Sharp UX-B20 Service Manual

UX-B20U/UX-B20C/B25C
5 – 16
6. Signal/DTMF transmission level & receiving level
• Signal transmission level setting: ATT -8 dB Circuit output: -11.5
dBm.
• DTMF transmission level setting: HF -2.5 dBm SLF -4.0 dBm Thus,
set the level.
7. Power supply and bias circuit
• The voltage of +5 V and +24 V are supplied from the control PWB
unit.
1.4. Signal selection
The following signals are used to control the transmission line of TEL/
FAX signal. For details, refer to the signal selector matrix table.
[Control signals from output port]
(Example: SENDING/RECEIVING)
[Signals for status recognition according to input signals]
[Other signals]
Signal Name Description
CML Line connecting relay and DP generating relay
H: Line make
L: Line break
SP MUTE Speaker tone must control signal
H: Muting
L: Muting cancel
TELMUTE Handset reception mute control signal
H: Muting
L: Muting cancel
RCVOL
DTMFMUTE
Speaker volume control signal
RCVOL DPMFMUTE
High
Middle
L
L
L
H
Low & DTMF
H
H
Signal Name Function
RHS- H: The handset is in the on-hook state.
L: The handset is in the off-hook state.
CI- Incoming call (CI) detection signal.
Signal Name Function
TEL IN Receiving signal from line or modem.
SPOUT Speaker output signal.
TXOUT Transmission (DTMF) analog signal output from
modem.
RXIN Reception (DTMF, others) analog signal input into
modem.
NO Signal Name (CNLIU) NO Signal Name (CNLIU)
1+24V 7TELMUTE
2ADG 8RXIN
3ADG 9TXOUT
4 +5V 10 CML
5RHS- 11CI-
6TELIN 12MICMUTE
LINE
RX
TX
HANDSET
LIU PWB CONTROL PWB
IC5 SCE209L
FAX ENGINE
IC4 UPD65945
ASIC
CML
CI DETECTOR
IC101A
OP AMP
OP AMP
OP AMP
OP AMP
IC101B
OP AMP
IC101C
OP AMP
IC101D
OP AMP
IC6
T1
TXOUT
SIGTX
SPKRP
0,20dB
Mute,0,-6,-12dB
Line In Enable
Line Out Enable
LninSel
1,1
0,0
0,0
1,1
RTLoop
DAC SIN
LPF
ADC
SOUT
(20438 I/A)
SPKRN
SPOUT
SPMUTE
(H:MUTE)
SPEAKER
PH
SP Out Enable
Mic Enable
Mic/
Line
Sel
ect
LINEOUT
SIGRX MICP
RXIN
C
C
E
B
4
5
3
TELMUTE
(H:MUTE)
DG
C
E
B
TELMUTE
(H:MUTE)
DG
C
E
B
DG
DG
C
E
B
DGDG
DTMFMUTE
RCVOL
SPMUTE
TELMUTE
MICMUTE
CI
CML
RHS
+24V
+5V
DG
: FAX SENDING/RECEVING
Fig. 7

Sharp UX-B20 Specifications

General

Brand	Sharp
Model	UX-B20
Category	Fax Machine
Language	English