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SC1548CSK.TR

SC1548CSK.TR

  • 厂商:

    GENNUM(升特)

  • 封装:

    SC-74A

  • 描述:

    IC REGULATOR CONTROLLER SOT23

  • 数据手册
  • 价格&库存
SC1548CSK.TR 数据手册
SC1548 Linear FET Controller POWER MANAGEMENT Description Features The SC1548 is a power supply controller designed to provide a simple single regulated power supply with over current protection. It is part of Semtech’s SmartLDO™ family of products. The SC1548 can provide a 1.818V power supply for the I/O plane or 1.515V for GTL+ / AGP from either 3.3V or 2.5V. An adjustable option allows generation and control of any voltage from 1.263V up to 5V. ‹ ± 2.5% output accuracy over line, load and temperature ‹ 1.515V, 1.818V and adjustable output voltage options available ‹ Enable control ‹ Over current protection ‹ 5-pin SOT-23 package Applications SC1548 features include tight output voltage regulation, an enable control and over current protection. Over current protection is provided by feedback to the sense pin. If the output drops below 50% of the nominal output voltage (typical) for greater than 4ms (typical), the output will be shut down. ‹ ‹ ‹ ‹ Motherboards Graphics cards Microcontrollers Simple power supplies The SC1548 is available in a tiny 5-pin SOT-23 surface mount package. Typical Application Circuit Fixed Output Voltage Versions 3.3V IN Q1 IRL530N 1.818V OUT + C1 100uF + C2 100uF + C3 22uF 12V IN U1 1 2 3 SNS EN 5 ENABLE GND DRV IN 4 SC1548CSK-1.8 C4 0.1uF Adjustable Output Voltage Version 3.3V IN Q1 IRL530N 2.5V OUT R1 97.6 + C1 100uF + C2 100uF + 12V IN C3 22uF U1 1 2 R2 100 3 ADJ EN 1 ENABLE GND DRV IN SC1548CSK Revision: November 10, 2004 5 4 C4 0.1uF www.semtech.com SC1548 POWER MANAGEMENT Absolute Maximum Ratings Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not implied. Exposure to Absolute Maximum rated conditions for extended periods of time may affect device reliability. Parameter Symbol Maximum Units VIN -0.5 to +15 V VADJ, VEN, VSNS -0.5 to +7 V Thermal Impedance Junction to Case θJ C 81 °C/W Thermal Impedance Junction to Ambient θJ A 256 °C/W Operating Ambient Temperature Range TA 0 to +70 °C Operating Junction Temperature Range TJ 0 to +125 °C Storage Temperature Range TSTG -65 to +150 °C Lead Temperature (Soldering) 10 Sec TLEAD 300 °C Input Supply Voltage Input Pins Electrical Characteristics(1) Unless specified: TA = 25°C, VIN = 12V, VPWR = 3.3V, IOUT = 0A. Values in bold apply over full operating temperature range. Parameter Symbol Test Conditions Min Typ Max Units 11.28 12.00 12.72 V 1.0 1.5 mA IN Supply Voltage VIN Quiescent Current IQ 2.0 Undervoltage Lockout Start Threshold UVLO 7 8 9 V 100 150 µA 2.3 V EN Enable Pin Current IEN V E N = 0V Threshold Voltage VTH(EN) VEN rising Hysteresis VHYST Enable Delay Time(2)(3) tD(ON) Disable Delay Time(2)(3) tD(OFF) 1.8 200 mV VEN = Low to High, measured from VEN = VTH(EN) to 10% VDRV 500 ns VEN = High to Low, measured from VEN = VTH(EN) to 90% VDRV 150 ns SNS (Fixed Output Voltage Parts) Sense Pin Current ISNS Sinking 75 100 125 µA ADJ (Adjustable Output Voltage Parts) Adjust Pin Current IADJ Sourcing Reference Voltage(2) V AD J 3.0V ≤ VPWR(4) ≤ 3.6V, 1mA ≤ IOUT ≤ 1A 0.25 -1.5% -2.5%  2004 Semtech Corp. 2 1.263 µA +1.5% V +2.5% www.semtech.com SC1548 POWER MANAGEMENT Electrical Characteristics (Cont.)