| 摘要 |
PURPOSE: A voltage level detecting circuit of a current mode output driver is provided to prevent a discordance between a voltage drop amount of a high level of an output signal and a voltage drop amount of a low level of the output signal. CONSTITUTION: A voltage level detecting circuit of a current mode output driver comprises a current generating part(21) which is connected to a current source(21a) and generates the predetermined amount of current when a current control enable signal is activated. An internal high voltage generating part(22) receives the current from the current generating part(21) and a data high voltage from an external pad, and outputs an internal high voltage(VOH_INT) which is identical to the high voltage applied from the exterior. An internal low voltage generating part(23) receives the current from the current generating part(21) and a data low voltage from an external pad, and outputs an internal low voltage(VOL_INT) which is identical to the low voltage applied from the exterior. A voltage divider(24) receives the internal high and low voltages, and generates an intermediate voltage(Vmid) of the voltages(VOH_INT,VOL_INT). An amplification part(25) compares the intermediate voltage(Vmid) from the voltage divider(24) with a reference voltage(Vref), and detects a difference between the voltages(Vmid,Vref).
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