Abstract: A Peltier control circuit detects a temperature of a device combined with a Peltier device and controls a current flowing through the Peltier device so as to keep the temperature of the device at a predetermined value. The circuit has a temperature sensing section for detecting the temperature of a device, a comparing section for comparing a temperature detection value with a predetermined temperature reference value, a limiting section for providing a comparison output with the limitation of a current flowing through the Peltier device and providing the limitation with a predetermined temperature characteristics, and a driving section for providing the Peltier device with an input or output driving current in accordance with the comparison output via the limiting section.

Abstract: A synchronization control unit for synchronizing serial-to-parallel (S/P) converters operating in parallel, or parallel-to-serial (P/S) converters operating in parallel. More specifically, first and serial-to-parallel (S/P) converters produce respectively corresponding first and second clock signals and operate in parallel. The first and second clock signals are in synchronization, and a synchronization failure occurs when the first and second clock signals fall out of synchronization. When a synchronization failure occurs, the synchronization control unit resets one of the first and second clock signals so that synchronization between the first and second clock signals is restored within a definite time period. Moreover, the synchronization control unit can perform the same operation with parallel-to-serial (P/S) converters, instead of with S/P converters.

Abstract: A Peltier control circuit detects a temperature of a device combined with a Peltier device and controls a current flowing through the Peltier device so as to keep the temperature of the device at a predetermined value. The circuit has a temperature sensing section for detecting the temperature of a device, a comparing section for comparing a temperature detection value with a predetermined temperature reference value, a limiting section for providing a comparison output with the limitation of a current flowing through the Peltier device and providing the limitation with a predetermined temperature characteristics, and a driving section for providing the Peltier device with an input or output driving current in accordance with the comparison output via the limiting section.