(Hong Kong)
Product Summary
The ht18-d is an electronic line switch circuit that replaces the mechanical hook switch contact or a discrete hook switch in a telephone handset or modem. The ht18-d switches the positive side of the telephone line using control inputs that are referenced to the negative side of the line. In the off state, The ht18-d can withstand 350V on the positive input. In the on state the ht18-d’s series resistances are 18 Ω maximum. The ht18-d provides current limiting determined by an external resistor. The ht18-d is three control inputs. The HKS pin turns on the hook switch when connected to the TPG pin. This can be accomplished by using a mechanical switch which closes when the handset is physically off-hook. The LS pin of the ht18-d allows a logic signal to turn on the hook switch. The dial pulse, Pin 6, is used to turn the hook switch off for pulse dialing. For the HT18, the dial pulse is active high (DP) whereas for the HT19, it is active low (DP). The applications of the ht18-d include Telephone handsets, Modems, Fax machines, Answering machines, Remote meter reading, Phone interface products.
Parametrics
ht18-d absolute maximum ratings: (1)VTPG, Input line voltage: +350 V; (2)VTP, Output line voltage: +18 V; (3)DP/DP continuous input voltage: +10 V; (4)Storage temperature: –65 to +150 ℃; (5)Junction temperature: +150 ℃; (6)Soldering temperature: +300 ℃; (7)Power dissipation: 0.8 Watt.
Features
ht18-d features: (1)350V breakdown voltage; (2)18 Ω maximum switch resistance; (3)Current limiting protection; (4)Operates at 2.0V input.
Diagrams
