View CM3503-02SN_1226916.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

CALIFORNIA MICRO DEVICES USB 5V Single 1.4A Overcurrent Switch
Features
* * * * * * * * * * High-side high current switch with active low Enable Very low on-resistance switch (0.07? typ.) Up to 1.4A continuous current on the output Over-current limits at 1.4A min 10msec min fault blanking delay on OC# output prevents false overcurrent alarms Prevents backdrive current when host powered off Low operating current (95A typ.) Low quiescent current when disabled (<1A max) Small 8-Lead SOIC package
PRELIMINARY CM3503
Pin Diagram
GND VCC VCC EN# SOIC-8
VOUT VOUT VOUT OC#
Applications
2 USB ports 5V supply overcurrent protection
Product Description
California Micro Devices' CM3503 is a USB overcurrent power switch that provides power to two USB ports. The device has a very low on-resistance power switch that provides the VBUS voltage at the USB output ports with minimal voltage drop. When the EN# pin is logic low, the power switch is ON, and VCC is connected to the output VOUT. When the EN# pin is logic high, the power switch is OFF, and no power is available at the output. The power switch has full over-current protection. Whenever the current limit of the switch is exceeded, the device enters a constant-current mode, where the output voltage is progressively reduced to prevent the current from increasing further. The OC# output becomes active low only if the overcurrent condition exceeds at least 10ms. This fault blanking delay prevents false alarms from being reported to the host USB controller. If the overcurrent condition is severe enough that the part heats up to the thermal limit TMAX, then the switch will be turned off and the temperature cools down. At TMIN the switch then turns on again, and the device heats up again, and so on, until the fault is removed. The CM3503 also prevents backdrive current flowing into the host from the connected peripheral. This can occur when VCC is removed as the host powers down, and the peripheral still has normal power applied. The 5V from the peripheral can therefore be linked to the host's VBUS, potentially causing backdrive current into the host and overloading the peripheral power supply.
Typical Application Circuit
GND VCC VCC VCC EN# VOUT VOUT VOUT OC# VBUS
VBUS 1 USB Port 1 USB Port
Simplified Electrical Schematic
EN# VCC Over current protect VOUT OC#
(c) 2003 California Micro Devices Corp. All rights reserved.
C0970500
09/10/03
430 N. McCarthy Blvd, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
1
CALIFORNIA MICRO DEVICES
Absolute Maximum Ratings Parameter Rating ESD Protection (All pins, HBM) 2000 VCC Input Voltage + 5.6, Gnd - 0.5 Storage Temperature Range -55 to +150 Operating Ambient -40 to +85 Operating Junction -40 to +150* Output Current Loading Internally limited Package Power Dissipation 0.5
*Internally limited
PRELIMINARY CM3503
Unit V V C A W
Operating Conditions (unless specified otherwise) Parameter Range VCC Input Voltage 4.5 to 5.5 Ambient Temperature -40 to +85 ILOAD VCC 0 to 1400
Unit V C mA
Symbol UVLO RSW RSWa RSWb VOUT ILIM tFBD
TMAX TMIN IRCC ICC ICCQ VIH-EN VIL-EN VOL-OC
Electrical Operating Characteristics (over operating conditions unless specified otherwise) Parameter Conditions MIN TYP MAX VCC voltage under which circuit 2.2 2.5 T=25C locks out - will not operate Switch ON-Resistance ILOAD = 0 to 1400mA; VCC = 5V, 0.07 0.1 T = 25C Switch ON-Resistance ILOAD = 0 to 1400mA; VCC = 5V, 0.125 T = 0 to +85C Switch ON-Resistance ILOAD = 0 to 1400mA; VCC = 5V, 0.125 T = -40 to +85C Output Voltage ILOAD = 1000mA, VCC = 5.0V, 4.9 EN#=0V, T=25C Over-current limit 1400 2000 2600 VCC = 5V T=25C 10 20 30 Time delay from overcurrent detection to OC# output indication (fault blanking delay) Temperature at which switch 150 turns off during overcurrent Temperature at which switch 125 turns on, after cooling from TMAX Reverse leakage from output to VCC = 0V, VOUT = 5V, EN# = high, 10 input T=25C Operating supply current EN# = low 95 Quiescent current EN# = high 1 EN# input Logic-1 threshold VCC = 5V 2 EN# input Logic-0 threshold VCC = 5V 0.8 OC# output Logic-0 threshold IOC = 1mA to VCC 0.4
UNIT V V mA ms C C A A A V V V
