MAX1563ETC+ Maxim Integrated Products, MAX1563ETC+ Datasheet - Page 9

• Manufacturer Part Number: MAX1563ETC+
• Description: IC CURR-LIM SW SNGL PROG 12-TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX1563ETC+

• Applications: USB
• Interface: USB
• Voltage - Supply: 4 V ~ 5.5 V
• Package / Case: 12-TQFN Exposed Pad
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

successfully power USB loads with additional bypass
capacitance and/or large startup currents while pro-
tecting the upstream power source. No fault is reported
if the switch brings up the load within the 20ms blank-
ing period. See Table 2 for a summary of current-limit
and fault behavior.
Connect both IN inputs together externally. IN powers
the internal control circuitry and charge pump for the
switch, allowing a decreased R
with a 1µF ceramic capacitor. When driving inductive
loads or operating from inductive sources, which may
occur when the device is powered by long leads or PC
traces, larger input bypass capacitance is required to
prevent voltage spikes from exceeding the absolute
maximum ratings during short-circuit events.
Bypass OUT to GND with a 4.7µF ceramic capacitor for
local decoupling. Additional bulk capacitance (up to
470µF) reduces output-voltage transients under dynam-
ic load conditions. Using output capacitors greater than
470µF might assert FAULT if the current limit cannot
Table 2. Current Limiting and Fault Behavior
Output Short-Circuit
(V
Output Overload Current
(V
Thermal Fault
(T
OUT
OUT
J
> +160°C)
CONDITION
< +1V)
> +1V)
Input Power Supply and Capacitance
Switches with Autoreset and Fault Blanking
Applications Information
_______________________________________________________________________________________
Programmable 4A USB Current-Limited
• If a short is detected at the output, the channel turns off, and the blanking timer begins. FAULT
• If the short persists during the fault-blanking period, the output pulses at 0.30 x I
• If the short-circuit persists after the fault-blanking period. FAULT goes low, autoreset mode begins,
• If the output voltage rises above 0.5V for 20ms, the channel resets, the output turns on, and FAULT
• If an overload occurs, output current regulates at I
• Continuous current at I
• If overcurrent persists after 20ms, FAULT goes low, autoreset mode is enabled, and the output
• If the output voltage rises above 0.5V for 20ms, the channel resets, the output turns on, and
• A junction temperature of +160
remains high during the blanking timeout period.
is removed before the 20ms short-circuit blanking timeout period, the next ramped current pulse soft-
starts the output. FAULT remains high.
and the output sources 25mA.
goes high.
high during the blanking timeout period.
fault occurs.
sources 25mA.
FAULT goes high (see the Overload Response into 1.4Ω graph in the Typical Operating
Characteristics section).
does not apply for thermal faults) and turns off the switch. When the junction cools by 15°C, the
thermal fault is cleared and FAULT goes high. Note that if other fault conditions are present when
a thermal fault clears, those fault states take effect.
ON
. Bypass IN to GND
Output Capacitor
LIM
persists until either the 20ms blanking period expires or a thermal
MAX1562/MAX1562H/MAX1563 BEHAVIOR
o
C immediately asserts FAULT low (the blanking timeout period
charge the output capacitor within the 20ms fault-
blanking period. In addition to bulk capacitance, small-
value (0.1µF or greater) ceramic capacitors improve the
output’s resilience to electrostatic discharge (ESD).
A wide variety of devices (mice, keyboards, cameras,
and printers) typically connect to the USB port with
cables, which might add an inductive component to the
load. This inductance causes the output voltage at the
USB port to oscillate during a load step. The
MAX1562/MAX1562H/MAX1563 drive inductive loads,
but avoid exceeding the device’s absolute maximum
ratings. The load inductance is usually relatively small,
and the MAX1562/MAX1562H/MAX1563s’ input
includes a substantial bulk capacitance from an
upstream regulator, as well as local bypass capacitors,
limiting overshoot. If severe ringing occurs because of
large-load inductance, clamp the MAX1562/MAX1562H/
MAX1563 outputs below +6V and above -0.3V.
When turned on, the MAX1562/MAX1562H/MAX1563 out-
put ramps up over 2.5ms to eliminate load transients on
the upstream power source. When turned off, the output
LIM
and the blanking timer turns on. FAULT remains
Turn-On and Turn-Off Behavior
Driving Inductive Loads
LIM
RMS. If the short
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