LTC1154CN8

LTC1154 High Side Micropower MOSFET Driver Features Description n n n n n n n n The LTC®1154 single high side gate driver allows using low cost N-channel FETs for high side switching applications. An internal charge pump boosts the gate drive voltage above the positive rail, fully enhancing an N-channel MOS switch with no external components. Micropower operation, with 8µA standby current and 85µA operating current, allows use in virtually all systems with maximum efficiency. n Fully Enhances N-Channel Power MOSFETs 8µA IQ Standby Current 85µA IQ ON Current No External Charge Pump Capacitors 4.5V to 18V Supply Range Short-Circuit Protection Thermal Shutdown via PTC Thermistor Status Output Indicates Shutdown Available in 8-Pin SOIC and PDIP Packages Included on chip is programmable overcurrent sensing. A time delay can be added to prevent false triggering on high inrush current loads. An active high shutdown input is also provided and interfaces directly to a standard PTC thermistor for thermal shutdown. An open-drain output is provided to report switch status to the µP. An active low enable input is provided to control multiple switches in banks. Applications n n n n n n Laptop Computer Power Switching SCSI Termination Power Switching Cellular Telephone Power Management Battery Charging and Management High Side Industrial and Automotive Switching Stepper Motor and DC Motor Control The LTC1154 is available in both 8-pin DIP and 8-pin SOIC packages. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Typical Application Ultralow Voltage Drop High Side Switch with Short-Circuit Protection Standby Supply Current 50 5V VIN = 0V TJ = 25°C 45 µP IN VS EN DS 0.036Ω* 0.1µF** 200k** LTC1154 STATUS GND IRLR024 G SD 40 2.7A MAX SUPPLY CURRENT (µA) 51k 35 30 25 20 15 10 5V LOAD 5 0 ALL COMPONENTS SHOWN ARE SURFACE MOUNT. * IMS026 INTERNATIONAL MANUFACTURING SERVICE, INC. (401) 683-9700 ** NOT REQUIRED IF LOAD IS RESISTIVE OR INDUCTIVE. LTC1154 • TA01 0 5 10 15 SUPPLY VOLTAGE (V) 20 LTC1153 • TA02 1154fc For more information www.linear.com/LTC1154 1 LTC1154 Absolute Maximum Ratings (Note 1) Supply Voltage...........................................................22V Input Voltage........................(VS + 0.3V) to (GND – 0.3V) Enable Input Voltage............(VS + 0.3V) to (GND – 0.3V) Gate Voltage..........................(VS + 24V) to (GND – 0.3V) Status Output Voltage................................................15V Current (Any Pin)....................................................50mA Operating Temperature LTC1154C.................................................. 0°C to 70°C LTC1154H........................................... –40°C to 150°C Storage Temperature Range................... –65°C to 150°C Lead Temperature (Soldering, 10 sec.)................... 300°C Pin Configuration TOP VIEW TOP VIEW IN 1 8 VS IN 1 8 VS EN 2 7 DS EN 2 7 DS STATUS 3 6 G STATUS 3 6 G GND 4 5 SD GND 4 5 SD N8 PACKAGE 8-LEAD PLASTIC DIP S8 PACKAGE 8-LEAD PLASTIC SOIC TJMAX = 100°C, θJA = 130°C/W TJMAX = 100°C, θJA = 150°C/W order information (http://www.linear.com/product/LTC1154#orderinfo) LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC1154CN8#PBF LTC1154CN8#TRPBF LTC1154 8-Lead Plastic DIP 0°C to 70°C LTC1154CS8#PBF LTC1154CS8#TRPBF 1154 8-Lead Plastic SIOC 0°C to 70°C LTC1154HS8#PBF LTC1154HS8#TRPBF 1154H 8-Lead Plastic SIOC –40°C to 150°C LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC1154CN8 LTC1154CN8#TR LTC1154 8-Lead Plastic DIP 0°C to 70°C LTC1154CS8 LTC1154CS8#TR 1154 8-Lead Plastic SIOC 0°C to 70°C LTC1154HS8 LTC1154HS8#TR 1154H 8-Lead Plastic SIOC –40°C to 150°C Consult LTC Marketing for parts specified with wider operating temperature ranges. