UBA2050 View Datasheet(PDF) - Philips Electronics

Part Name

Description

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UBA2050

One-chip telephone ICs with speech, dialler and ringer functions

Philips Electronics 

Philips Semiconductors

One-chip telephone ICs with speech,

dialler and ringer functions

Product specification

UBA2050(A); UBA2051(A;C)

3

handbook, halfpage

IP

(mA)

1.9 mA

2

1.6 mA

1

MGL827

(2) (1)

handbook, halfpage RCC

VCC

VCC0

Irec

PERIPHERAL

CIRCUITS

IP

0

0

1

2

3

4

VCC (V)

VCC ≥ 2.5 V; VLN = 4.35 V at Iline = 15 mA; RCC = 619 Ω;

RSLPE = 20 Ω.

(1) This curve is valid when the receiving amplifier is not loaded.

(2) This curve is valid when the receiving amplifier is loaded;

Vo(rms) = 150 mV; RL = 150 Ω.

Fig.8 Typical current IP available from VCC for

peripheral circuitry.

GND

FCA130

Fig.9 VCC used as supply voltage for peripheral

circuits.

Regulated supply point (pin VDD)

The VDD regulator delivers a stabilized voltage to supply

the internal dialler and ringer parts and peripheral circuits

in transmission mode (nominal VLN) and in ringer mode

(VLN = 0 V). The maximum supply current for peripherals

is 1.9 mA in dialling mode (DTMF generator on) and

2.6 mA in speech mode (DTMF generator off). The supply

conditions in ringer and trickle (on-hook condition) modes

must not be disturbed by the peripheral supply currents.

The regulator (see Fig.7) consists of a sense input circuitry

(pin LN), a current switch and a VDD output stabilizer

(pin VDD). VDD is decoupled by capacitor CVDD.

The regulator function depends on the transmission, ringer

and trickle modes as follows:

• Transmission mode: The regulator operates as a current

source at the LN input; it takes a constant current of

ISUP = 4.5 mA (at nominal conditions) from pin LN.

The current switch reduces the distortion on the line at

large signal swings.

Output VDD follows the DC voltage at pin LN (with

typically 0.35 V difference) up to VDD = 3.3 V. The input

current of the regulator is constant while the output

(source) current is determined by the consumption of

the peripherals. The difference between input and

output current is shunted by the internal VDD stabilizer.

• Ringer mode: The regulator operates as a shunt

stabilizer to keep VDD at 3.3 V. The input voltage

VLN equals 0 V while the input current into pin VDD is

delivered by the ringing signal.

• Trickle mode: When VDD is below typically 2 V, the

regulator is inhibited. The current consumption of the

VDD regulator in trickle mode is very low to save most of

the trickle current for memory retention of the dialler and

ringer parts.

2000 May 19

10

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