Datasheet

MAX9996
Detailed Description
The MAX9996 high-linearity downconversion mixer pro-
vides 8.3dB of conversion gain and 26.5dBm 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, dou-
ble-throw (SPDT) switch provides 50ns switching time
between the two LO inputs with 43dB of LO-to-LO isola-
tion. Furthermore, the integrated LO buffer provides a
high drive level to the mixer core, reducing the LO drive
required at the MAX9996’s inputs to a -3dBm to +3dBm
range. The IF port incorporates a differential 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
MAX9996 is specified to operate over a 1700MHz to
2200MHz RF frequency range, a 1900MHz to 2400MHz
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 low-side LO injection appli-
cations with an extended LO range, but performance
degrades as f
LO
continues to decrease. The
MAX9994—a variant of the MAX9996—provides better
low-side performance since it is tuned for a lower LO
range of 1400MHz to 2000MHz.
RF Input and Balun
The MAX9996 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 15dB over the entire
1700MHz to 2200MHz RF frequency range.
LO Inputs, Buffer, and Balun
The MAX9996 can be used for either high-side or low-
side injection applications with a 1900MHz to 2400MHz
LO frequency range. For a device with a 1400MHz to
2000MHz LO frequency range, refer to the MAX9994
data sheet. As an added feature, the MAX9996 includes
an internal LO SPDT switch that can be used for fre-
quency-hopping applications. The switch selects one of
the two single-ended LO ports, allowing the external
oscillator to settle on a particular frequency before it is
SiGe High-Linearity, 1700MHz to 2200MHz
Downconversion Mixer with LO Buffer/Switch
8 _______________________________________________________________________________________
Pin Description
PIN NAME FUNCTION
1, 6, 8, 14 V
CC
Power-Supply Connection. Bypass each V
CC
pin to GND with capacitors as shown in the Typical
Application Circuit.
2RF
Single-Ended 50Ω RF Input. This port is internally matched and DC shorted to GND through a balun.
Requires an external DC-blocking capacitor.
3 TAP
Center Tap of the Internal RF Balun. Bypass to GND with capacitors close to the IC, as shown in the
Typical Application Circuit.
4, 5, 10, 12,
13, 17
GND Ground
7 LOBIAS Bias Resistor for Internal LO Buffer. Connect a 549Ω ±1% resistor from LOBIAS to the power supply.
9 LOSEL Local Oscillator Select. Logic control input for selecting LO1 or LO2.
11 LO1 Local Oscillator Input 1. Drive LOSEL low to select LO1.
15 LO2 Local Oscillator Input 2. Drive LOSEL high to select LO2.
16 LEXT
External Inductor Connection. Connect a low-ESR, 10nH inductor from LEXT to GND. This inductor
carries approximately 100mA DC current.
18, 19 IF-, IF+
Differential IF Outputs. Each output requires external bias to V
CC
through an RF choke (see the
Typical Application Circuit).
20 IFBIAS IF Bias Resistor Connection for IF Amplifier. Connect an 806Ω resistor from IFBIAS to GND.
EP GND Exposed Ground Paddle. Solder the exposed paddle to the ground plane using multiple vias.