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix. Electrical Characteristics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = 4.5V to 18V, TA = 25°C, VEN = 0V, VSD = 0V unless otherwise noted. SYMBOL PARAMETER VS Supply Voltage IQ Quiescent Current OFF VS = 5V, VIN = 0V Quiescent Current ON VS = 5V, VIN = 5V Quiescent Current ON VS = 12V, VIN = 5V VINH 2 CONDITIONS MIN l Input High Voltage TYP 4.5 2 UNITS 18 V 20 µA 85 120 µA 180 400 µA 8 l MAX V 1154fc For more information www.linear.com/LTC1154 LTC1154 Electrical Characteristics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VS = 4.5V to 18V, TA = 25°C, VEN = 0V, VSD = 0V unless otherwise noted. SYMBOL PARAMETER CONDITIONS VINL Input Low Voltage IIN Input Current CIN Input Capacitance VENH ENABLE Input High Voltage l VENL ENABLE Input Low Voltage l 0V < VIN < VS 0V < VEN < VS MIN TYP MAX UNITS l 0.8 V l ±1 µA 3.5 5 pF 2.6 V 1 0.6 V ±1 µA IEN ENABLE Input Current VSDH Shutdown Input High Voltage l VSDL Shutdown Input Low Voltage l 0.8 V ISD Shutdown Input Current l ±1 µA VSEN Drain Sense Threshold Voltage 120 125 mV mV ±0.1 µA 7 8.3 18 9 15 25 V V V 0.05 0.4 V 1 µA 0V < VSD < VS l l 2 80 75 V 100 100 ISEN Drain Sense Input Current 0V < VSEN < VS l VGATE – VS Gate Voltage Above Supply VS = 5V VS = 6V VS = 12V l l l VSTATUS Status Output Low Voltage ISTATUS = 400µA l ISTATUS Status Output Leakage Current VSTATUS = 12V l tON Turn-ON Time VS = 5V, CGATE = 1000pF Time for VGATE > VS + 2V Time for VGATE > VS + 5V 30 100 110 450 300 1000 µs µs VS = 12V, CGATE = 1000pF Time for VGATE > VS + 5V Time for VGATE > VS + 10V 20 50 80 160 200 500 µs µs VS = 5V, CGATE = 1000pF, Time for VGATE < 1V 10 36 60 µs VS = 12V, CGATE = 1000pF, Time for VGATE < 1V 10 28 60 µs tOFF tSC tSD Turn-OFF Time Short-Circuit Turn-OFF Time Shutdown Turn-OFF Time 6 7.5 15 VS = 5V, CGATE = 1000pF, Time for VGATE < 1V 5 25 40 µs VS = 12V, CGATE = 1000pF, Time for VGATE < 1V 5 23 40 µs VS = 5V, CGATE = 1000pF, Time for VGATE < 1V 17 40 µs VS = 12V, CGATE = 1000pF, Time for VGATE < 1V 13 35 µs Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. 1154fc For more information www.linear.com/LTC1154 3 LTC1154 Typical Performance Characteristics Standby Supply Current Supply Current ON 50 VIN = 0V TA = 25°C 22 20 800 SUPPLY CURRENT (µA) SUPPLY CURRENT (µA) 40 TA = 25°C 900 35 30 25 20 18 700 VGATE – VS (V) 45 600 500 400 12 10 200 8 5 100 6 0 5 10 15 SUPPLY VOLTAGE (V) 0 20 0 5 Input Threshold Voltage VON 1.6 VOFF 1.4 1.2 1.0 0.8 0.6 0.4 0 5 15 10 SUPPLY VOLTAGE (V) 30 140 27 130 24 120 21 110 18 100 90 70 6 60 3 0 5 35 VGS = 5V 200 VGS = 2V 100 0 0 5 10 15 SUPPLY VOLTAGE (V) 20 LTC1153 • TPC07 4 6 SUPPLY VOLTAGE (V) 40 30 25 20 15 35 10 LTC1154 • TPC06 30 25 20 15 10 10 5 5 0 8 0 5 10 15 SUPPLY VOLTAGE (V) CGATE = 1000pF TIME FOR VGATE < 1V VSEN = VS – 1V NO EXTERNAL DELAY 45 TURN-OFF TIME (µs) 40 TURN-OFF TIME (µs) 800 500 2 50 CGATE = 1000pF TIME FOR VGATE < 1V 45 600 0 Short-Circuit Turn-OFF Delay Time 50 700 300 0 20 Turn-OFF Time CGATE = 1000pF 400 15 10 SUPPLY VOLTAGE (V) LTC1154 • TPC05 Turn-ON Time 900 12 9 LTC1154 • TPC04 1000 15 80 50 20 Low Side Gate Voltage 150 VGATE (V) DRAIN SENSE THRESHOLD VOLTAGE (mV) 2.0 20 10 15 SUPPLY VOLTAGE (V) LTC1154 • TPC03 Drain Sense Threshold Voltage 2.2 5 0 LTC1154 • TPC02 2.4 1.8 0 20 10 15 SUPPLY VOLTAGE (V) LTC1154 • TPC01 INPUT THRESHOLD VOLTAGE (V) 14 10 0 TURN-ON TIME (µs) 16 300 15 4 High Side Gate Voltage 24 1000 20 LTC1154 • TPC08 0 0 5 10 15 SUPPLY VOLTAGE (V) 20 LTC1154 • TPC09 1154fc For more information www.linear.com/LTC1154 LTC1154 Typical Performance Characteristics Supply Current ON 1000 VIN = 0V VEN = 0V 45 900 VIN = 5V VEN = 0V 2.2 800 SUPPLY CURRENT (µA) 35 30 25 20 15 VS = 18V 10 5 –25 50 25 0 75 TEMPERATURE (°C) 600 500 400 VS = 12V 300 200 VS = 5V 100 VS = 5V 0 –50 700 100 0 –50 125 –25 25 0 50 75 TEMPERATURE (°C) LTC1154 • TPC10 Shutdown Threshold Voltage 2.2 2.0 1.8 1.6 VS = 5V 1.2 VS = 18V 1.0 0.8 0.6 0.4 –50 –25 25 0 50 75 TEMPERATURE (°C) 100 1.6 