7232

NTE7232
Integrated Circuit
12
2 CMOS LSI Decoder for
Remote Control Systems
Description:
The NTE7232 is a 212 CMOS LSI decoder in an 18−Lead DIP type package for use in remote control
system applications. For proper operation, the NTE7232 should be paired with the NTE7233 encoder
or similar device with the same number of addresses and data format.
The NTE7232 decoder receives serial addresses and data from a programmed 212 encoder that is
transmitted by a carrier using an RF or an IR transmission medium. They compare the serial input
data three times continuously with their local addresses. If no rror or unmatched codes are found, the
input data codes are decoded and then transferred to the output pins. The VT pin also goes high to
indicate a valid transmission.
The NTE7232 is capable of decoding informations that consist of N bits of address and 12−N bits of
data and is arranged to provide 8 address bits and 4 data bits.
Features:
D Operating Voltage: 2.4V to 12V
D Low Power and High Noise Immunity CMOS
Technology
D Low Standby Current
D Capable of Decoding 12 Bits of Information
D Binary Address Setting
Features:
D Burglar Alarm Systems
D Smoke and Fire Alarm Systems
D Garage Door Controllers
D Car Door Controllers
D
D
D
D
D
Received Codes are Checked 3 Times
8 Address Bits and 4 Data Bits
Built−In Oscillator Needs Only 5% Resistor
Valid Transmission Indicator
Easy Interface with an RF or an IR Transmission Medium
D
D
D
D
Car Alarm Systems
Security Systems
Cordless Telephones
Other Remote Control Systems
Absolute Maximum Ratings: (Note 1)
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3V to 13V
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VSS−0.3 to VDD+0.3V
Operating Temperature Range, Topr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −205 to +755C
Storage Temperature Range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −505 to +1255C
Note 1. These are stress ratings only. Stresses exceeding the range specified under “Absolute
Maximum Ratings” may cause substantial damage to the device. Functional operation of
this device at other conditions beyond those listed in this specification is not implied and
prolonged exposure to extreme conditions may affect device reliability.
Electrical Characteristics: (VDD = 5V, TA = +255C unless otherwise specified)
Parameter
Symbol
Operating Voltage
VDD
Standby Current
ISTB
Test Conditions
Min
Typ
Max
Unit
2.4
5.0
12
V
Oscillator Stops
−
0.1
1.0
A
Oscillator Stops, VDD = 12V
−
2
4
A
−
200
400
A
Operating Current
IDD
No Load, fOSC = 150kHz
Data Output Source Current (D8−D11)
ID
VOH = 4.5V
−1.0 −1.6
−
mA
Data Output Sink Current (D8−D11)
ID
VOL = 0.5V
1.0
1.6
−
mA
VT Output Source Current
IVT
VOH = 4.5V
−1.0 −1.6
−
mA
VT Output Sink Current
IVT
VOL = 0.5V
1.0
1.6
−
mA
“H” Input Voltage
VIH
3.5
−
5.0
V
“L” Input Voltage
VIL
0
−
1
V
−
150
−
kHz
Oscillator Frequency
fOSC
ROSC = 51k5
Functional Description:
Operation
The NTE7232 decoder receives data that is transmitted by an encoder (NTE7233 or similar type) and
interprets the first N bits of code period as addresses and the last 12−N bits as data, where N is the
address code number. A signal on the DIN pin activates the oscillator which in turn decodes the incoming address and data. The decoder will then check the received address three times continuously.
If the received address codes all match the contents of the decoder’s local address, the 12−N bits of
data are decoded to activate the output pins and the VT pin is set high to indicate a valid transmission.
This will last unless the address code is incorrect or no signal is received.
The output of the VT pin is high only when the transmission is valid. Otherwise it is always low.
Pin Connection Diagram
A0 1
18 VDD
A1 2
17 VT
A2 3
16 OSC1
A3 4
15 OSC2
A4 5
14 DIN
A5 6
13 D11
A6 7
12 D10
A7 8
11 D9
VSS 9
10 D8
18
10
1
9
.920 (23.4) Max
.260 (6.6)
.155
(3.94)
.100 (2.54)
.115 (2.9) Min
.430 (10.9)
Max