CM2009
VGA Port Companion Circuit
Features
•
•
Includes ESD protection, level-shifting, buffering
and sync impedance matching
7 channels of ESD protection for all VGA port con-
nector pins meeting IEC-61000-4-2 Level 4 ESD
requirements (
±
8kV contact discharge)
Very low loading capacitance from ESD protection
diodes on VIDEO lines, 4pF maximum
5V drivers for HSYNC and VSYNC lines
Integrated impedance matching resistors on sync
lines
Bi-directional level shifting N-channel FETs pro-
vided for DDC_CLK & DDC_DATA channels
Backdrive protection on DDC lines
Compact 16-lead QSOP package
Product Description
The CM2009 connects between a video graphics con-
troller embedded in a PC, graphics adapter card or set
top box and the VGA or DVI-I port connector. The
CM2009 incorporates ESD protection for all signals,
level shifting for the DDC signals and buffering for the
SYNC signals. ESD protection for the video, DDC and
SYNC lines is implemented with low-capacitance cur-
rent steering diodes.
All ESD diodes are designed to safely handle the high
current spikes specified by IEC-61000-4-2 Level 4
(±8KV contact discharge if C
BYP
is present,
±4KV
if
not). The ESD protection for the DDC signal pins are
designed to prevent "back current" when the device is
powered down while connected to a monitor that is
powered up.
Separate positive supply rails are provided for the
VIDEO, DDC and SYNC channels to facilitate interfac-
ing with low voltage video controller ICs to provide
design flexibility in multi-supply-voltage environments.
(cont’d
next page)
•
•
•
•
•
•
Applications
•
VGA and DVI-I ports in:
- Desktop and Notebook PCs
- Graphics Cards
- Set Top Boxes
Simplified Electrical Schematic
9
V
CC_VIDEO
2
12
DDC_OUT1
DDC_OUT2
V
CC_DDC
7
BYP
8
V
CC_SYNC
1
VIDEO_1
VIDEO_2
VIDEO_3
3
4
5
R
T
R
T
GND
6
16
14
DDC_IN1
DDC_IN2
SYNC_IN1
SYNC_IN2
10
11
13
15
GND
SYNC_OUT2
SYNC_OUT1
©
2004 California Micro Devices Corp. All rights reserved.
08/12/04
430 N. McCarthy Blvd., Milpitas, CA 95035-5112
▲
Tel: 408.263.3214
▲
Fax: 408.263.7846
▲
www.calmicro.com
1
CALMIRCO [ CALIFORNIA MICRO DEVICES CORP ]