1.4 125 LTC1154 • TPC13 VS = 5V 1.2 VS = 18V 1.0 0.8 100 0.4 –50 125 –25 25 0 50 75 TEMPERATURE (°C) 4.5 VS = 12V 4.0 3.5 DISABLE 2.5 2.0 1.5 1.0 0.5 0 –50 125 Gate Drive Current 1000 3.0 100 LTC1154 • TPC12 ENABLE Threshold Voltage 5.0 1.4 1.8 LTC1154 • TPC11 ENABLE THRESHOLD VOLTAGE (V) SHUTDOWN THRESHOLD VOLTAGE (V) 2.4 2.0 0.6 GATE DRIVE CURRENT (µA) SUPPLY CURRENT (µA) 40 Input ON Threshold Voltage 2.4 INPUT THRESHOLD VOLTAGE (V) Standby Supply Current 50 TA = 25°C 100 VS = 18V VS = 12V 10 VS = 5V 1 ENABLE –25 25 0 50 75 TEMPERATURE (°C) 100 125 LTC1154 • TPC14 0.1 0 4 8 12 16 GATE VOLTAGE ABOVE SUPPLY (V) 20 LTC1154 • TPC15 Pin Functions IN and SD (Pins 1, 5): Input and Shutdown Pins. The LTC1154 input pin is active high and activates all of the protection and charge pump circuitry when switched ON. The shutdown pin is designed to immediately disable the switch if a secondary fault condition (over temperature, etc.) is detected. The LTC1154 logic and shutdown inputs are high impedance CMOS gates with ESD protection diodes to ground and supply and therefore should not be forced beyond the power supply rails. The shutdown pin should be connected to ground when not in use. EN (Pin 2): ENABLE Input Pin. The ENABLE input can be used to enable a number of LTC1154 high side switches in banks or to provide a secondary means of control. It can also act as an inverting input. The ENABLE input is a high impedance CMOS gate with ESD clamp diodes to ground and supply and therefore should not be forced beyond the power supply rails. This pin should be grounded when not in use. 1154fc For more information www.linear.com/LTC1154 5 LTC1154 Pin Functions G (Pin 6): Gate Drive Pin. The gate drive pin is either driven to ground when the switch is turned OFF or driven above the supply rail when the switch is turned ON. This pin is a relatively high impedance when driven above the rail (the equivalent of a few hundred kΩ). Care should be taken to minimize any loading of this pin by parasitic resistance to ground or supply. VS (Pin 8): Supply Pin. The supply pin of the LTC1154 serves two vital purposes. The first is obvious: it powers the input, gate drive, regulation and protection circuitry. The second purpose is less obvious: it provides a Kelvin connection to the top of the drain sense resistor for the internal 100mV reference. The LTC1154 is designed to be continuously powered so that the gate of the MOSFET is actively driven at all times. If it is necessary to remove power from the supply pin and then re-apply it, the input pin (or enable pin) should be cycled a few milliseconds after the power is re-applied to reset the input latch and protection circuitry. Also, the input and enable pins should be isolated with 10k resistors to limit the current flowing through the ESD protection diodes to the supply pin. The supply pin of the LTC1154 should never be forced below ground as this may result in permanent damage to the device. A 300Ω resistor should be inserted in series with the ground pin if negative supply voltage transients are anticipated. DS (Pin 7): Drain Sense Pin. The drain sense pin is compared against the supply pin voltage. If the voltage at this pin is more than 100mV below the supply pin, the input latch will be reset and the MOSFET gate will be quickly discharged. Cycle the input, or ENABLE input, to reset the short-circuit latch and turn the MOSFET back on. This pin is also a high impedance CMOS gate with ESD protection and therefore should not be forced beyond the power supply rails. To defeat the overcurrent protection, short the drain sense to supply. Some loads, such as large supply capacitors, lamps, or motors require high inrush currents. An RC time delay can be added between the sense resistor and the drain sense pin to ensure that the drain sense circuitry does not false-trigger during