Design Of The EEPROM Trimming Circuit For The Integrated ATCXO

As communications, handheld electronic devices, 3G mobile phones, GPS consumer electronics are quickly developing, the market demand of the integrated ATCXO is also expanding rapidly. The EEPROM trimming circuit is to trim the temperature compensated cubic voltage in the integrated ATCXO,and its reliability, speed and power consumption effect the performance of the whole ATCXO heavily. So the EEPROM trimming circuit in the integrated ATCXO is researched and designed in this thesis.Firstly, The temperature compensation cubic voltage generation circuit of the integrated ATCXO is researched in the thesis. Then the digital trimming circuit is designed according to the circuit parameters which need to be adjusted. Finally, the particular EEPROM circuit is designed, which is specific to the characteristics of the stored data in the integrated ATCXO. The technology vendors'EEPROM cell is adopted in the designed circuit,and the whole circuit has the following characteristics: (1) Each circuit parameter is trimmed with a single EEPROM register, and an address selecting signal corresponds to an EEPROM register, so the size of each register is flexible and can be adjusted as needed, and the whole EEPROM memory can be controlled flexibility; (2) A sensitive current amplifier corresponds to an EEPROM cell in the register, so all data can be read out in parallel at the same time, which meet the requirement in the normal operation, and the reading reliability of the EEPROM circuit is also improved. This is the first highlight in the thesis; (3) The data is input serially and be converted into internal parallel in the EEPROM circuit, which reduces the pins of the integrated ATCXO and improves the programming speed and reading speed of the EEPROM circuit; (4) The structure of the sensitive current amplifier is simple, and the amplifier has fast reading speed and low power consumption, which effectively reduce the area and power consumption of the EEPROM circuit, and improve the reading speed of the data in the EEPROM circuit. This is the second highlight in the thesis.After the theory analysis of the circuit and the designing of the basic sub-modules, the functional simulation and performance simulation of the whole EEPROM circuit is conducted at the SMIC 0.35μm technology. The results show the designed EEPROM circuit had normal operating mode and the three test modes——ROM WRITE, EEPROM WRITE and EEPROM READ, which make the circuit successfully, trim the temperature compensation cubic voltage. The power consumption of the EEPROM circuit is 0.27mW in the normal operations, and it obtains the requirement of low power consumption. The reading speed is decided by the reading time of a sensitive amplifier, and it makes the data in the EEPROM can be read out quickly and ensures the start-up time of the integrated ATCXO is short.