LT1117/LT1117-2.85 LT1117-3.3/LT1117-5 800mA Low Dropout Positive Regulators Adjustable and Fixed 2.85V, 3.3V, 5V DESCRIPTIO U FEATURES ■ ■ ■ ■ ■ ■ ■ Space Saving SOT-223 Surface Mount Package 3-Terminal Adjustable or Fixed 2.85V, 3.3V, 5V Output Current of 800mA Operates Down to 1V Dropout Guaranteed Dropout Voltage at Multiple Current Levels 0.2% Line Regulation Max 0.4% Load Regulation Max U APPLICATIO S ■ ■ ■ ■ ■ Active SCSI Terminators High Efficiency Linear Regulators Post Regulators for Switching Supplies Battery Chargers 5V to 3.3V Linear Regulators The LT®1117 is a positive low dropout regulator designed to provide up to 800mA of output current. The device is available in an adjustable version and fixed output voltages of 2.85V, 3.3V and 5V. The 2.85V version is designed specifically to be used in Active Terminators for the SCSI bus. All internal circuitry is designed to operate down to 1V input to output differential. Dropout voltage is guaranteed at a maximum of 1.2V at 800mA, decreasing at lower load currents. On chip trimming adjusts the reference/output voltage to within ± 1%. Current limit is also trimmed in order to minimize the stress on both the regulator and the power source circuitry under overload conditions. The low profile surface mount SOT-223 package allows the device to be used in applications where space is limited. The LT1117 requires a minimum of 10µF of output capacitance for stability. Output capacitors of this size or larger are normally included in most regulator designs. Unlike PNP type regulators where up to 10% of the output current is wasted as quiescent current, the quiescent current of the LT1117 flows into the load, increasing efficiency. , LTC and LT are registered trademarks of Linear Technology Corporation. U TYPICAL APPLICATIO Dropout Voltage (VIN – VOUT) 1.4 Active Terminator for SCSI-2 Bus –40°C ≤ TJ < 0°C 110Ω 110Ω LT1117-2.85 IN 4.75V TO 5.25V GND + 10µF 110Ω OUT + 22µF 110Ω 18 TO 27 LINES DROPOUT VOLTAGE (V) 1.2 0°C ≤ TJ ≤ 125°C 1.0 TJ = 25°C 0.8 TJ = 125°C 0.6 0.4 0.2 INDICATES GUARANTEED TEST POINT LT1117 • TA01 0 0 100 200 300 400 500 600 700 800 OUTPUT CURRENT (mA) LT1117 • TPC01 1 LT1117/LT1117-2.85 LT1117-3.3/LT1117-5 W W W AXI U U ABSOLUTE RATI GS (Note 1) Input Voltage Operating Voltage LT1117, LT1117-3.3, LT1117-5 ...................... 15V LT1117-2.85 ................................................... 10V Surge Voltage LT1117, LT1117-3.3, LT1117-5 ...................... 20V Operating JunctionTemperature Range C Grade ................................................. 0°C to 125°C I Grade ............................................. – 40°C to 125°C Storage Temperature Range ................. – 65°C to 150°C Lead Temperature ................... (See Soldering Methods) U U W PACKAGE/ORDER I FOR ATIO FRONT VIEW 3 TAB IS VOUT 2 1 IN OUT ADJ/GND ST PACKAGE 3-LEAD PLASTIC SOT-223 TJ MAX = 125°C,θJC = 15°C/W ORDER PART NUMBER LT1117CST LT1117CST-2.85 LT1117CST-3.3 LT1117CST-5 LT1117IST LT1117IST-2.85 LT1117IST-3.3 LT1117IST-5 ST PART MARKING 1117 1117I 11172 11172I 11173 11173I 11175 11175I ORDER PART NUMBER LT1117CM LT1117CM-2.85 LT1117CM-3.3 LT1117CM-5 FRONT VIEW TAB IS VOUT 3 IN 2 OUT 1 ADJ/GND M PACKAGE 3-LEAD PLASTIC DD DD PART MARKING TJ MAX = 125°C,θJC = 10°C/W 1117 11172 11173 11175 Consult factory for Military grade parts. ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TJ = 25°C. PARAMETER Reference Voltage Output Voltage CONDITIONS LT1117 LT1117-2.85 LT1117-3.3 LT1117-5 Line Regulation 2 LT1117 LT1117-2.85 LT1117-3.3 LT1117-5 MIN TYP MAX UNITS IOUT = 10mA, (VIN – VOUT) = 2V, TJ = 25°C 10 ≤ IOUT ≤ 800mA, 1.4V ≤ (VIN – VOUT) ≤ 10V ● 1.238 1.225 1.250 1.262 1.250 1.270 V V IOUT = 10mA, VIN = 4.85V, TJ = 25°C 0 ≤ IOUT ≤ 800mA, 4.25V ≤ VIN ≤ 10V 0 ≤ IOUT ≤ 500mA, VIN = 3.95V ● ● 2.820 2.790 2.790 2.850 2.880 2.850 2.910 2.850 2.910 V V V IOUT = 10mA, VIN = 5V, TJ = 25°C 0 ≤ IOUT ≤ 800mA, 4.75V ≤ VIN ≤ 10V ● 3.267 3.235 3.300 3.333 3.300 3.365 V V IOUT = 10mA, VIN = 7V, TJ = 25°C 0 ≤ IOUT ≤ 800mA, 6.50V ≤ VIN ≤ 12V ● 4.950 4.900 5.000 5.050 5.000 5.100 V V IOUT = 10mA, 1.5V ≤ VIN – VOUT ≤ 15V (Note 2) IOUT = 0mA, 4.25V ≤ VIN ≤ 10V (Note 2) IOUT = 0mA, 4.75V ≤ VIN ≤ 15V (Note 2) IOUT = 0mA, 6.5V ≤ VIN ≤ 15V (Note 2) ● ● ● ● 0.035 1 1 1 0.2 6 6 10 % mV mV mV LT1117/LT1117-2.85 LT1117-3.3/LT1117-5 ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TJ = 25°C. PARAMETER Load Regulation CONDITIONS MIN TYP MAX UNITS 0.1 1 1 1 0.4 10 10 15 % mV mV mV IOUT = 100mA, 0°C ≤ TJ ≤ 125°C (Note 3) IOUT = 500mA, 0°C ≤ TJ ≤ 125°C (Note 3) IOUT = 800mA, 0°C ≤ TJ ≤ 125°C (Note 3) 1.00 1.05 1.10 1.10 1.15 1.20 V V V IOUT = 100mA, – 40°C ≤ TJ < 0°C (Note 3) IOUT = 500mA, – 40°C ≤ TJ < 0°C (Note 3) IOUT = 800mA, – 40°C ≤ TJ < 0°C (Note 3) 1.00 1.05 1.10 1.20 1.25 1.30 V V V 950 1200 mA (VIN – VOUT) = 3V, 10mA ≤ IOUT ≤ 800mA (Note 2) VIN = 4.25V, 0 ≤ IOUT ≤ 800mA (Note 2) VIN = 4.75V, 0 ≤ IOUT ≤ 800mA (Note 2) VIN = 6.5V, 0 ≤ IOUT ≤ 800mA (Note 2) LT1117 LT1117-2.85 LT1117-3.3 LT1117-5 Dropout Voltage Current Limit ● ● ● ● (VIN – VOUT) = 5V, TJ = 25°C, 800 Minimum Load Current LT1117 (VIN – VOUT) = 15V (Note 4) ● 1.7 5 mA Quiescent Current LT1117-2.85 LT1117-3.3 LT1117-5 VIN ≤ 10V VIN ≤ 15V VIN ≤ 15V ● ● ● 5 5 5 10 10 10 mA mA mA 0.01 0.1 %/W Thermal Regulation TA = 25°C, 30ms Pulse Ripple Rejection fRIPPLE = 120Hz, (VIN – VOUT) = 3V, VRIPPLE = 1VP-P ● Adjust Pin Current 10mA ≤ IOUT ≤ 800mA, 1.4V ≤ (VIN – VOUT) ≤ 10V Adjust Pin Current Change 60 75 dB ● 55 120 µA ● 0.2 5 µA Temperature Stability 0.5 Long Term Stability TA = 125°C, 1000Hrs RMS Output Noise (% of VOUT), 10Hz ≤ f ≤ 10kHz Thermal Resistance (Junction-to-Case, at Tab) Note 1: Absolute Maximum Ratings are those values beyond which the life to the device may be imparied. Note 2: See thermal regulation specification for changes in output voltage due to heating effects. Load regulation and line regulation are measured at a constant junction temperature by low duty cycle pulse testing. % 0.3 % 0.003 % °C/W 15 Note 3: Dropout voltage is specified over the full output current range of the device. Dropout voltage is defined as the minimum input/output differential measured at the specified output current. Test points and limits are also shown on the Dropout Voltage curve. Note 4: Minimum load current is defined as the minimum output current required to maintain regulation. U W TYPICAL PERFOR A CE CHARACTERISTICS Minimum Operating Current (Adjustable Device) Short-Circuit Current Load Regulation 1.25 TJ = 125°C TJ = 25°C 2 TJ = –55°C 1 0 0.10 TJ = 125°C 1.00 OUTPUT VOLTAGE DEVIATION (%) 3 SHORT CIRCUIT CURRENT (A) MINIMUM OPERATING CURRENT (mA) 4 TJ = 