Sharp FO-CC500 Service Manual page 67

Microphone Input. The Codec provides a microphone interface for
an electret microphone. The microphone input is differential to reduce
common mode noise pickup. The microphone must be AC-coupled to
the MICINP and MICINN inputs. A quiet, clean voltage (MICBIAS) is
available to provide a bias for the electret microphone. The micro-
phone input amplifier has programmable gains from -4 to 28 dB (-4, 0,
6, 12, 18, 24, and 28 dB), to accommodate a wide range of micro-
phone sensitivities. The microphone input is multiplexed with the line
input signal before the A/D conversion.
Line Input. The Codec line input is an auxiliary input which may be
used as an alternative analog interface. For example, this interface
may be used between the base station Codec and the PSTN. The
line input, before final A/D conversion, is multiplexed with the micro-
phone input signal.
Base Station
/PSTN
Interface
earpiece
microphone
optional
Base station only
Handset only
Serial
EEPROM
LINEIN
32-Pin
SPKROP
Merlin
Codec
SPKRON
MICINN
MICINP
LINEO
(on handset,AUXDAC and
GPIOA6 may be used)
DATA[7:0]
ROMCSP
External
ROM
ADDR[15:0]
RDP
HOSTCSP
HOSTIRQ
External
HOSTACK
device
WRP
Fig. 12 Typical System Block Diagram for the 128-pin Merlin XROM ASIC
Line output. LINEO is a single-ended output capable of driving a 1
kΩ load. The output amplifier has programmable gains from -35 dB to
1.1 dB in 6 dB steps.
Speaker Output. The SPKROP and SPKRON signals form a differ-
ential output capable of driving a 150 Ω resistive load or a highly ca-
pacitive (100 nF) ceramic receiver via dual 150 Ω series resistors.
This output may be used to drive either the PSTN or the handset
earpiece. The output amplifier has programmable gains from -29 dB
to 3 dB.
7) Power Requirements
All six of the ASICs in the Merlin family of spread spectrum devices
operate within +2.7 to +3.3 V. Each of the ASICs has an active, low
power consumption of less than 60 mW (+3.3 V) and a very low power
stand-by consumption of less than 3 mW (+3.3 V).
MVCS
128-Pin
MVDI
LNAATN
Merlin
MVDO
RXEN
XROM
MVCLK
RXQP
RXQN
SYNEN
OHP
REFOSC
RINGP
SYNSTB
SYNDATA
SYNCLK
CDCDATAI TXDATA
CDCDATAO TXEN
CDCFRAME TXPWR0
ICLK TXPWR1
MCLK TRSW
RESETOP
column 1-6
Keypad
row 1-8
LCDRS
LCDPWR
LCDRW
LCDEN
EMUCLK
5 – 17
900MHz
or
2.4GHz
RXIP
Radio
RXIN
AGC
Keypad
Keypad
DATA
LCD
SYNC
NMIP
Emulator
(Development
System Only)
FO-CC500A
FO-K01A