start-up. This time constant can be set from a few microseconds to many seconds. However, very long delays may put the MOSFET in risk of being destroyed by a short-circuit condition. (see Applications Information Section). STATUS (Pin 3): STATUS Pin. The STATUS pin is an opendrain output which is driven low whenever a fault condition is detected. A 51k pull-up resistor should be connected between this output and a logic supply. The STATUS pins of multiple LTC1154s can be OR’d together if independent fault sensing is not required. No connection is required to this pin when not in use. Block Diagram DRAIN SENSE ANALOG SECTION VS LOW STANDBY CURRENT REGULATOR 100mV REFERENCE ANALOG SHUTDOWN TTL-TO-CMOS CONVERTER 10µs DELAY COMP SHUTDOWN GATE CHARGE AND DISCHARGE CONTROL LOGIC DIGITAL GATE R INPUT ENABLE STATUS 6 TTL-TO-CMOS CONVERTER VOLTAGE REGULATORS ONE SHOT INPUT LATCH S OSCILLATOR AND CHARGE PUMP FAST/SLOW GATE CHARGE LOGIC GND FAULT DETECTION AND STATUS OUTPUT DRIVER LTC1154 • BD01 1154fc For more information www.linear.com/LTC1154 LTC1154 TRUTH TABLE INPUTS OUTPUTS SWITCH CONDITION IN EN SD X H X L H SWITCH OFF L X X L H SWITCH OFF H L L H H SWITCH ON H L L L L SWITCH LATCHED OFF (OVER CURRENT) H L L L SWITCH LATCHED OFF (SHUTDOWN) L = LOGIC LOW H = LOGIC HIGH X = IRRELEVANT GATE STATUS = EDGE TRIGGERED The Truth Table demonstrates how the LTC1154 receives inputs and returns status information to the µP. The ENABLE and input signal from the µP controls the switch in its normal operating mode, where the rise and fall time of the gate drive are controlled to limit EMI and RFI emissions. The shutdown and overcurrent detection circuitry however, switch the gate off at a much higher rate to limit the exposure of the MOSFET switch and the load to dangerous conditions. The STATUS pin remains high as long as the switch is operating normally, and is driven low only when a fault condition is detected. Note that the shutdown pin is edge-sensitive and latches the output off even if the shutdown pin returns to a low state. Operation The LTC1154 is a single micropower MOSFET driver with built-in protection, status feedback and gate charge pump. The LTC1154 consists of the following functional blocks: TTL and CMOS Compatible Inputs The LTC1154 input and shutdown input have been designed to accommodate a wide range of logic families. Both input thresholds are set at about 1.3V with approximately 100mV of hysteresis. A low standby current voltage regulator provides continuous bias for the TTL-to-CMOS converter. The TTL-to-CMOS converter output enables the rest of the circuitry. In this way the power consumption is kept to a minimum in the standby mode. ENABLE Input The ENABLE input is CMOS compatible and inhibits the input signal whenever it is held logic high. This input should be grounded when not in use. Internal Voltage Regulation The output of the TTL-to-CMOS converter drives two regulated supplies which power the low voltage CMOS logic and analog blocks. The regulator outputs are isolated from each other so that the noise generated by the charge pump logic is not coupled into the 100mV reference or the analog comparator. Gate Charge Pump Gate drive for the MOSFET switch is produced by an adaptive charge pump circuit which generates a gate voltage substantially higher than the power supply voltage. The charge pump capacitors are included on chip and therefore no external components are required to generate the gate drive. Drain Current Sense The LTC1154 is configured to sense the current flowing into the drain of the power MOSFET in a high side application. An internal 100mV reference is compared to the drop across a sense resistor (typically 0.002Ω to 0.10Ω) in series with the drain lead. If the drop across this resistor exceeds the internal 100mV threshold, the input latch is reset and the gate is quickly discharged