HCS473T-I/SN Microchip Technology, HCS473T-I/SN Datasheet - Page 11

• Manufacturer Part Number: HCS473T-I/SN
• Description: IC KEELOQ 3AXIS TRANSCODER 8SOIC
• Manufacturer: Microchip Technology
• Series: KEELOQ®r
• Type: Code Hopping Encoder and Transponderr

Specifications of HCS473T-I/SN

• Applications: Access Control Systems
• Mounting Type: Surface Mount
• Package / Case: *
• Lead Free Status / RoHS Status: Request inventory verification / Request inventory verification

2.3.5
The HCS473 runs on an internal RC oscillator. The
internal oscillator may vary ±10% over the device’s
rated voltage and temperature range for commercial
temperature devices. A certain percentage of indus-
trial temperature devices vary further on the slow side,
-20%, when used at higher voltages (V
cold temperature. The LF and RF communication
timing values are subject to these variations.
2.3.6
The HCS473’s battery voltage detector detects when
the supply voltage drops below a predetermined value.
The value is selected by the Low Voltage Trip Point
Select (VLOWSEL) configuration option (Section 3.3).
The low voltage detector result is included in encoder
transmissions (VLOW) allowing the receiver to indicate
when the transmitter battery is low (Section 3.1.4.6).
The HCS473 also indicates a low battery condition by
changing the LED operation (Section 3.1.5).
2.3.7
The S3/RFEN pin may be used as a button input or RF
enable output to a compatible PLL. Select between S3
button input and RFEN functionality with the RFEN
configuration option (Table 2-2).
TABLE 2-2:
 2002 Microchip Technology Inc.
0
1
RFEN
S3 button input pin with Schmitt Trigger
detector and internal pull-down resistor.
RFEN output driver.
S3 may not be used as a button input if the
RFEN option is enabled
INTERNAL RC OSCILLATOR
LOW VOLTAGE DETECTOR
THE S3/RFEN PIN
Resulting S3/RFEN Configuration
RFEN OPTION
DD
> 3.5V) and
Preliminary
HCS473
DS40035C-page 9