Showing posts with label 4. Show all posts
Showing posts with label 4. Show all posts
Sunday, September 7, 2014
4 x 50W quad power amplifier TDA7564B
Features:
■ Multipower BCD technology
■ MOSFET output power stage
■ DMOS power output
■ New high efficiency (class SB)
■ High output power capability 4x28 W/4 @
14.4 V, 1 kHz, 10 % THD, 4x50 W max, power
■ Max. output power 4x72 W/2
■ Full I2C bus driving:
– Standby
– Independent front/rear soft play/mute
– Selectable gain (for low noise line output
function)
– High efficiency enable/disable
– I2C bus digital diagnostics (including AC
and DC load detection)
■ Full fault protection
■ DC offset detection
■ Four independent short circuit protection
■ Clipping detector (2 %/10 %)
■ Linear thermal shutdown with multiple thermal
warning
■ ESD protection
Description:
The TDA7564B is a new BCD technology quad bridge type of car radio amplifier in Flexiwatt25 / PowerSO36 package specially intended for car radio applications. Thanks to the DMOS output stage the TDA7564B has a very low distortion allowing a clear powerful sound. Among the features, its superior efficiency performance coming from the internal exclusive structure, makes it the most suitable device to simplify the thermal management in high power sets. The dissipated output power under average listening condition is in fact reduced up to 50% when compared to the level provided by conventional class AB solutions. This device is equipped with a full diagnostics array that communicates the status of each speaker through the I2C bus.
Circuit Diagram:
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| 4 x 50W quad power amplifier TDA7564B |
Tuesday, August 26, 2014
TDA7384 4 x 22W car power amplifier
TDA7384 - 4 x 22W car power amplifier
I didn’t find much information about this chip on the internet so I decided to built it and try on my own. As datasheets of TDA7384 says it is low distortion, low output noise, low external component count. Also has Stand-By function and Mute function. It has several protections like from output short circuit to GND or to Vs, capable to handle very inductive loads, thermal limiter, load dump voltage. TDA7384 is an AB power amplifier cased in flexiwatt25 (eagle library is included in project archive) package wich is designed for high end car radio applications. It allows rail to rail output voltage swing with no need of boot-strap capacitors.
| Schematics TDA7384 |
I have followed the schematic in datasheed when building circuit. In datasheet you may also find PCB layout but it is two layered and didn’t fit to may box I’ve chosen. So I have made single sided PCB 50X100mm.
| PCB TDA7384 amplifier |
As I put pins on PCB for ST-BY and Mute but I not using them, I connected these pins to VCC like it is shown in PCB view. According to datasheet St-By and Mute turns off amplifier if signal in input is lower than 3.5V. So it is recommended to connect these pins to Vcc if not used.
Maximum power dissipation of chip is 80W(Tcase=70ºC), so it can handle 4 channels working at power of 20W each. But of course chip in a box doesn’t have good ventilation so I’ve put a radiator to ensure that amplifier effectively dissipates heats. I didn’t try to load amplifier to maximum to se if it doesn’t heat up to much. But at normal sound level it stays warm what is normal.
| On box amplifier |
Dont forget to put thermal paste between chip and radiator to ensure lower thermal resistance. And here we go – brand new power amplifier ready to go:
| Already to use |
source: [link]
Friday, August 22, 2014
Simple 4 Transistor Amplifier for Small Speakers
The schema above shows a 4-transistor utility amplifier suitable for a variety of projects including receivers, intercoms, microphones, telephone pick-up coils, and general audio monitoring. The amplifier has a power isolation schema and bandwidth limiting to reduce oscillations and "motorboating". The values are not particularly critical and modest deviations from the indicated values will not significantly degrade the performance.
Three cell battery packs giving about 4.5 volts are recommended for most transformerless audio amplifiers driving small 8 ohm speakers. The battery life will be considerably longer than a 9 volt rectangular battery and the cell resistance will remain lower over the life of the battery resulting in less distortion and stability problems.
Three cell battery packs giving about 4.5 volts are recommended for most transformerless audio amplifiers driving small 8 ohm speakers. The battery life will be considerably longer than a 9 volt rectangular battery and the cell resistance will remain lower over the life of the battery resulting in less distortion and stability problems.
4 Transistor Amplifier for Small Speakers Circuit Diagram
The amplifier may be modified to work with a 9 volt battery if desired by moving the output transistors bias point. Lowering the 33k resistor connected from the second transistors base to ground to about 10k will move the voltage on the output electrolytic capacitor to about 1/2 the supply voltage.
This bias change gives more signal swing before clipping occurs and this change is not necessary if the volume is adequate. As before, the two 4.7 ohm resistors may be replaced with a single 10 ohm resistor in series with either emitter.
This bias change gives more signal swing before clipping occurs and this change is not necessary if the volume is adequate. As before, the two 4.7 ohm resistors may be replaced with a single 10 ohm resistor in series with either emitter.
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