| 摘要 |
A temperature compensated ring oscillator (10) integrated with a differential transconductance amplifier (20) has two outputs (22, 24), one output (22) provides current to a constant shunt resistance (30), the second output (24) supplies power to a ring circuit (12) having a dynamic resistance. Both outputs (22, 24) are tied to the inputs (26, 28) of the amplifier (20) such that the voltages across the ring circuit (12) and shunt resistance (30) are driven to be substantially the same. This fixes the dynamic resistance of the ring circuit (12). The supply signal (18) to the ring circuit (12) is isolated from the supply to the amplifier (20) which isolates noise from the ring circuit (12). Additionally, temperature stable capacitors (38) are added to outputs (16) of inverter stages (14) of the ring circuit (12) to overwhelm temperature variable parasitic capacitances. The fixed dynamic resistance, isolated power and controlled parasitic capacitances all improve frequency stability of the ring oscillator (10).
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