NTE1690 Datasheet, PDF (1/4 Pages) NTE Electronics – Integrated Circuit Telephone DTMF Dialer

NTE1690
Integrated Circuit
Telephone DTMF Dialer
Description:
The NTE1690 is a low threshold voltage, field–implanted, metal gate CMOS integrated circuit in a
16–Lead DIP type package. This device interfaces directly to a standard telephone keypad and gen-
erates all dual tone multi–frequency pairs required in tone dialing systems. The tone synthesizers
are locked to an on–chip reference oscillator using an inexpensive 3.579545MHz crystal for high tone
accuracy. The crystal and an output load resistor are the only external components required for tone
generation. A MUTE OUT logic signal, which changes state when any key is depressed is also pro-
vided.
Features:
D 3V to 10V Operation When Generating Tones
D 2V Operation of Keyscan and MUTE Logic
D Static Sensing of Key Closures or Logic Inputs
D On–Chip 3.579545MHz Crystal–Controlled Oscillator
D Output Amplitudes Proportional to Supply Voltage
D High Group Pre–Emphasis
D Low Harmonic Distortion
D Open Emitter–Follower Low–Impedance Output
D SINGLE TONE INHIBIT Pin
Absolute Maximum Ratings:
Supply Voltage (V_DD – V_SS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15V
Maximum Voltage at Any Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V_DD+0.3V to V_SS–0.3V
Power Dissipation, P_D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500mW
Operating Temperature Range, T_opr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –30° to +60°C
Storage Temperature Range, T_stg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –55° to +150°C
Electrical Characteristics: (–30°C < T_A < +60°C, 3V < V_DD < 10V unless otherwise specified)
Parameter
Test Conditions Min Typ Max Unit
Minimum Supply Voltage for Keysense and
MUTE Logic Functions
–
–
2
V
Operating Current, Idle
Operating Current, Generating Tones
R_L = 10kΩ
V_O = 5V
– 20 –
µA
–
2
–
mA