JAN-03 Datasheet, PDF (1/5 Pages) Vishay Siliconix – Basic Definitions

VISHAY
Basic Definitions
Vishay Semiconductors
Basic Sinterglass Diode Parameters
The major parameters for the selection of the appro-
priate sinterglass diodes are the maximum reverse
voltage (V_RRM), the average forward current (I_FAV)
and for switching application the reverse recovery
characteristic (t_rr), too. Additional parameters may be
for example the reverse avalanche energy capability
(E_R) and forward surge capability (I_FSM) etc.
V_R
V_RRM
V_(BR)R
I_R
I_F
V_F
I_FAV
Reverse voltage
Repetitive peak reverse voltage, including all repeated reverse transient voltages
Reverse breakdown voltage
Reverse (leakage) current, at a specified reverse voltage V_R and temperature T_J
Forward current
Forward voltage drop, at a specified forward current I_F and temperature T_J
Average forward output current, at a specified current waveform (normally 10ms/50Hz half-sine-
wave, sometimes 8.3ms/60Hz half-sine-wave), a specified reverse voltage and a specified mounting
condition (e.g. lead-length = 10mm or PCB mounted with certain pads and distance)
I_FSM
Peak forward surge current, with a specified current waveform (normally 10ms/50Hz half-sine-wave,
sometimes 8.3ms/60Hz half-sine-wave),
t_rr
Reverse recovery time, at a specified forward current (normally 0.5A), a specified reverse current
(normally 1.0A) and specified measurement conditions (normally from 0 to 0.25A)
E_R
Reverse avalanche energy, non-repetitive
Polarity Conventions
The voltage direction is given
• by an arrow which points from the measuring point
to the reference point
or
• by a two letter subscript, where the first letter is the
measuring point and the second letter is the refer-
ence point.
In the case of alternating voltages, once the voltage
direction is selected it is maintained throughout. The
alternating character of the quantity is given with the
time dependent change in sign of its numerical values
.
A
I₁
B
A
I₂ = –I₁
B
A
A
A
94 9316
V₁
V_AB
V₂=–V₁=V_BA=–V_AB
Figure 2.
B
B
B
94 9315
Figure 1.
The numerical value of the voltage is positive if the
potential at the arrow tail is higher than at the arrow
head; i.e., the potential difference from the measuring
point (A) to the reference point (B) is positive.
The numerical value of the voltage is negative if the
potential at the arrow head is higher than the tail; i.e.,
the potential difference from the measuring point to
the reference point is negative.
The numerical value of the current is positive if the
charge of the carriers moving in the direction of the
arrow is positive (conventional current direction), or if
the charge of the carriers moving against this direc-
tion is negative. The numerical value of the current is
negative if the charge of the carriers moving in the
direction of the arrow is negative, or if the charge of
the carriers moving against this direction is positive.
The general rules stated above are also valid for alter-
nating quantities. Once the direction is selected, it is
maintained throughout. The alternating character of
the quantity is given with the time-dependent change
in sign of its numerical values.
Document Number 84067
Rev. 7, 07-Jan-03
www.vishay.com
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