MAX9987 MAXIM [Maxim Integrated Products], MAX9987 Datasheet - Page 10

• Manufacturer Part Number: MAX9987
• Manufacturer: MAXIM [Maxim Integrated Products]

+14dBm to +20dBm LO Buffers/Splitters
with ±1dB Variation
Table 1. External Resistor Values for +14dBm to +20dBm Output Power
Table 2. Component Values for Typical
Application Circuit
Each of the output amplifiers are similar to the input
amplifier, except they are biased higher to provide more
output power. For example, with an input power of
+10dBm, the MAX9987 can deliver +20dBm at both out-
puts. The bias is adjustable; see Table 1 for details.
Both RF outputs are internally matched to 50Ω, with a
typical VSWR limit of 2:1. Provide DC blocking capaci-
tors at the outputs.
10
C2, C4, C5, C7, C8,
C9, C12, C13, C14
OUTPUT POWER
DESIGNATION
R1, R2, R4, R5
______________________________________________________________________________________
C1, C3, C6
NOMINAL
C10, C11
(dBm)
+20
+19
+18
+17
+16
+15
+14
R3
Driver Amplifiers and Outputs
(LOWBAND)
See Table 1.
MAX9987
R
1.35k
Open
Open
Open
Open
2.2k
5.0k
100pF
1
100Ω
47pF
5pF
(Ω)
COMPONENT VALUE
(HIGHBAND)
R
See Table 1.
Open
Open
Open
Open
2.0k
3.0k
6.0k
MAX9988
2
100nF
(Ω)
100Ω
22pF
10pF
R
Open
Open
Open
Open
1.8k
0.9k
0.6k
4
(Ω)
All input and output matching is accomplished on-chip;
no external matching circuitry is required. Use a DC
block of about 47pF (lowband) or 22pF (highband) at
the input and the outputs. Because these parts are
internally broadband matched, adjusting external com-
ponent values can optimize performance for a particu-
lar band.
In the case of the MAX9987, the typical required input
drive level is +7dBm for +17dBm output, or +10dBm for
+20dBm output. The MAX9988 uses slightly higher
input levels (see Table 1). The typical VCO cannot pro-
vide sufficient drive by itself; the typical application fol-
lows the VCO with attenuation (about +3dB), and then
with a low-noise gain block. This allows the VCO to
drive the MAX9987/MAX9988 input at the required level
without being load-pulled.
The output drive of the MAX9987/MAX9988 is nominally
+17dBm ±1dB. This is the typical application, with no
external bias-setting resistors at INBIAS and OUTBIAS.
Output power can be set from +14dBm to +20dBm by
using the bias-setting resistor values listed in Table 1.
TRANSISTOR COUNT: 89
PROCESS: BiCMOS
R
Open
Open
Open
Open
3.0k
1.1k
0.6k
5
(Ω)
Applications Information
Input and Output Matching
INPUT DRIVE
MAX9987
(dBm)
Chip Information
10 ±3
9 ±3
8 ±3
7 ±3
6 ±3
5 ±3
4 ±3
Output Drive Level
Input Drive Level
INPUT DRIVE
MAX9988
(dBm)
12 ±3
11 ±3
10 ±3
9 ±3
8 ±3
7 ±3
6 ±3