Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsLinear ICsMAX9981ETX+

General Description

The MAX9981 dual high-linearity mixer integrates a local

oscillator (LO) switch, LO buffer, LO splitter, and two

active mixers. On-chip baluns allow for single-ended RF

and LO inputs. The active mixers eliminate the need for

an additional IF amplifier because the mixer provides a

typical overall conversion gain of 2.1dB.

The MAX9981 active mixers are optimized to meet the

demanding requirements of GSM850, GSM900, and

CDMA850 base-station receivers. These mixers provide

exceptional linearity with an input IP3 of greater than

+27dBm. The integrated LO driver allows for a wide

range of LO drive levels from -5dBm to +5dBm. In addi-

tion, the built-in high-isolation switch enables rapid LO

selection of less than 250ns, as needed for GSM trans-

ceiver designs.

The MAX9981 is available in a 36-pin QFN package

(6mm ✕ 6mm) with an exposed paddle, and is specified

over the -40°C to +85°C extended temperature range.

Applications

GSM850/GSM900 2G and 2.5G EDGE Base-

Station Receivers

Cellular cdmaOne™ and cdma2000™ Base-

Station Receivers

TDMA and Integrated Digital Enhanced Network

(iDEN)™ Base-Station Receivers

Digital and Spread-Spectrum Communication

Systems

Microwave Point-to-Point Links

Features

♦ +27.3dBm Input IP3

♦ +13.6dBm Input 1dB Compression Point

♦ 825MHz to 915MHz RF Frequency Range

♦ 70MHz to 170MHz IF Frequency Range

♦ 725MHz to 1085MHz LO Frequency Range

♦ 2.1dB Conversion Gain

♦ 10.8dB Noise Figure

♦ 42dB Channel-to-Channel Isolation

♦ -5dBm to +5dBm LO Drive

♦ +5V Single-Supply Operation

♦ Built-In LO Switch with 52dB LO1 to LO2 Isolation

♦ ESD Protection

♦ Integrated RF and LO Baluns for Single-Ended

Inputs

MAX9981

825MHz to 915MHz, Dual SiGe High-Linearity

Active Mixer

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

19-2588; Rev 0; 9/02

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

MAX9981EGX-T -40°C to +85°C 36 QFN-EP* (6mm × 6mm)

27 LO2

GND

MAINBIAS

DIVBIAS

TAPDIV

TAPMAIN

RFMAIN

RFDIV

GND

IFDIV+

IFDIV-

IFMAIN+

IFMAIN-

LO1

LOSEL

GND

MAX9981

6mm x 6mm QFN-EP

TOP VIEW

Pin Configuration/

Functional Diagram

*EP = Exposed paddle.

cdmaOne is a trademark of CDMA Development Group.

cdma2000 is a trademark of Telecommunications Industry

Association.

iDEN is a trademark of Motorola, Inc.

Summary of content (15 pages)

