CD4055B and CD4056B types are single-digit BCD-to-7-segment decoder/driver circuits that provide level-shifting functions on the chip. This feature permits the BCD input-signal swings (V_DD to V_SS) to be the same as or different from the 7-segment output-signal swings (V_DD to V_EE). For example, the BCD input-signal (V_DD to V_SS) may be as small as 0 to -3 V, whereas the output-display drive-signal swing (V_DD to V_EE) may be as large as from 0 to -15 V. If V_DD to V_EE exceeds 15 V, V_DD to V_SS should be at least 4V (0 to -4V). The 7-segment outputs are controlled by the DISPLAY-FREQUENCY (DF) input which causes the selected segment outputs to be low, high, or a square-wave output (for liquid-crystal displays). When the DF input is low the output segments will be high when selected by the BCD inputs.