Low power, high speed hybrid clock divider circuit

The Clock Divider circuit has found immense application in Multiple Clock Domain (MCD) systems like ASICs, SoC and GALS. In MCD systems, we generate many clock signals of various frequencies from a high frequency clock by frequency division. Power is an important parameter to be minimized since the nodes in a clock divider circuit will toggle at clock frequency. In this paper, we present a low power hybrid clock divider circuit which can take an input frequency up to 6 GHz and perform frequency division. The divider is hybrid because it uses two different flip flops - a Modified Extended True Single-Phase Clock flip flop (METSPC-FF) and a self blocking FF (SBFF).The METSPC-FF is fast enough to divide a GHz frequency, but consumes more power when compared to SBFF, while the SBFF is relatively slow but consumes less power compared to METSPC. We analyze the performance of these 2 FFs across PVT variations and implement them in a clock divider circuit. Our clock divider circuit consumes 149.56 µW power for ‘divide by’ 8 operation on a 6 GHz clock. Simulation of these flip flops in TSMC 90 nm technology using CADENCE SPECTRE simulator shows that they are very energy efficient and hence can be used for other high speed applications without compromising on the power.