UBA2050(A)

Speech/transmission part
` Low DC line voltage; operates down to 1.45 V (excluding voltage drop over external polarity guard)
` Line voltage regulator with adjustable DC voltage
` Regulated 3.3 V supply (VDD) for the dialler part and peripherals compatible with:
    Speech mode
    Ringer mode
    Trickle mode.
` Unregulated supply (VCC) for the transmission part and peripherals
` Transmit stage with:
    Microphone amplifier with symmetrical high-impedance inputs
    DTMF input with confidence tone on receive output.
` Receive stage with:
    Receive amplifier with asymmetrical output
    Earpiece amplifier with adjustable gain (and gain boost facility) for all types of earpieces.
` AGC: line loss compensation for microphone and receive amplifiers.
Dialler part
` Last Number Redial (LNR) (32 digits)
` Pulse dialling:
    10 PPS and 20 PPS (resistor option)
    M/B 2 : 3 and 1 : 2 (resistor option).
` DTMF timing:
    Manual dialling with minimum duration for bursts and pauses (85/85 ms)
    Calibrated timing during redialling (85/85 ms).
` Pulse or tone mode select at start-up (resistor option)
` Flash function (600, 300, 98 and 80 ms) (resistor options)
` Access pause time 2.0 and 3.6 s (resistor option);access pauses in series are possible
` [*/T] key (for mixed mode dialling) or separate [P ® T] key
` Repertory memory integrity check
` Keytone generation (only UBA2050, UBA2050A and UBA2051C)
` Dial Mode Output (DMO) function during pulse dialling and flash function (only UBA2050 and UBA2051)
` LED output for DTMF dialling indication (only UBA2050A and UBA2051A)
` Function keys:
    [LNR/P], [R] and [P ® T]
    [STORE], [MEM], [M1], [M2] and [M3] (only UBA2051, UBA2051A and UBA2051C).
` Resistor options:
    [*/T] key definition (MMS)
    Pulse or Tone mode Selection (PTS)
    Flash Time Selection (FTSA and FTSB)
    Make/Break ratio Selection (MBS)
    Pulses Per Second (PPS)
    Access Pause Time (APT).
` 13 repertory numbers (only UBA2051, UBA2051A and UBA2051C):
    3 direct memories (21 digits)
    10 indirect memories (21 digits).
` Supply and temperature independent tone output
` On-chip DTMF filtering for low output distortion ("CEPT CS 203" compatible)
` On-chip oscillator suitable for low-cost 3.579545 MHz quartz crystal or ceramic resonator
` Uses standard single-contact keyboard
` Keyboard entries fully debounced.
Ringer part
` Ringer input frequency discrimination
` 3-tone ringer with 4 programmable melodies (selectable via keyboard by keys [1] to [4])
` 4-level volume control (selectable via keyboard by keys [5] to [8]).