1) Design a lithium battery pack discharge overheating protection circuit which senses the temperature of a 7.4V lithium battery pack (which consists of two 3.7V batteries in series) and disconnects it from the load which it's powering if the pack gets too hot, and reconnects it again when it cools. You should use a thermistor to sense temperature, and may use any commercially available op-amps, comparators, FETs, BJTs, Zener (your choice of voltage) and other types of diodes, resistors and any capacitors or inductors you need. The thermistor has a resistance of greater than 10 kΩ when the battery is cool and reduces to below 8 kΩ when too hot; your circuit should disconnect when the resistance decreases to below 8 kΩ and reconnect when the resistance increases again to above 10 kΩ. Your circuit should operate from the voltages available from the two series-connected batteries in the pack (and you have access to the terminal between the two series-connected batteries).For highest credit on this problem give manufacturer part numbers for all semiconductors (such as are given in the Analog Devices parts kit).
2) Design a ten-bit D/A converter which generates an output voltage in the range of 0 to 1.023 V (i.e. 1 mV LSb). You may use op-amps, comparators, FETs, BJTs, Zener (your choice of voltage) and other types of diodes, resistors and any capacitors or inductors you need. Assume that you have whatever power supply voltages you need and that the digital inputs are Ov for logic O and +5V for logic 1.