HCS412_11 Datasheet, PDF (4/52 Pages) Microchip Technology – KEELOQ® Code Hopping Encoder and Transponder Burglar alarm systems

HCS412
2.0 DEVICE DESCRIPTION
2.1 Pinout Description
The HCS412’s footprint is identical to other encoders in
the KEELOQ family, except for the two pins reserved for
low frequency communication.
TABLE 2-1: PINOUT SUMMARY
Pin
Name
Pin
Number
Description
S0
1
Button input pin with Schmitt Trigger detector and internal 60 kΩ (nominal) pull-down
resistor (Figure 2-1).
S1
2
Button input pin with Schmitt Trigger detector and internal 60 kΩ (nominal) pull-down
resistor (Figure 2-1).
S2/RFEN/LC1
3
Multi-purpose input / output pin (Figure 2-2).
• Button input pin with Schmitt Trigger detector and internal pull-down resistor.
• RFEN output driver.
• LC1 low frequency (LF) antenna output driver for inductive responses and LC bias.
• Programming clock signal input.
LC0
4
Low frequency (LF) antenna input with automatic gain control for inductive reception and
low frequency output driver for inductive responses (Figure 2-3).
GND
5
Ground reference.
DATA
6
Transmission data output driver. Programming input / output data signal (Figure 2-4).
LED
7
LED output driver (Figure 2-5).
VDD
8
Positive supply voltage.
FIGURE 2-1: S0/S1 PIN DIAGRAM
S0
S1
60 kΩ
SWITCH
> IN
FIGURE 2-2: S2/RFEN/LC1 PIN DIAGRAM
S2LC OPTION
VDD
VBIAS
RFEN
OUT
100Ω
10V
>SWITCH 2
INPUT
< LC
OUTPUT
FIGURE 2-3: LC0 PIN DIAGRAM
RECTIFIER AND
REGULATOR
VDD
LC0 _100Ω
10V
S2LC OPTION
AMP
AND
DET
>
LC
INPUT
<^LOCUTPUT
DS41099D-page 4
© 2011 Microchip Technology Inc.