Datasheet

Connect all capacitors as close to the device as possible.
V
BUS
and V
CC
bypass capacitors should have trace
lengths as short as possible
±15kV ESD Protection
To protect the MAX3353E against ESD, D+, D-, ID_IN,
and V
BUS,
have extra protection against static electricity
to protect the device up to ±15kV. The ESD structures
withstand high ESD in all states—normal operation,
shutdown, and powered down. In order for the 15kV
ESD structures to work correctly, a 1µF or greater
capacitor must be connected from V
BUS
to GND. ESD
protection can be tested in various ways; D+, D-, ID_IN,
and V
BUS
are characterized for protection to the follow-
ing limits:
1) ±15kV using the Human Body Model
2) ±6kV using the IEC 1000-4-2 Contact Discharge
method
3) ±11kV using the IEC 1000-4-2 Air-Gap Discharge
method
ESD Test Conditions: ESD performance depends on
a variety of conditions. Contact Maxim for a reliability
report that documents test setup, test methodology,
and test results.
Human Body Model
Figure 11 shows the Human Body Model and Figure 12
shows the current waveform it generates when dis-
charged into a low impedance. This model consists of
a 100pF capacitor charged to the ESD voltage of inter-
est, which is then discharged into the test device
through a 1.5kΩ resistor.
IEC 1000-4-2
The IEC 1000-4-2 standard covers ESD testing and
performance of finished equipment; it does not specifi-
cally refer to integrated circuits. The major difference
between tests done using the Human Body Model and
IEC 1000-4-2 is a higher peak current in IEC 1000-4-2,
because series resistance is lower in the IEC 1000-4-2
model. Hence, the ESD withstand voltage measured to
IEC 1000-4-2 is generally lower than that measured
using the Human Body Model. Figure 13 shows the IEC
1000-4-2 model. The Air-Gap Discharge test involves
approaching the device with a charged probe. The
Contact Discharge method connects the probe to the
device before the probe is energized. Figure 14 shows
the IEC 1000-4-2 current waveform.
Machine Model
The Machine Model for ESD tests all pins using a
200pF storage capacitor and zero discharge resis-
tance. Its objective is to emulate the stress caused by
contact that occurs with handling and assembly during
manufacturing. All pins require this protection during
manufacturing. The Machine Model is less relevant to
I/O ports after PC board assembly.
Layout Considerations
The MAX3353E high oscillator frequency makes proper
layout important to ensure stability and maintain the
output voltage under all loads. For best performance,
minimize the distance between the capacitors and the
MAX3353E.
UCSP Reliability
For the latest application details on UCSP construction,
dimensions, tape-carrier information, printed circuit board
techniques, bump-pad layout, and recommended reflow
temperature profile as well as the latest information on
reliability testing results, refer to Maxim Application Note:
UCSP – A Wafer-Level Chip Scale Package available on
Maxim’s website at www.maxim-ic.com/ucsp.
MAX3353E
USB On-the-Go Charge Pump with Switchable
Pullup/Pulldown Resistors
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