| 摘要 |
To reduce power consumption and operation frequency, a speech synthesizer comprises a volume control unit to receive a control signal and generate a control bias, a signal transform unit to receive the control bias Vbias and a series of digital speech codes and under the control of the most significant bit of the digital speech codes to transform the other bits of the digital speech codes or its inverse into an analog signal, and a current output unit to receive the analog signal from the signal transform unit and output the analog signal from its two current output terminals under the control of the most significant bit of the digital speech codes. The speech synthesizer therefore needs no additional transistor to drive a speaker connected between the two current output terminals and save power.
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