WE9140

The WE9140 series are TONE I PULSE switchable telephone diaiers with the last number redial memory. The ICs are enabled either DTMF or pulse dialing by selecting mode pin or P-T key. For preventing the mistake of dialing number caused by rapid key-in and for easily component with MC, the Cs set the minimum tone duration=100ms in normal dialing. P-T and PAUSE keys are provided for PBX and LDC operation. The P-T key which will change pulse mode into tone mode is convenient for user in LDC operation. Pause lasts 3.4 sec which will be auto accessed per PAUSE or P-T during redialing. The ICs work in wide operation voltage range (2.0V~5.5V for both pulse mode and tone mode], and consume very low retention current (0.2A, at VDD=1.0V andHKS=1).

The features of WE9140 can be summarized as (1)tone/pulse switchable; (2)one 34 digits memory for the last number redial; (3)both key-in and key-released debounce are 20ms; (4)minimum tone duration=100ms for rapid key-in in normal dialing; (5)PAUSE and P-T keys for PBX and LDC operation; (6)pause lasts 3.1 sec, per PAUSE or P-T during redialing; (7)HOLD key for line held function; (8)internally power on reset; (9)electronic keypad input is available; low actlve; (10)use 3.579545 MHz crystal; (11)low operation voltage; 2.0V for both tone and pulse mode; (12)low memory retention current; 0.2A at VDD=1.0V, HKS=1; (13)dual-in-line plastic package; (14)the ditterences of the WE9140 series are listed in TABLE 1.

The absolute maximum ratings of WE9140 are (1)DC suppw wage VDD: 6.0V; (2)input voltage range VIN: -0.5~VDD+0.5V; (3)power dissipation per package PD: 500 (for TA=-25~ +60°C)mW; (4)operating temperature TA: - 25~ +85 °C; (5)storage temperature TSTG: -65~ + 450°C.