DATASHEET ISL6121 FN9004 Rev 2.00 Single Supply Integrated Current Limiting Controller November 12, 2004 The ISL6121 is a single supply Overcurrent (OC) fault Features protection IC for 2.5V to 5V applications where 2A current 0.05 Integrated Power N-channel MOSFET Switch limiting is desired. This device features internal current monitoring and limiting along with a 50m integrated power Accurate Current Sensing and Limiting switch and a current limited time out to latch-off feature for 12ms Timed Fault Latch-Off, No thermal Dependency system protection. The time to latch-off is independent of 2.5V to 5.5V Operating Range device temperature, and magnitude of OC. Under Voltage Lockout Each ISL6121 incorporates in a 8 lead SOIC package a 50m N-channel MOSFET power switch for power control. Disabled Output Internally Pulled Low The switch is driven by a constant current source giving a Controlled Turn On/Off Ramp Times controlled ramp up of the output voltage. This provides a soft start turn-on eliminating bus voltage drooping caused by in- Fault Output Signal rush current while charging heavy load capacitances. Logic Level Enable High Inputs (ISL6121H) or Enable Low (Enable high (ISL6121H) and enable low (ISL6121L) options Inputs (ISL6121L) are) available with a fault reporting output compatible with Logic Level Compatible Enable Input and Fault Output 3V and 5V logic level signals allowing for external control and monitoring. Pb-Free Available (RoHS Compliant) The Under Voltage (UVLO) lockout feature prevents turn-on Applications of the output unless the correct ENABLE signal and VIN > 2.5V are both present. During initial turn-on the ISL6121 Fibre Channel design prevents a fault from being presented by blanking the Industrial Power Control fault signal, unlike other vendor devices needing additional Hot Plug external circuitry to accomplish this. Rising and falling output is a current-limited voltage ramp so that both the inrush current and voltage slew rate are limited, Ordering Information independent of load. This reduces supply droop due to surge and eliminates the need for external EMI filters. PART TEMP. RANGE PKG. NUMBER (C) PACKAGE DWG. During operation once an OC condition is detected the output is current limited to 2A to allow for a transient ISL6121HIB -40 to 85 8 Ld SOIC M8.15 condition to pass. If still in current limit after the current limit ISL6121HIBZA -40 to 85 8 Ld SOIC M8.15 period has elapsed the output is latched off and the fault is (See Note) (Pb-free) reported by pulling the FAULT low. The FAULT signal is ISL6121HIB-T -40 to 85 8 Ld SOIC Tape and Reel latched low until reset by the enable signal being deasserted at which time the FAULT signal will clear. ISL6121HIBZA-T -40 to 85 8 Ld SOIC Tape and Reel (See Note) (Pb-free) See Figure 1 for typical application configuration. ISL6121LIB -40 to 85 8 Ld SOIC M8.15 ISL6121LIBZA -40 to 85 8 Ld SOIC M8.15 OUT 1 GND 8 (See Note) (Pb-free) R L ISL6121LIB-T -40 to 85 8 Ld SOIC Tape and Reel VIN OUT 2 7 ISL6121LIBZA-T -40 to 85 8 Ld SOIC Tape and Reel 3 VIN OUT 6 (See Note) (Pb-free) C L ISL6121HEVAL1 Evaluation Platform 4 EN 5 FAULT NOTE: Intersil Pb-free products employ special Pb-free material sets molding compounds/die attach materials and 100% matte tin plate termination finish, which are RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products FIGURE 1. ISL6121 TYPICAL APPLICATION are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020C. FN9004 Rev 2.00 Page 1 of 11 November 12, 2004ISL6121 Simplified Block Diagram GND OUT VIN OUT Q-PUMP POR VIN CURRENT AND TEMP. OUT MONITORING, GATE AND OUTPUT CONTROL LOGIC EN LOGIC FAULT Pin Descriptions PIN SYMBOL FUNCTION DESCRIPTION 1 GND IC GND Reference 2, 3 VIN Chip Bias, Controlled VIN provides chip bias voltage. At VIN < 2.5V chip functionality is disabled, FAULT latch Supply Input, Undervoltage is cleared and floating. OUT is pulled and held low. Lock-Out 4 ENABLE / Enable / Enable Not Input Enables chip when VIN and ENABLE > 2.5V or ENABLE < 0.6V ENABLE 5 FAULT Over Current Fault Indicator Overcurrent fault indicator. FAULT is disabled for 12ms after turn-on. This output is pulled low to GND after the current limit time-out period has expired and stays latched until ENABLE is deasserted. 6, 7, 8 VOUT Controlled Supply Output Voltage output, connect to load to protect. Upon an overcurrent condition VOUT is current limited to 2A. Current limit response time is within 200 S. This output will remain in current limit for approximately 12ms before being latched off. FN9004 Rev 2.00 Page 2 of 11 November 12, 2004