OQ2538HP NXP Semiconductors, OQ2538HP Datasheet - Page 7

• Manufacturer Part Number: OQ2538HP
• Manufacturer: NXP Semiconductors

Specifications of OQ2538HP

• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Supplier Unconfirmed

Philips Semiconductors
An external 200
recommended in order to match the inputs to a differential
transmission line, coupled microstrip or stripline with an
odd mode impedance Z
For single-ended excitation, separate matching networks
on IN and INQ, as depicted in Fig.5, achieve optimum
matching. Care should be taken to avoid DC loading, since
the OQ2538HP controls its own DC input voltage.
The resistors on the unused input INQ may be combined
for convenience.
In both cases, the essence of good matching is the equity
of the circuitry on both input pins. The impedance seen on
pins IN and INQ should be as equal as possible. For more
information see “Application Note AN96051 ” describing
the OM5801 STM16 demo board.
1998 Oct 14
handbook, halfpage
handbook, halfpage
SDH/SONET STM16/OC48 main amplifiers
Z o(odd) = 50
transmission line
differential line
Fig.5 Single-ended input matching.
Fig.4 Differential input matching.
Z o = 50
50
resistor between IN and INQ is
o(odd)
22 nF
22 nF
22 nF
22 nF
200
= 50 , as shown in Fig.4.
100
100
22 nF
22 nF
IN
INQ
IN
INQ
MGM116
MGM115
7
RF output matching circuit
Matching of the main amplifier outputs, OUT and OUTQ, is
not mandatory. In most applications, the receiving end of
the transmission line will be properly matched, so very little
reflection will occur. Matching the transmitting end to
absorb these reflections is only recommended for very
sensitive applications. In such cases, 100
resistors should be connected from OUT and OUTQ to
ground, as close as possible to the IC pins. These
matching resistors will not be needed in most applications,
however. The output circuit of the OQ2538HP is depicted
in Fig.6. For more information see “Application Note
AN96051” describing the OM5801 STM16 demo board.
handbook, halfpage
OUT
Fig.6 RF output topology.
OQ2538HP; OQ2538U
100
100
Product specification
MGM117
GND
OUTQ
pull-up