u4089b-m ATMEL Corporation, u4089b-m Datasheet - Page 6

• Manufacturer Part Number: u4089b-m
• Description: Multi-standard Feature Phone Circuit With Voice Switch
• Manufacturer: ATMEL Corporation

DC Line Interface and Supply-Voltage Generation
The DC line interface consists of an electronic inductance
and an output stage which charges the capacitor at V
The value of the equivalent inductance is given by:
In order to improve the supply during worst-case
operating conditions, PNP current source * I
U4089B-M
6 (23)
L = R
V
L
SENSE
V
Figure 5. DC line interface with electronic inductance and generation of regulated and unregulated supply
L
LIDET
supply
Power
C
10 F
R
R
IND
C
10
SENSE
DC
IND
Figure 6. The supply of functional blocks is controlled by input voltages V
V
TXACL
LON
TXA
(R
SENSE
IND
DC
< 5 mA
R
30 k
I
R
OFFSA
BOPT
COMP
30
30
V
) / (R
OFFS
+
–
DC
BOPT
+ R
regulator
SAL, SA
Voltage
30
SACL
*
B
)
.
supplies an extra amount of current to the supply voltages
when the NPN in parallel is unable to conduct current.
The U4089B-M contains a series regulator which
provides a supply voltage V
for a microprocessor.
AFS
+
–
7 V
3.3 V
MUT REC, STBAL
MIC, DTMF
TX MUTE
AGA, RA
7V
RECATT
ES
V
12688
V
MP
B
MP
L
CONTR
IMPED
, V
3.3 V/
2 mA
of 3.3 V at 2 mA suitable
B
Rev. A3, 06-Mar-01
12689
47 F
220 F
V
V
IMPSEL
B
MP