MAX1563ETC+T Maxim Integrated Products, MAX1563ETC+T Datasheet - Page 10

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

Specifications of MAX1563ETC+T

• 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

ramps down for 800µs. Under fault conditions, the output
of the switches turns off rapidly to provide maximum safe-
ty for the upstream power source and downstream
devices. Internal blocks shut down to minimize supply
current when the switch is off.
Keep all traces as short as possible to reduce the effect
of undesirable parasitic inductance and optimize the
switch response time to output short-circuit conditions.
Place the input and output capacitors no more than
5mm from the device leads. Connect IN and OUT to the
power bus with short traces. Wide power bus planes at
IN and OUT provide superior heat dissipation.
Calculate the power dissipation for a normal loaded
condition as follows:
At a 3A operating current and the maximum on-resis-
tance of the switch (50mΩ), the power dissipation is:
The worst-case power dissipation occurs when the out-
put current is just below the current-limit threshold (set
to 3A in this example) with an output voltage greater
than +1V. In this case, the power dissipated in the
switch is the voltage drop across the switch multiplied
by the current limit:
For a +5V input and +1V output, the maximum power
dissipation is:
Because the package power dissipation is 471mW for
Programmable 4A USB Current-Limited
Switches with Autoreset and Fault Blanking
10
SEL
ON
IN
______________________________________________________________________________________
MAX1563 Functional Diagram
MAX1563
P = (3A)
P = 3A x (5V - 1V) = 12W
P = I
P = (I
LIM
Layout and Thermal Dissipation
2
ULVO
CHARGE
FAULT LOGIC
20ms TIMERS
PUMP
x 0.05Ω = 450mW
SHUTDOWN
OUT
THERMAL
x (V
25kHz
OSC
GND
)
2
IN
x R
- V
BIAS
ON
OUT
25mA
REF
)
ILIM
FAULT
OUT
IN
the MAX1562/MAX1562H and 1.35W for the MAX1563,
the devices’ die temperature exceeds the +160°C ther-
mal-shutdown threshold, and the switch output shuts
down until the junction temperature cools by 15°C. The
duty cycle and period are strong functions of the ambi-
ent temperature and the PC board layout.
If the output current exceeds the current-limit threshold,
or the output voltage is pulled below the short-circuit
detect threshold, the MAX1562/MAX1562H/MAX1563
enter a fault state for 20ms, after which autoreset mode
is enabled and 25mA is sourced by the output. For a
+5V input, OUT short-circuited to GND, and autoreset
mode active, the power dissipation is as follows:
TOP VIEW
() FOR MAX1562H.
+4V TO +5.5V
ON (ON)
FAULT
GND
ISET
INPUT
ON
1
2
4
OFF
3
1µF
+
Typical Application Circuit
MAX1562H
MAX1562
P = 0.025A x 5V = 0.125W
SO
*USB APPLICATIONS MAY REQUIRE
ADDITIONAL BULK CAPACITANCE.
IN
IN
ON
SEL
ISET
8
7
6
5
OUT
IN
OUT
IN
MAX1563
Pin Configurations
GND
OUT
N.C.
SEL
1
2
3
FAULT
OUT
OUT
+
ON
IN
12
4
4 mm x 4 mm
THIN QFN
MAX1563
FAULT
N.C.
11
5
100kΩ
OUT
GND
10
4.7µF*
6
USB
PORT
9
8
7
IN
N.C.
ISET