CM3511 Datasheet, PDF (3/13 Pages) California Micro Devices Corp – Dual USB Overcurrent Switch 1.2A (VCC) / 200mA (VSBY)

CALIFORNIA MICRO DEVICES
Pin Functions
PRELIMINARY
CM3511
V_CC is the higher current power source. Whenever the
SEL pin is above 2V it will be selected, and V_SBY will be
deselected.
During the cold-start interval when the input is initially
applied, internal circuitry provides a soft turn-on for
the switches, which limits peak in-rush current.
V_SBY is the lower current power source. Whenever the
SEL pin is below 0.8V it will be selected, and V_CC will
be deselected. The two V_SBY power switches can only
supply 200mA each.
Note that the internal supply current (95uA typ.) will be
taken from whichever input supply pin (V_CC or V_SBY) is
higher. V_SB
V_OUT1 provides the power for a USB port. The internal
MOSFET switches are designed for low voltage drops
from the voltage input pins at their full rated currents.
V_OUT2 provides the power for a second USB port. The
internal MOSFET switches are designed for low voltage
drops from the voltage input pins at their full rated
currents.
Current loads of up to 1.2A are allowed (sourced from
Vcc).
Current loads above 1.2A may cause the constant-
current limiting circuit to operate – reducing the output
voltage.
Continuous over-current loads will cause the part’s
internal temperature to rise. If the internal temperature
exceeds 150’C then any switch that is in overcurrent
mode will be immediately turned off. Any switch that is
not in overcurrent mode will remain on – it will not be
affected by the over-temperature detection. Once the
part has cooled to 125’C then the switch or switches
that were in overcurrent mode will be automatically
turned on again.
SEL is the 3-level logic input pin that is used to
control which of the power switch pairs are turned on.
Set SEL high to select V_CC, set SEL low to select
V_SBY, or allow SEL to float to deselect both power
switches. The external device driving the SEL pin
must able to source and sink 100µA while
maintaining the proper V_IL/V_IH levels.
OC1#, OC2# are independent, active low open-
drain outputs, indicating an overcurrent fault condition
has been detected at V_OUT1 or V_OUT2. There is a built-
in 10msec (min.) fault blanking period after the
overcurrent fault condition has been detected, before
these outputs become active. The OC# outputs
become deasserted only when both the overcurrent
condition stops and when the voltage drop across the
switch is less than 1V. External pull-up resistors of
10k - 100k are required if the OC# outputs are used.
Because they are open-drain, the two OC# outputs
can be shorted together to make one OC# signal.
GND is the negative reference for all voltages.
Pin No.
1
2
3
4
5
6
7
8
Symbol
GND
V_CC
V_SBY
SEL
OC2#
V_OUT2
V_OUT1
OC1#
Description
Pin Functions
Negative reference for all voltages.
High current positive supply input.
Standby positive supply input. Also provides internal power.
3-level logic input. High = V_CC, Low = V_SBY, Floating = both off
Active low when V_OUT2 is in overcurrent mode.
Output voltage internally switched to either V_CC or V_SBY input source.
Output voltage internally switched to either V_CC or V_SBY input source.
Active low when V_OUT1 is in overcurrent mode.
Pins
Package
STANDARD PART ORDERING INFORMATION
Ordering Part Number¹
Part Marking
8
SOIC
CM3511-04SN
CM3511-04SN
© 2003 California Micro Devices Corp. All rights reserved
11/10/03 ^{430 N. McCarthy Blvd, Milpitas, California 95035 Tel: [phone] Fax: [phone]}
www.calmicro.com
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