HCS201-I/SN Microchip Technology, HCS201-I/SN Datasheet - Page 5

• Manufacturer Part Number: HCS201-I/SN
• Description: IC CODE HOPP ENCODER 7FUNC 8SOIC
• Manufacturer: Microchip Technology
• Type: Code Hopping Encoderr

Specifications of HCS201-I/SN

• Applications: Remote Secure Access, Keyless Entry
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Ic Function: Encoder IC
• Supply Voltage Range: 3.5V To 13V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: SOIC
• No. Of Pins: 8
• Peak Reflow Compatible (260 C): Yes
• Termination Type: SMD
• Rohs Compliant: Yes
• Filter Terminals: SMD
• Leaded Process Compatible: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

2.0
As shown in the typical application circuits (Figure 2-1),
the HCS201 is a simple device to use. It requires only
the addition of buttons and RF circuitry for use as the
transmitter in your security application. A description of
each pin is given in Table 2-1.
FIGURE 2-1:
2001 Microchip Technology Inc.
External components sample values:
R = 5.1 K
C = 1.0 uF
(see Section 5.6 for a description of the Step Up circuit)
Note:
B0
B1
2.0-6.0V
V
B3 B2 B1 B0
Three button remote control with Step up regulator
ENCODER OPERATION
DD
Up to 7 functions can be implemented by pressing
more than one button simultaneously or by using a
suitable diode array.
S0
S1
S2
V
DDB
Four button remote control
Two button remote control
S0
L = 390 uH
D = ZHCS400CT (40V 0.4A Zetex)
S1
S2
V
DDB
STEP
DATA
TYPICAL CIRCUITS
S0
S1
S2
V
V
V
DDB
DD
SS
STEP
DATA
V
V
DD
SS
STEP
DATA
V
Tx out
V
R
DD
SS
Q = 2N3904
V
DD
Q
L
Tx out
Tx out
D
C
V
DD
TABLE 2-1:
The HCS201 will wake-up upon detecting a button
press and delay approximately 10 ms for button
debounce (Figure 2-2). The synchronization counter,
discrimination value and button information will be
encrypted to form the hopping code. The hopping code
portion will change every transmission, even if the
same button is pushed again. A code word that has
been transmitted will not repeat for more than 64K
transmissions. This provides more than 18 years of use
before a code is repeated; based on 10 operations per
day. Overflow information sent from the encoder can be
used to extend the number of unique transmissions to
more than 192K.
If in the transmit process it is detected that a new but-
ton(s) has been pressed, a RESET will immediately
occur and the current code word will not be completed.
Please note that buttons removed will not have any
effect on the code word unless no buttons remain
pressed; in which case the code word will be completed
and the power-down will occur.
Name
STEP
DATA
V
V
V
Pin
S0
S1
S2
DDB
SS
DD
Number
Pin
1
2
3
4
5
6
7
8
PIN DESCRIPTIONS
Switch input 0
Switch input 1
Switch input 2 / Clock pin for
Programming mode
Battery input pin, supplies power
to the step up control circuitry
Ground reference connection
Pulse Width Modulation (PWM)
output pin / Data pin for
Programming mode
Positive supply voltage
Step up regulator switch control
Pin Description
HCS201
DS41098C-page 5