(1) Unless specified: TA = 25°C, VIN = 12V, VPWR = 3.3V, IOUT = 0A. Values in bold apply over full operating temperature range. Parameter Symbol Test Conditions Min Typ Max Units -1.5% VOUT +1.5% V Output Voltage Regulation (Fixed Output Voltage Parts) Output Voltage(2) VOUT 3.0V ≤ VPWR(4) ≤ 3.6V, 1mA ≤ IOUT ≤ 1A -2.5% +2.5% DRV Output Current IDRV VDRV = 4V, VSNS = 1.2V 5 10 mA Output Voltage VDRV Full On, IDRV = 0mA 9.0 10.5 V Rise Time(2)(3) tr VEN = Low to High, measured from VEN = VTH(EN) to 90% VDRV 1.0 ms Fall Time(2)(3) tf VEN = High to Low, measured from VEN = VTH(EN) to 10% VDRV 550 µs Overcurrent Protection Trip Threshold VTH(OC) Power-up Output Short Circuit Immunity Output Short Circuit Glitch Immunity 30 50 70 %VOUT 1 5 60 ms 0.5 4 30 ms Control Section Bandwidth VDRV = 9V, THD = 5%, CL = 600pF 5 MHz Notes: (1) This device is ESD sensitive. Use of standard ESD handling precautions is required. (2) See Application Circuit on page 1. (3) See Timing Diagram on page 4. (4) Connected to FET drain.  2004 Semtech Corp. 3 www.semtech.com SC1548 POWER MANAGEMENT Timing Diagram  2004 Semtech Corp. 4 www.semtech.com SC1548 POWER MANAGEMENT Pin Configuration Ordering Information Part Number(1)(2) Top View SC1548CSK-X.XTR SC1548CSKTRT(3) P ackag e SOT-23-5 Notes: (1) Where -X.X denotes voltage options. Available voltages are: 1.515V (-1.5) and 1.818V (-1.8). Leave blank for adjustable version. (2) Only available in tape and reel packaging. A reel contains 3000 units. (3) Lead free product. This product is fully WEEE and RoHS compliant. SOT-23-5L Block Diagram Pin Descriptions Pin 1 Pin Name Pin Function SNS Regulator sense input for fixed output voltage options. Use as a remote sense to the source of the N-channel MOSFET. AD J Regulator sense i nput for adjustable output voltage versi on. Set output voltage as follows (refer to application circuit on page 1): R1   VO = 1 .263 •  1 +  R2   2 GND Ground. 3 DRV O u t p u t o f r e g u l a t o r. D r i v e s t h e g a t e o f a n N - c h a n n e l M O S F E T t o m a i n t a i n t h e o u t p u t voltage desired. 4 IN +12V supply. 5 EN A c t i ve hi g h e na b l e c o nt r o l w i t h i nt e r na l p ul l up . O ut p ut o f r e g ul a t o r t ur ns o f f w he n E N i s taken low.  2004 Semtech Corp. 5 www.semtech.com SC1548 POWER MANAGEMENT Typical Characteristics(1) 1000 Quiescent Current vs. Start Threshold vs. Junction Temperature Junction Temperature 9.0 VIN = 12V, VEN = 3.3V 900 8.5 800 8.0 600 UVLO (V) IQ (µA) 700 500 400 7.5 7.0 300 200 6.5 100 0 6.0 0 25 50 75 100 0 125 25 50 2.30 Enable Hysteresis vs. vs. Junction Temperature Junction Temperature 500 2.20 400 2.15 350 2.10 300 2.05 2.00 125 100 125 100 125 250 200 1.95 150 1.90 100 1.85 50 1.80 0 0 25 50 75 100 125 0 25 50 150 Enable Pin Current vs. Enable Delay Time vs. Junction Temperature Junction Temperature 1000 VIN = 12V VEN = 0V 125 75 TJ (°C) TJ (°C) VIN = 12V 900 800 700 tD(ON) (ns) 100 IEN (µA) 100 VIN = 12V VEN falling 450 VHYST (mV) VTH(EN) (V) Enable Threshold Voltage VIN = 12V VEN rising 2.25 75 TJ (°C) TJ (°C) 75 50 600 500 400 300 200 25 100 0 0 0 25 50 75 100 125 0 TJ (°C)  2004 Semtech Corp. 25 50 75 TJ (°C) 6 www.semtech.com SC1548 POWER MANAGEMENT Typical Characteristics (Cont.)