MAX9987:+14dBm to +20dBm LO Buffers/Splitters with ±1dB Variation

The MAX9987 and MAX9988 LO buffers/splitters each integrate a passive two-way power splitter with highisolation input and output buffer amplifiers. These buffers are designed to provide the high output (+14dBm to +20dBm) necessary to drive the LO inputs of high-linearity passive mixers, while offering 40dB reverse isolation to prevent LO pulling. The MAX9987 is internally matched for the cellular/GSM bands, and the MAX9988 is matched for the DCS/PCS/UMTS bands. The typical application circuit provides a nominal +17dBm output power with ±1dB variation over supply, temperature, and input power. With two optional resistors, the output power can be precision set from +14dBm to +20dBm. The devices offer more than 30dB output-to-output port isolation, and are offered in 5mm x 5mm 20-pin thin QFN packages with exposed paddle.

Key Features
  • ±1dB Output Power Variation
  • +14dBm to +20dBm Adjustable Output Power
  • Two-Way Power Splitting
  • 40dB Reverse Isolation
  • More than 30dB Output-to-Output Isolation
  • Low Output Noise: -170dBc/Hz at +17dBm
  • 160mA Supply Current at +17dBm
  • Isolated PLL Output (+3dBm)
MAX9987, MAX9988: Typical Operating Circuit
MAX9987, MAX9988: Typical Operating Circuit
Applications/Uses
  • Base-Station Main and Diversity Channels
  • Cellular/GSM/DCS/PCS/UMTS Base Station
  • Coherent Receivers
  • ISM Wireless LAN
  • Local Multipoint Distribution Service
  • Point-to-Point Systems
  • Tx/Rx LO Drive
  • Wireless Local Loop (WLL)
DataSheet
titleDownload file
MAX9987-MAX9988 Data SheetMAX9987-MAX9988.pdf
Parametrics
Part NumberLO Driver OutputsPLL Driver OutputsRF Freq.
(MHz)
RF Freq.
(MHz)
POUT
(dBm)
POUT
(dBm)
VCC
(V)
ISUPPLY
(mA)
Footprint
(mm x mm)
Package/Pins
minmaxminmax
MAX9987YesYes700110014.319.74.75 to 5.251555.0 x 5.0TQFN/20
MAX99881500220014.219.5162TQFN/20
Design kits & evaluation modules
Related Products
  • MAX9989:+14dBm to +20dBm LO Buffers with ±1dB Variation
  • MAX9990:+14dBm to +20dBm LO Buffers with ±1dB Variation
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX9987ETPNo Longer AvailableMAX9987ETP+TQFN,;20 pin;26 mm²-40°C to +85°CNo
MAX9987ETP+ActiveTQFN,;20 pin;26 mm²-40°C to +85°CLead Free
MAX9987ETP+TActiveTQFN,;20 pin;26 mm²-40°C to +85°CLead Free
MAX9987ETP-TNo Longer AvailableMAX9987ETP+TQFN;20 pin-40°C to +85°CSee data sheet
MAX9987-MAX9988.pdf MAX9988
Simplifying Tomorrow's LO Drive Designs with the MAX9987-90 Family of LO Buffers/Splitters MAX9990
MAX9987-MAX9988.pdf MAX9988