NX-300(S)57Universal connectorPin No. Name I/O SignalType Function Rating and ConditionParameter Min Typ Max Unit1 SSW I DigitalEXT/INT speaker switch inputL: External speaker ONH: Internal speaker ONVIH 2.8 - 5.3 VVIL 0 - 0.7 V2 SP+ O Analog BTL output + for external speaker[8 load]Max output power (1kHz, Batt=7.5V) 1.3 1.8 W[8 load] DC Bias 2.5 V[8 load] Allowable Frequency 300 3000 Hz3 SP– O Analog BTL output – for external speaker[16 load]Max output power (1kHz, Batt=7.5V) 0.9 1.4 W[16 load] DC Bias 2.5 V[16 load] Allowable Frequency 300 3000 Hz4 MSW I DigitalEXT/INT MIC switch inputL: External MIC ONH: Internal MIC ONVIH 2.8 - 5.3 VVIL 0 - 0.5 V5 EMC I Analog External MIC inputAudio Level (STD deviation) 7.7 12.5 17.3 mVDC Bias 3.3 VAllowable Frequency 300 3000 HzInput Impedance - 1.8 - k6 ME - - External MIC GND7 PTT I Digital External PTT inputL: PTT ONVIH 2.8 - 5.3 VVIL 0 - 0.7 V8 PF I Analog Programmable function key inputV (PF2 key ON) 2.2 - 2.8 VV (PF1 key ON) 1.7 - 2.2 VV (PF1, PF2 key ON) 1.3 - 1.7 V9 OPT I Digital Man-down inputProgrammable active H/LVIH 2.8 - 5.3 VVIL 0 - 0.7 V10 E - - GND11 5V - Power 5V power supply output(Output control is FPU programmable)Output Voltage (Iout=100mA) 4.9 5.0 5.1 VMaximum Current - - 0.2 A12 TXD O Digital Serial data outputVOH (Io=–5mA) 4.0 - 5.3 VVOL (Io=5mA) 0 - 0.8 VBaud Rate 19200 bps13 RXD I Digital Serial data inputVIH 2.8 - 5.3 VVIL 0 - 0.8 VBaud Rate 115200 bps14 NC - - Not used (reserved for future option)TERMINAL FUNCTION