SL6440 Plessey Semiconductors, SL6440 Datasheet - Page 3

• Manufacturer Part Number: SL6440
• Description: High Level Mixer
• Manufacturer: Plessey Semiconductors

SL6440
CIRCUIT DESCRIPTION
RF performance. The linearity can be programmed using the
IP pin (11).
conversion gain and output loads can be chosen for the
specific application.
returned to a supply V
the voltage on pins 3 and 14 is not low enough to saturate the
output transistors and so limit the signal swing unnecessarily.
If the voltage on pins 3 and 14 is always greater than V
outputs will not saturate. The output frequency response will
reduce as the output transistors near saturation.
output saturates.
buffer (pin 4).
The SL6440 is a high level mixer designed to have a linear
The output pins are open collector outputs so that the
Since the outputs are open collectors they should be
The choice of V
In this case the signal will be limiting at the input before the
The device has a separates supply (V
VCC2
Minimum V
where I
if the signal swing is not known:
minimum V
OUTPUT
INPUT
LO
Fig.2 Typical application and test circuit
RL
V
10µ
P
S
CC
CC
CC
50
0.1µ
1
1 = 2 (I
1 is important since it must be ensured that
0.001µ
CC
4
5
1 through a load.
P
50
=
=
=
=
x RL) + V
3
6
50
SL6440
14
(IP x RL) + VS + VCC2
programmed current
DC load resistance
max signal swing at output
-10
-11
-12
-1
-2
-3
-4
-5
-6
-7
-8
-9
0
11
12
500
0.001µ
CC
13
RF INPUT 0dBm
LOCAL OSCILLATOR INPUT LEVEL
V
V
I
V
V
Fig.4 Frequency response at constant output IF
2
P
CC
CC
CC
CC
CC
= 24mA
1 = 6V
2 = 5V
1 = 12V
2 = 10V
0.1µ
0.001µ
2) for the oscillator
+
+ +
VCC1
10µ
0.1µ
50
LOCAL OSCILLATOR FREQUENCY MHz
CC
INPUT
RF
10
2 the
a resistor from V
GdB = 20 Log
GdB = 20 Log
V
the device dissipation will have to be calculated for any
particular application.
The curves are independent of V
becomes too low the output signal swing cannot be
accommodated, and if V
not provide enough drive to sink the programmed current.
Examples are shown of performance at various supply
voltages.
equal to the current in pin 11.
CC
The current (I
The conversion gain is equal to
Device dissipation is calculated using the formula
mW diss
where V
As an example Fig.7 shows typical dissipations assuming
Fig.5 shows the intermodulation performance against I
The current in pin 14 is equal to the current in pin 3 which is
1 and V
+10
-10
Fig.3 Compression point v. total output current
0
V
V
100
I
P
P
CC
O
O
are equal. This may not be the case in pratice and
2 Diss = dissipation obtained from graph (Fig.6)
-1dBm COMPRESSION POINT
+ +
THAN LOCAL OSCILLATOR
56.61 I
56.61 I
10
SIGNAL 10MHz HIGHER
P
+
) programmed into pin 11 can be supplied via
CC
1 or form a current source.
= 2 I
= voltage on pin 3 or pin 14
= voltage on pin 11
= programming current (mA)
2RL I
TOTAL OUTPUT CURRENT (2I
RL I
20
P
P
+ 0.0785
+ 0.0785
CC
P
P
P
V
2 becomes too low the circuit will
1000
30
O
+ V
(mA)
+
+ +
for single-ended output
for differential output
LOCAL OSCILLATOR = 30MHz 0dBm
RF INPUT = 40MHz
IF = 10MHz
P
V
V
V
V
40
I
CC
CC
CC
CC
CC
P
1 = 15V
2 = 12V
1 = 12V
2 = 10V
+ V
1 and V
CC
50
2 Diss
P
)
CC
60
2 but if V
+ +
+
70
CC
P
1
.