LM1872

Manufacturer Part NumberLM1872
DescriptionRadio Control Receiver/Decoder
ManufacturerNational Semiconductor
LM1872 datasheet
 


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AC Electrical Characteristics
Parameter
Conditions
Mixer Input Impedance
Pin 5 to Pin 4
(See Curves)
Mixer Output Impedance
Pin 18 to GND
IF Transconductance
Pin 17 to Pin 15 (AGC Off)
IF Input Impedance
Pin 17 to GND
IF Output Impedance
Pin 15 to GND (AGC Off)
IF Carrier Level
Pin 15 V
e
IN
(AGC On)
Detector Threshold
Relative to RF Input
V
Pin 5
IN
Relative to IF Output
Analog Pulse Width
Ratio of Received Pulse Width
Accuracy
Pins 11
12 to Transmitted
Pulse Width
V
100 V
e
IN
Note 1 The criteria for the outputs to be considered ‘‘solid’’ are as follows
DIGITAL In order to check the decoding section four RF frames are inputted in sequence with the proper codes to exercise all four possible logical
output combinations at pins 7 and 9 For each frame the proper output logic state must exist
ANALOG Each analog pulse width (measured at pins 11
widths obtained for V
100 V
e
IN
Note 2 For operation in ambient temperatures above 25 C the device must be derated based on a 150 C maximum junction temperature and a package
thermal resistance of 75 C W junction to ambient
Typical Performance Characteristics
Supply Current vs
Supply Voltage
Sensitivity vs Supply Voltage
(Continued)
Min
49 MHz
20 k
455 kHz
2 6
(AGC On)
100 V
Pin 15
V
0 015
a
a
0 95
Pin 5 for
12) in any of the above four successive frames must not vary more than
Analog Channel Output
Voltage vs Load Current
Mixer Transconductance (g
)
m
vs Input Frequency
3
Typ
Max
Units
5 pF
a
250
k
4 1
5 6
mmhos
5500
800
k
2
M
70
mVrms
20
V
V
0 025
V
0 040
V
a
a
a
a
1 0
1 05
ms ms
5% from the pulse
g
Digital Channel
Collector Output Voltage
vs Load Current
IF Output Signal Level vs RF
Input Signal Level
TL H 7912– 2