YM7405

The YM7405 is a kind of ISDN basic access interface with D channel packet (IDNDCH).It is an upgraded version of YM7303 (IDNI92) chip with the ISDN user-network interface function (digital four-wire time-division full-duplex operation).In only one chip,the YM7405 is compatible with CCITTR Recommondation I.430, I.440 (Q.920), I.441 (Q.921) [1990 edition], supports Layer 1 (physical layer) and Layer 2 (LAP-D protocol) and is making it suitable for D channel packet mode terminals.The YM7405 also includes the Layer 3 processor interface function and analog driver and receiver in an 80-pin QFP package and has great potential for mounting and functional designing of terminal equipments (TE) and PBX (NT2) trunk circuits.

There are some features of YM7405 as follows.First is Layer 1.The second is Layer 2.Then is Layer 3 interface function.Next is power-down mode (low-power operation).The fifth is CMOS technology with single +5 V supply.The sixth is 80-pin QFP.The last one is YM7303 pin and software compatible.

What comes next is about the absolute maximum ratings of YM7405 based on DVSS, AVSS=0.0 V.The VDD (power supply voltage) is from -0.3 V to +7.0 V.The VIN (input voltage) is from -0.3 V to VDD+0.3 V.The TOP (ambient operating temperature) is from 0 to +70.The TST (storage temperature) is from -50 to +125.Then is about the recommended operating conditions.The supply voltage is 5 V ±5% (based on DVSS, AVSS=0.0 V).The ambient operating temperature is from 0 to +70.