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DIY Stompboxes => Building your own stompbox => Topic started by: phillip on January 22, 2004, 07:59:52 PM

Title: Testing ICs
Post by: phillip on January 22, 2004, 07:59:52 PM
Can anyone tell me how to test an IC in circuit to tell if it's functioning propely (without knowing the voltages that are supposed to be present on each pin)?  The IC in question is the BA728N, which in the DS-1 is a SIP8 package instead of the DIP8.  Here's the data sheet:

www.rohm.com/products/databook/standard/pdf/ba728.pdf

The schematic for this version looks that same as the one that I posted a while back, except the 1K resistor between +9V and pin 7 of the IC isn't there:

http://axiseffects.home.att.net/misc/DS1.gif

Here's what I'm getting:
Pin 8 = 8.79V (slightly weak battery)
Pin 7 = 0.7V (drops lower the longer the meter leads are touching it)
Pin 6 = 0.7V (drops lower the longer the meter leads are touching it)
Pin 5 = 0V
Pin 4 = 0V
Pin 3 = 4.33V
Pin 2 = 0V
Pin 1 = 0V

TIA
Phillip