ESD8011
www.onsemi.com
5
Latch−Up Considerations
ON Semiconductor’s 8000 series of ESD protection
devices utilize a snap−back, SCR type structure. By using
this technology, the potential for a latch−up condition was
taken into account by performing load line analyses of
common high speed serial interfaces. Example load lines for
latch−up free applications and applications with the
potential for latch−up are shown below with a generic IV
characteristic of a snapback, SCR type structured device
overlaid on each. In the latch−up free load line case, the IV
characteristic of the snapback protection device intersects
the load−line in one unique point (V
OP
, I
OP
). This is the only
stable operating point of the circuit and the system is
therefore latch−up free. In the non−latch up free load line
case, the IV characteristic of the snapback protection device
intersects the load−line in two points (V
OPA
, I
OPA
) and
(V
OPB
, I
OPB
). Therefore in this case, the potential for
latch−up exists if the system settles at (V
OPB
, I
OPB
) after a
transient. Because of this, ESD8011 should not be used for
HDMI applications − ESD8104 or ESD8040 have been
designed to be acceptable for HDMI applications without
latch−up. Please refer to Application Note AND9116/D for
a more in−depth explanation of latch−up considerations
using ESD8000 series devices.
I
I
V
V
ESD8011 Latch−up free:
USB 2.0 LS/FS, USB 2.0 HS, USB 3.0 SS,
DisplayPort
V
OP
V
DD
I
SSMAX
I
OP
ESD8011 Potential Latch−up:
HDMI 1.4/1.3a TMDS
V
OPB
V
OPA
V
DD
I
SSMAX
I
OPB
I
OPA
Figure 4. Example Load Lines for Latch−up Free Applications and Applications with the Potential for Latch−up
Table 1. SUMMARY OF SCR REQUIREMENTS FOR LATCH−UP FREE APPLICATIONS
Application
VBR (min) IH (min) VH (min) ON Semiconductor ESD8000 Series
(V) (mA) (V) Recommended PN
HDMI 1.4/1.3a TMDS 3.465 54.78 1.0 ESD8104, ESD8040
USB 2.0 LS/FS 3.301 1.76 1.0 ESD8004, ESD8011
USB 2.0 HS 0.482 N/A 1.0 ESD8004, ESD8011
USB 3.0 SS 2.800 N/A 1.0 ESD8004, ESD8006, ESD8011
DisplayPort 3.600 25.00 1.0 ESD8004, ESD8006, ESD8011