25°C 0.75 0.50 0.25 0 0 5 10 15 INPUT/OUTPUT DIFFERENTIAL (V) 20 LT1117 • TPC02 0 5 10 INPUT/OUTPUT DIFFERENTIAL (V) 15 LT1117 • TPC03 ∆ ILOAD = 800mA 0.05 0 – 0.05 – 0.10 – 0.15 – 0.20 –50 –25 0 25 50 75 TEMPERATURE (°C) 100 125 LT1117 • TPC04 3 LT1117/LT1117-2.85 LT1117-3.3/LT1117-5 U W TYPICAL PERFOR A CE CHARACTERISTICS LT1117 Ripple Rejection LT1117 Ripple Rejection vs Current 100 60 50 40 (VIN – VOUT) ≥ VDROPOUT 30 10 0 100 fRIPPLE = 120Hz VRIPPLE ≤ 3VP-P 70 60 fRIPPLE = 20kHz 50 40 VRIPPLE ≤ 0.5VP-P 30 20 CADJ = 200µF AT f < 60Hz CADJ = 25µF AT f > 60Hz IOUT = 0.5A 10 1.0 0 –1.0 10 –2.0 –50 –25 0 1k 10k FREQUENCY (Hz) 0 100k 0.2 0.4 0.6 OUTPUT CURRENT (A) LT1117 • TPC05 0.8 0.3 OUPUT VOLTAGE DEVIATION (V) 100 80 70 60 LT1117-5 Load Transient Response 0.3 CIN = 10µF COUT = 10µF TANTALUM VIN = 4.25V PRELOAD = 0.1A 0.2 0.1 0 CIN = 10µF 0.2 COUT = 10µF TANTALUM VIN = 6.5V 0.1 PRELOAD = 0.1A 0 –0.1 40 –0.2 –0.2 20 10 0 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) 0.5 0 –0.5 0 10 20 30 40 50 60 70 80 90 100 TIME (µs) LT1117 • TPC08 –0.5 0 10 20 30 40 50 60 70 80 90 100 TIME (µs) LT1117 • TPC10 60 OUPUT VOLTAGE DEVIATION (mV) CIN = 1µF 40 COUT = 10µF TANTALUM IOUT = 0.1A 20 0 20 0 –20 –40 –40 5.25 4.25 3.25 20 40 60 80 100 120 140 160 180 200 TIME (µs) LT1117 • TPC11 CIN = 1µF COUT = 10µF TANTALUM IOUT = 0.1A 40 –20 INPUT VOLTAGE (V) OUPUT VOLTAGE DEVIATION (mV) INPUT VOLTAGE (V) 0 LT1117-5 Line Transient Response 60 4 0.5 LT1117 • TPC09 LT1117-2.8 Line Transient Response 0 LOAD CURRENT (A) –0.1 LOAD CURRENT (A) 50 30 25 50 75 100 125 150 TEMPERATURE (°C) LT1117 • TPC07 LT1117-2.85 Load Transient Response 90 0 LT1117 • TPC06 Adjust Pin Current AJUST PIN CURRENT (µA) OUTPUT VOLTAGE CHANGE (%) 70 RIPPLE REJECTION (dB) (VIN – VOUT) ≥ 3V OUPUT VOLTAGE DEVIATION (V) 80 RIPPLE REJECTION (dB) VOUT = 5V 90 CADJ = 25µF COUT = 25µF 80 VRIPPLE ≤ 0.5VP-P VRIPPLE ≤ 3VP-P 90 20 Temperature Stability 2.0 100 7.50 6.50 5.50 0 20 40 60 80 100 120 140 160 180 200 TIME (µs) LT1117 • TPC12 LT1117/LT1117-2.85 LT1117-3.3/LT1117-5 W BLOCK DIAGRA IN + – THERMAL LIMIT ADJ GND OUT FOR FIXED VOLTAGE DEVICE LT1117 • BD01 U U APPLICATIO HI TS The LT1117 family of 3-terminal regulators are easy to use. They are protected against short circuit and thermal overloads. Thermal protection circuitry will shut down the regulator should the junction temperature exceed 165°C at the sense point. These regulators are pin compatible with older 3-terminal adjustable regulators, offer lower dropout voltage and more precise reference tolerance. Reference stability over temperature is improved over older types of regulators. Stability The LT1117 family of regulators requires an output capacitor as part of the device frequency compensation. A minimum of 10µF of tantalum or 50µF of aluminum electrolytic is required. The ESR of the output capacitor should be less than 0.5Ω. Surface mount tantalum capacitors, which have very low ESR, are available from several manufacturers. When using the LT1117 adjustable device the adjust terminal can be bypassed to improve ripple rejection. When the adjust terminal is bypassed the required value of the output capacitor increases. The device will require an output capacitor of 22µF tantalum or 150µF aluminum electrolytic when the adjust pin is bypassed. Normally, capacitor values on the order of 100µF are used in the output of many regulators to ensure good load transient response with large load current changes. Output capacitance can be increased without limit and larger values of output capacitance further improve stability and transient response. Protection Diodes In normal operation, the LT1117 family does not need any protection diodes. Older adjustable regulators required protection diodes between the adjust pin and the output and between the output and input to prevent over stressing the die. The internal current paths on the LT1117 adjust pin are limited by internal resistors. Therefore, even with capacitors on the adjust pin, no protection diode is needed to ensure device safety under short-circuit conditions. 5 LT1117/LT1117-2.85 LT1117-3.3/LT1117-5 U U APPLICATIO HI TS The adjust pin can be driven, on a transient basis, ± 25V with respect to the output without any device degradation. Diodes between input and output are not usually needed. The internal diode between the output and input pins of the device can withstand microsecond surge currents of 10A to 20A. Normal power supply cycling can not generate currents of this magnitude. Only with extremely large output capacitors, such as 1000µF and larger, and with the input pin instantaneously shorted to ground can damage occur. A crowbar circuit at the input of the LT1117 in combination with a large output capacitor could generate currents large enough to cause damage. In this case a diode from output to input is recommended, as shown in Figure 1. D1 1N4002 (OPTIONAL) LT1117 VIN IN OUT ADJ + R1 + CADJ 10µF VOUT COUT 150µF R2 to set the overall output voltage. Normally this current is chosen to be the specified minimum load current of 10mA. Because IADJ is very small and constant when compared to the current through R1, it represents a small error and can usually be ignored. For fixed voltage devices R1 and R2 are included in the device. Load Regulation Because the LT1117 is a 3-terminal device, it is not possible to provide true remote load sensing. Load regulation will be limited by the resistance of the wire connecting the regulator to the load. The data sheet specification for load regulation is measured at the output pin of the device. Negative side sensing is a true Kelvin connection, with the bottom of the output divider returned to the negative side of the load. Although it may not be immediately obvious, best load regulation is obtained when the top of the resistor divider (R1) is returned directly to the output pin of the device, not to the load. This is illustrated in Figure 3. Connected as shown, RP is not multiplied by the divider ratio. If R1 were connected to the load, the effective resistance between the regulator and the load would be: LT1117 • TA02 RP × Figure 1 R2 + R1 ,RP = Parasitic Line Resistance R1 Output Voltage RP PARASITIC LINE RESISTANCE LT1117 The LT1117 develops a 1.25V reference voltage between the output and the adjust terminal (see Figure 2). By placing a resistor between these two terminals, a constant current is caused to flow through R1 and down through R2 VIN IN OUT ADJ R1 CONNECT R1 TO CASE RL R2 LT1117 LT1117 • TA04 VIN + IN ADJ IADJ 50µA VOUT OUT ( ) VREF R2 VOUT = VREF 1 + — + IADJ R2 R1 R1 Figure 3. Connections for Best Load Regulation R2 LT1117 • TA03 