Abstract: A driver circuit having shapable transition signals is disclosed. The driver circuit includes multiple branches of inverter banks connected in parallel. Each of the inverter banks includes an equal number of impedance-controllable inverters connected in series, and a capacitor can be connected between two impedance-controllable inverters within an inverter bank. Each of the impedance-controllable inverter includes an up-level impedance control and a down-level impedance control. Within an inverter bank, the impedance of the impedance-controllable inverters and the capacitance of the capacitors form a set of controlled time constants. By selecting the proper time constants, a desirable up transistor shape and a desirable down transition shape can be obtained for the driver circuit.