via a large N-channel transistor. Controlled Gate Rise and Fall Times When the input is switched ON and OFF, the gate is charged by the internal charge pump and discharged in a controlled manner. The charge and discharge rates have been set to 1154fc For more information www.linear.com/LTC1154 7 LTC1154 Operation minimize RFI and EMI emissions in normal operation. If a short-circuit or current overload condition is encountered, the gate is discharged very quickly (typically a few microseconds) by a large N-channel transistor. Status Output Driver The status circuitry continuously monitors the fault detection logic. This open-drain output is driven low when the gate of the MOSFET is driven low by the protection circuitry. The status circuitry is reset along with the input latch when the input, or ENABLE input, is cycled. Applications Information MOSFET and Load Protection The LTC1154 protects the power MOSFET switch by removing drive from the gate as soon as an overcurrent condition is detected. Resistive and inductive loads can be protected with no external time delay in series with the drain sense pin. Lamp loads, however, require that the overcurrent protection be delayed long enough to start the lamp but short enough to ensure the safety of the MOSFET. stored energy to ground. Many inductive loads have these diodes included. If not, a diode of the proper current rating should be connected across the load, as shown in Figure 2, to safely divert the stored energy. 12V IN VS 100µF 0.036Ω DS EN LTC1154 Resistive Loads STATUS Loads that are primarily resistive should be protected with as short a delay as possible to minimize the amount of time that the MOSFET is subjected to an overload condition. The drain sense circuitry has a built-in delay of approximately 10µs to eliminate false triggering by power supply or load transient conditions. This delay is sufficient to “mask” short load current transients and the starting of a small capacitor (0.1mH) may require diodes connected directly across the inductor to safely divert the G 15V IN 8 + VS + 100µF 0.036Ω DS LTC1154 STATUS G IRFZ24 15V SD GND 1N5400 12V, 1A SOLENOID LTC1154 • F02 Figure 2. Protecting Inductive Loads 1154fc For more information www.linear.com/LTC1154 LTC1154 Applications Information Capacitive Loads Lamp Loads Large capacitive loads, such as complex electrical systems with large bypass capacitors, should be powered using the circuit shown in Figure 3. The gate drive to the power MOSFET is passed through an RC delay network, R1 and C1, which greatly reduces the turn-on ramp rate of the switch. And since the MOSFET source voltage follows the gate voltage, the load is powered smoothly and slowly from ground. This dramatically reduces the start-up current flowing into the supply capacitor(s) which, in turn, reduces supply transients and allows for slower activation of sensitive electrical loads. (Diode, D1, provides a direct path for the LTC1154 protection circuitry to quickly discharge the gate in the event of an overcurrent condition). The inrush current created by a lamp during turn-on can be 10 to 20 times greater than the rated operating current. The circuit shown in Figure 4 shifts the current limit threshold up by a factor of 11:1 (to 30A) for 100ms when the bulb is first turned on. The current limit then drops down to 2.7A after the inrush current has subsided. 