Tel: 886-2-66296288
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
Remote Control Decoder IC
PT2270
VALID TRANSMISSION
When PT2270 receives a transmission code word, it initially checks whether this is a valid transmission.
For a transmission to be valid, (1) it must be a Complete Code Word, and (2) the Address Bits must
match the Address Setting at the Address Pins. After two consecutive valid transmissions, PT2270 (1)
drives the data pins according to the data bits received, and (2) raises VT to high voltage (high state).
The timings are shown in the following diagram.
Sync Bit
1st Word
2nd Word
Sync Bit
DIN
2tc
Data Pins
(M om entary)
VT
Note: tc=Width of 1 Code Word
LATCH OR MOMENTARY DATA OUTPUT TYPE
PT2270 uses either the latch or the momentary data output type depending on the PT2270 version
used. The latch type (PT2270-Lx) activates the data out during transmission and this data is sustained
in the memory until another data is inputted or entered. A momentary type (PT2270-Mx), on the other
hand, activates the data out only during transmission. In the momentary type, the data does not remain
in the memory after the transmission is completed. Please refer to the diagram below.
Data Words (X)
Data Words (Y)
DIN
2tc
≤
2tc
Data Output X
2tc
≤
2tc
Data Output Y
DATA PINS
(Momentary)
DATA PINS
(Latch)
Data Output X
Data Output Y
VT
Note: tc=Width of 1 Code Word
PT2270 V1.3
-8-
May, 2006
PTC [ PRINCETON TECHNOLOGY CORP ]
