The delivery of a fluid cutaneously is effected by generating a suction force on a surface of a housing. To provide the utmost speed of operation, all circuits including the phase locked loop, operate as differential circuits which include a number of improvements in the design of the charge pump, the decision feedback equalizer, the slicing level control, and others. At the data reading operation, the states of the memory elements are read out by changing the read voltage to intermediate values of the individual threshold values and are transferred to and latched in a register for storing the multi-value data, so that the original data may be restored by a data inverse transforming logic circuit on the basis of the multi-value data stored in the register.