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Details, datasheet, quote on part number:LC508
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| Part: | LC508 |
| Category: | Analog & Mixed-Signal Processing => Amplifiers => Operational Amplifiers |
| Description: | Class a Amplifier With 3 Independent Gain Blocks, 5V DC |
| Company: | Gennum Corporation |
| Datasheet: | Download LC508 datasheet File size : 82 kB |
| Request For quote: | Find where to buy LC508
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Datasheet text preview:
Class A Amplifier with 3 Independent Gain Blocks
LC508 DATA SHEET
FEATURES · 1 µV input referred noise · 1.0 to 5 VDC operating range · 73 dB typical gain (adjustable) · 0.28 to 2.0 mA range of transducer current · 1% electrical distortion · the first and second blocks, or second and third blocks can be DC coupled · 100 Hz to 50 kHz frequency response · suitable for active filtering STANDARD PACKAGING · 10 PIN MICROpac ·10 pin PLID® · 10 pin SLT · Chip (52 x 49 mils)
DESCRIPTION The LC508 is a 10 pin Class A amplifier utilizing Gennum's proprietary low voltage bipolar JFET technology. It consists of 3 single ended, low noise inverting gain blocks. The first two blocks have a typical open loop gain of 50 dB. The closed loop gain is set by the ratio of the feedback resistor to the source impedance. The third block is an open collector output stage with the bias being set by RE and VRE at pin 8 which is 54 mV. Typically, the gain of the first two blocks is set to 25 dB each, with the third block at 23 dB, giving a total gain of 73 dB. Gain trim can be accomplished with the use of a feedback resistor on the first block, while the volume control is used as the feedback control on the second block. This gives a volume control range greater than 40 dB.
VB 6 5
MIC
RMIC
V
A IN
4
7 -A -B -C 8 RE
C OUT RE
2 A OUT
3 B IN
10 B OUT
9 C IN
1 GND
BLOCK DIAGRAM
Revision Date: January 2001
Document No. 500 - 61 - 12
GENNUM CORPORATION P.O. Box 489, Stn. A, Burlington, Ontario, Canada L7R 3Y3 tel. +1 (905) 632-2996 Web Site: www.gennum.com E-mail: hipinfo@gennum.com
ABSOLUTE MAXIMUM RATINGS
PARAMETER Supply Voltage Power Dissipation Operating Temperature Storage Temperature VALUE / UNITS 5V DC 25 mW -10o to + 40oC -20o to + 70oC
V MIC A IN B IN A OUT
PIN CONNECTION
5
6
V
B
C OUT RE C IN 1 10 B OUT
CAUTION CLASS 1 ESD SENSITIVITY
GND
ELECTRICAL CHARACTERISTICS
Conditions: Supply Voltage =1.3 VDC, Frequency = 1 kHz, Temperature = 25 oC
PARAMETER Gain (Closed Loop) Amplifier Current Transducer Current Transducer Current Distortion Input Referred Noise Stable with Battery Resistance to Input Bias Current On Chip Emitter Resistor Emitter Bias Voltage (pin 8) Microphone Decoupling Resistor
SYMBOL A CL IAMP ITRANS H ITRANS L THD IRN RB IB RE VRE RMIC
CONDITIONS VOUT = 500 VRMS IAMP = IA + IMIC RE = 47.5 RE = VOUT = 500 VRMS NFB 0.2 to 10kHz at 12dB/Oct
MIN 69 160 1.1 200 -50 -
TYP 73 245 1.3 275 1 1 0 200 54 4
MAX 77 340 1.7 350 4 2 22 50 -
UNITS dB µA mA µA % µV nA mV k
All switches and parameters remain as shown in Test Circuit unless otherwise stated in Conditions column.
IAMP
VB=1.3 VDC R B =4.7
6 IMIC 5 RMIC V OUT RL = 1K 3.3 K 33 K 1.0 8 10 IB V
IN
4
-A
-B
-C
7
ITRA NS
RE
CS 0.015
1kHz R FA 56.2K
2 R1
3 CS IB R FB 47.5K
10
9
1
2.7K 1.0
1.0
R E =47.5
All resistors in ohms, all capacitors in µF unless otherwise stated
Fig. 1 Test Circuit
500 - 61 - 12
2
5
RMIC
6
7
2
10
33K
8
4
3 9 RE 1
All external resistors in ohms, all capacitors in µF unless otherwise stated
Fig. 2 Functional Schematic
VB=1.3 VDC
6 5 10 R S 3.9k CS 0.22 RE 0.015 4 7 RMIC RL = 1K -A -B -C
2 50K 2.7K R1 R GT
3 50K
10
9
1
8
47 0.033 R VC
All resistors in ohms, all capacitors in µF unless otherwise stated
Gain of Stage A = 20 Log10 (
RGT RS
)
Gain of Stage B = 20 Log10 (
RVC R1
)
Gain of Stage C = 20 Log10 (
RL RE //47
)
Fig. 3 Typical Hearing Aid Application
3
500 - 61 - 12
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