U4090B-P Datasheet, PDF (7/35 Pages) ATMEL Corporation – Monolithic Integrated Feature Phone Circuit EMI Improved

U4090B-P
Figure 3-1. DC Line Interface with Electronic Inductance and Generation of a Regulated and an Unregulated Supply
V_L 10Ω SENSE
R_SENSE
C_IND
10 µF
IND
R_DC
I_BOPT
< 5 mA
+
-
R₃₀
30 kΩ
I_MPSOPT
< 5 mA
6.3V
V_MPS
-
=
+
3.3V
+
-
V_MP
3.3V/
2 mA
470 µF
47 µF
=
V_OFFS
7.0V
V_B
220 µF
Figure 3-2. Supply Capacitors CMPS and CB Are Charged with Priority on CMPS
VMPS < 6.3V
Y
VSENSE - VMPS > 200 mV
N
N
Y
Charge CMPS
(IMPSOPT)
VSENSE - VB > 200 mV
N
IMPSOPT = 0
IBOPT = 0
Y
N
VB < 6.3V
Y
Charge CB
(IBOPT)
Reduce IBOPT
(IMPSOPT = 0)
7
4741C–CORD–11/05