12V VS DS EN GND G VS + 10k 470µF 0.036Ω 100k DS EN VN2222LL LTC1154 G STATUS 1M 0.1µF SD GND MTP3055EL 9.1V 470µF CD 0.01µF 0.036Ω RD 100k 12V/1A BULB D1 1N4148 LTC1154 STATUS IN R1 100k SD LTC1154 • F04 R2 100k Figure 4. Lamp Driver with Delayed Protection MTP3055E C1 0.33µF OUT 15V + CLOAD 100µF LTC1154 • F03 Figure 3. Powering Large Capacitive Loads The RC network, RD and CD, in series with the drain sense input should be set to trip based on the expected characteristics of the load after start-up. With this circuit, it is possible to power a large capacitive load and still react quickly to an overcurrent condition. The ramp rate at the output of the switch as it lifts off ground is approximately: dV/dt = (VG – VTH)/(R1 • C1) And therefore the current flowing into the capacitor during start-up is approximately: Selecting RD and CD Figure 5 is a graph of normalized overcurrent shutdown time versus normalized MOSFET current. This graph is used to select the two delay components, RD and CD, which make up a simple RC delay between the drain sense resistor and the drain sense input. 10 OVERCURRENT SHUTDOWN TIME (1 = RC) IN + 12V 1 0.1 0.01 ISTART-UP = CLOAD • dV/dt Using the values shown in Figure 3, the start-up current is less than 100mA and does not false-trigger the drain sense circuitry which is set at 2.7A with a 1ms delay. 1 10 100 MOSFET CURRENT (1 = SET CURRENT) LTC1154 • F05 Figure 5. Overcurrent Shutdown Time vs MOSFET Current 1154fc For more information www.linear.com/LTC1154 9 LTC1154 Applications Information The Y axis of the graph is normalized to one RC time constant. The X axis is normalized to the current. (The set current is defined as the current required to develop 100mV across the drain sense resistor). Note that the shutdown time is shorter for increasing levels of MOSFET current. This ensures that the total energy dissipated by the MOSFET is always within the bounds established by the manufacturer for safe operation. (See MOSFET data sheet for further information). 12V + 5V 120k 10k 5V µP OR CONTROL LOGIC 10µF IN 10k VS 0.05Ω DS EN LTC1154 10k MTP12N06 G STATUS 15V SD GND 10k LOAD 300Ω Using a Speed-Up Diode LTC1154 • F07 To reduce the amount of time that the power MOSFET is in a short-circuit condition, “bypass” the delay resistor with a small signal diode as shown in Figure 6. The diode will engage when the drop across the drain sense resistor exceeds about 0.7V, providing a direct path to the sense pin and dramatically reducing the amount of time the MOSFET is in an overload condition. The drain sense resistor value 12V IN + VS 0.01µF DS EN 100µF 1N4148 0.036Ω 100k LTC1154 STATUS IRF530 G 15V GND SD LOAD Figure 7. Reverse Battery Protection Since the LTC1154 draws very little current while in normal operation, the drop across the ground resistor is minimal. The 5V µP (or control logic) is protected by the 10k resistors in series with the input and status pins. Current Limited Power Supplies The LTC1154 requires at least 3.5V at the supply pin to ensure proper operation. It is therefore necessary that the supply to the LTC1154 be held higher than 3.5V at all times, even when the output of the switch is short circuited to ground. The output voltage of a current limited regulator may drop very quickly during short-circuit and pull the supply pin of the LTC1154 below 3.5V before the shutdown circuitry has had time to respond and remove drive from the gate of the power MOSFET. A supply filter should be LTC1154 • F06 Figure 6. Using a Speed-Up Diode is selected to limit the maximum DC current to 2.8A. The diode conducts when the drain current exceeds 20A and reduces the turn-off time to 15µs. >7V 5V/2A REGULATOR + + *20Ω 100µF + IN VS 0.1µF DS EN 0.1Ω 10µF 47µF* 1N4148 100k LTC1154 Reverse Battery Protection STATUS The LTC1154 can be protected against reverse battery conditions by connecting a resistor in series with the ground lead as shown in Figure 7. The resistor limits the supply current to less than 50mA with –12V applied. GND IRLR024 G SHORTCIRCUIT SD *SUPPLY FILTER COMPONENTS LTC1154 • F08 Figure 8. Supply Filter for Current Limited Supplies 10 1154fc For more information www.linear.com/LTC1154 LTC1154 Applications Information added as shown in Figure 8 which holds the supply pin of the LTC1154 high long enough for the overcurrent shutdown