Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsLinear ICsMAX9988ETP+

General Description

The MAX9987 and MAX9988 LO buffers/splitters each

integrate a passive two-way power splitter with high-

isolation 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 resis-

tors, 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

5mm 20-pin thin QFN packages with exposed paddle.

Applications

Cellular/GSM/DCS/PCS/UMTS Base Station

Tx/Rx LO Drive

Base Station Main and Diversity Channels

Coherent Receivers

ISM Wireless LAN

Wireless Local Loop

Local Multipoint Distribution Service

Point-to-Point Systems

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

+14dBm to +20dBm LO Buffers/Splitters

with ±1dB Variation

________________________________________________________________ Maxim Integrated Products 1

MAX9987

MAX9988

BIAS

BIASIN

RF LO

TO PLL

PRESCALER

PLL BUFFER

INPUT AMP

OUTPUT AMP

(2)

OUTPUT AMP

(1)

RF INPUT

(1)

IF OUTPUT

(1)

PASSIVE TWO-WAY

POWER SPLITTER

(+7dBm)

OUTPLL

(+3dBm)

OUT1

(+17dBm)

OUT2

(+17dBm)

BIASOUT

BIAS

CONTROL

NETWORK

RF INPUT

(2)

IF OUTPUT

(2)

Typical Operating Circuit and Block Diagram

Ordering Information

19-2416; Rev 2; 3/04

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

PART

TEMP

RANGE

PIN-

PACKAGE

FREQUENCY

RANGE

MAX9987ETP-T

-40°C to 85°C

20 Thin

QFN-EP*

700MHz to

1100MHz

MAX9988ETP-T

-40°C to 85°C

20 Thin

QFN-EP*

1500MHz to

2200MHz

*EP = Exposed paddle.

Summary of content (12 pages)

