LD511 Datasheet, PDF (1/4 Pages) Gennum Corporation – Class A Compression Amplifier

Class A
Compression Amplifier
LD511 DATA SHEET
FEATURES
• 64 dB typical electrical gain
• 0.94 VDC voltage regulator
• 7 ms attack time, 40 ms release time
• 15 dB threshold adjustment
• low noise and distortion
• compression ratio ∞ : 1
• 0.3 kHz - 6 kHz frequency response
STANDARD PACKAGING
• 10 pin MICROpac
• 10 pin MINIpac
• 10 pin PLID ^®
• 10 pin SLT
• Chip (59 x 59 mils)
Au Bump
DESCRIPTION
The LD511 is a Class A compression amplifier which can
operate over a range of DC battery voltages from 1.1 V
to 2.4 V. A voltage regulator, which is independent of supply
voltage variations, is on-chip to supply a stable 0.94 VDC bias
to the amplifier circuitry and to the microphone.
The LD511, in compression, has approximately 15 dB of
threshold adjustment by varying R_TH (see application circuit)
and a compression function ratio of ∞ : 1.
Minimum attack and release times are fixed at 7 ms and 40 ms
respectively and they can be adjusted simultaneously by
changing the filter capacitor on pin 8, although the ratio of
attack to release time is kept constant.
The output stage bias can be set to accommodate different
receiver impedances by changing the value of R_E . The
voltage across R_E (pin 2 to ground) is a constant 27 mV so the
bias current is 27 mV divided by the total value of R_E in parallel
with 500 Ω.
7
V_REG
A OUT
10
VOLTAGE
REGULATOR
B IN
1
9
A IN
R_IN ^{- A}
10K
35K
VB
6
20K
3
-B
B OUT
R_E
RECTIFIER
8
C_AGC
All resistors in ohms, all capacitors
in farads unless otherwise stated
4
GND
BLOCK DIAGRAM
5
AGC
2
R_E
Revision Date: January 2001
500 - 32 - 11
GENNUM CORPORATION P.O. Box 489, Stn. A, Burlington, Ontario, Canada L7R 3Y3 tel. [phone]
Web Site: www.gennum.com E-mail: [e-mail]