RF COMMUNICATIONS PRODUCTS
SA578
Unity gain level programmable low power
compandor
Product specification
Replaces data of 1993 December 15
IC17 Data Handbook
1997 Nov 07
Philips Semiconductors
Philips Semiconductors
Product specification
Unity gain level programmable low power compandor
SA578
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.
PIN CONFIGURATION
D Package
GCELL
IN
RECT
IN
EXP
CAP
EXP
OUT
1
2
3
4
16
15
14
13
12
11
V
CC
COMP
CAP2
COMP
IN
COMP
CAP1
RECT
IN
GCELL
IN
V
REF
5
I
REF
GND
PWRDN/
MUTE
6
7
8
FEATURES
•
Operating voltage range: 1.8V to 7V
•
Low power consumption (1.4mA @ 3.6V)
•
0dB level programmable
•
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
CC
= 170µA @ 3.6V)
•
Mute function
•
Multiple external summing capability
•
600Ω drive capability
(10mV
RMS
to 1.0V
RMS
)
10 COMP
OUT
9
SUM NODE
SR00719
Figure 1. Pin Configuration
APPLICATIONS
•
High performance portable communications
•
Cellular radio
•
Cordless telephone
•
Consumer audio
•
Wireless microphones
•
Modems
•
Electric organs
•
Hearing aids
•
Automatic level control (ALC)
ORDERING INFORMATION
DESCRIPTION
16-Pin Plastic Small Outline (SO)
TEMPERATURE RANGE
–40 to +85
°
C
ORDER CODE
SA578D
DWG #
SOT109-1
ABSOLUTE MAXIMUM RATINGS
SYMBOL
V
CC
T
A
T
STG
θ
JA
Supply voltage
Operating ambient temperature range
Storage temperature range
Thermal impedance
SO
PARAMETER
RATING
SA578
8
–40 to +85
–65 to +150
125
UNITS
V
°
C
°
C
°
C/W
1997 Nov 07
2
853-1537 18660
Philips Semiconductors
Product specification
Unity gain level programmable low power compandor
SA578
BLOCK DIAGRAM and TEST AND APPLICATION CIRCUIT
10k
EXP
IN
C1
+
10µF
R1*
RECTIFIER
RECT
IN
EXP
CAP
+
C2
2.2µF
C3
+
EXP
OUT
10µF
V
REF
C4
+
10µF
10k
5k
COMP
CAP2
GAINCELL
10k
1
∆G
Σ
16
V
CC
2
30k
30k
10k
15
C7
+
C8
2.2µF
3
EXPANDOR
14
+
10µF
COMP
CAP1
COMP
IN
4
Σ
10k
8.6k
RECTIFIER
13
+ C6
2.2µF
5
V
REF
BANDGAP
10k
V
CC
GND PWRDN
MUTE
COMPRESSOR
∆G
GAINCELL
12
RECT
IN
R3*
6
R2*
I
REF
11
GCELL
IN
+ C5
10µF
7
GND
10
R4
10kΩ
+
C9
+
10µF
COMP
OUT
PWRDN/
MUTE
*R1, R2 and R3 are 1% resistors.
8
9
SUM
IN
C10
10µF
SR00720
Figure 2. Block Diagram and Test and Application Circuit
1997 Nov 07
3
Philips Semiconductors
Product specification
Unity gain level programmable low power compandor
SA578
ELECTRICAL CHARACTERISTICS
T
A
= 25
°
C, V
CC
= 3.6VDC, compandor 0dB level = –20dBV = 100mV
RMS
, output load R
L
= 10kΩ, Freq = 1kHz, unless otherwise specified.
R1, R2 and R3 are 1% resistors.
