LT1036 Logic Controlled Regulator U DESCRIPTIO The LT®1036 features two positive regulators in the same package. The 12V main regulator offers excellent performance while supplying load currents up to 3A, and the 5V auxiliary regulator provides similar performance while supplying lighter loads of 75mA. The main regulator has the additional feature of being under the shutdown control of a logic signal. When the enable pin is taken to a low logic level, the main regulator shuts down and its output voltage goes to near 0V. During this command, the auxiliary output is unaffected by the main regulator’s condition and continues to provide a 5V output. FEATURES ■ ■ ■ ■ ■ ■ Two Regulated Outputs: 12V at 3A 5V at 75mA 2% Output Voltage Tolerance 60dB Ripple Rejection 0.7% Load Regulation TTL and CMOS Compatible Logic Control 100% Thermal Burn-In on All Devices The main output has current and power limiting combined with thermal shutdown to make it virtually blowout proof. The auxiliary output is not affected by the thermal shut down mechanism or the state of the main output, allowing it to be used as a back-up in case of overloads or shorts on the main supply. U APPLICATIO S ■ ■ ■ ■ Power Supply Sequencing Remote On/Off Power Control Selective System Power During Emergency Power Operation Memory Power Supply with Back-Up The logic input of the LT1036 (enable pin) has a 1.6V threshold and can be driven from a high source impedance. This allows it to be driven by most logic families, including TTL and CMOS. For a dual 5V version of the LT1036, please see the LT1035 data sheet. , LTC and LT are registered trademarks of Linear Technology Corporation. U TYPICAL APPLICATIO Guaranteed Load Current, 12V Output Functional Diagram 5 4.5 12V VIN 5 IN OUT 4 1 OV LOGIC 2 EN GND AUX 4 CURRENT (A) LT1036 ENABLE 3.5 5V 3 3 2.5 2 1.5 LT1036M/1036C • FD01 1 0.5 0 14 16 18 20 22 24 26 INPUT VOLTAGE (V) 28 30 LT1036M/1036C • FD02 1036fa 1 LT1036 W W W AXI U U ABSOLUTE RATI GS (Note 1) Power Dissipation Continuous (Note 6) ........................................... 24W Fault Conditions .............................. Internally Limited Input Voltage (VIN) .................................................. 30V Enable Voltage (VEN) ............................................... 30V Operating Junction Temperature LT1036M (OBSOLETE) ..................... – 55°C to 150°C LT1036C ................................................ 0°C to 125°C Storage Temperature Range ................. – 65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C U UU PRECO DITIO I G 100% Burn-In in Thermal Limit U U W PACKAGE/ORDER I FOR ATIO ORDER PART NUMBER BOTTOM VIEW VIN VO 5 1 CASE IS GND 2 4 LT1036MK LT1036CK ORDER PART NUMBER FRONT VIEW 5 AUX 3 GND 2 AUX VEN 1 VEN VO K PACKAGE 4-LEAD TO-3 METAL CAN T PACKAGE 5-LEAD PLASTIC TO-220 TJMAX = 125°C, θJC = 3°C/W TJMAX = 150°C, θJC = 2.5°C/W TJMAX = 125°C, θJC = 2.5°C/W OBSOLETE PACKAGE LT1036CT VIN 4 Consider the T Package as an Alternate Source Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range. Main regulator (Note 2) VIN = 15V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS VO Output Voltage TJ = 25°C 11.76 12 12.24 V 12.48 V High 15V ≤ VIN ≤ 30V, IOUT ≤ IMAX (Note 7) ● Low 7V ≤ VIN ≤ 30V ● 0.1 0.3 V ● 10 80 mV 1 4 mV/V ∆VO ∆IO Load Regulation (Note 7) VIN = 16V 0 ≤ IO ≤ 3A (Note 3) ∆VO ∆VIN Line Regulation 15V ≤ VIN ≤ 30V (Note 3) Ripple Rejection 50Hz ≤ f ≤ 500Hz (Note 9) Thermal Regulation ∆PD = 20W (Note 5) IO Available Load Current (Note 7) 15V ≤ VIN ≤ 20V VIN = 25V ISC Short Circuit Current VIN = 15V VIN = 25V VIN Input Voltage to Maintain Regulation (Dropout Voltage) (Note 6) IO = 1A IO = 3A 11.52 50 60 0.003 ● ● ● ● 3 2 dB 0.012 4 2.7 %/W A A 2.3 1 4 2 A A 13.8 14.4 14.5 15 V V 1036fa 