DA9138.005
12 April, 2006
MAS9138
ASYNCHRONOUS TO SYNCHRONOUS CONVERTER
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Pin compatible with MAS7838
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Interfaces a duplex asynchronous to synchronous channel
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Modem speeds of 600, 1.2k, 2.4k, 4.8k, 7.2k, 9.6k, 12k,
14.4k, 19.2k and 38.4k bps with a single 4.9152 MHz crystal
DESCRIPTION
MAS9138 is a single chip duplex asynchronous to
synchronous converter. It converts asynchronous start
stop characters to synchronous format, with stop bit
deletion when required as defined in the CCITT
recommendation V.14. On the receiver channel
MAS9138 converts the incoming synchronous data to
asynchronous start stop character format with stop bit
insertion when required as defined in the CCITT
recommendation V.14. MAS9138 implements the data
modes for the synchronous interface as specified in the
V.14. MAS9138 can be configured to operate at any
frequency up to 38.4 kbits/s within these modes. The
device contains a bit generator and frequency selection
logic to allow easy operation at other data rates. With
just one crystal the device can adapt to ten (10)
different bit rates so it is ideally suited to be used with
the most common modem systems ranging from V.22
to V.34.
FEATURES
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Implements CCITT recommendation V.14
Bypass operation
Character length from 8 to 11 bits including start
stop and parity bits
CMOS and LS-TTL compatible interface
Low power consumption (typically 10 mW)
No additional circuitry needed to perform conversion
Single +3.3...+5V supply
Operating temperature -40
o
C to 85
o
C
16-pin PDIP and SO package
APPLICATION
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Data communication systems
Adapts asynchronous terminals to synchronous
modems
Full or half card PC modems using UART as a data
source
Simplifying data multiplexing systems
BLOCK DIAGRAM
CL1
CL2
XESR
TMG
OSC
TSL
TXC
TDO
RXC
RDI
XASY
XHST
VSS
>
1
_
ASYNC
TO
SYNC
SYNC
TO
ASYNC
O
S
C
CONTROL
VDD
TDI
RDO
MAS9138
1 (10)
MAS [ MICRO ANALOG SYSTEMS ]