(1) 200 Disable Delay Time vs. Sense Pin Current vs. Junction Temperature Junction Temperature 125 VIN = 12V 115 150 110 125 ISNS (µA) tD(OFF) (ns) VIN = 12V VEN = 3.3V VSNS = VO(NOM) 120 175 100 75 105 100 95 90 50 85 25 80 0 75 0 25 50 75 100 125 0 25 50 TJ (°C) 12.00 Output Voltage (SC1548CSK-1.8) Junction Temperature vs. Junction Temperature 1.845 125 VIN = 12V VEN = 3.3V 3.0V ≤ VPWR ≤ 3.6V 1mA ≤ IO ≤ 1A 1.840 1.835 1.830 11.00 1.825 VO (V) VDRV (V) 100 Drive Output Voltage vs. VIN = 12V VSNS = 0V IDRV = 0mA 11.50 75 TJ (°C) 10.50 1.820 1.815 1.810 10.00 1.805 1.800 9.50 1.795 9.00 1.790 0 25 50 75 100 0 125 25 50 1.2 Power-Up Output Short Circuit Immunity vs. Junction Temperature vs. Junction Temperature 10 Power-up Short Circuit Immunity (ms) 0.8 VTH(OC) (V) 100 OCP Trip Threshold (SC1548CSK-1.8) VIN = 12V VEN = 3.3V 1 75 125 TJ (°C) TJ (°C) 0.6 0.4 0.2 0 VIN = 12V VEN switched from 0V to 3.3V ROUT = 0Ω Two representative parts shown 9 8 7 6 5 4 3 2 1 0 0 25 50 75 100 125 0 TJ (°C)  2004 Semtech Corp. 25 50 75 100 125 TJ (°C) 7 www.semtech.com SC1548 POWER MANAGEMENT Typical Characteristics (Cont.)(1) Output Short Circuit Glitch Immunity Drive Pin Rise Time vs. vs. Junction Temperature Junction Temperature 1200 VIN = 12V VEN = 3.3V ROUT of 0Ω applied to output Two representative parts shown 7 6 1000 800 tr (µs) 5 4 3 600 400 2 VIN = 12V VEN switched from 0V to 3.3V Two representative parts shown 200 1 0 0 0 25 50 75 100 0 125 25 SC1548CSK-1.8 Small Signal Gain Junction Temperature and Phase Shift vs. Frequency 80 VIN = 12V VEN switched from 3.3V to 0V Two representative parts shown 900 800 100 Drive Pin Fall Time vs. 1000 IOUT = 1.8A 60 125 0 -45 40 700 -90 f (Hz) 500 400 300 200 20 -135 0 -180 -20 -225 -40 -270 -60 100 0 0 25 50 75 100 -80 1.00E+02 125 Phase 1.00E+03 TJ (°C) -360 1.00E+06 1.00E+05 SC1548CSK-1.5 Small Signal Gain SC1548CSK Small Signal Gain and Phase Shift vs. Frequency and Phase Shift vs. Frequency 80 0 IOUT = 1.8A 40 -90 Gain 20 -135 0 -180 -20 -225 -40 -270 -60 Phase  2004 Semtech Corp. 1.00E+04 f (Hz) 1.00E+05 VOUT = 2V IOUT = 1.8A 60 40 0 -45 -90 Gain Gain (dB) -45 Phase (°) 60 1.00E+03 -315 Gain (dB) 80 -80 1.00E+02 1.00E+04 Phase (°) Gain 600 tf (µs) 75 TJ (°C) TJ (°C) Gain (dB) 50 20 -135 0 -180 -20 -225 Phase (°) Short Circuit Glitch Immunity (ms) 8 Phase -315 -40 -270 -60 -315 -80 1.00E+02 -360 1.00E+06 1.00E+03 1.00E+04 1.00E+05 -360 1.00E+06 f (Hz) 8 www.semtech.com SC1548 POWER MANAGEMENT Typical Characteristics (Cont.)(1) Load Transient Response, Expanded Load Transient Response Trace 1: VOUT, AC coupled, 50mV/div. Trace 2: VDRV, 2V/div. Trace M3: load stepping from 0A to 1A Timebase: 1µs/div Trace 1: VOUT, AC coupled, 50mV/div. Trace 2: VDRV, 2V/div. Trace M3: load stepping from 0A to 1A to 0A Timebase: 10µs/div Load Transient Response, Expanded Disable Delay Time, tD(OFF) Trace 1: VDRV, 1V/div. Trace 2: VEN, 2V/div. Timebase: 100ns/div tD(OFF) ≈ 36ns Trace 1: VOUT, AC coupled, 50mV/div. Trace 2: VDRV, 2V/div. Trace M3: load stepping from 1A to 0A Timebase: 1µs/div  2004 Semtech Corp. 9 www.semtech.com SC1548 POWER MANAGEMENT Typical Characteristics (Cont.)