PAGE 1
9-2416; Rev 2; 3/04 +14dBm to +20dBm LO Buffers/Splitters with ±1dB Variation Features 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.
PAGE 2
MAX9987/MAX9988 +14dBm to +20dBm LO Buffers/Splitters with ±1dB Variation ABSOLUTE MAXIMUM RATINGS VCC1, VCC2, VCC3, VCCREF to GND.................................................-0.3V to +6.0V IN to GND ...................................................-0.3V to (VCC + 0.3V) OUT1, OUT2, OUTPLL to GND ......................................-0.3V to (VCC + 0.3V) REF to GND ......................................................Source/Sink 5mA INBIAS, OUTBIAS, to GND..................................-0.
PAGE 3
+14dBm to +20dBm LO Buffers/Splitters with ±1dB Variation (Typical Application Circuit, VCC = 4.75V to 5.25V, 50Ω environment, +4dBm < PIN < +10dBm, 700MHz < fIN < 1100MHz, TA = -40°C to +85°C, unless otherwise noted. Typical specifications are for VCC = 5.0V, PIN = +7dBm, fIN = 900MHz, and TA = +25°C, unless otherwise noted.) (Note 1) PARAMETER Operating Frequency Output Power (Main Drivers) SYMBOL f POUTLO CONDITIONS MIN 700 TYP Low power setting, PIN = +4dBm (see Table 1 for resistor values) 14.
PAGE 4
MAX9987/MAX9988 +14dBm to +20dBm LO Buffers/Splitters with ±1dB Variation AC ELECTRICAL CHARACTERISTICS—MAX9988 (Typical Application Circuit, VCC = 4.75V to 5.25V, 50Ω environment, +6dBm < PIN < +12dBm, 1500MHz < fIN < 2200MHz, and TA = -40°C to +85°C, unless otherwise noted. Typical specifications are for VCC = 5.0V, PIN = +9dBm, fIN = 1800MHz, and TA = +25°C unless otherwise noted.
PAGE 5
+14dBm to +20dBm LO Buffers/Splitters with ±1dB Variation MAX9987 SUPPLY CURRENT vs. OUTPUT POWER OUTMAIN 155 TA = -40°C 150 16 14 13 14 13 12 11 11 140 10 0 5 10 15 20 OUTPUT POWER vs. INPUT POWER, OUTPLL 3 2 TA = -40°C 1 TA = +25°C 0 -1 -2 TA = +85°C -3 19 OUTPUT POWER (dBm) 4 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 INPUT POWER (dBm) OUTPUT POWER vs. FREQUENCY, OUT2 OUTPUT POWER vs.
PAGE 6
Typical Operating Characteristics (continued) (VCC = 5.0V, nominal bias, fIN = 900MHz, PIN = +7dBm, TA = +25°C, unless otherwise noted.) (Shaded regions are outside the guaranteed operating range, and are provided for reference only.) MAX9987 SMALL-SIGNAL GAIN vs. FREQUENCY OUT2 -10 17 GAIN (dB) 160 PLL BIASED 155 16 OUT1 15 150 VCC = 5.0V TA = +25°C PIN = +7dBm -5 MAX9987 toc12 18 VCC = 5.0V TA = +25°C PIN = -15dBm NOMINAL BIAS INPUT RETURN LOSS vs.
PAGE 7
+14dBm to +20dBm LO Buffers/Splitters with ±1dB Variation MAX9988 160 TA = +25°C 155 TA = -40°C 150 16 15 TA = +85°C 14 13 13 11 10 10 15 OUTPUT POWER vs. INPUT POWER, OUTPLL OUTPUT POWER vs. FREQUENCY, OUT1 TA = -40°C 0 -1 -2 OUTPUT POWER vs.
PAGE 8
Typical Operating Characteristics (continued) (VCC = 5.0V, nominal bias, fIN = 1800MHz, PIN = +7dBm, TA = +25°C, unless otherwise noted.) (Shaded regions are outside the guaranteed operating range, and are provided for reference only.) MAX9988 SMALL-SIGNAL GAIN vs. FREQUENCY OUT2 15 14 13 155 OUT1 -18 11 10 150 4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.5 -20 1.5 1.6 1.7 SUPPLY VOLTAGE (V) OUTPUT RETURN LOSS vs. FREQUENCY 2.1 2.2 1.
PAGE 9
+14dBm to +20dBm LO Buffers/Splitters with ±1dB Variation PIN NAME FUNCTION 1, 4, 8, 9, 13, 17, 18, EP GND 2 IN 3 VCCREF 5 REF 6 BIASIN Bias Connection for Input Buffer. Set compressed power point for input amplifier with a resistor to REF or GND. For +17dBm output power, no external biasing resistors are required. See Applications Information section for information. 7 BIASOUT Bias Connection for Output Amplifiers.
PAGE 10
MAX9987/MAX9988 +14dBm to +20dBm LO Buffers/Splitters with ±1dB Variation Table 1. External Resistor Values for +14dBm to +20dBm Output Power NOMINAL OUTPUT POWER (dBm) R1 (Ω) R2 (Ω) R4 (Ω) R5 (Ω) MAX9987 INPUT DRIVE (dBm) MAX9988 INPUT DRIVE (dBm) +20 1.35k 2.0k Open Open 10 ±3 12 ±3 +19 2.2k 3.0k Open Open 9 ±3 11 ±3 10 ±3 +18 5.0k 6.0k Open Open 8 ±3 +17 Open Open Open Open 7 ±3 9 ±3 +16 Open Open 1.8k 3.0k 6 ±3 8 ±3 +15 Open Open 0.9k 1.
PAGE 11
+14dBm to +20dBm LO Buffers/Splitters with ±1dB Variation 5.0V 5.0V C1 C2 C3 MAX9987 MAX9988 C4 TO OUTPUT 1 C13 C14 20 GND 19 18 17 OUT1 GND GND OUT TO PLL (+3dBm) VCC1 OUTPLL R3 100Ω EXPOSED PAD 1 5.0V 16 15 VCC2 C11 INPUT FROM LO IN 2 14 3 13 4 12 C12 VCC2 C5 VCCREF 5.0V C6 GND C7 GND REF BIAS 11 5 VCC3 5.0V VCC3 C10 R4* OUT2 10 9 GND 8 BIASOUT BIASIN 7 GND 6 C9 TO OUTPUT 2 R5* C8 R1* R2* * FOR THESE VALUES, SEE TABLE 1.
PAGE 12
Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) 32L QFN.EPS MAX9987/MAX9988 +14dBm to +20dBm LO Buffers/Splitters with ±1dB Variation Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.