Holtek HT658/S Data Sheet
WIRELESS MADE SIMPLE
FEATURES Operating voltage: 2.4V~12V Low power and high noise immunity CMOS technology Low standby current Capable of decoding 18 bits of information Pairs with HOLTEKs HT640 encoder 10 address pins 8 data pins Trinary address setting Two times of receiving check Built-in oscillator needs only a 5% resistor Valid transmission indictor Easily interface with an RF or an infrared transmission medium Minimal external components APPLICATIONS Burglar alarm system Smoke and fire alarm system Garage door controllers Car door controllers Car alarm system Security system Cordless telephones Other remote control systems
GENERAL DESCRIPTION The HT658/S decoder is a CMOS LSI for remote control system applications. It is paired with the HT640/S encoder. The HT658 decoder receives serial address and data from the encoder that are transmitted by a carrier using an RF or an IR transmission medium. It then compares the serial input data twice continuously with its local address. If no errors or unmatched codes are encountered, 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 decoder is capable of decoding 18 bits of information that consists of 10 bits of address and 8 bits of data.
Note:
This product is manufactured and supported by Holtek Semiconductor. This data sheet is provided as a courtesy to Linx customers and is believed to be accurate at the time of publication, however these specifications may change at any time without notice. Linx Technologies makes no representation as to the accuracy or suitability of this information for any purpose. For more information please contact Holtek at www.holtek.com.
Holtek HT658/S Data Sheet
PIN OUT
D1 D2 D3 D4 D5 D6 D7 VT DIN OSC2 OSC1 VSS 1 2 3 4 5 6 7 8 9 10 11 12 24 23 22 21 20 19 18 17 16 15 14 13 VDD D0 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
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PIN DESCRIPTIONS
Pin Name A0-A17 D10-D17 DIN VT OSC1 OSC2 VSS VDD I/O I O I O I O I I Internal Connection TRANSMISSION GATE CMOS OUT CMOS IN CMOS OUT OSCILLATOR OSCILLATOR Description Input pins for address A0-A17 setting They can be externally set to VDD, VSS or left open. Output data pins Serial data input pin Valid transmission, active high Oscillator input pin Oscillator output pin Negative power supply (GND) Positive power supply
APPROXIMATE INTERNAL CIRCUITS
TRANSMISSION GATE
CMOS OUT
CMOS IN
OSCILLATOR
EN OSC1
OSC2
Holtek HT658/S Data Sheet
ABSOLUTE MAXIMUM RATINGS*
Supply Voltage .............. 0.3V to 13V Input Voltage..................VSS0.3V to VDD+0.3V
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Storage Temperature................. 50C to 125C Operating Temperature............... 20C to 75C
*Note: Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only. Functional operation of this device at these or any other conditions above those indicated in the operational sections of this specification is not implied and exposure to absolute maximum rating conditions for extened periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
Test Conditions Symbol
V DD I STB I DD
Parameter
Operating Voltage Standby Current Operating Current Data Output Source Current (D10-D17) Data Output Sink Current (D10-D17) VT Output Source Current VT Output Sink Current "H" Input Voltage "L" Input Voltage Oscillator Frequency
V DD 5V 12V 5V
Conditions
Min. 3
Typ. 0.1 2 0.2 1 1 4 2 100
Max. 12 1 4 1 5 1
Unit
V
Oscillator Stops No Load F OSC = 100kHz V OH = 4.5V
A A
mA mA mA mA mA V V kHz
0.5 0.5 2 1 3.5 0
IO
5V V OL = 0.5V 5V 5V 5V 10V
V OH = 4.5V
I VT V IH V IL F OSC
V OL = 0.5V ROSC = 330k
DECODER OSCILLATOR FREQUENCY VS SUPPLY VOLTAGE
300 275 250 225 200 Fosc (kHz) 175 150 125 100 75 50 25 2 3 4 5 6 7 VDD (VDC) 8 9 10 11 150k 180k 220k 270k 330k 390k 470k 560k 680k 820k 1M 1.5M 2M 12 12.5 Rosc (ohms) 120k
Holtek HT658/S Data Sheet
FUNCTIONAL DESCRIPTION The HT658 decoder provides ten address and 8 data pins in a 24 pin SOP package. It is paired with the HT640 encoder. The decoders receive data transmitted by the encoders and interpret the first 10 bits of the code period as address and the last 8 bits as data. A signal on the DIN pin then activates the oscillator, which in turns decodes the incoming address and data. The decoders will check the received address twice continuously. If all the received address codes match the contents of the decoders local address, the 8 bits of data are decoded to activate the output pins, and the VT pin is set high to indicate a valid transmission. That will last until the address code is incorrect or no signal has been received. The output of the VT pin is high only when the transmission is valid. Otherwise it is low always. The output type is momentary. The data outputs follow the encoder during a valid transmission and then reset. Note: The oscillator is disabled in the standby state and activated as long as a logic high signal is applied to the DIN pin. i.e., the DIN should be kept low if there is no signal input.
No Power On
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Standby Mode
Disable VT & Ignore the Rest of This Word
No
Code In? Yes Address Bits Matched? Yes
Store Data
No
Match Previous Stored Data?
No
Yes No
2 Times of Checking Completed?
Yes
Data to Output & Activate VT
Address or Data Error?
Yes
BLOCK DIAGRAM
OSC2 OSC1
Oscillator
Divider
Data Shift Register
Data
DIN
Buffer
Data Detector
Sync. Detector
Comparator
Comparator
Control Logic
Transmission Gate Circuit
Buffer
VT
Address
VDD
VSS
Holtek HT658/S Data Sheet
ENCODER/DECODER TIMING Encoder Transmit Enable Encoder Data Out
3 Words 2 Words Check Check
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< 1 Word
Transmitted Continuously 214 Clocks
3 Words 214 Clocks
Decoder VT Decoder Data Out
1/2 Clock Time
1/2 Clock Time
ENCODER/DECODER DATA STRUCTURE
SYNC BITS ADDRESS BITS DATA BITS
A&D BITS PULLED TO VCC
A&D BITS OPEN
A&D Bits PULLED TO GND
SYNC PERIOD
SYNC BITS
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9
D0
D1
D2
D3
D4
D5
D6
D7
15.1mS
5.6mS
26mS
TIME DEPENDANT ON OSCILLATOR RESISTOR CHOSEN (390k)
21mS
22.30%
8.27%
38.40%
PERCENTAGES OF TOTAL TIME FOR ONE WORD PLUS SYNC
31.02%
Bit Pattern Interpretation
fosc/33 "One" "Zero" "Open"
Holtek HT658/S Data Sheet
SOP-24 PACKAGE DIMENSIONS
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0.419 (10.643)
0.300 (7.620)
0.020 (0.508)
0.038 (0.965)
0.012 (0.305)
10
0.614 (15.596) 0.104 (2.642) 0.050 typ. (1.27)
0.004 min. (0.102)
APPLICATION CIRCUIT
ANTENNA VCC
1 2 VCC 3 4 GND 5 1uF GND 8 6 7
NC NC NC GND VCC PDN RSSI DATA RXM-xxx-LR-S
ANT GND NC NC NC NC NC NC
16 15 14 GND 13 12 11 10 9 390k 1 D1 2 3 D3 D4 D5 6 7 8 VT DIN OSC1 11 OSC2 12 GND HT_658/S GND VCC D0 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 24 23 22 21 20 19 18 17 16 15 14 13 GND
