Philips Semiconductors RF Communications Products
Product specification
Low-voltage digital IF receiver
DESCRIPTION
SA637
FEATURES
The SA637 is a low-voltage high performance
monolithic digital system with high-speed
RSSI incorporating a mixer, oscillator with
buffered output, two limiting intermediate
frequency amplifiers, fast logarithmic
received signal strength indicator (RSSI),
voltage regulator, RSSI op amp and power
down pin. The SA637 is available in SSOP
(shrink small outline package).
The SA637 was designed for portable digital
communication applications and will function
down to 2.7V. The limiter amplifier has
differential outputs with 2MHz small signal
bandwidth. The RSSI output has access to
the feedback pin. This enables the designer
to level adjust the outputs or add filtering.
PIN CONFIGURATION
• VCC = 2.7 to 5.5V
• Low power receiver (3.8mA @ 3V)
• Power down mode (ICC = 110µA)
• Fast RSSI rise and fall times
• Extended RSSI range with temperature
DK Packages
20 MIXER
OUTPUT
19 IF AMP
DECOUP
18 IF AMP IN
RFIN 1
RFIN 2
OSC E 3
17 IF AMP
DECOUP
16 IF AMP OUT
OSC B 4
compensation
• RSSI op amp
• 2MHz limiter small signal bandwidth
• 455kHz filter matching (1.5kΩ)
• Differential limiter output
• Oscillator buffer
• SSOP-20 package
OSC 5
BUFFER
6
V
15 GND
CC
RSSI 7
14 LIMITER IN
13 LIMITER
DECOUP
12 LIMITER
DECOUP
11 LIM OUT (+)
RSSI 8
FEEDBACK
POWER 9
DOWN
LIM OUT (-) 10
APPLICATIONS
• ADC (American Digital Cellular)
• Digital receiver systems
• Cellular radio
ORDERING INFORMATION
DESCRIPTION
TEMPERATURE RANGE
ORDER CODE
DWG #
-40 to +85°C
SA637DK
1563
20-Pin Plastic Shrink Small Outline Package (Surface-mount)
BLOCK DIAGRAM
20
19
18
17
16
15
14
13
12
11
GND
IF
AMP
LIMITER
MIXER
FAST RSSI
OSCILLATOR
+ –
+
E
1
October 27, 1993
POWER
DOWN
–
2
3
B
4
VCC
5
6
2
7
8
9
10
853-1718 11205