Specifications
Circuit description of CCM420 monitor Application Note
AN97032
Philips Semiconductors
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1. INTRODUCTION
The CCM420 demo monitor is a full I
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C bus controlled monitor. Extensive geometry control, a very wide deflec-
tion frequency range (horizontal: 15 - 84 kHz; vertical: 50 - 160 Hz), wide bandwidth video channels (maximum
pixel rate 180 Mhz) with perfect grey scale tracking, a full mains range supply combined with complete software
control result in a monitor with outstanding specifications while maintaining an economic design.
The CCM420 demo monitor is meant to show the latest products of Philips Semiconductors and Philips Com-
ponents. Key components are:
• monitor microcontroller P83C181
• CCM420S monitor control software
• I
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C-bus autosync deflection controller for PC/TV monitors TDA4854
• I
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C-bus controlled octuple eight bit DAC TDA8447
• full bridge vertical booster TDA8354
• 150 Mhz video controller with I
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C-bus TDA4885
• hybrid video output stage CR6927
• low power line driver transformer CU15/35
• monitor line deflection transistor BU2532AL
• DC controlled linearity corrector PE4025/01
• EHT transformer AT2097/M1
• 0.27 mm dot triplet pitch CRT M41EHN
• Optionally available is an active convergence control circuit with the vector processor TDA4845
The monitor microcontroller P83C181 has a DDC interface, auto-sync detection and a hardware sync proces-
sor. The DDC interface is DDC2AB compliant. The hardware mode detector has 12 bit resolution for the hori-
zontal and vertical frequency, polarity detection and sync presence detection. The built-in sync processor also
has a free-running mode. In this design the microcontroller runs with newly developed software CCM420S. This
software allows extensive user control of geometry and colour adjustment.
The autosync deflection controller for PC/TV monitors TDA4854 is fully I
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C-bus controlled and in this application
operating with a horizontal frequency range of 15 to 90 kHz (maximum 150 kHz; maximum ratio 6.5 :1). It al-
lows very extensive control of geometry both horizontally and vertically, built-in B+ control part and focus sec-
tion. Built-in soft-start as well as controlled shut down for B+ and deflection drive signals safeguard the output
stages at power-up and power-down, while smooth caption of horizontal frequency during mode-changes en-
sures adequate protection of the line output stage. The B+ control part is used in the feed-forward mode without
any feedback (omitting loop stability problems). The focus section has a fixed correction for the delay in the high
voltage output stage.
The vertical booster is the newly introduced TDA8354. This is a LVDMOS full bridge current driven output stage
for 3.2 Ampere peak-peak maximum and a flyback supply voltage of 68 Volt maximum.
The horizontal output stage is separated from the EHT supply to get maximum front of screen performance.
The line driver uses a low-power design with the CU15/35 driver transformer and a high-speed switching line
output transistor BU2532AL. To obtain optimum scan performance six S-correction switches and a newly de-
signed DC-controlled linearity corrector PE4025/01 are used.
The separate EHT supply section is synchronised with the horizontal deflection and uses a dedicated trans-
former AT2097/M1. Incorporated in this application are a number of protections to prevent spot burn-in.