| 摘要 |
<p>An apparatus and method therefor wherein instead of applying a high bias voltage 100 per cent of the time to leads susceptible to dendrite formation, the bias voltage is switched from a low bias voltage to a high voltage bias mode when the leads (19) are to be read or scanned by a microprocessor (14), and the bias voltage is then switched back to a low bias voltage mode when the lines are not being read, e.g., at other times, thereby greatly reducing the high bias "on" time and dramatically reducing the probability of dendrite formation. The reduction of high bias voltage "on" time is accomplished by programming the microprocessor (14) to switch the applicable input ports (16) to be output ports when the leads (19) are not to be read. As output ports, the output impedance and output voltage of the microprocessor are low as opposed to a high input impedance when the terminals are input terminals. When the leads are configured as output leads, the voltage division of the microprocessor low output impedance, in combination with a large valued pull-up resistor (12) which provides the high bias voltage when the leads are input leads, makes the voltage bias on the leads low, thus greatly reducing the probability of dendrite formation.</p> |