Figure 2. Basic Adjustable Regulator 6 CONNECT R2 TO LOAD For fixed voltage devices the top of R1 is internally Kelvin connected, and the ground pin can be used for negative side sensing. LT1117/LT1117-2.85 LT1117-3.3/LT1117-5 U U APPLICATIO HI TS Thermal Considerations LT1117 series regulators have internal thermal limiting circuitry designed to protect the device during overload conditions. For continuous normal load conditions however, the maximum junction temperature rating of 125°C must not be exceeded. It is important to give careful consideration to all sources of thermal resistance from junction to ambient. For the SOT-223 package, which is designed to be surface mounted, additional heat sources mounted near the device must also be considered. Heat sinking is accomplished using the heat spreading capability of the PC board and its copper traces. The thermal resistance of the LT1117 is 15°C/W from the junction to the tab. Thermal resistances from tab to ambient can be as low as 30°C/W. The total thermal resistance from junction to ambient can be as low as 45°C/W. This requires a reasonable sized PC board with at least one layer of copper to spread the heat across the board and couple it into the surrounding air. Experiments have shown that the heat spreading copper layer does not need to be electrically connected to the tab of the device. The PC material can be very effective at transmitting heat between the pad area, attached to the tab of the device, and a ground plane layer either inside or on the opposite side of the board. Although the actual thermal resistance of the PC material is high, the Length/Area ratio of the thermal resistor between layers is small. The data in Table 1 was taken using 1/16" FR-4 board with 1oz. copper foil. It can be used as a rough guideline in estimating thermal resistance. Table 1. COPPER AREA TOPSIDE* BACKSIDE THERMAL RESISTANCE BOARD AREA (JUNCTION-TO-AMBIENT) 2500 Sq. mm 2500 Sq. mm 2500 Sq. mm 45°C/W 1000 Sq. mm 2500 Sq. mm 2500 Sq. mm 45°C/W 225 Sq. mm 2500 Sq. mm 2500 Sq. mm 53°C/W 100 Sq. mm 2500 Sq. mm 2500 Sq. mm 59°C/W 1000 Sq. mm 1000 Sq. mm 1000 Sq. mm 52°C/W 1000 Sq. mm 0 1000 Sq. mm 55°C/W The thermal resistance for each application will be affected by thermal interactions with other components on the board. Some experimentation will be necessary to determine the actual value. The power dissipation of the LT1117 is equal to: PD = ( VIN – VOUT )( IOUT ) Maximum junction temperature will be equal to: TJ = TA(MAX) + PD(Thermal Resistance (junction-toambient)) Maximum junction temperature must not exceed 125°C. Ripple Rejection The curves for Ripple Rejection were generated using an adjustable device with the adjust pin bypassed. These curves will hold true for all values of output voltage. For proper bypassing, and ripple rejection approaching the values shown, the impedance of the adjust pin capacitor, at the ripple frequency, should be < R1. R1 is normally in the range of 100Ω to 200Ω. The size of the required adjust pin capacitor is a function of the input ripple frequency. At 120Hz, with R1 = 100Ω, the adjust pin capacitor should be > 13µF. At 10kHz only 0.16µF is needed. For fixed voltage devices, and adjustable devices without an adjust pin capacitor, the output ripple will increase as the ratio of the output voltage