CM2009 Datasheet, PDF (1/6 Pages) California Micro Devices Corp – VGA Port Companion Circuit

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
Applications
• VGA and DVI-I ports in:
- Desktop and Notebook PCs
- Graphics Cards
- Set Top Boxes
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)
Simplified Electrical Schematic
3
VIDEO_1
4
VIDEO_2
VIDEO_3 ⁵
V_{CC_VIDEO}
2
V_{CC_DDC}
7
6
GND
DDC_IN1 ¹⁰
DDC_IN2 ¹¹
SYNC_IN1 ¹³
SYNC_IN2 ¹⁵
GND
BYP
8
V_{CC_SYNC}
1
9
DDC_OUT1
12 _{DDC_OUT2}
R_T
R_T
16 _{SYNC_OUT2}
14 _{SYNC_OUT1}
© 2004 California Micro Devices Corp. All rights reserved.
08/12/04 430 N. McCarthy Blvd., Milpitas, CA 95035-5112
▲ Tel: [phone] ▲ Fax: [phone] ▲ www.calmicro.com
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