Philips sa578 DATASHEETS
RF COMMUNICATIONS PRODUCTS
SA578
Unity gain level programmable low power
compandor
Product specification
Replaces data of 1993 December 15
IC17 Data Handbook
Philips Semiconductors
1997 Nov 07
Philips Semiconductors Product specification
SYMBOL
PARAMETER
UNITS
SA578Unity gain level programmable low power compandor
DESCRIPTION
The SA578 is a unity gain level programmable compandor designed
for low power applications. The SA578 is internally configured as an
expandor and a compressor to minimize external component count.
The summing amplifiers of the SA578 have 600Ω drive capability
and the inverting input of the compressor amplifier is accessible
through Pin 9 for summing multiple external signals. Power
Down/Mute function is active low and requires an open collector
output logic configuration at Pin 8. If Power Down/Mute is not
needed, Pin 8 should be left open. When the part is muted, supply
current drops to 170mA at 3.6V .
FEATURES
•Operating voltage range: 1.8V to 7V
•Low power consumption (1.4mA @ 3.6V)
•0dB level programmable
(10mV
RMS
to 1.0V
RMS
)
•Over 90dB of dynamic range
•Wide input/output swing capability
•Low external component count
•SA578 meets cellular radio specifications
•ESD hardened
•Power Down mode (I
= 170µA @ 3.6V)
CC
•Mute function
•Multiple external summing capability
•600Ω drive capability
PIN CONFIGURATION
D Package
GCELL
RECT
EXP
EXP
PWRDN/
1
IN
2
IN
3
CAP
4
OUT
5
V
REF
6
I
REF
7
GND
89
MUTE
Figure 1. Pin Configuration
16
15
14
13
12
11
10
V
COMP
COMP
COMP
RECT
GCELL
COMP
SUM NODE
APPLICATIONS
•High performance portable communications
•Cellular radio
•Cordless telephone
•Consumer audio
•Wireless microphones
•Modems
•Electric organs
•Hearing aids
•Automatic level control (ALC)
CC
CAP2
IN
CAP1
IN
IN
OUT
SR00719
ORDERING INFORMATION
DESCRIPTION TEMPERATURE RANGE ORDER CODE DWG #
16-Pin Plastic Small Outline (SO)
–40 to +85°C
SA578D SOT109-1
ABSOLUTE MAXIMUM RATINGS
RATING
SA578
V
CC
T
A
T
STG
θ
JA
1997 Nov 07 853-1537 18660
Supply voltage 8 V
Operating ambient temperature range –40 to +85
Storage temperature range –65 to +150
Thermal impedance SO 125
2
°C
°C
°C/W
Philips Semiconductors Product specification
SA578Unity gain level programmable low power compandor
BLOCK DIAGRAM and TEST AND APPLICATION CIRCUIT
C1
EXP
IN
+
10µF
RECT
EXP
CAP
+
2.2µF
C2
C3
+
OUT
V
REF
PWRDN/
MUTE
R2*
10µF
C4
10µF
+
GND
EXP
*R1, R2 and R3 are 1% resistors.
IN
R1*
10k
Σ
5k
1
GAINCELL
10k
RECTIFIER
∆G
10k
2
30k 30k 10k
3
EXPANDOR
4
Σ
8.6k
5
V
REF
6
I
REF
BANDGAP
PWRDN
GND
V
MUTE
CC
COMPRESSOR
7
8
Figure 2. Block Diagram and Test and Application Circuit
10k
RECTIFIER
∆G
GAINCELL
10k
16
15
14
13
12
11
10
V
CC
COMP
CAP2
C8
+
2.2µF
C7
+
COMP
10µF
COMP
CAP1
RECT
R3*
GCELL
+
C5
10µF
R4
10kΩ
9
+
C10
10µF
IN
+
C6
2.2µF
IN
IN
+
COMP
SUM
IN
SR00720
OUT
10µF
C9
1997 Nov 07
3
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