CS8420-CS 데이터 시트보기 (PDF) - Cirrus Logic

부품명

상세내역

제조사

CS8420-CS

Digital Audio Sample Rate Converter

Cirrus Logic 

CS8420

The TXP pin may be used to drive TTL or CMOS gates as shown in Figure 32. This circuit may be used for

optical connectors for digital audio since they usually have TTL or CMOS compatible inputs. This circuit is

also useful when driving multiple digital audio outputs since RS422 line drivers have TTL compatible inputs.

CS8420

TXP

TXN

TTL or

CMOS Gate

Figure 32. TTL/CMOS Output Circuit

14.2 AES3 Receiver External Components

The CS8420 AES3 receiver is designed to accept both the professional and consumer interfaces. The dig-

ital audio specifications for professional use call for a balanced receiver, using XLR connectors, with 110 Ω

±20% impedance. The XLR connector on the receiver should have female pins with a male shell. Since the

receiver has a very high input impedance, a 110 Ω resistor should be placed across the receiver terminals

to match the line impedance, as shown in Figure 33. Although transformers are not required by the AES,

they are, however, strongly recommended.

XLR

110 Ω

Twisted

Pair

1

* See Text

110 Ω

CS8420

RXP

RXN

Figure 33. Professional Input Circuit

If some isolation is desired without the use of transformers, a 0.01 μF capacitor should be placed in series

with each input pin (RXP and RXN) as shown in Figure 34. However, if a transformer is not used, high

frequency energy could be coupled into the receiver, causing degradation in analog performance.

XLR

110 Ω

Twisted

* See Text 0.01 μF

110 Ω

0.01 μF

CS8420

RXP

Pair

1

RXN

Figure 34. Transformerless Professional Input Circuit

Figures 33 and 34 show an optional DC blocking capacitor (0.1 μF to 0.47 μF) in series with the cable input.

This improves the robustness of the receiver, preventing the saturation of the transformer, or any DC current

flow, if a DC voltage is present on the cable.

In the configuration of systems, it is important to avoid ground loops and DC current flowing down the shield

of the cable that could result when boxes with different ground potentials are connected. Generally, it is

good practice to ground the shield to the chassis of the transmitting unit, and connect the shield through a

capacitor to chassis ground at the receiver. However, in some cases it is advantageous to have the ground

of two boxes held to the same potential, and the cable shield might be depended upon to make that electrical

DS245F4

79

Share Link: