Philips Semiconductors

Product specification

NE/SA600

1GHz LNA and mixer

1993 Dec 15

57

OVERALL PERFORMANCE: ISOLATION CHARACTERISTICS

4.5

Isolation From LNA Output to Mixer

RF Input vs Frequency

0

800

FREQUENCY (MHz)

ENABLE=HI

ENABLE=LO

–10

–20

–30

–40

–50

–60

900

1000

1100

1200

Isolation From LO vs Frequency

0

800

FREQUENCY (MHz)

At LNA input – ENABLE = LO

–10

–20

–30

–40

–50

–60

900

1000

1100

1200

At LNA input – ENABLE = HI

At Mixer RF input

SR00091

Figure 10. Overall Performance: Isolation Characteristics

SPECIFICATIONS

The goal of the Specifications section of the datasheet is to provide

information on the NE/SA600 in such a way that the designer can

estimate statistical variations, and can reproduce the

measurements. To this end the high frequency measurements are

specified with a particular PC board layout. Variations in board

layout will cause parameter variations (sensitive parameters are

discussed in the sections on the LNA and mixer below). For many

RF parameters the

±3 sigma limits are specified. Statistically only

0.26% of the units will be outside these limits.

The LNA + mixer conversion gain is measured with an incident

900MHz signal and a 83MHZ SAW filter at the IF output. This

measurement along with a gain measurement of the LNA ensure the

correct operation of the chip and also allows a calculation of mixer

conversion gain.

PIN DESCRIPTIONS AND OPERATIONAL LIMITS

Input of LNA, AC coupling required, DC = 0.78V, frequency range

from DC to 2GHz, gain at low frequencies is 40dB — so be careful

of overload, impedance below 50

Ω, shunt 15-18nH inductor helps

input match and noise figure.

Output of LNA, AC coupling required, DC = 1.27V, frequency range

from DC to 2GHz, impedance above 50

Ω.

BYPASS

Bypass capacitor should be 100 times larger than the largest signal

coupling capacitor for the LNA, DC = 1.05V.

Mixer RF port, AC coupling required, DC = 1.43V, frequency range

from 100MHz to 2.5GHz, impedance close to 50

Ω resistive.

Mixer LO port, AC coupling required, DC=3.35V, frequency range

from 100MHz to 2.5GHz, impedance close to 50

Ω resistive.

Mixer IF port, open-collector output with 1.6mA DC, frequency range

DC to 1GHz, impedance approximately 1pF capacitive.

Enable

TTL/CMOS compatible input. Bias current approximately zero.

CONVERSION GAIN DEFINITIONS

Conversion Gain, or more simply Voltage Conversion Gain,

VO

10

µH

RL1

1k

Ω

IF FILTER

LO

RF

VI

VA

RL2

SR00092

Figure 11.

VG

V

A

V

I