(1) Enable Delay Time, tD(ON) Drive Output Fall Time, tf Trace 1: VDRV, 1V/div. Trace 2: VEN, 2V/div. Timebase: 100ns/div tf ≈ 350ns Trace 1: VDRV, 1V/div. Trace 2: VEN, 2V/div. Timebase: 250ns/div tD(ON) ≈ 550ns Drive Output Rise Time, tr Power-up Output Short Circuit Immunity Trace 1: VDRV, 1V/div. Trace 2: VEN, 2V/div. Timebase: 500µs/div tr ≈ 1ms  2004 Semtech Corp. Trace 1: VDRV, 5V/div. Trace 2: VEN, 2V/div. Timebase: 2ms/div SC1548 enabled into a short, therefore VOUT < VTH(OC) immediately the device is enabled. This device shuts down after 8ms. 10 www.semtech.com SC1548 POWER MANAGEMENT Typical Characteristics (Cont.)(1) Note: (1) See Applications Circuit on page 1. Output Short Circuit Glitch Immunity Trace 1: VDRV, 5V/div. Trace 2: VOUT, 1V/div. Timebase: 1ms/div SC1548 enabled, then shorted, therefore VOUT < VTH(OC) immediately the short is applied. This device shuts down after 5ms. Applications Infomation Theory Of Operation The SC1548 linear FET controller provides a simple way to drive an N-channel MOSFET to produce a tightly regulated output voltage from an available, higher, supply voltage. It takes its power from a 12V supply, drawing typically 2mA while operating. Also included is an overcurrent protection circuit that monitors the output voltage. If the output voltage drops below 50% of nominal, as would occur during an overcurrent or short condition, the device will pull the drive pin low and latch off. It contains an internal bandgap reference which is compared to the output voltage via a resistor divider. This resistor divider is internal on the fixed output voltage options, and user selectable on the adjustable option. Since the drive pin can pull up to a 9V guaranteed minimum, the device can be used to regulate a large range of output voltages by careful selection of the external MOSFET (see component selection, below). Fixed Output Voltage Options Please refer to the Application Circuit on Page 1. The fixed output voltage parts have an internal resistor divider that draws a nominal 100µA from the output. The voltage at the common node of the resistor divider is then compared to the bandgap reference voltage of 1.263V. The drive pin voltage is then adjusted to maintain the output voltage set by the resistor divider. Referring to the block diagram on page 5, the nominal resistor values are: The SC1548 includes an active high enable control with an internal pullup resistor. If this pin is pulled low, the drive pin is pulled low, turning off the N-channel MOSFET. If the pin is left open or pulled up to 2.5V, 3.3V or 5V, then the drive pin will be enabled.  