Philips Semiconductors
Compandor
Product data
NE570
GENERAL DESCRIPTION
The NE570 is a versatile low cost dual gain control circuit in which
either channel may be used as a dynamic range compressor or
expandor. Each channel has a full-wave rectifier to detect the
average value of the signal, a linerarized temperature-compensated
variable gain cell, and an operational amplifier.
The NE570 is well suited for use in cellular radio and radio
communications systems, modems, telephone, and satellite
broadcast/receive audio systems.
FEATURES
• Complete compressor and expandor in one IC
• Temperature compensated
• Greater than 110 dB dynamic range
• Operates down to 6 VDC
• System levels adjustable with external components
• Distortion may be trimmed out
APPLICATIONS
• Cellular radio
• Telephone trunk comandor
• High level limiter
• Low level expandor—noise gate
• Dynamic noise reduction systems
• Voltage-controlled amplifier
• Dynamic filters
PIN CONFIGURATION
RECT_CAP_1 1
RECT_IN_1 2
∆G_CELL_IN_1 3
GND 4
INV_IN_1 5
RES_R3_1 6
OUTPUT_1 7
THD_TRIM_1 8
16 RECT_CAP_2
15 RECT_IN_2
14 ∆G_CELL_IN_2
13
NE570D
12
VCC
INV_IN_2
11 RES_R3_2
10 OUTPUT_2
9 THD_TRIM_2
TOP VIEW
SR02503
Figure 1. Pin configuration.
ORDERING INFORMATION
Type number Package
Name
Description
NE570D
SO16
plastic small outline package; 16 leads; body width 7.5 mm
Version
SOT162-1
Temperature range
0 °C to +70 °C
BLOCK DIAGRAM
∆G CELL IN
RECT IN
THD TRIM
R2 20 kΩ
VARIABLE
GAIN
R1 10 kΩ
RECTIFIER
R3
INVERTER IN
R3
20 kΩ
–
R4
30 kΩ
VREF
1.8 V
+
RECT CAP
Figure 2. Block diagram
OUTPUT
SR02507
2003 Apr 03
2