USB Current-Limited Switch

in Pin-Compatible Package

counter starts. If the load fault persists beyond the

10ms overcurrent-blanking timeout, the OC output

asserts low. Ensure that the MAX1607 input is ade-

quately bypassed to prevent input glitches from trigger-

ing spurious OC outputs. Input voltage glitches less

than 150mV will not cause a spurious OC output. Load-

transient faults less than 10ms (typ) will not cause an

OC output assertion.

Only current-limit faults are blanked. Die overtempera-

ture faults and input voltage droops below the UVLO

threshold will cause an immediate OC output.

Applications Information

Input Capacitor

To limit the input voltage drop during momentary output

short-circuit conditions, connect a capacitor from IN to

GND. A 1µF ceramic capacitor will be adequate for

most applications; however, higher capacitor values will

further reduce the voltage drop at the input (Figure 2).

Output Capacitor

Connect a 0.1µF capacitor from OUT to GND. This

capacitor helps to prevent inductive parasitics from

pulling OUT negative during turn-off.

Layout and Thermal Dissipation

Important: Optimize the switch response time to output

short-circuit conditions by keeping all traces as short

as possible to reduce the effect of undesirable parasitic

inductance. Place input and output capacitors as close

as possible to the device (no more than 5mm away). All

IN and OUT pins must be connected with short traces

to the power bus. Wide power-bus planes will provide

superior heat dissipation through the MAX1607’s IN

and OUT pins.

Under normal operating conditions, the package can

dissipate and channel heat away. Calculate the maxi-

mum power dissipation as follows:

Ω max).

When the output is short circuited, foldback-current lim-

iting activates and the voltage drop across the switch

equals the input supply. The power dissipated across

the switch increases, as does the die temperature. If

the fault condition is not removed, the thermal-over-

load-protection circuitry activates (see Thermal

Shutdown section). Wide power-bus planes connected

to IN and OUT and a ground plane in contact with the

device will help dissipate additional heat.

Figure 2. Typical Application Circuit

MAX1607

IN

OUTPUT

OUT

INPUT

1

μF

0.1

μF*

*USB SPECIFICATIONS REQUIRE

A HIGHER VALUE CAPACITOR.

OVERCURRENT

OUTPUT

ON

100k

OFF

GND

OC

EN

Chip Information

TRANSISTOR COUNT: 715

_______________________________________________________________________________________

7

Pin Configurations (continued)

TOP VIEW

1

2

3

4

5

10

98

7

6

MAX1607

+

EP*

*EP = EXPOSED PADDLE