KESRX05
Name
RFOUT
Function
Output from internal RF amplifier
The RF amplifier has a high output impedance. The
internal 300Ω resistor is used to improve the ESD
protection of RFOUT.
For further information refer to the AC Electrical
Characteristics.
10
11
V
EE
RF
RFIN
Negative supply for RF circuits
nternal input RF amplifier
To a first order approximation the input impedance
of the RF amplifier at UHF frequencies is set by the
internal bias resistor and capacitor network. Effects
of internal and external stray parasitics ignored.
For further information please refer to the AC
Electrical Characteristics.
12
AGC
RF AGC time constant
The attack and decay time constant of the AGC is
set by the internal series resistor, current sink and
the external capacitor C8. Increasing the decay time
constant of the AGC circuit will impair the time to
good data of the receiver from power up PD0 to PD2.
For further information please refer to the IF Amp/
RSSI Detector section of the Functional Description.
13
PEAK
Data signal peak detector output
The peak detector output is designed to be a low
impedance output. The peak detector monitors the
peak of the signal at pin 20 (DF2).
For further information please refer to the Baseband
section of the Functional Description.
14
DATAOP
Sliced data output
The data output is the inverted sense of the input
signal at pin 20 (DF2) and is designed as a high im-
pedance output via two internal sink and source cur-
rent generators
Table 1 Pin descriptions (continued)
HIGH
240µA
RFIN
1k
5p
830
10p
V
EE
RF
Pin
9
Schematic
RFOP
300
240µA
(AGC OFF)
360
AGC
6µA
300
PEAK
190k
V
EE
1
20µA
DATAOP
LOW
2
20µA
Cont…
4
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