The signal input can be directly coupled to large voltage signals, or indirectly coupled (with a series capacitor) to small voltage signals. A self-bias input circuit keeps small voltage signals within the linear region of the input amplifiers. With a passive low-pass filter, the SN74LV4046A forms a second-order loop PLL. The excellent VCO linearity is achieved by the use of linear operational amplifier techniques. ORDERING INFORMATION (1)