circuitry to respond and fully discharge the gate. Five volt linear regulators with small output capacitors are the most difficult to protect as they can “switch” from a voltage mode to a current limited mode very quickly. The large output capacitors on many switching regulators may be able to hold the supply pin of the LTC1154 above 3.5V sufficiently long that this extra filtering is not required. Because the LTC1154 is micropower in both the standby and ON state, the voltage drop across the supply filter is less than 2mV, and does not significantly alter the accuracy of the 100mV drain sense threshold voltage. Typical Applications High Side Driver with Thermal Shutdown 6V 5V µP OR CONTROL LOGIC IN VS EN DS High Side Driver with Overvoltage Shutdown EN DS 10µF 5.6V LTC1154 30k IRLD024 G GND PTC THERMISTOR (100°C)* *RL3006-50-100-25-PT0 KEYSTONE VS STATUS† IRLZ24 SD IN 100Ω µP OR CONTROL LOGIC G GND + 100µF LTC1154 STATUS† 4.75V TO 5.25V 5V + SD 6V LOAD 5V LOAD SWITCH IS SHUTDOWN WHEN VS > 5.7V LTC1154 • TA03 LTC1154 • TA05 †A 51k pull-up resistor should be connected between Status Output and 5V Logic Supply. High Side Driver with Undervoltage Shutdown 5V + 24V TO 28V 100µF 1N4148* 10k + 5V µP OR CONTROL LOGIC 24V to 28V High Side Switch with Thermal Shutdown IN VS EN DS 1µF** 2N2907 GND IRLZ24 *OPTIONAL IF SUPPLY VOLTAGE LESS THAN 6V. **CAPACITOR CHARGED TO SUPPLY VOLTAGE. SHUTDOWN OCCURS WHEN SUPPLY VOLTAGE DROPS BY 0.6V. 10k + 10µF VS DS EN LTC1154 STATUS† GND SD 3k 18V IN µP OR CONTROL LOGIC G 100µF 5V LTC1154 STATUS† + MTP12N06 G SD 6V LOAD * KEYSTONE RL2006-100-100-30-PT. MOUNT ON MOSFET OR LOAD HEAT SINK 200k PTC THERMISTOR (100°C)* 24V TO 28V LOAD LTC1154 • TA06 LTC1154 • TA04 1154fc For more information www.linear.com/LTC1154 11 LTC1154 Typical Applications 24V to 28V Switch with Bootstrapped Supply 24V TO 28V + 12V 100µF 5V µP OR CONTROL LOGIC High Side Relay Driver with Overcurrent Protection and Status Feedback 18V IN VS EN DS STATUS GND 10µF 6.2k µP OR CONTROL LOGIC 1N4148 * KEYSTONE RL2006-100-100-30-PT. MOUNT ON MOSFET OR LOAD HEAT SINK. IQ(OFF) = 60µA, IQ(ON) = 1mA. IN VS EN DS 10k 0.01µF 1N4148 MTD3055E LTC1154 † MTP15N06E G STATUS 15V 200k GND PTC THERMISTOR (100°C)* 0.02Ω 5V G SD 100µF 2Ω + LTC1154 † + 100k TO 12V LOAD SD 1N4001 24V TO 28V LOAD COIL CURRENT LIMITED TO 350mA. CONTACT CURRENT LIMITED TO 5A. LTC1154 • TA07 LTC1154 • TA08 †A 51k pull-up resistor should be connected between Status Output and 5V Logic Supply. “4-Cell-to-5V” Extremely Low Voltage Drop Regulator with Overcurrent Shutdown, Status Feedback, Ramped Turn-ON and 8µA Standby Current 4-CELL BATTERY PACK + 100µF 0.036Ω 5V µP OR CONTROL LOGIC IN VS EN DS LTC1154 STATUS† G 200pF 100k 100k 0.22µF GND SD IRLR024 1N4148 10k 8 7 1 3 LT1431 6 5 4 5V/2A + 470µF ESR < 0.5Ω LTC1154 • TA09 12 1154fc For more information www.linear.com/LTC1154 LTC1154 Typical Applications Bank Controlled High Side Switches with “Global” Thermal and Overvoltage Shutdown 12V IN VS 100Ω DS EN + 470µF LTC1154 STATUS 5V GND SD IN VS IRLR024 15V OUTPUT 1 DS EN LTC1154 51k STATUS µP OR CONTROL LOGIC G G GND SD IN VS IRLR024 15V OUTPUT 2 DS EN LTC1154 STATUS G GND SD IN VS EN DS IRLR024 15V OUTPUT 3 120k LTC1154 STATUS GND G IRLR024 15V SD OUTPUT 4 15V *KEYSTONE RL2006-100-100-30-PT. MOUNT ON COMMON HEAT SINK. PTC THERMISTOR (100°C)* LTC1154 • TA10 1154fc For more information www.linear.com/LTC1154 13 LTC1154 Typical Applications 12V Step-Up Regulator with Ultralow Standby Current, Overcurrent Protection and Status Feedback 0.02Ω 5V + + 20Ω 470µF + ON/OFF IN VS EN DS 47µF 10k + 1N4148 5 VIN 150µF 1N4148 LTC1154 STATUS STATUS 100k G 1 330µF 1.24k 1% 1k 0.1µF SD GND 3 100k 12V/1A 10.72k 1% 4 VSW LT1070 2 FB V GND C 0.22µF 51k 1N5820 50µH IRLZ24 1µF LTC1154 • TA11 12V Step-Up Regulator with 1A Overcurrent Protection, Switch Status Feedback and Ramped Output 