  • 8-pin header for input
  • 8-pin header for output
  • Configuration Options (Speed enhanced, Bypass Input transistors, Remove Output collector resistors)
  • 49x49mm
  • (4) 4-40 mounting holes

Schematic (One channel)

OPTOFAST-2-Schematic-TransIn.PNG

  • U1 represents U1-U4 (channels 1-4)
  • Q1 represents Q1-Q4 (channels 1-4)
  • R1 (VCC) represents R1,R4,R7,R10 (channels 1-4)
  • R2 (DIR) represents R2,R5,R8,R11 (channels 1-4)
  • R3 (BASE) represents R3,R6,R8,R12 (channels 1-4)
  • R13 (FAST) represents R13-R16 (channels 1-4)
  • R17 (COLL) represents R17-R20 (channels 1-4)

Input Options

  • Refer to schematic for impact of options

Use Input Transistor - Standard Option

  • Common VCC in option
  • Install transistor Q1
  • H1 do not short
VCC(In) 5.00 3.30 V
R1 180.00 100.00 Ohms
Vf LED 1.30 1.30 V
V LED 3.70 2.00 V
Icc 20.56 20.00 mA
CTR 0.20 0.20 A/A
Iout 4.11 4.00 mA

Direct Drive - Special Option

OPTOFAST-2-Schematic-Direct.PNG

  • Do not install Q1
  • Do not install R1
  • R2 = 150
    • Input current = LED current = 3.5V/150 Ohms = 23 mA
  • Do not install R3
  • Do not install Q1
  • Short H1

Output Options

Standard Output

  • R17 = 2.2K
    • 5V/2.2K = 2mA of output transistor B-E current
    • Leaves 4-2 mA = 2 mA of output low current
VCC(In) 5.00 3.30 V
Iout 4.11 4.00 mA
VCC (Out) 5.00 3.30 V
R17 (COLL) 2200.00 2200.00 Ohms
I COL 2.27 1.50 mA
Iol 1.84 2.50 mA
Ioh 2.27 1.50 mA

Open Collector Output - Special Option

  • Do not install R17

Fast Option - Standard

  • R13 = 20K (empirically determined from the scope eye)

Connectors

P1 - Input

8-pin, right angle, 0.1" pitch

  1. Vcc (In)
  2. Vcc (In)
  3. IN 1
  4. IN 2
  5. IN 3
  6. IN 4
  7. GND (In)
  8. GND (In)

P2 - Output

8-pin, right angle, 0.1" pitch

  1. Vcc (Out)
  2. Vcc (Out)
  3. OUT 1
  4. OUT 2
  5. OUT 3
  6. OUT 4
  7. GND (Out)
  8. GND (Out)

Test Card Measurements

OptoFast-TestSetup-720px.jpg

Setup

  • Goal was to determine the performance of the OPTOFAST card
  • 5V operation
  • Same 5V input/output power supply
  • Each of the channels were configured uniquely/individually
  • MHS-5200A - Digital DDS Dual-channel Signal Generator
    • 1 KHz square wave
    • 5V signal level
  • Single channel checked at a time
  • Oscilloscope
    • Rigol DS1054Z
    • 50 MHz
    • Ultra Sigma software used for screen captures

Notes

  • Note that the input buffer transistor inverts the signal
  • Built a card that has four different configurations
  • Options
    • Fast/Slow
    • Direct drive input LED/Transistor Buffered input

Test Results

Channel Fast/Slow TransBuff/Direct Input Rise/Fall Time(uS)
1 Slow Transistor Buffer Fall 28.6
1 Slow Transistor Buffer Rise 1.8
2 Fast Transistor Buffer Fall 6.68
2 Fast Transistor Buffer Rise 3.6
3 Slow Direct Input Fall 1.84
3 Slow Direct Input Rise 27.4
4 Fast Direct Input Fall 4.24
4 Fast Direct Input Rise 5.28

Ch1-Slow-NPNBuffer-InFall

  • 28.6uS

Ch1-Slow-NPNBuffer-InFall.png

Ch1-Slow-NPNBuffer-InRise

  • 1.8uS

Ch1-Slow-NPNBuffer-InRise.png

Ch2-Fast-NPNBuffer-InFall

  • 6.68uS

Ch2-Fast-NPNBuffer-InFall.png

Ch2-Fast-NPNBuffer-InRise

  • 3.6uS

Ch2-Fast-NPNBuffer-InRise.png

Ch3-Slow-Direct-InFall

  • 1.84uS

Ch3-Slow-Direct-InFall.png

Ch3-Slow-Direct-InRise

  • 27.4uS

Ch3-Slow-Direct-InRise.png

Ch4-Fast-Direct-InFall

  • 4.24uS

Ch4-Fast-Direct-InFall.png]

Ch4-Fast-Direct-InRise

  • 5.28uS

Ch4-Fast-Direct-InRise.png

Layout

2017-01-28T19 34 38.489Z-OptoFast-Layout-720px.png

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