to the reference voltage (VOUT/ VREF). For example, with the output voltage equal to 5V, the output ripple will be increased by the ratio of 5V/1.25V. It will increase by a factor of four. Ripple rejection will be degraded by 12dB from the value shown on the curve. * Tab of device attached to topside copper 7 LT1117/LT1117-2.85 LT1117-3.3/LT1117-5 U TYPICAL APPLICATIO S 1.2V to 10V Adjustable Regulator 5V Regulator with Shutdown LT1117 LT1117 VIN IN VOUT† OUT R1 121Ω ADJ + IN R2 1k 121Ω 1% 10µF C2 100µF 5V OUT ADJ + + C1* 10µF VIN + 100µF 1k 2N3904 TTL 1k 365Ω 1% * NEEDED IF DEVICE IS FAR FROM FILTER CAPACITORS R2 †V — OUT = 1.25V 1 + R1 ( ) LT1117 • TA06 LT1117 • TA05 Remote Sensing RP (MAX. DROP 300mV) LT1117 VIN IN OUTPUT 5V OUT ADJ VIN + 100µF 25Ω + 7 6 – LM301A 1 10µF 121Ω 2 + 8 4 5µF + 365Ω RL 3 1k 100pF RETURN 25Ω RETURN LT1117 • TA07 Adjusting Output Voltage of Fixed Regulators Regulator with Reference LT1117-5 LT1117-5 VIN > 12V IN + OUT GND 10µF + 5V TO 10V 100µF 10µF + IN OUT GND + 10V 100µF 5VOUT + 10µF* VIN > 11.5V LT1029 1k LT1117 • TA06 * OPTIONAL IMPROVES RIPPLE REJECTION LT1117 • TA05 8 LT1117/LT1117-2.85 LT1117-3.3/LT1117-5 U TYPICAL APPLICATIO S Battery Charger Battery Backed Up Regulated Supply LT1117 VIN LT1117-5 IF OUT IN VOUT RS 1.25V VIN + 50Ω ( ) ( ) R2 VOUT – 1.25V 1 + — R1 SELECT FOR CHARGE RATE R2 –RS 1 + — R1 ∆IF = ∆VOUT 1 ( ) R2 –RS 1 + — R1 6.5V 10µF OUT GND 10µF + 100µF LT1117 • TA07 LT1117 • TA08 Automatic Light Control LT1117 LT1117 + LT1117-5 IN + Improving Ripple Rejection IN GND R1 IF = 5.2V LINE 5.0V BATTERY OUT 10µF ADJ VIN IN OUT ADJ R2 365Ω * C1 IMPROVES RIPPLE 1% REJECTION. XC SHOULD BE ≈ R1 AT RIPPLE FREQUENCY VIN ≥ 16.5V R1 121Ω 1% IN + 10µF + OUT ADJ 1.2k 100µF 150µF C1 10µF LT1117 • TA10 LT1117 • TA09 High Efficiency Dual Supply FEEDBACK PATH MUR410 3.3V OUTPUT (TYPICAL) + 470µF LT1117-5 MUR410 IN +5V 0.5A OUT + GND + 470µF 10µF 1N4002 10µF 1N4002 +VIN LT1117-5 MUR410 SWITCHING REGULATOR IN OUT GND + 470µF + –5V 0.5A LT1117 • TA11 9 LT1117/LT1117-2.85 LT1117-3.3/LT1117-5 U TYPICAL APPLICATIO S High Efficiency Dual Linear Supply L1 285µH MBR360 (HEAT SINK) 2N6667 Q1 (DARLINGTON) 10k 1k LT1117-5 IN + 1000µF GND 2.4k 510k LT1004-2.5 30k + MDA201 V+ + – 5V 0.5A OUT + 20k* + 100µF D11 1N4002 100µF D2 1N4002 30.1k* 1/2 LT1018 4700µF – 130VAC TO 90VAC L1 285µH STANCOR P-8685 MBR360 (HEAT SINK) 2N6667 (DARLINGTON) 10k 1k LT1117-5 IN + 1000µF 2.4k 510k 30k + MDA201 LT1004-2.5 + 20k* + + – OUT GND 30.1k* 1/2 LT1018 4700µF V– – –5V 0.5A * = 1 % FILM RESISTORS MDA = MOTOROLA L1 = PULSE ENGINEERING, INC. #PE-92106 LT1117 • TA12 Low Dropout Negative Supply LT1117-5 VIN IN + 10µF FLOATING INPUT 10 OUT GND + 100µF VOUT = –5V LT1117 • TA13 LT1117/LT1117-2.85 LT1117-3.3/LT1117-5 W U SOLDERI G ETHODS The SOT-223 is manufactured with gull wing leadform for surface mount applications. The leads and heat sink are solder plated and allow easy soldering using nonactive or mildly active fluxes. The package is constructed with three leads exiting one side of the package and one heat sink exiting the other side, and the die attached to the heat sink internally. these methods can easily damage the part with excessive thermal gradients across the package. Care must be exercised during surface mount to minimize large (> 30°C per second) thermal shock to the