Philips Semiconductors
High performance low power mixer FM IF system
with high-speed RSSI
Product specification
SA625
DESCRIPTION
The SA625 is pin-to-pin compatible with the SA605, but has faster
RSSI rise and fall times. The SA625 is a high performance
monolithic low-power FM IF system incorporating a mixer/oscillator,
two limiting intermediate frequency amplifiers, quadrature detector,
muting, logarithmic received signal strength indicator (RSSI) with
fast rise and fall time, and voltage regulator. The SA625 combines
the functions of Signetics’ SA602A and SA624. The SA625 is
available in 20-lead SSOP (shrink small outline package).
For additional technical information please refer to application notes
AN1994, 1995 and 1996, which include example application
diagrams, a complete overview of the product and artwork for
reference.
FEATURES
• Fast RSSI rise and fall times
• Low power consumption: 5.8mA typical at 6V
• Mixer input to >500MHz
• Mixer conversion power gain of 13dB at 45MHz
• Mixer noise figure of 4.6dB at 45MHz
• XTAL oscillator effective to 150MHz (L.C. oscillator to 1GHz local
oscillator can be injected)
• 102dB of IF Amp/Limiter gain
• 25MHz limiter small signal bandwidth
• Temperature compensated logarithmic Received Signal Strength
Indicator (RSSI) with a dynamic range in excess of 90dB
• Two audio outputs - muted and unmuted
• Low external component count; suitable for crystal/ceramic/LC
filters
• Excellent sensitivity: 0.22µV into 50Ω matching network for 12dB
SINAD (Signal to Noise and Distortion ratio) for 1kHz tone with RF
at 45MHz and IF at 455kHz
• SA625 meets cellular radio specifications
PIN CONFIGURATION
DK Package
RFIN 1
RF BYPASS 2
XTAL OSC 3
XTAL OSC 4
MUTEIN 5
VCC 6
RSSIOUT 7
MUTED AUDIO OUT 8
UNMUTED AUDIO OUT 9
QUADRATURE IN 10
20 MIXER OUT
19 IF AMP DECOUPLING
18 IF AMP IN
17 IF AMP DECOUPLING
16 IF AMP OUT
15 GND
14 LIMITER IN
13 LIMITER DECOUPLING
12 LIMITER DECOUPLING
11 LIMITER OUT
Figure 1. Pin Configuration
• ESD hardened
SR00456
APPLICATIONS
• Digital cellular base stations
• High performance communications receivers
• Single conversion VHF/UHF receivers
• SCA receivers
• RF level meter
• Spectrum analyzer
• Instrumentation
• FSK and ASK data receivers
• Log amps
• Wideband low current amplification
• Digital cordless telephones
ORDERING INFORMATION
DESCRIPTION
20-Pin Plastic Shrink Small Outline Package (SSOP) (Surface-mount)
TEMPERATURE RANGE
-40 to +85°C
ORDER CODE
SA625DK
DWG #
SOT266-1
1997 Nov 07
2
853-1648 18664