PAGE 1
9-2588; Rev 0; 9/02 825MHz to 915MHz, Dual SiGe High-Linearity Active Mixer The MAX9981 active mixers are optimized to meet the demanding requirements of GSM850, GSM900, and CDMA850 base-station receivers. These mixers provide exceptional linearity with an input IP3 of greater than +27dBm. The integrated LO driver allows for a wide range of LO drive levels from -5dBm to +5dBm.
PAGE 2
MAX9981 825MHz to 915MHz, Dual SiGe High-Linearity Active Mixer ABSOLUTE MAXIMUM RATINGS VCC ........................................................................-0.3V to +5.5V IFMAIN+, IFMAIN-, IFDIV+, IFDIV-, MAINBIAS, DIVBIAS, LOSEL..................-0.3V to (VCC + 0.3V) TAPMAIN, TAPDIV ..............................................................+5.5V MAINBIAS, DIVBIAS Current ................................................5mA RFMAIN, RFDIV, LO1, LO2 Input Power ........................
PAGE 3
825MHz to 915MHz, Dual SiGe High-Linearity Active Mixer (Typical Application Circuit, VCC = +4.75V to +5.25V, PLO = -5dBm to +5dBm, fRF = 825MHz to 915MHz, fLO = 725MHz to 1085MHz, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VCC = +5.0V, PRF = -5dBm, PLO = 0dBm, fRF = 870MHz, fLO = 770MHz, TA = +25°C, unless otherwise noted.
PAGE 4
Typical Operating Characteristics (Typical Application Circuit, VCC = 5.0V, PRF = -5dBm, PLO = 0dBm, TA = +25°C, unless otherwise noted.) 2 TA = +85°C 1 5 3 2 PLO = -5dBm, 0dBm, +5dBm MAX9981 toc03 CONVERSION GAIN vs. RF FREQUENCY LOW-SIDE INJECTION fIF = 100MHz MAIN MIXER 4 CONVERSION GAIN (dB) 3 fIF = 100MHz MAIN MIXER 4 CONVERSION GAIN (dB) 4 CONVERSION GAIN (dB) fIF = 100MHz MAIN MIXER TA = -40°C 5 MAX9981 toc01 5 CONVERSION GAIN vs.
PAGE 5
825MHz to 915MHz, Dual SiGe High-Linearity Active Mixer 50 TA = +25°C 45 55 50 PLO = 0dBm 45 40 820 840 860 880 fIF = 100MHz DIVERSITY MIXER PRF = -5dBm MAX9981 toc12 60 55 50 VCC = 4.75V, 5.0V, 5.25V 45 PLO = -5dBm TA = -40°C 900 920 40 820 840 860 880 900 920 820 840 860 880 900 920 RF FREQUENCY (MHz) RF FREQUENCY (MHz) RF FREQUENCY (MHz) 2 LO - 2 RF RESPONSE vs. RF FREQUENCY HIGH-SIDE INJECTION 2 LO - 2 RF RESPONSE vs.
PAGE 6
Typical Operating Characteristics (continued) (Typical Application Circuit, VCC = 5.0V, PRF = -5dBm, PLO = 0dBm, TA = +25°C, unless otherwise noted.) 29 INPUT IP3 (dBm) 27 27 26 25 860 27 VCC = 5.0V 26 PLO = -5dBm 25 840 28 PLO = 0dBm TA = +25°C 820 fIF = 100MHz MAIN MIXER VCC = 5.25V 28 TA = -40°C 880 920 900 VCC = 4.75V 25 820 840 860 880 900 920 820 840 860 880 900 920 RF FREQUENCY (MHz) RF FREQUENCY (MHz) INPUT IP3 vs. RF FREQUENCY HIGH-SIDE INJECTION INPUT IP3 vs.
PAGE 7
825MHz to 915MHz, Dual SiGe High-Linearity Active Mixer 15 14 fIF = 120MHz MAIN MIXER 16 13 17 16 PLO = -5dBm VCC = 5.25V 15 14 PLO = 0dBm 13 fIF = 120MHz MAIN MIXER MAX9981 toc30 TA = +85°C TA = +25°C INPUT P1dB (dBm) INPUT P1dB (dBm) 16 17 INPUT P1dB (dBm) fIF = 120MHz MAIN MIXER MAX9981 toc28 17 INPUT P1dB vs. RF FREQUENCY HIGH-SIDE INJECTION INPUT P1dB vs. RF FREQUENCY HIGH-SIDE INJECTION MAX9981 toc29 INPUT P1dB vs. RF FREQUENCY HIGH-SIDE INJECTION PLO = +5dBm VCC = 5.
PAGE 8
Typical Operating Characteristics (continued) (Typical Application Circuit, VCC = 5.0V, PRF = -5dBm, PLO = 0dBm, TA = +25°C, unless otherwise noted.) 54 53 TA = +25°C TA = +-40°C 52 55 LO OFFSET 1MHz fIF = 100MHz DIVERSITY MIXER PLO = -5dBm 54 53 PLO = 0dBm 52 LO SWITCH ISOLATION vs.
PAGE 9
825MHz to 915MHz, Dual SiGe High-Linearity Active Mixer 15 20 25 LO RETURN LOSS vs. LO FREQUENCY MAX9981 toc47 0 MAIN MIXER SET BY EXTERNAL MATCHING 5 LO INPUT SELECTED 5 LO RETURN LOSS (dB) IF RETURN LOSS (dB) PLO = -5dBm, 0dBm, +5dBm 10 15 10 PLO = -5dBm 15 20 25 PLO = 0dBm 30 30 PLO = +5dBm 35 20 800 900 1000 1100 50 75 RF FREQUENCY (MHz) 100 125 150 200 175 800 1000 1100 SUPPLY CURRENT vs.
PAGE 10
825MHz to 915MHz, Dual SiGe High-Linearity Active Mixer MAX9981 Pin Description PIN NAME FUNCTION Main Channel RF Input. This input is internally matched to 50Ω and is DC shorted to ground through a balun. 1 RFMAIN 2 TAPMAIN Main RF Balun Center Tap. Connect bypass capacitors from this pin to ground. 3 MAINBIAS Bias control for the Main Mixer. Connect a 267Ω resistor from this pin to ground to set the bias current for the main mixer.
PAGE 11
825MHz to 915MHz, Dual SiGe High-Linearity Active Mixer C14 L1 3 R3 T1 6 IFMAIN_OUT 5.0V 2 C13 4:1 (200:50) TRANSFORMER C16 L2 4 1 R4 C15 5.0V 5.0V C5 C1 RFMAIN RF_MAIN TAPMAIN C11 C2 R1 MAINBIAS GND GND R2 GND DIVBIAS C12 C3 TAPDIV RFDIV RF_DIV GND 28 GND 29 30 31 VCC GND IFMAIN32 IFMAIN+ 33 GND 34 GND 35 36 VCC C10 C8 1 27 MAX9981 2 26 3 25 4 24 5 23 6 22 7 21 8 20 9 19 LO2 LO2 GND GND GND LOSEL LO SELECT GND 5.
PAGE 12
825MHz to 915MHz, Dual SiGe High-Linearity Active Mixer MAX9981 Component List COMPONENT VALUE SIZE C1, C4 33pF 0603 C2, C3 3.9pF 0603 Murata GRM1885C1H3R9C C5, C6, C9, C10 100pF 0603 Murata GRM1885C1H101J C7, C8 15pF 0603 Murata GRM1885C1H150J C11, C12 0.
PAGE 13
825MHz to 915MHz, Dual SiGe High-Linearity Active Mixer Chip Information TRANSISTOR COUNT: 358 PROCESS: BiCMOS ______________________________________________________________________________________ 13 MAX9981 Power Supply Bypassing Proper voltage supply bypassing is essential for high-frequency circuit stability. Bypass each VCC pin, TAPMAIN, and TAPDIV with the capacitors shown in the typical application circuit.
PAGE 14
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.) 36L,40L, QFN.
PAGE 15
825MHz to 915MHz, Dual SiGe High-Linearity Active Mixer Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.