General Description
YTD421B (IDR) is an analog driver/receiver LSI for the ISDN BRI S/T interface. Since YTD421B can be used on both TE (Terminal Equipment) side and NT (Network Termination) side, with connecting TTL in terface LSI for TE (YTD418 or YTD423B), or that for DSU (YTD426B), each chip set allows layer 1 function conforming to ITU-T Recommendation I.430.

FEATUREs
1. Compatible with ITU-T Recommendation I.430 [1992 edition] and TTC Standard JT-I430 [1993 edition]
2. Connects directly to the Yamaha YTD418, YTD423B or YTD426B using TTL interface
3. Allows direct connection to +3.3 volt supply operation LSI(YTD418C)
4. Neither external relay nor common mode choke is required
5. 1:2 pulse transformer interface
6. Low power consumption
7. CMOS tec hnology
8. 20-pin SSOP
9. Operates on single +5 volt supply