6ED family - 2nd generation
Technical Description
Application Note
9
Rev. 1.3, 2014-03-23
AN-EICEDRIVER-6EDL04-1
3
Technical description of the 6ED family – 2
nd
generation
3.1
General data sheet review
The datasheet of the 6ED family
– 2
nd
generation shows an essential difference to many competitor parts such
as [1] or [2] and others. The 6ED datasheets give the absolute maximum ratings referenced to VSS. This is an
important aspect, when estimating the robustness of the IC. VSS is the ground reference for the IC as well as
for the application and all other parameters vary against this point. All parameters can be measured at any pin
with reference to ground, which is VSS and which is the common way of measuring electrical values. Figure 2
shows the fundamental difference between VSS-rated devices and COM-rated devices, which are also available
in the market. There are also devices available, which do not give any information about the reference potential
at all. A close look to the reference level is therefore highly recommended.
a)
b)
Figure 2
Different reference systems for
a) 6ED family
– 2
nd
generation
b) many other 6channel gate drive IC
There is usually an additional levelshifter designed with a capability of a few volts in order to provide stability for
the COM pin. This can be used e.g. for decoupling a shunt from the ground network. However, it is this levelshift
structure, which gives another option for the pin COM to float in respect to VSS (=ground of application). The
result is that the 6ED family
– 2
nd
generation has another margin of 5.7 V with respect to COM. The relevant
maximum rating of 6ED family
– 2
nd
generation in the datasheet on p. 14 are:
-
The 6ED family
– 2
nd
generation gives a maximum rating for VCC in respect to VSS (20 V)
-
The 6ED family
– 2
nd
generation gives a maximum rating for COM in respect to VSS (± 5.7 V)
-
The 6ED family
– 2
nd
generation give a maximum rating for VBSx in respect to VSx (20 V)
One can now calculate a scenario of absolute maximum ratings for a potential COM-rated 6ED device:
VCC,max* = VCOM = 25 V with reference to COM
VBS,max* = VBS,max + VCOM = 20V + 5.7 V = 25.7 V with reference to COM and VS = VSS
VS,min* =VCC,max
–VBS,max–6V–VCOM =20V–20V–6V–5.7V = –11.7V with reference to COM
It is easy to see, that the 6ED family
– 2
nd
generation has same or even higher rated values, when ratings are
referenced to pin COM instead of pin VSS. Please not here, that rated values, which are referenced to COM are
– if at all – only of little relevance for the application.
3.2
Control input section
All control input pins (HIN, LIN, ITRIP, EN) contain clamping zener diodes. The purpose of these diodes is ESD
protection. Therefore they are designed to manage low energy single pulse stresses only. A continuous
operation above the absolute maximum ratings is forbidden, such as hard pull-up to voltages above 10 V with a
pull-up resistance of 0
However, a soft pull-up up to VCC is allowed, if the input current is less than 1 mA.
Please note, that this causes additional losses and must be considered in the losses calculation.
6ED -
2nd
gen.
VCC
HO
VS
V
Bus
C
VCC
LO
VSS
T1
T2
D2
D1
Rsh
COM
20V
max
Max.
± 5.7V
Other
6ch.
gate
drive
IC
VCC
HO
VS
V
Bus
LO
VSS
T1
T2
D2
D1
Rsh
COM
25V
max
C
VCC
