CM3501-02SN

CALIFORNIA MICRO DEVICES PRELIMINARY CM3501 Dual USB Overcurrent Switch 750mA (VCC) / 100mA (VSBY) Features • • • • • • • • • • • Dual outputs, each with independent over-current protection circuitry and indicator Supports standby mode in PCs so that a peripheral can ramp down safely to a current VCC, SEL floating 40 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 Ω Ω mA mA ms °C °C µA µA µA µA µA µA µA µA V V V The “H” version has a higher ON-resistance. All other functions are identical to the regular version. © 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 higher current power source. Whenever the SEL pin is above 2V it will be selected, and VSBY will be deselected. PRELIMINARY CM3501 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. VSBY is the lower current power source. Whenever the SEL pin is below 0.8V it will be selected, and VCC will be deselected. The two VSBY power switches can only supply 100mA. VSB VOUT1 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. 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 VCC, set SEL low to select VSBY, 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 VIL/VIH levels. VOUT2 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 750mA are allowed (from Vcc). Current loads above 750mA may cause the constantcurrent 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. OC1#, OC2# are independent, active low opendrain outputs, indicating an overcurrent fault condition has been detected at VOUT1 or VOUT2. There is a builtin 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. GND is the negative reference for all voltages. Pin No. 1 2 3 4 5 6 7 8 Symbol GND VCC VSBY SEL OC2# VOUT2 VOUT1 OC1# Pin Functions Description Negative reference for all voltages. High current positive supply input. Standby positive supply input. Also provides internal power. 3-level logic input. High = VCC, Low = VSBY, Floating = both off Active low when VOUT2 is in overcurrent mode. Output voltage internally switched to either VCC or VSBY input source. Output voltage internally switched to either VCC or VSBY input source. Active low when VOUT1 is in overcurrent mode. STANDARD PART ORDERING INFORMATION Pins 8 Package SOIC Ordering Part Number CM3501-02SN 1 Part Marking CM3501-02SN Note 1: Parts are shipped in Tape & Reel form unless otherwise specified. © 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 PRELIMINARY CM3501 OC# Response to Momentary Overcurrent Fault >750mA