Ramp generator using Schmitt trigger
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Ramp generator using Schmitt trigger Jea-Duck Kim, and Yeong-Seuk Kim Department of Semiconductor Engineering, Chungbuk National University, Cheong ju, Korea E-mail : [email protected] I.
INTRODUCTION
Current electronic equipment have to meet the complex functions and require different power. Power, stable operation and high energy efficiency are required. Ramp generator is a circuit for controlling the pulse width modulation of the DCDC converter. Therefore, it is essential to stable operation of the DC-DC converter.
II.
DESCRIPTION
A. Proposed ramp generator Fig 2. Output frequency for bias voltage variation
Fig 1. Proposed ramp generator block diagram Fig 3. Output frequency for capacitance variation
Fig. 1 shows designed ramp generator. A Schmitt trigger circuit and inverter are added to an existing ramp generator circuit. To be able to get the triangular waveform of interest, the values of the current and capacitor are needed to adjust.
III. CHIP IMPLEMENTAION AND RESULTS Fig. 2 shows the change of the output frequency with respect to the change of the capacitor and bias voltage. The size of the capacitor was varied to 220pF~820pF. As the value of the capacitor is small, the output frequency of the ramp generator is increased.
Fig 4. Micrograph of the fabricated ramp generator
Bias voltage was varied to 0.75V~2.25V. As voltage is higher, the output frequency of the ramp generator is decreased.
REFERENCE
The size of the triangle waveform were remained constant from 0.85V to 1.87V.
[1]
RJ Baker, CMOS: circuit design, layout, and simulation, 3rd ed, WILEY, 2011, pp 523-528.
This work was supported by the IDEC.
2015 ISOCC Chip Design Contest
Ramp generator using Schmitt trigger Jea-Duck Kim, and Yeong-Seuk Kim Department of Semiconductor Engineering, Chungbuk National University, Cheong ju, Korea E-mail : [email protected] I.
INTRODUCTION
Current electronic equipment have to meet the complex functions and require different power. Power, stable operation and high energy efficiency are required. Ramp generator is a circuit for controlling the pulse width modulation of the DCDC converter. Therefore, it is essential to stable operation of the DC-DC converter.
II.
DESCRIPTION
A. Proposed ramp generator Fig 2. Output frequency for bias voltage variation
Fig 1. Proposed ramp generator block diagram Fig 3. Output frequency for capacitance variation
Fig. 1 shows designed ramp generator. A Schmitt trigger circuit and inverter are added to an existing ramp generator circuit. To be able to get the triangular waveform of interest, the values of the current and capacitor are needed to adjust.
III. CHIP IMPLEMENTAION AND RESULTS Fig. 2 shows the change of the output frequency with respect to the change of the capacitor and bias voltage. The size of the capacitor was varied to 220pF~820pF. As the value of the capacitor is small, the output frequency of the ramp generator is increased.
Fig 4. Micrograph of the fabricated ramp generator
Bias voltage was varied to 0.75V~2.25V. As voltage is higher, the output frequency of the ramp generator is decreased.
REFERENCE
The size of the triangle waveform were remained constant from 0.85V to 1.87V.
[1]
RJ Baker, CMOS: circuit design, layout, and simulation, 3rd ed, WILEY, 2011, pp 523-528.
This work was supported by the IDEC.
2015 ISOCC Chip Design Contest
