HCS201 Datasheet, PDF (19/28 Pages) Microchip Technology – KEELOQ Code Hopping Encoder

HCS201
FIGURE 8-1:
POWER-UP AND TRANSMIT TIMING
Button Press
Detect
TBP
TTD
Multiple Code Word Transmission
TDB
DATA
Output ^TS
Code
Word
1
Code
Word
2
TTO
Code
Word
3
Code
Word
4
Code
Word
n
Button
Input
Sn
TABLE 8-3: POWER-UP AND TRANSMIT TIMING⁽²⁾
Standard Operating Conditions (unless otherwise specified):
Commercial(C): Tamb = 0°C to +70°C
Industrial(I): Tamb = -40°C to +85°C
Symbol
Parameter
Min.
Typ.
Max.
Unit Conditions
TBP Time to second button press
10 + Code
Word
26 + Code ms
Word
(Note 1)
TTD Transmit delay from button detect
12
26
ms
TDB Debounce Delay
6
20
ms
TTO Auto-shutoff time-out period
27
s
Ts
START Pulse Delay
4.5
ms
Note 1: TBP is the time in which a second button can be pressed without completion of the first code word
(the intention was to press the combination of buttons).
2: Typical values - not tested in production.
FIGURE 8-2:
CODE WORD FORMAT
TE TE TE
LOGIC ‘0’
LOGIC ‘1’
Bit Period
TBP
50% Duty Cycle
Preamble
TP
Header
TH
Encrypted Portion
of Transmission
THOP
Fixed Portion of
Transmission
TFIX
Guard
Time
TG
© 2001 Microchip Technology Inc.
DS41098C-page 19