Rainbow Electronics MAX3541 User Manual
Page 8

MAX3541
Complete Single-Conversion
Television Tuner
8
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IFVGA VOLTAGE GAIN vs. IFAGC VOLTAGE
IFAGC VOLTAGE (V)
IFVGA VOLTAGE GAIN (dB)
MAX3541 toc21
0.5
1.0
1.5
2.0
2.5
3.0
10
20
30
40
50
60
+25
°C
-40
°C
+85
°C
IFVGA IM3 vs. IFAGC VOLTAGE
IFAGC VOLTAGE (V)
IFVGA IM3 (dBc)
MAX3541 toc22
INPUT POWER (dBm)
-80
-60
-40
-20
0.5
1.0
1.5
2.0
2.5
3.0
-60
-50
-40
-30
-20
P
IN
V
OUT
= 1.5 V
P-P
IM3
Pin Description
Typical Operating Characteristics (continued)
(MAX3541EV kit, V
CC
= +3.3V, V
IFAGC
= 3.0V, V
RFAGC
= 3.0V, T
A
= +25°C, unless otherwise noted.)
PIN
NAME
DESCRIPTION
1
SCL
2-Wire Serial-Clock Interface. Requires a pullup resistor to V
CC
.
2
SDA
2-Wire Serial-Data Interface. Requires a pullup resistor to V
CC
.
3, 10, 23, 28,
32, 33, 37,
41, 44
V
CC
Power Supply Connections. Bypass each supply pin to ground with a 1000pF capacitor.
4
UHF_IN
UHF RF Input. Requires a DC-blocking capacitor.
5
VHF_IN
VHF RF Input. Requires a DC-blocking capacitor.
6
RFGND2
RF Ground. Bypass to the PCB’s ground plane with a 1000pF capacitor. Do not connect RFGND2
and RFGND3 together.
7
LEXT
RF VGA Supply Voltage. Connect through a 270nH pullup inductor to V
CC
.
8
RFGND3
RF Ground. Bypass to the PCB’s ground plane with a 1000pF capacitor. Do not connect RFGND2
and RFGND3 together.
9
RFAGC
RF V G A G ai n C ontr ol V ol tag e. Accep ts a D C vol tag e fr om 0.5V ( m i ni m um g ai n) to 3V ( m axi m um g ai n) .
11–22, 27, 31
GND
Ground. Connect to the PCB’s ground plane.
24
IFOUT2-
Inver ti ng IF V G A Outp ut. C onnect to the i np ut of an anti - al i asi ng fi l ter . Req ui r es a D C - b l ocki ng cap aci tor .
25
IFOUT2+
N oni nver ti ng IF V GA O utp ut. C onnect to the i np ut of an anti - al i asi ng fi l ter . Req ui r es a D C - b l ocki ng cap aci tor .
26
IFAGC
IF VGA Gain Control Voltage. Accepts a DC voltage from 0.5V (minimum gain) to 3V (maximum gain).
29
IFIN-
Inverting IF VGA Input. Connect to the output of an IF-SAW filter.
30
IFIN+
Noninverting IF VGA Input. Connect to the output of an IF-SAW filter.
34
IFOVLD
IF Overload Detector Open-Collector Output. Requires a 10k
Ω pullup resistor to V
CC
.
35
IFOUT1+
Noninverting IF LNA Output. Requires a DC-blocking capacitor.
36
IFOUT1-
Inverting IF LNA Output. Requires a DC-blocking capacitor.
38
LDO
VCO LDO Bypass. Bypass to ground with a 0.47μF capacitor.