2004 Semtech Corp. 11 Output Voltage R1 (kΩ) R2 (kΩ) 1.515V 2.52 12.63 1.818V 5.55 12.63 www.semtech.com SC1548 POWER MANAGEMENT Applications Infomation (Cont.) It is possible to adjust the output voltage of the fixed voltage options, by applying an external resistor divider to the sense pin (please refer to Figure 1 below). Since the sense pin sinks a nominal 100µA, the resistor values should be selected to allow 10mA to flow through the divider. This will ensure that variations in this current do not adversely affect output voltage regulation. Thus a target value for R2 (maximum) can be calculated: R2 ≤ V OUT ( FIXED ) Ω 10 mA The output voltage can only be adjusted upwards from the fixed output voltage, and can be calculated using the following equation: VOUT ( ADJUSTED ) R1   = VOUT ( FIXED ) •  1 +  + R1 • 100 µ A R2   12V IN VPWR Q1 Volts VOUT R1 + C1 100uF + C2 100uF + C3 22uF U1 1 2 R2 3 SNS EN 5 ENABLE GND DRV IN 4 C4 0.1uF SC1548CSK-X.X Figure 1: Adjusting The Output Voltage of Fixed Output Voltage Options 12V IN VPWR Q1 VOUT R1 + C1 100uF + C2 100uF + C3 22uF U1 1 2 R2 3 ADJ EN 5 ENABLE GND DRV IN 4 SC1548CSK C4 0.1uF Figure 2: Setting The Output Voltage of the Adjustable Output Voltage Option Adjustable Output Voltage Option Again, a target value for R2 (maximum) can be calculated: The adjustable output voltage option does not have an internal resistor divider. The adjust pin connects directly to the inverting input of the error amplifier, and the output voltage is set using external resistors (please refer to Figure 2 above). In this case, the adjust pin sources a nominal 0.5µA, so the resistor values should be selected to allow 50µA to flow through the divider.  2004 Semtech Corp. R2 ≤ 1 . 263 V 50 µ A Ω The output voltage can be calculated as follows: R1   VOUT = 1 .263 •  1 +  − 0 .5 µ A • R1 R 2  12 www.semtech.com SC1548 POWER MANAGEMENT Applications Infomation (Cont.) Please see Table 1 below for recommended resistor values for some standard output voltages. All resistors are 1%, 1/10W. VOU T (V) R 1 (Ω) R 2 (Ω) 1.5 18.7 100 1.8 42.2 100 2.5 97.6 100 2.8 124 102 3.0 140 102 3.3 169 105 To be most effective, the MOSFET RDS(ON) should not be selected artificially low. The MOSFET should be chosen so that at maximum required current, it is almost fully turned on. If, for example, a supply of 1.5V at 4A is required from a 3.3V ± 5% rail, the maximum allowable RDS(ON) would be: R DS ( ON )( MAX ) = 4 To allow for temperature effects 200mΩ would be a suitable room temperature maximum, allowing a peak short circuit current of approximately 15A for a short time before shutdown. Capacitor Selection Table 1: Recommended Resistor Values For SC1548 Output Capacitors: low ESR aluminum electrolytic or tantalum capacitors are recommended for bulk capacitance, with ceramic bypass capacitors for decoupling high frequency transients. The maximum output voltage that can be obtained from the adjustable option is determined by the input supply voltage and the RDS(ON) and gate threshold voltage of the external MOSFET. Assuming that the MOSFET gate threshold voltage is sufficiently low for the output voltage chosen and a worst-case drive voltage of 9V, VOUT(MAX) is given by: Input Capacitors: placement of low ESR aluminum electrolytic or tantalum capacitors at the input to the MOSFET (VPWR) will help to hold up the power supply during fast load changes, thus improving overall transient response. The 