Datasheet

MAX3543 Evaluation Kit
Evaluates: MAX3543
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4) Verify that the device has locked to the correct fre-
quency by checking the LOCK light in the bottom-
right corner of the window. A green light indicates a
successful lock.
5) Set the RF signal generator to a 666MHz frequency
and a -90dBm power level. Enable the RF signal
generator’s output.
6) Set the center frequency of the spectrum analyzer
to 36.15MHz and the span to 1MHz. Set the refer-
ence level to 0dBm. Increase the input power of the
signal generator until the output level reaches
-22dBm. This is the output level that corresponds
to approximately 1V
P-P
output across the IC's
DTVOUT+ and DTVOUT- pins. The voltage gain of
the receiver can be calculated by taking the differ-
ence in dB between the input and output power and
applying correction factors to compensate for the
50ω-to-75ω min loss pad at the input (R10 and R11),
T1 balun (4:1 impedance ratio), and R7 442ω series
resistor at the output.
Voltage gain can be calculated from:
A
V
= 3.96dB + 20 LOG(V
OUT,RMS
/V
IN,RMS
)
+ 6dB +19.86dB
or
A
V
= (P
OUT
- P
IN
) + 29.82dB
where:
3.96dB is the voltage loss due to the input min
loss pad,
( )
IN
IN,RMS
P dBm 30
V 50x10
10
 
−
=
 
 
is the input RMS voltage calculated from the input
power P
IN
(i.e., power from the RF signal genera-
tor),
( )
OUT
OUT,RMS
P dBm 30
V 50x10
10
 
−
=
 
 
is the output RMS voltage calculated from the
output power P
OUT
(i.e., power at the spectrum
analyzer input),
6dB is the output transformer voltage ratio,
19.86dB (i.e., 20 LOG(492/50)) is the voltage loss
due to R7 series resistor.
The calculated voltage gain should be approxi-
mately 85dB.
RF Gain-Control Range (RFVGC)
To measure the gain-control range in the RF stage, follow
the steps below:
1) Set RFVGC to +3V.
2) Set IFVGC to +3V.
3) Adjust the RF input power to achieve -22dBm at the
IFOUT_DTV output. Record this as the reference
output level.
4) Set RFVGC to +0.5V and record the change in the
IFOUT_DTV output level in dB relative to -22dBm.
This change in output power is the gain-control
range of the RF stage.
5) The RF gain-control range should be approximately
53dB.
6) Note that it might be necessary to increase the input
power level with RFVGC = +0.5V in order to make
an accurate level measurement. If this is necessary,
calculate the RF gain-control range by first calculat-
ing the gain with RFVGC = +3V, then calculate the
gain with RFVGC = +0.5V and take the difference
between these two gain levels.
IFVGA Gain-Control Range (IFVGC)
To measure the gain-control range in the IFVGA stage,
follow the steps below:
1) Set RFVGC to +1V.
2) Set IFVGC to +3V.
3) Adjust the RF input power to achieve -40dBm at the
IFOUT_DTV output. Record this as the reference
output level.
4) Set IFVGC to +0.5V and record the change in the
IFOUT_DTV output level in dB relative to -40dBm.
This change in output power is the gain-control
range of the IFVGA stage.
5) The IFVGA gain-control range should be approxi-
mately 42dB.
6) Note that it might be necessary to increase the input
power level with IFVGC = +0.5V in order to make
an accurate level measurement. If this is necessary,
calculate the IFVGA gain control range by first cal-
culating the gain with IFVGC = +3V, then calculate
the gain with IFVGC = +0.5V and take the difference
between these two gain levels.