ISL59311_14 Datasheet, PDF (12/14 Pages) Intersil Corporation – Differential Video Amplifier with Common Mode Sync Encoder and Serial Digital Interface

ISL59311
11 S_DATA
12 _TRANSMIT
+5V
19
V_{CCS SIN+}
R
S_IN-
S_OUT+
S_OUT-
+
0.1μF
15
16
17 ^RT
13
+
0.1μF
+5V
8
V_CC
R_T
7 B/Z
6 A/Y
DI 4
D
DE ³
RE ²
D
ISL59311
GND
7
R ^{RO 1}
GND
5 _ISL83088
FIGURE 21. RS-485 SERIAL INTERFACE CONNECTION DIAGRAM
Digital Transceiver Block Diagram
TXEN
S_OUT+ _R1
TXDATA
(S_DATA)
ENCODING
TRANSMIT
S_OUT- _R3
RDATA
(S_DATA)
S_IN+
S_IN-
Proper Layout Technique
A critical concern with any PCB layout is the establishment
of a “healthy” ground plane. It is imperative to provide
ground planes terminated close to inputs to minimize input
capacitance. Additionally, the ground plane can be
selectively removed from inputs to prevent load and supply
currents from flowing near the input nodes.
In general the following guidelines apply to all PCB layout:
• Keep all traces as short as possible.
• Keep power supply bypass components as close to the
chip as possible - extremely close.
• Create a healthy ground with low impedance and
continuous ground pathways available to all grounded
components board-wide.
• In high frequency applications on multi-level boards try to
keep one level of board with continuous ground plane and
minimum via cutouts - providing it is affordable.
• Provide extremely short loops from power pin to ground.
• If it is affordable, a ferrite bead is always of benefit to
isolate device from Power Supply noise and the rest of the
circuit from the noise of the device.
12
FN6372.3
April 25, 2007