HCS473T-I/SN Microchip Technology, HCS473T-I/SN Datasheet - Page 35

• 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

FIGURE 3-22:
3.2.8
3.2.8.1
The wake-up Acknowledge sequence has the shortest,
but fixed, PLL setup time, 1LF
3.2.8.2
PLL setup occurs on the rising edge of the first VID bit
in anticipation of the TID Acknowledge. The setup time
before the ACK begins is therefore a function of...
• LF baud rate
• VID value
• TID value
3.2.8.3
Command sequences ending with CRC bits and
expecting an Acknowledge response have a similar
PLL setup sequence. This includes “Present Transport
Code”, “Write” and “Anticollision Off”.
PLL setup occurs on the rising edge of the first CRC bit
in anticipation of the Acknowledge. The setup time is
therefore a function of...
• LF baud rate
• CRC value
• Response time: T
 2002 Microchip Technology Inc.
Response
SKIPACK = 0 - Field Acknowledge sent when device wakes
Inductive
125 kHz Field
Communication from reader to HCS473
Communication from HCS473 to reader
(on LC pins)
(DATA)
(LC)
RF
RFEN DURING LF
COMMUNICATION (Figure 3-23)
Wake-up Sequence
Transponder Select Sequence
ACK Response Sequences
Concluding with CRC
TPACK
Calculating Communication T
T
SF
, T
WRT
TE
Simultaneous LF
Acknowledge
.
, T
3LF
3LF
RF Acknowledge
(LFRSP=1)
AOACK
(RFRSP=1)
TE
TE
8LF
3LF
8LF
TE
.
TE
TE
3LF
TE
Preliminary
T
CMD
E
Command
3.2.8.4
Command sequences ending with CRC bits and
expecting data response (code hopping word) have a
similar PLL setup sequence. This includes “IFF”,
“Read” and “Request Hopping Code”.
PLL setup occurs on the rising edge of the first CRC bit
in anticipation of the data transmission. The setup time
is therefore a function of...
• LF baud rate
• CRC value
• Response time: T
T
CMD
Data Response Sequences
Concluding with CRC
IFF
, T
READ
, T
HOP
HCS473
DS40035C-page 33
.