+
V
CC
-
DESCRiPTion
Phase 2 – Vss transfer from C2 to C4.
Meanwhile C1 is charged to Vcc
+
+
V
CC
-
Phases 1 and 3: Store/Double.
Double charge from C1 onto C2.
C2 is now charged to -2xVcc
C
+
1
C
+
2
V+
e
-
e
-
C
+
3
e
-
C
Vss
4
+
C
+
1
C
+
2
V+
V-
C
+
3
Patented 5,306,954
+
V
CC
-
e
-
e
-
C
4
Phase 4 V
DD
transfer from C2 to C3.
Meanwhile C1 is charged to Vcc
V
e
+
DD
e
+
+
C
+
1
C
+
2
V+
V-
C
+
3
e
-
C
4
Figure . Charge pump phases
ESD ToLERAnCE
The SP202E, 232E, 233E, 30E and 32E
devices incorporates ruggedized ESD cells on
all driver outputs and receiver input pins. The
ESD structure is improved over our previous
family for more rugged applications and envi-
ronments sensitive to electro-static discharges
and associated transients. The improved ESD
tolerance is at least +/-5kV Human Body
Model without damage nor latch-up.
The Human Body Model has been the gener-
ally accepted ESD testing method for semi-
conductors. This method is also specified in
MIL-STD-883, Method 305.7 for ESD testing.
The premise of this ESD test is to simulate
the human body's potential to store electro-
static energy and discharge it to an intergrated
circuit. The simulation is peformed by using a
test model as shown in figure 2. This method
will test the IC's capability to withstand an ESD
transient during normal handling such as in
manufacturing areas where the IC's tend to be
handled frequently.
R
C
R
S
SW1
DC Power
Source
SW2
C
S
Device
Under
Test
Figure 2. ESD test circuit for Human Body
Model
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (50)668-7000 • www.exar.com SP202E,232E,233E, 30E, 32E_00_0608
7
EXAR [ EXAR CORPORATION ]
