micrf220 Micrel Semiconductor, micrf220 Datasheet - Page 12

• Manufacturer Part Number: micrf220
• Description: 300mhz To 450mhz, 3.3v Ask/ook Receiver With Rssi And Squelch
• Manufacturer: Micrel Semiconductor

Micrel, Inc.
When four or less out of eight pulses (at DO′signal labeled
in Figure 1) are good, the DO output is squelched. If good
pulse count increases to seven or more in any eight
sequential pulses, squelch is disabled, thereby allowing
data to output at DO pin. A good pulse has a duration that
is greater than the values listed in Table 5, and it can be a
high or a low pulse. For other frequencies pulse times are
calculated as follows:
PW = PW
August 2010
@433.92 MHz
×
⎛
⎜ ⎜
⎝
Operating
433.92
Freq(MHz)
⎞
⎟ ⎟
⎠
Eq. 6
12
V
V
V
0V
0V
SEL1
DD
DD
Table 5. Pulse Width Settings in Squelch
V
V
V
0V
0V
SEL0
DD
DD
Pulse Width at
315MHz (μs)
420
210
105
53
Pulse Width at
M9999-082610-A
433.92MHz
(μs)
305
152
MICRF220
76
38