Block diagram of MC44603

16

1

Vref

Iref

 

DEMAGNETISATION

 

 

 

 

Vref

 

 

 

 

 

 

 

 

 

 

enable

 

 

 

 

 

8

DETECT

DEMAGNETISATION

REFERENCE

SUPPLY

 

 

 

 

 

 

UVL01

 

 

 

 

 

MANAGEMENT

 

BLOCK

INITIALISATION BLOCK

 

 

 

 

 

 

 

 

 

 

 

 

Iref

 

 

 

 

 

 

 

 

 

 

 

 

VOSC PROT

 

 

 

 

 

 

 

9

SYNC INPUT

 

OSCILLATOR

VOSC

 

 

 

 

 

VC

2

 

 

 

 

 

 

 

 

 

 

 

10 CT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1Set

 

 

 

OUT

3

 

 

 

 

 

 

 

 

 

BUFFER

15 RF STANDBY

 

Vstby

 

 

LATCH

C

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

=1

1Reset

 

 

 

GND

4

12 RP STANDBY

 

STANDBY

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(REDUCED FREQUENCY)

 

 

 

 

 

 

 

 

 

2.5V

 

 

 

 

THERMAL

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SHUTDOWN

 

Vref

Voc

 

 

 

 

VS8 OUT

 

 

Iref

 

 

 

 

 

VOLTAGE

ERROR

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

14 FEEDBACK

AMP

 

CURRENT

 

 

 

 

 

OVER

 

 

 

 

 

 

 

 

 

 

VOLTAGE

 

 

 

 

 

SENSE

 

 

 

 

OVER

 

 

 

 

 

 

 

 

 

PROTECT

6

 

 

 

 

 

 

Dmax &

UVL01

 

 

 

 

 

 

VOLTAGE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SOFT-START

 

 

 

13 E/A OUT

 

 

 

 

 

MANAGEMENT

 

 

 

 

 

 

CONTROL

Vref

 

 

 

 

 

 

 

 

 

 

 

 

FOLDBACK

 

 

 

 

 

 

 

 

 

 

FOLDBACK

CURRENT SENSE

 

 

SOFT-START

 

 

 

 

 

 

INPUT

INPUT

 

 

 

 

 

 

 

 

 

 

& DMAX

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5

7

11

CL 96532076_032.eps

 

 

 

290799

Figure 8-13

Operating description of MC44603

The input voltage Vcc (pin 1) is monitored by a comparator with hysteresis, enabling the circuit at 14.5V and disabling the circuit below 7.5V. The error amplifier compares a voltage Vfb (pin 14) related to the output voltage of the power supply, with an internal 2.5V reference. The current sense comparator compares the output of the error amplifier with the switch current Isense (pin 7) of the power supply. The output of the current sense comparator resets a latch, which is set every cycle by the oscillator. The output stage is a totem pole, capable of driving a MOSFET directly.

Start up sequence of P816

t1: Charging the capacitors at Vcc

C829 will be charged via R823 and R832, C833 and

C811 v i a R829. The output is switched off during t1. t2: Charging of output capacitors

When the input voltage of the IC exceeds 14.5V, the circuit is enabled and starts to produce output pulses. The current consumption of the circuit increases to about 17mA, depending on the external loads of the IC. At first, the capacitors at the Vcc pin will discharge because the primary auxiliary voltage, coming from winding 7-9 is below the Vcc voltage. At some moment during t2, the primary auxiliary voltage reaches the same level as Vcc. This primary auxiliary voltage now determines the Vcc voltage.

t3: Regulation

The output voltage of the power supply is in regulation. t4: Overload

When the output is shorted, the supply voltage of the circuit will decrease and after some time drop below the lower threshold voltage. At that moment, the output will be disabled and the process of charging the Vcc capacitors starts again. If the output is still shorted at the next t2 phase, the complete start- and stop sequence will repeat. The power supply goes in a hiccup mode.

14.5V

Vcc

10V

7.5V

p.a.v.

0V

17mA

Icc 1mA

OUTPUT

short

Vo

0

t1

 

t2

t3

t4

 

 

 

 

 

 

CL 96532076_035.eps 290799

Figure 8-14 ‘Start-up sequence’

Regulation of P816

Figure 8-14 shows the most relevant signals during the regulation phase of the power supply.

The oscillator voltage ramps up and down between V1 and V2. The voltage at the current sense terminal is compared every cycle with the output of the error amplifier Vcomp. The output

22

Page 24
Image 24
Marantz MAR770 Block diagram of MC44603, Operating description of MC44603, Start up sequence of P816, Regulation of P816

MAR770, MAR775, DR-6000 specifications

The Marantz DR-6050 and DR-6000 are revered components in the world of high-fidelity audio systems, reflecting the brand's long-standing commitment to quality and performance. These models have gained popularity among audiophiles for their comprehensive features and advanced technologies, which cater to both casual listeners and serious music enthusiasts.

The Marantz DR-6050 is a CD recorder and player that stands out with its dual functionality. It allows users to enjoy CDs while also having the capability to record directly from various sources, including analog inputs and digital connections. This functionality is essential for those who wish to preserve their vinyl records, cassettes, or other audio formats onto CD. The machine supports CD-R and CD-RW media, providing flexibility for repeated use and recording.

One of the standout technologies in the DR-6050 is its high-quality Digital-to-Analog Converter (DAC), which significantly enhances sound performance by converting digital signals to analog with incredible accuracy. This contributes to the unit's ability to reproduce audio with rich detail and clarity. Additionally, the recorder is equipped with a Microprocessor that ensures precise recording levels and optimizes the quality of the output.

On the other hand, the Marantz DR-6000 offers similar capabilities but with an emphasis on simplicity and ease of use. Designed for users who appreciate an intuitive interface, it features straightforward controls and an ergonomic design. The DR-6000 supports multiple recording formats, including standard audio CDs, making it versatile for various playback systems.

Both models are built with high-grade components that promise longevity and reliability. They feature robust construction, ensuring minimal vibration and interference to enhance playback quality. Integrated analog and digital inputs allow for diverse connectivity options, which is crucial for users with elaborate audio setups.

In terms of audio performance, both the DR-6050 and DR-6000 exhibit impressive frequency response and low distortion levels, characteristics that are vital for a satisfying listening experience. The devices also include features like playback speed control and disc finalization options, providing the user with complete control over their audio sessions.

The Marantz DR-6050 and DR-6000 are ultimate companions for those who appreciate high-quality sound and need versatile recording solutions. With their blend of advanced technologies, clear audio output, and user-friendly designs, they remain solid choices for anyone looking to enhance their audio collection and experience.