MAX9994 Ver la hoja de datos (PDF) - Maxim Integrated

Número de pieza

componentes Descripción

fabricante

MAX9994

SiGe High-Linearity, 1700MHz to 2200MHz Downconversion Mixer with LO Buffer/Switch

Maxim Integrated 

SiGe High-Linearity, 1700MHz to 2200MHz

Downconversion Mixer with LO Buffer/Switch

PIN

1, 6, 8, 14

2

3

4, 5, 10, 12,

13, 17

7

9

11

15

16

18, 19

20

EP

NAME

VCC

RF

TAP

GND

LOBIAS

LOSEL

LO1

LO2

LEXT

IF-, IF+

IFBIAS

GND

Pin Description

FUNCTION

Power-Supply Connection. Bypass each VCC pin to GND with capacitors as shown in the Typical

Application Circuit.

Single-Ended 50Ω RF Input. This port is internally matched and DC shorted to GND through a balun.

Requires an external DC-blocking capacitor.

Center Tap of the Internal RF Balun. Bypass to GND with capacitors close to the IC, as shown in the

Typical Application Circuit.

Ground

Bias Resistor for Internal LO Buffer. Connect a 549Ω ±1% resistor from LOBIAS to the power supply.

Local Oscillator Select. Logic control input for selecting LO1 or LO2.

Local Oscillator Input 1. Drive LOSEL low to select LO1.

Local Oscillator Input 2. Drive LOSEL high to select LO2.

External Inductor Connection. Connect a low-ESR, 10nH inductor from LEXT to GND. This inductor

carries approximately 100mA DC current.

Differential IF Outputs. Each output requires external bias to VCC through an RF choke (see the

Typical Application Circuit).

IF Bias Resistor Connection for IF Amplifier. Connect an 806Ω resistor from IFBIAS to GND.

Exposed Ground Paddle. Solder the exposed paddle to the ground plane using multiple vias.

Detailed Description

The MAX9994 high-linearity downconversion mixer pro-

vides 8.3dB of conversion gain and 26.2dBm of IIP3,

with a typical 9.7dB noise figure. The integrated baluns

and matching circuitry allow for 50Ω single-ended inter-

faces to the RF and the two LO ports. A single-pole,

double-throw (SPDT) switch provides 50ns switching

time between the two LO inputs with 45dB of LO-to-LO

isolation. Furthermore, the integrated LO buffer pro-

vides a high drive level to the mixer core, reducing the

LO drive required at the MAX9994’s inputs to a range

of -3dBm to +3dBm. The IF port incorporates a differ-

ential output, which is ideal for providing enhanced IIP2

performance.

Specifications are guaranteed over broad frequency

ranges to allow for use in UMTS, cdma2000, and

2G/2.5G/3G DCS1800 and PCS1900 base stations. The

MAX9994 is specified to operate over a 1700MHz to

2200MHz RF frequency range, a 1400MHz to 2000MHz

LO frequency range, and a 40MHz to 350MHz IF fre-

quency range. Operation beyond these ranges is pos-

sible; see the Typical Operating Characteristics for

additional details.

This device can operate in high-side LO injection appli-

cations with an extended LO range, but performance

degrades as fLO continues to increase. See the Typical

Operating Characteristics for measurements taken with

fLO up to 2200MHz. The MAX9996—a variant of the

MAX9994—provides better high-side performance

since it is tuned for a higher LO range of 1900MHz to

2400MHz. Contact the factory for details. As a result of

these higher LO frequencies, the MAX9996 may also

be a better choice for extending the RF frequency

range beyond 2200MHz.

RF Input and Balun

The MAX9994 RF input is internally matched to 50Ω,

requiring no external matching components. A DC-

blocking capacitor is required because the input is

internally DC shorted to ground through the on-chip

balun. Input return loss is typically 21dB over the entire

1700MHz to 2200MHz RF frequency range.

LO Inputs, Buffer, and Balun

The MAX9994 can be used for either high-side or low-

side injection applications with a 1400MHz to 2000MHz

LO frequency range. For a device with a 1900MHz to

2400MHz LO frequency range, refer to the MAX9996

8 _______________________________________________________________________________________

Share Link: