LTC1478CS#PBF Analog Devices

LTC1477/LTC1478 Single and Dual Protected High Side Switches FEATURES DESCRIPTION n Extremely Low R Switch: 0.07 The LTC 1477/LTC1478 protected high side switches DS(ON) n No Parasitic Body Diode provide extremely low R switching with built-in DS(ON) n Built-In Short-Circuit Protection: 2A protection against short-circuit and thermal overload con- n Built-In Thermal Overload Protection ditions. A built-in charge pump generates gate drive n Operates from 2.7V to 5.5V higher than the supply voltage to fully enhance the internal n Inrush Current Limited NMOS switch. This switch has no parasitic body diode and n Ultralow Standby Current: 0.01A therefore no current flows through the switch when it is n Built-In Charge Pump turned off and the output is forced above the input supply n Controlled Rise and Fall Times: t = 1ms voltage. (DMOS switches have parasitic body diodes that R n Single Switch in 8-Pin SO Package become forward biased under these conditions.) n Dual Switch in Narrow 16-Pin SO Package Two levels of protection are provided by the LTC1477/LTC1478. The first level of protection is short- U circuit current limit which is set at 2A. The short-circuit APPLICATIONS current can be reduced to as low as 0.85A by disconnect- n Notebook Computer Power Management ing portions of the power device (see Applications Infor- n Power Supply/Load Protection mation). The second level of protection is provided by n Supply/Battery Switch-Over Circuits thermal overload protection which limits the die tempera- n Circuit Breaker Function ture to approximately 130C. nHot Swa Board Protection The LTC1477 single is available in 8-lead SO packaging. n Peripheral Power Protection The LTC1478 dual is available in 16-lead SO packaging. , LTC and LT are registered trademarks of Linear Technology Corporation. SI PLIFIED BLOCK DIAGRAM V V V V INS IN1 IN2 IN3 Switch Output Voltage 5.20 T = 25C A GATE CHARGE V = V = V = V = 5V IN1 IN2 IN3 INS 5.10 AND *** DISCHARGE CONTROL LOGIC 5.00 4.90 4.80 CURRENT LIMIT CHARGE V EN AND THERMAL OUT PUMP 4.70 SHUTDOWN 4.60 0 0.5 0.75 1.00 1.25 1.50 0.25 OUTPUT CURRENT (A) *NMOS SWITCHES WITH NO PARASITIC BODY DIODES LTC1477/1478 TA01 LTC1477/1478 TP02 1 OUTPUT VOLTAGE (V) WW ULTC1477/LTC1478 ABSOLUTE MAXIMUM RATINGS Supply Voltage .......................................................... 7V Operating Temperature Enable Input Voltage...................... (7V) to (GND 0.3V) LTC1477C/LTC1478C .............................. 0C to 70C Output Voltage (OFF) (Note 1) ....... (7V) to (GND 0.3V) Storage Temperature Range ................. 65C to 150C Output Short-Circuit Duration .......................... Indefinite Lead Temperature (Soldering, 10 sec).................. 300C Junction Temperature........................................... 110C PACKAGE/ORDER INFORMATION TOP VIEW ORDER PART ORDER PART NUMBER AV 1 16 AV NUMBER OUT OUT TOP VIEW AV 2 15 AV IN IN2 LTC1478CS LTC1477CS8 V 1 8 V AV 3 14 AV OUT OUT INS IN3 V 2 7 V AEN 4 13 GND IN1 IN2 GND 5 12 BEN V 3 6 V INS IN3 BV 6 11 BV EN GND 4 5 IN3 INS S8 PART MARKING BV 7 10 BV IN2 IN1 S8 PACKAGE BV 8 9 BV 8-LEAD PLASTIC SO OUT OUT T = 110C, = 120C/ W JMAX JA 1477 S PACKAGE 16-LEAD PLASTIC SO T = 110C, = 100C/ W JMAX JA Consult factory for Industrial and Military grade parts. ELECTRICAL CHARACTERISTICS V = V = V = V = 5V (Note 2), T = 25C, unless otherwise noted. Each channel of the LTC1478 is tested separately (Note 3). INS IN1 IN2 IN3 A SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V Supply Voltage Range 2.7 5.5 V IN I Supply Current Switch OFF, Enable = 0V l 0.01 10 A VIN Switch ON, Enable = 5V, V = 5V l 120 180 A IN Switch ON, Enable = 3.3V, V = 3.3V l 80 120 A IN R ON Resistance V = V = V = V = 5V, I = 1A 0.07 0.12 ON INS IN1 IN2 IN3 OUT V = V = V = V = 3.3V, I = 1A 0.08 0.12 INS IN1 IN2 IN3 OUT V = V = 5V, V = V = NC, I = 0.5A 0.12 0.20 INS IN1 IN2 IN3 OUT V = V = 3.3V, V = V = NC, I = 0.5A 0.13 0.20 INS IN1 IN2 IN3 OUT I Output Leakage Current OFF Switch OFF, Enable = 0V l 20 A LKG I Short-Circuit Current Limit V = V = V = V = 5V, V = 0V, (Note 4) 1.60 2.00 2.40 A SC INS IN1 IN2 IN3 OUT V = V = 5V, V = V = NC, V = 0V, (Note 4) 0.68 0.85 1.02 A INS IN1 IN2 IN3 OUT V Enable Input High Voltage 3.0V V 5.5V l 2.0 V ENH INS V Enable Input Low Voltage 3.0V V 5.5V l 0.8 V ENL INS I Enable Input Current 0V V 5.5V l 1 A EN EN t Delay and Rise Time R = 100, C = 1F, to 90% of Final Value 0.50 1.00 2.00 ms D+R OUT OUT The l denotes specifications which apply over the full operating increase the ON resistance of the switch. The LTC1478 GND pins must be temperature range. connected together. (See Pin Functions and Block Diagram for more detail.) Note 1: The V pins must be connected together. Note 3: Other channel turned OFF, i.e. AEN and BEN = 0V. OUT Note 2: The V and V pins must be connected together. The V and Note 4: The output is protected with fold-back current limit which reduces INS IN1 IN2 V pins are typically connected to V and V pins but can be the short-circuit (0V) currents below peak permissible current levels at IN3 INS IN1 selectively disconnected to reduce the short-circuit current limit and higher output voltages. (See Typical Performance Characteristics for further detail on output current versus output voltage). 2 U W U W U WW