ame7106 AME, Inc., ame7106 Datasheet - Page 14

• Manufacturer Part Number: ame7106
• Description: 3-1/2 Digit A/d Converter High Accuracy, Low Power
• Manufacturer: AME, Inc.

mA X 3.2 V X 24 segments = 622mW. However, once the
AME7107 output voltage is above two volts, the LED cur-
rent is essentially constant as output voltage increases.
Reducing the output voltage by 0.7V, results in 7.7mA of
LED current, only a 5 percent reduction. Maximum power
dissipation is only 7.7mA X 2.5V X 24 = 462 mW, a re-
duction of 26%. An output voltage reduction of 1 volt re-
duces LED current by 10% (7.3mA) power dissipation by
38%. (7.3mA X 2.2V X 24 = 385mW).
either a 5.1 ohm resistor or a 1 Amp diode placed in
series with the display (but not in series with the
AME7107). The resistor will reduce the AME7107 output
voltage, when all 24 segments are “ ON” . When seg-
ments turn off, the output voltage will increase. The di-
ode, on the other hand, will result in a relatively steady
output voltage.
resistor reduces the change in power dissipation as the
display changes. As fewer segments are “ ON” each
“ ON” output drops more voltage and current. For the
best case of six segments (a “ 111” display) to worst
case (a “ 1888” display) the resistor will change about
230 mW. While a circuit without the resistor will change
about 470 mW. Therefore, the resistor will reduce the
variation of power dissipation by about 50%.
is almost unnoticeable as more segments turn off. If
steady display brightness is very important, a diode is
recommended.
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AME7106 / 7106A / 7106R
AME7107 / 7107A / 7107R
Output is at 3.2V. Maximum power dissipation is 8.1
There are two ways to reduce the power dissipation:
In addition to limiting maximum power dissipation, the
The change in LED brightness caused by the resistor
AME, Inc.
High Accuracy, Low Power
3-1/2 Digit A/D Converter
Rev.H.02