12V supply should be bypassed with a 0.1µF ceramic capacitor. V OUT ( MAX ) = V PWR ( MIN ) − I OUT ( MAX ) • R DS ( ON )( MAX ) Short Circuit Protection Layout Guidelines The short circuit protection feature of the SC1548 is implemented by using the RDS(ON) of the MOSFET. As the output current increases, the regulation loop maintains the output voltage by turning the FET on more and more. Eventually, as the RDS(ON) limit is reached, the MOSFET will be unable to turn on any further, and the output voltage will start to fall. When the output voltage falls to approximately 50% of nominal, the LDO controller is latched off, setting output voltage to 0V. Toggling the enable pin or cycling the power will reset the latch. One of the advantages of using the SC1548 to drive an external MOSFET is that the bandgap reference and control circuitry do not need to be located right next to the power device, thus a very accurate output voltage can be obtained since heating effects will be minimal. The 0.1µF bypass capacitor should be located close to the supply pin, and connected directly to the ground plane. The ground pin of the device should also be connected directly to the ground plane. The sense or adjust pin does not need to be close to the output voltage plane, but should be routed to avoid noisy traces if at all possible. To prevent false latching due to capacitor inrush currents or low supply rails, the current limit latch is initially disabled. It is enabled at a preset time (nominally 5ms) after both IN and EN rise above their lockout points. If EN is left floating (using the internal resistor pullup), then VPWR should come up before VIN, or the device will latch off. If the enable function is not being used, EN should be tied to VPWR.  2004 Semtech Corp. (0 .95 • 3 .3 − 1 .5 • 1 .025 ) ≈ 400 m Ω Power dissipation within the device is practically negligible, requiring no special consideration during layout. 13 www.semtech.com SC1548 POWER MANAGEMENT Outline Drawing - SOT-23-5 A DIM e1 D A A1 A2 b c D E1 E e e1 L L1 N 01 aaa bbb ccc N 2X E/2 E EI 1 2 ccc C 2X N/2 TIPS e B D aaa C A2 DIMENSIONS INCHES MILLIMETERS MIN NOM MAX MIN NOM MAX .035 .000 .035 .010 .003 .110 .060 - .045 - .057 .006 .051 .020 .009 .118 .069 0.90 0.00 .90 0.25 0.08 2.80 1.50 - 1.15 - 1.45 0.15 1.30 0.50 0.22 3.00 1.75 2.90 1.60 2.80 BSC 0.95 BSC 1.90 BSC 0.30 0.45 0.60 (0.60) 5 0° 10° 0.10 0.20 0.20 .114 .063 .110 BSC .037 BSC .075 BSC .012 .018 .024 (.024) 5 0° 10° .004 .008 .008 A SEATING PLANE A1 C H bxN bbb C A-B D c GAGE PLANE 0.25 L 01 (L1) SEE DETAIL DETAIL A A SIDE VIEW NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. DATUMS -A- AND -B- TO BE DETERMINED AT DATUM PLANE -H3. DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. Land Pattern - SOT-23-5 X DIM (C) G Z Y P C G P X Y Z DIMENSIONS MILLIMETERS INCHES (.098) .055 .037 .024 .043 .141 (2.50) 1.40 0.95 0.60 1.10 3.60 NOTES: 1. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. Contact Information Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805)498-2111 FAX (805)498-3804  2004 Semtech Corp. 14 www.semtech.com
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