RF2402 RF Micro Devices, RF2402 Datasheet - Page 3

• Manufacturer Part Number: RF2402
• Description: UHF Quadrature Modulator
• Manufacturer: RF Micro Devices

Rev B1 010329
Pin
1
2
3
4
5
6
7
8
9
Function
PHASE
Q REF
Q SIG
VDD2
VDD1
LO IN
I REF
I SIG
PD
Description
Power supply for the RF Output amplifier. An external RF bypass
capacitor is needed. The trace length between the pin and the bypass
capacitor should be minimized. The ground side of the capacitor should
connect immediately to the ground plane.
Power supply for all other circuits. An external RF bypass capacitor is
needed.
Power Down control. When this pin is 0V all circuits are turned off, and
when +5V all circuits are operating. This is a high impedance input,
internally connected to the gates of a few FETs. To minimize current
consumption in power down mode, this pin should be as close to 0V as
possible. In order to maximize output power this pin should be as close
to +5V as possible during normal operation.
Baseband input to the I mixer. This pin is DC coupled. Maximum output
power is obtained when the input signal has a peak to peak amplitude
of 5V. The DC level supplied to this pin should be 2.5±0.5V. The SIG
and REF inputs are inputs of a differential amplifier. Therefore the REF
and SIG inputs are interchangeable. If swapping the I SIG and I REF
pins, the Q SIG and Q REF also need to be swapped to maintain the
correct phase. It is also possible to drive the SIG and REF inputs in a
balanced mode. This will increase the gain.
Reference voltage for the I mixer. This voltage should be the same as
the DC voltage supplied to the I SIG pin. To obtain a carrier suppres-
sion of better than 40dB it may be tuned ±0.15V (relative to the I SIG
DC voltage). Without tuning, it will typically be better than 25dB.
Reference voltage for the Q mixer. This voltage should be the same as
the DC voltage supplied to the Q SIG pin. To obtain a carrier suppres-
sion of better than 40dB it may be tuned ±0.15V (relative to the Q SIG
DC voltage). Without tuning, it will typically be better than 25dB. The
SIG and REF inputs are inputs of a differential amplifier. Therefore the
REF and SIG inputs are interchangeable. If swapping the I SIG and I
REF pins, Q SIG and Q REF also need to be swapped to maintain cor-
rect phase. It is also possible to drive the SIG and REF inputs in a bal-
anced mode. This will increase the gain.
Baseband input to the Q mixer. This pin is DC coupled. Maximum out-
put power is obtained when the input signal has a peak to peak ampli-
tude of 5V. The DC level supplied to this pin should be 2.5±0.5V.
The input of the phase shifting network. This high impedance input can
be matched with an external 56
nally connected to ground through a 4k resistor. Putting a DC voltage
on this pin is not recommended. However, connecting this pin to
ground, e.g. through a shunt inductor, is allowed.
This pin adjusts the phase of the I/Q signals. However, the control is
very sensitive and hard to control. Control voltage change for a few
degrees adjustment is in the order of 10mV. Device to device and tem-
perature variation are not characterized. Therefore it is not recom-
mended to use this pin; leave it not connected. Do NOT connect it to
ground. For compensating large errors in the I/Q signals supplied to the
device or in control loops, this pin may prove useful.
termination resistor. This pin is inter-
Interface Schematic
Q REF
Q SIG
I REF
I SIG
LO IN
RF2402
PHASE
5-3
5