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MDxxx Series
Newseries of high voltage Bipolar Transistors for slim CRT displays

MDxxx Series Product Page

Although traditional CRT (Cathode Ray Tube) displays have lost ground in recent years to flat screen displays based on LCD (Liquid Crystal Display) or PDP (Plasma Display Panel) technologies, CRT technology continues to offer the best trade-off between picture quality and cost. ST’s new MDx family of high voltage power bipolar transistors is specifically designed to meet the challenging requirements for horizontal deflection in slim CRT displays.
MDxxx Series
Because these new displays employ picture tubes of significantly reduced depth, the angle through which the electron beam must be deflected during each horizontal scan has increased from 110° to typically 124°. This obviously places stringent new demands on the bipolar power transistors that control the flow of current through the horizontal deflection coils.
To meet this requirement, the MDx devices are built with the EHVS1 state-of-the-art technology.

EHVS1 Technology And Features


EHVS1 is a planar technology realized by a float-zone collector on a diffused substrate, with a redesigned high voltage edge structure. The silicon efficiency has been improved thanks to the reduction of the capacitance in the base-collector junction by adopting a special deep-base process.
As a result, MD devices offer:
Both high current capability and high switching speed
A wider range of optimum drive conditions
A reduced saturation voltage at high current

Benefits


Major benefits for MD products are:
Tighter hFE range
Improved R.B.S.O.A. for safer switching performance
Reliable very high-voltage breakdown
Very low leakage current
Low power dissipation
Cool working temperature
Stable thermal performance vs driving variation
Better compatibility for easy replacement

Part Numbering Description


MDxxx Series
MDxxx series nomenclature


MD Series Product Range In TO-3PF


Part number
Diode
VCES
[V]
IC
[A]
Target use
1500
6
up to 21"
 
10
up to 29"

12
up to 32"

14
up to 36"
N.B. These parts are also available in TO-220FH, identified by last digit H,
instead of X (i.e. MD2103DFH)

Applications


Besides being primarily aimed at horizontal deflection in slim CRT displays, both MD1802FX/– FH part numbers are also very cost effective in TV power supply applications (RCC topology). They are suitable for TVs with screen sizes in the range 14” to 25”.