Motorola Corporation

Other

Mark S Weidner

Clinton C Kuo

Ko-Min Chang

Thomas R Toms

Philip S Smith

The concentrate holding lower portion of a sample and concentrate holding vessel has a jacket for shielding such concentrate holding portion from heat sufficient to volatilize appreciable solvent therefrom when the vessel is subjected to sufficient heat for effecting evaporative concentration of solution in such vessel.

Concentrating evaporator

A bias voltage generator (12) provides a bias control voltage that is connected to a gate of transistor (32) to sink a predetermined amount of bias current. The bias voltage generator (12) is also connected to a gate of a transistor (31) to limit the voltage to a selected bit-line within an array of flash EEPROM cells (26). The predetermined bias current is summed with the current from a selected flash EEPROM cell (46). A reference current generator portion (22), establishes both a reference current and a reference voltage at a second input to a differential amplifier (35). A current-voltage (I-V) characteristic curve of the reference voltage at the second input of the differential amplifier is approximately symmetrically located between the I-V characteristic curves of a flash EEPROM cell when the logic state of the flash EEPROM cell is in an erased state and a programmed state.

Bias current generator circuit for a sense amplifier

Zener diodes that are formed concurrently with flash EEPROM cells are utilized to regulate programming voltages for programming a flash EEPROM cell (37). A selected bit-line (38) is voltage regulated with both a zener diode (19) and a bias transistor (36). The bias transistor is activated during programming to prevent breaking down a drain junction of a flash EEPROM cell, which would generate hot-electrons and cause a runaway programming problem. The regulated voltage on the bit-line is also utilized to optimize programming characteristics of a flash EEPROM cell, and to minimize disturbing a programmed logic state of flash EEPROM cells connected to a commonly selected bit-line. A separate zener diode (17) provides a regulated voltage for a selected word-line (40) during programming. By regulating the voltage of the word-line during programming, a program disturb problem associated with a high voltage word-line is minimized.

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Austin, TX, United States of America

Mark S Weidner