The TP3064 (m-law) and TP3067 (A-law) are monolithic PCM CODEC Filters utilizing the A D and D A conversion architecture shown in Figure 1 and a serial PCM interface The devices are fabricated using National's advanced double-poly CMOS process (microCMOS) Similar to the TP305X family these devices feature an additional Receive Power Amplifier to provide push-pull balanced output drive capability The receive gain can be adjusted by means of two external resistors for an output level of up to g 6 6V across a balanced 600X load Also included is an Analog Loopback switch and a TSX output See also AN-370 ``Techniques for Designing with CODEC Filter COMBO Circuits ''