Note: This is a preliminary datasheet only. Data subject to change at any time. (c) 2003 California Micro Devices Corp. All rights reserved
09/10/03
430 N. McCarthy Blvd, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
2
CALIFORNIA MICRO DEVICES
Pin Functions VCC is the power source.
Pins 2 & 3 must be connected together externally
PRELIMINARY CM3503
EN# is the active low logic input pin that is used to VOUT provides the power for the loads. The internal
MOSFET switch is designed for very low voltage drops from the voltage input pins at the full rated current. Pins 6, 7 & 8 must be connected together externally. Current loads of up to 1.4A are allowed. Current loads above 1.4A 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 the switch immediately turns off. Once the part has cooled to 125'C then the switch automatically turns on again. During the cold-start interval when the input is initially applied, internal circuitry provides a soft turn-on for the switch, which limits peak in-rush current. control the power switch. Set EN# high (>2V) to deselect VOUT, and set EN# low (<0.8V) to select VOUT.
OC# is an active low open-drain output voltage,
indicating an overcurrent fault condition has been detected at VOUT. There is a built-in 10msec (min.) fault blanking delay after the overcurrent fault condition has been detected, before this output becomes active low. The OC# output deasserts only when both the overcurrent condition stops and when the voltage drop across the switch is less than 1V. An external pull-up resistor of 10k - 100k is required if the OC# output is used.
GND is the negative reference for all voltages.
Pin No. 1 2 3 4 5 6 7 8
Symbol GND VCC VCC EN# OC# VOUT VOUT VOUT
Pin Descriptions Description Negative reference for all voltages. Power Primary High current Positive supply input. Power supply input connected to pin 2 Active low enable pin Active low when VOUT is in overcurrent mode. External pull-up resistor required. Output connected to pins 7 and 8 Output connected to pins 6 and 8 Output connected to pins 6 and 7
STANDARD PART ORDERING INFORMATION Pins 8 Package SOIC Ordering Part Number CM3503-02SN
1
Part Marking CM3503-02SN
Note 1: Parts are shipped in Tape & Reel form unless otherwise specified.
Note: This is a preliminary datasheet only. Data subject to change at any time. (c) 2003 California Micro Devices Corp. All rights reserved
09/10/03
430 N. McCarthy Blvd, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
3
CALIFORNIA MICRO DEVICES
Response to Momentary Overcurrent Fault
>1400mA
PRELIMINARY CM3503
<1300mA
IOUT
VOUT drops to reduce IOUT
VOUT
OC#
OC# goes active after 10ms (min) 20ms (typ.) delay
OC# goes inactive as soon as overcurrent condition stops
<150'C
Temp.
Response to Continuous Overcurrent Fault
>1400mA IOUT
VOUT drops to reduce IOUT VOUT Total powerdown when over-temperature limit reached
Re-powers when temperature drops to 125'C
OC#
OC# goes active after 10ms (min) 20ms (typ.) delay OC# stays low TMAX = 150'C 150'C
Temp.
TMIN = 125'C
Note: This is a preliminary datasheet only. Data subject to change at any time. (c) 2003 California Micro Devices Corp. All rights reserved
09/10/03
430 N. McCarthy Blvd, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
4
CALIFORNIA MICRO DEVICES
Typical Operating characteristics
CM3503 Quiescent supply current vs. supply voltage 120 100 80 ICC [uA]
PRELIMINARY CM3503
60 40 20 0 4 4.2 4.4 4.6 4.8 V CC [V] 5 5.2 5.4 5.6
OC# Fault Blanking Delay
60
50
40 Delay [msec]
30
20
10
0 3.5 4 4.5 V CC [V] 5 5.5 6
CM3503 V OUT - IOUT characteristic
6
5
4 VOUT [V]
3
2
1
0 0 1 2 3 IOUT [A] 4 5 6
Note: This is a preliminary datasheet only. Data subject to change at any time. (c) 2003 California Micro Devices Corp. All rights reserved
09/10/03
430 N. McCarthy Blvd, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
5
CALIFORNIA MICRO DEVICES
PRELIMINARY CM3503
SOIC-8 Package Dimensions
Note: This is a preliminary datasheet only. Data subject to change at any time. (c) 2003 California Micro Devices Corp. All rights reserved
09/10/03
430 N. McCarthy Blvd, Milpitas, California 95035
Tel: (408) 263-3214
Fax: (408) 263-7846
www.calmicro.com
6

▲Up To Search▲

Price & Availability of CM3503-02SN

	To Download CM3503-02SN Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .