CX81801-7x/8x SmartV.XX Modem Data Sheet
Table 3-15. CX20442 VC Pin Signal Definitions (Continued)
Label
VREF
11
Pin
I/O
R
I/O Type
Reference Voltage
REF
Signal Name/Description
High Voltage Reference.
Connect to analog ground through
10 µF (polarized, + terminal to VREF) and 0.1 µF (ceramic) in
parallel. Ensure a very close proximity between these capacitors
and VREF pin.
Low Voltage Reference.
Connect to analog ground through
10 µF (polarized, + terminal to VC) and 0.1 µF (ceramic) in
parallel. Ensure a very close proximity between these capacitors
and VC pin.
For handset interface, also connect to handset interface circuit
(VC_HAND).
Not Used
VC
12
R
REF
M_DIG_SPEAKER
M_LINE_OUTM
M_RELAYA
M_RELAYB
M_MIC_BIAS
M_ACT90
M_1BIT_OUT
D_LPBK_BAR
NC
Notes:
1. I/O types*:
Ia
It
Itpd
Itpu
Oa
Ot2
Ot2od
AGND
GND
2
10
24
16
15
29
30
31
7, 8, 32
O
O
O
O
O
I
O
I
Ot2
Oa
Ot
Ot
Oa
Itpu
Ot2
It
Not Used.
Leave open.
Not Used.
Leave open.
Not Used.
Leave open.
Not Used.
Leave open.
Not Used.
Leave open.
Not Used.
Leave open.
Not Used.
Leave open.
Not Used.
Leave open.
Internal No Connect.
Leave open.
Analog input
Digital input, TTL-compatible
Digital input, TTL-compatible, internal 75k
±
25k
Ω
pull-down
Digital input, TTL-compatible, internal 75k
±
25k
Ω
pull-up
Analog output
Digital output, TTL-compatible, 2 mA, ZINTERNAL = 120
Ω
Digital output, TTL-compatible, 2 mA, open drain, ZINTERNAL = 120
Ω
Analog Ground
Digital Ground
Table 3-13. CX20442 VC DC Electrical Characteristics
Parameter
Input Voltage
Input Voltage Low
Input Voltage High
Output Voltage Low
Output Voltage High
Symbol
VIN
VIL
VIH
VOL
VOH
Min.
-0.30
-0.30
0.4*VDD
0
0.8*VDD
Typ.
–
–
–
–
–
Max.
VDD+0.3
0.2 *VDD
VDD+0.3
0.4
VDD
Units
V
V
V
V
V
Test Conditions
Input Leakage Current
–
-10
–
10
µA
Output Leakage Current (High
–
-10
–
10
µA
Impedance)
Test Conditions unless otherwise stated: VDD = +3.3 ± 0.3 VDC; TA = 0°C to 70°C; external load = 50 pF
102199B
Conexant
3-33
CONEXANT [ CONEXANT SYSTEMS, INC ]