50µH 1N5820 5V + + 150µF 330µF 0.1Ω 5 VIN VSW 4 LT1070 2 FB VC GND 3 1 1k 1µF 10.72k 1% 1N4148 ON/OFF IN VS 10k 0.1µF 51k 1.24k 1% DS EN LTC1154 STATUS STATUS G 1N4148 100k 100k IRF530 12V GND SD 0.22µF + 12V/1A 47µF LTC1154 • TA12 14 1154fc For more information www.linear.com/LTC1154 LTC1154 Package Description Please refer to http://www.linear.com/product/LTC1154#packaging for the most recent package drawings. N Package 8-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510 Rev I) .400* (10.160) MAX 8 7 6 5 1 2 3 4 .255 ±.015* (6.477 ±0.381) .300 – .325 (7.620 – 8.255) .008 – .015 (0.203 – 0.381) ( +.035 .325 –.015 8.255 +0.889 –0.381 ) .130 ±.005 (3.302 ±0.127) .045 – .065 (1.143 – 1.651) .065 (1.651) TYP .100 (2.54) BSC .120 (3.048) .020 MIN (0.508) MIN .018 ±.003 (0.457 ±0.076) N8 REV I 0711 NOTE: 1. DIMENSIONS ARE INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm) 1154fc For more information www.linear.com/LTC1154 15 LTC1154 Package Description Please refer to http://www.linear.com/product/LTC1154#packaging for the most recent package drawings. S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch) (Reference LTC DWG # 05-08-1610 Rev G) .189 – .197 (4.801 – 5.004) NOTE 3 .045 ±.005 .050 BSC 7 8 .245 MIN .160 ±.005 .010 – .020 × 45° (0.254 – 0.508) NOTE: 1. DIMENSIONS IN .150 – .157 (3.810 – 3.988) NOTE 3 1 RECOMMENDED SOLDER PAD LAYOUT 2 .053 – .069 (1.346 – 1.752) 0°– 8° TYP .016 – .050 (0.406 – 1.270) .014 – .019 (0.355 – 0.483) TYP INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) 4. PIN 1 CAN BE BEVEL EDGE OR A DIMPLE 16 5 .228 – .244 (5.791 – 6.197) .030 ±.005 TYP .008 – .010 (0.203 – 0.254) 6 3 4 .004 – .010 (0.101 – 0.254) .050 (1.270) BSC SO8 REV G 0212 1154fc For more information www.linear.com/LTC1154 LTC1154 Revision History (Revision history begins at Rev B) REV DATE DESCRIPTION B 4/11 Updated Graph TPC05 4 Updated SCSI Termination Typical Application 18 Updated Related Parts 18 Corrected Pin Names 2, 3, 5, 6 C 2/16 PAGE NUMBER 1154fc Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. For more information www.linear.com/LTC1154 17 LTC1154 Typical Applications Auto-Reset High Side Switch with Overcurrent and Overcurrent Temperature Shutdown 12V + RT 1M** 1M 100µF 0.036Ω ON/OFF IN VS DS EN + LTC1154 CT 100µF** VN2222LL MTP12N06 G STATUS 200k SD GND 18V PTC THERMISTOR (100°C)* *KEYSTONE RL2006-100-100-30-PT. **AUTO-RESET PERIOD ≈ 800ms WITH COMPONENTS SHOWN 12V LOAD LTC1154 • TA13 SCSI Termination Power Switch with 1A Overcurrent Shutdown, Auto-Reset and Load Soft-Start 0.1Ω 5V MTD3055EL + 1M 1M ON/OFF 100µF IN + 20Ω 0.1µF + DS LTC1154 STATUS 1µF 10k + VS EN G 1N4148 4.25V/1A 10µF 47µF 1N4148 100k VN2222LL 100k 0.22µF SD GND 1N5817 LTC1154 • TA14 Related Parts PART NUMBER DESCRIPTION COMMENTS LTC4440/LTC4440-5 High Speed, High Voltage High Side Gate Driver Up to 80V Supply Voltage, 8V ≤ VCC ≤ 15V, 2.4A Peak Pull-Up/1.5Ω Peak Pull-Down LTC4441/LTC4441-1 N-Channel MOSFET Gate Driver Up to 25V Supply Voltage, 5V ≤ VCC ≤ 25V, 6A Peak Output Current LT1910 Protected High Side Gate Driver Up to 48V Supply Voltage, Short Circuit Protected LTC4446 High Voltage Synchronous N-Channel MOSFET Driver without Shoot Thru Protection Up to 100V Supply Voltage, 7.2V ≤ VCC ≤ 13.5V, 3A Peak Pull-Up/0.55Ω Peak Pull-Down LTC4444/LTC4444-5 High Voltage Synchronous N-Channel MOSFET Driver with Shoot Thru Protection Up to 100V Supply Voltage, 4.5V/7.2V ≤ VCC ≤ 13.5V, 3A Peak Pull-Up/ 0.55Ω Peak Pull-Down LTC4442/LTC4449 High Speed Synchronous N-Channel MOSFET Driver Up to 38V Supply Voltage, 4.5V/6V ≤ VCC ≤ 9.5V, 3.2A Peak Pull-Up/ 4.5A Peak Pull-Down 18 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 For more information www.linear.com/LTC1154 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com/LTC1154 1154fc LT 0216 REV C • PRINTED IN USA  LINEAR TECHNOLOGY CORPORATION 1992