package. The recommended methods of soldering SOT-223 are: vapor phase reflow and infrared reflow with preheat of component to within 65°C of the solder temperature. Hand soldering and wave soldering are not recommended since U PACKAGE DESCRIPTIO LT1117 • TA15 Dimensions in inches (millimeters) unless otherwise noted. M Package 3-Lead Plastic DD Pak (LTC DWG # 05-08-1460) 0.256 (6.502) 0.060 (1.524) 0.060 (1.524) TYP 0.390 – 0.415 (9.906 – 10.541) 0.165 – 0.180 (4.191 – 4.572) 0.045 – 0.055 (1.143 – 1.397) 15° TYP 0.060 (1.524) 0.183 (4.648) 0.059 (1.499) TYP 0.330 – 0.370 (8.382 – 9.398) ( +0.203 0.102 –0.102 BOTTOM VIEW OF DD PAK HATCHED AREA IS SOLDER PLATED COPPER HEAT SINK ) 0.095 – 0.115 (2.413 – 2.921) 0.075 (1.905) 0.300 (7.620) +0.008 0.004 –0.004 ( +0.012 0.143 – 0.020 +0.305 3.632 –0.508 ) 0.090 – 0.110 (2.286 – 2.794) 0.050 ± 0.012 (1.270 ± 0.305) 0.013 – 0.023 (0.330 – 0.584) 0.050 (1.270) BSC M (DD3) 1098 ST Package 3-Lead Plastic SOT-223 (LTC DWG # 05-08-1630) 0.248 – 0.264 (6.30 – 6.71) 0.114 – 0.124 (2.90 – 3.15) 10° – 16° 0.264 – 0.287 (6.70 – 7.30) 0.130 – 0.146 (3.30 – 3.71) 0.010 – 0.014 (0.25 – 0.36) 10° MAX 0.071 (1.80) MAX 10° – 16° 0.024 – 0.033 (0.60 – 0.84) 0.181 (4.60) NOM 0.0905 (2.30) NOM 0.012 (0.31) MIN 0.0008 – 0.0040 (0.0203 – 0.1016) ST3 (SOT-233) 1298 0.033 – 0.041 (0.84 – 1.04) 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. 11 LT1117/LT1117-2.85 LT1117-3.3/LT1117-5 U TYPICAL APPLICATIO High Efficiency Regulator LT1117 1mH 28V INPUT IN + 10,000µF MR1122 10k OUTPUT OUT ADJ 240Ω 470Ω 28V 1k + 100µF 2k OUTPUT ADJUST 1N914 1M 4N28 10k + LT1011 10k – 28V 1N914 LT1117 • TA14 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1120 125mA Low Dropout Regulator with 20µA IQ Includes 2.5V Reference and Comparator LT1121 150mA Micropower Low Dropout Regulator 30µA IQ, SOT-223 Package LT1129 700mA Micropower Low Dropout Regulator 50µA Quiescent Current LT1175 500mA Negative Low Dropout Micropower Regulator 45µA IQ, 0.26V Dropout Voltage, SOT-223 Package LT1374 4.5A, 500kHz Step-Down Converter 4.5A, 0.07Ω Internal Switch, SO-8 Package LT1521 300mA Low Dropout Micropower Regulator with Shutdown 15µA IQ, Reverse Battery Protection TM LT1573 UltraFast Transient Response Low Dropout Regulator Drives External PNP LT1575 UltraFast Transient Response Low Dropout Regulator Drives External N-Channel MOSFET LT1735 Synchronous Step-Down Converter High Efficiency, OPTI-LOOPTM Compensation LT1761 Series 100mA, Low Noise, Low Dropout Micropower Regulators in SOT-23 20µA Quiescent Current, 20µVRMS Noise, SOT-23 Package LT1762 Series 150mA, Low Noise, LDO Micropower Regulators 25µA Quiescent Current, 20µVRMS Noise, MSOP Package LT1763 Series 500mA, Low Noise, LDO Micropower Regulators 30µA Quiescent Current, 20µVRMS Noise, SO-8 Package LT1764 Series 3A, Low Noise, Fast Transient Response LDO 40µVRMS Noise, DD and TO-220 Packages LT1962 300mA, Low Noise, LDO Micropower Regulator 20µVRMS Noise, MSOP Package LT1963 1.5A, Low Noise, Fast Transient Response LDO 40µVRMS Noise, SOT-223 Package UltraFast and OPT-LOOP are trademarks of Linear Technology Corporation. 12 Linear Technology Corporation 1117fc LT/TP 0500 2K REV C • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408)432-1900 ● FAX: (408) 434-0507 ● www.linear-tech.com LINEAR TECHNOLOGY CORPORATION 1993