LIMITS
SYMBOL
PARAMETER
TEST CONDITIONS
MIN
V
CC
I
CC
V
REF
R
L
THD
E
NO
0dB
Supply voltage
1
Supply current
Reference voltage
2
Summing amp minimum output load
Total harmonic distortion
Expandor output noise voltage
Unity gain level
Programmable range
3
1kHz, 0dB, BW = 3.5kHz
BW = 20kHz, R
S
= 0Ω
0dB at 1kHz
R1 = R3 = 18.7kΩ, R2 = 24.3kΩ
R1 = R3 = 22.6kΩ, R2 = 100kΩ
R1 = R3 = 7.15kΩ, R2 = 100kΩ
R1 = R3 = 1.33kΩ, R2 = 200kΩ
V
OS
Output voltage offset
Expandor output DC shift
Tracking error relative to 0dB output
Crosstalk, COMP to EXP
Output swing low
V
O
Output swing high
Power Down/Mute low level
Power Down/Mute input current
Pin 8 grounded
0
–65
No signal
No signal to 0dB
-20dB expandor
1kHz, 0dB, C
REF
= 10µF
–150
–100
–1.0
–1.0
operating
power down
No signal, R
2
= 100kΩ
V
CC
= 3.6V
1.7
2
SA578
TYP
3.6
1.4
170
1.8
600
0.25
10
0.18
0
–10
–20
–40
1
7
0.3
–80
0.2
V
CC
– 0.2
0.4
V
V
µA
150
100
1.0
–65
mV
mV
dB
dB
dBV
1.0
20
1.0
MAX
7
2
1.9
V
mA
µA
V
Ω
%
µV
dB
UNITS
NOTE:
1. Operation down to V
CC
= 1.8V is possible.
2. Reference voltage, V
REF
, is typically at 1/2 V
CC
.
3. Unity gain level can be adjusted CONTINUOUSLY between –40dBV = 10mV
RMS
and 0dBV = 1.0V
RMS
. For details see application note
AN1762.
1997 Nov 07
4
Philips Semiconductors
Product specification
Unity gain level programmable low power compandor
SA578
TYPICAL PERFORMANCE CHARACTERISTICS
V
CC
= 3.6V, T
A
= 25°C, R1=R3=7.15kΩ, R2=100kΩ, 0dB level = 100mV, Freq. = 1kHz
SUPPLY CURRENT vs SUPPLY VOLTAGE
1.6
SUPPLY CURRENT vs TEMPERATURE
1.8
1.5
1.6
1.4
SUPPLY CURRENT (mA)
1.4
SUPPLY CURRENT (mA)
1.3
1.2
1.2
1
0.8
1.1
0.6
1
2
3
4
5
6
SUPPLY VOLTAGE (V)
7
8
1
-40
-20
0
20
40
60
AMBIENT TEMPERATURE (°C)
80
100
0.6
UNITY GAIN ERROR vs SUPPLY VOLTAGE
0.6
NOTE: UNITY GAIN ERROR MAY BE
SET TO 0 AT ANY V
CC
BY
ADJUSTING THE VALUE OF R1, R3
0.4
EXPANDOR
UNITY GAIN ERROR vs TEMPERATURE
0.4
EXPANDOR
UNITY GAIN ERROR (dB)
0.2
0.2
UNITY GAIN ERROR (dB)
0
COMPRESSOR
0
COMPRESSOR
-0.2
-0.2
-0.4
-0.4
-0.6
2
3
4
5
SUPPLY VOLTAGE (V)
6
7
-0.6
-40
-20
0
20
40
60
TEMPERATURE (°C)
80
100
TRACKING ERROR vs INPUT LEVEL
1
NOTE: RELATIVE
TO UNITY GAIN
0.5
THD vs TEMPERATURE
COMPRESSOR
0.5
EXPANDOR
OUTPUT ERROR (dB)
0.4
0
COMPRESSOR
THD (%)
0.3
EXPANDOR
-0.5
0.2
-1
2
3
4
INPUT LEVEL (dB)
5
6
0.1
-40
-20
0
20
40
60
TEMPERATURE (°C)
80
100
SR00715
Figure 3. Typical Performance Characteristics
1997 Nov 07
5
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