MAX155EVKIT-DIP Maxim Integrated, MAX155EVKIT-DIP Datasheet - Page 8

• Manufacturer Part Number: MAX155EVKIT-DIP
• Description: Data Conversion IC Development Tools Evaluation Kit for the MAX155
• Manufacturer: Maxim Integrated
• Series: MAX155, MAX156r

This section assumes that the board communicates
correctly with the host computer. However, the read-
ings displayed by the MAX155 program do not corre-
late to the input voltages.
Use a DVM to read the MAX155 V
the voltage is not more negative than -4.5V, the prob-
lem is the MAX660, J4 has been cut, or the MAX155 is
defective. J4 can be cut to see if the MAX660 output
returns to -5V.
If the -5V is correct and readings are erroneous, check
the following:
MAX155 Evaluation Kit
8
Is pin 2 of the MAX233 an inverted 0 to 5V copy of
the signal on pin 5? If not, the MAX233 is faulty.
Is pin 3 of the MAX233 an inverted 0 to 5V copy of
the signal on pin 5? If so, the ROM or other parts of
the board are at fault.
If pin 3 is okay, check pin 4. Is it a -10V to +10V
inverted copy of the signal on pin 5? If not, the
cable, the PC port, or the MAX233 could be at fault.
Make sure the reference input voltage on pin 22 is
between 2.45V and 2.55V. If not, and J6 is intact, the
MAX155 is at fault.
Make sure the input voltage is correct. Use a DVM to
measure the input voltage while doing conversions.
The reading agrees (within 8-bits resoIution) as long
as the input voltage level is 0 to +2.5V. If not, the
MAX155 or the 74HCT245 is at fault.
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Conversion Problems
SS
Analog Section
-5V Power Supply
voltage on pin 6. If