2 LT1036 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range. Main Regulator (Note 2) VIN = 15V unless otherwise noted. SYMBOL PARAMETER CONDITIONS IQ Quiescent Current θJC Thermal Resistance, Junction to Case MIN TYP MAX UNITS Output High Output Low 4 3 5.5 4.5 mA mA TO-220 2 3 °C/W Auxiliary Regulator (Note 2) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS VO Output Voltage TJ = 25°C 4.9 5.0 5.1 V 4.8 5.0 5.2 V 5 15 mV 1 2 mV/V mV/V 7.2V ≤ VIN ≤ 30V 0mA ≤ IO ≤ 75mA ● ● ∆VO ∆IO Load Regulation 7.2V ≤ VIN ≤ 30V 0mA ≤ IO ≤ 75mA (Note 3) ∆VO ∆VIN Line Regulation 7.2V ≤ VIN ≤ 30V (Note 3) 0.2 Ripple Rejection 50Hz ≤ f ≤ 500Hz 74 ISC Short Circuit Current (Note 8) 7.0V ≤ VIN ≤ 30V 140 VIN Input Voltage to Maintain Regulation (Dropout Voltage) (Note 6) IO ≤ 10mA IO = 75mA ● ● dB 250 mA 6.2 6.8 6.5 7.2 V V MIN TYP MAX UNITS Logic Control (Note 2) SYMBOL PARAMETER CONDITIONS VEN Enable Threshold Voltage 7.0V ≤ VIN ≤ 30V TJ = 25°C ● 1.45 1.3 1.6 1.6 1.7 1.8 V V VEN ≤ 1V (Note 4) ● 0 1.5 12 µA VEN ≤ 2.4V ● 0 6 µA Enable Pin Current Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: Unless otherwise indicated, these specifications apply for VIN = 15V, IO = 0mA, and TJ = 25°C. Note 3: Line and load regulation is measured using a low duty cycle pulse, causing little change in the junction temperature. Effects due to thermal gradients and device heating must be taken into account separately. Note 4: When the enable pin is at a low logic level, current flows out of the enable pin. Note 5: Pulse length for this measurement is 20ms. Note 6: Input voltage is reduced until output drops by 100mV from its initial value. Note 7: See “Guaranteed Load Current” graph. Note 8: Continuous shorts on the auxiliary output are not allowed unless adequate heat sinking is used to maintain junction temperature below 150°C. Note 9: Guaranteed but not tested. 1036fa 3 LT1036 U W TYPICAL PERFOR A CE CHARACTERISTICS Minimum Input-Output Differential of Main Output Minimum Input-Output Differential of Auxiliary Output 2.4 2.2 2.0 1.8 1.6 TJ = 25°C 1.4 TJ = 150°C 0 0.5 2.2 2.0 TJ = 150°C 1.8 TJ = 25°C 1.6 1.2 1.0 0.8 1.0 2.0 1.5 OUTPUT CURRENT (A) 2.5 0.6 3.0 20 0 60 80 40 OUTPUT CURRENT (mA) LT1036M/1036C • TPC01 SUPPLY CURRENT (mA) 4 CURRENT (A) 6 5 3 12V OUTPUT “OFF” 2 0 0 28 0 32 4 6 8 TIME (µs) 10 12 14 12.2 12.1 12.0 11.9 11.8 3 6 9 12 15 18 21 24 27 30 INPUT VOLTAGE (V) 5.1 5.0 4.9 4.8 4.7 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) LT1036M/1036C • TPC05 LT1036M/1036C • TPC04 Load Transient Response, 12V Output LT1036M/1036C • TPC06 Enable Pin Characteristics Enable Threshold 50 1.75 0 0 COUT = 1µF TANTALUM 1.70 –0.2 1.65 0.4 50 0 COUT = 10µF TANTALUM –50 LOAD TRANSIENT 0.2 TJ = 25°C 0.6 0.8 1.0 THRESHOLD (V) –50 CURRENT (µA) OUTPUT VOLTAGES CHANGE (V) 2 LT1036M/1036C • TPC03 12V OUTPUT “ON” 1 LOAD TRANSIENT (A) VIN = 18V 4 1 12 16 20 24 INPUT VOLTAGE (V) 0 0 MAIN OUTPUT (V) TJ = 25°C 8 ∆ VIN = 1V 1 Output Voltage vs Temperature 7 2 COUT = 10µF TANTALUM 0 Quiescent Current TJ = 25°C 4 20 100 8 5 0 0 –20 LT1036M/1036C • TPC02 Maximum Available Load Current, 12V Output DEVICE OUT OF REGULATION 3 BELOW 14V COUT = 1µF TANTALUM 20 –20 1.4 AUXILIARY OUTPUT (V) 1.2 TJ = –55°C INPUT TRANSIENT (V) TJ = –55°C INPUT-OUTPUT VOLTAGE (V) INPUT-OUTPUT VOLTAGE (V) 2.4 OUTPUT VOLTAGE CHANGE (mV) 2.6 2.6 1.0 Line Transient Response, 12V Output 1.60 1.55 1.50 1.2 1.45 0 1.4 IOUT = 1A ∆ IOUT = 0.2A 1.8 0 2 1.40 1.6 4 6 8 TIME (µs) 10 12 14 LT1036M/1036C • TPC07 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 20 ENABLE VOLTAGE (V)* *NOTE SCALE CHANGE 0 1.35 –50 –25 0 25 50 75 100 125 150 JUNCTION TEMPERATURE (°C) LT1036M/1036C • TPC09 LT1036M/1036C • TPC08 1036fa 4 LT1036 U W TYPICAL PERFOR A CE CHARACTERISTICS Short-Circuit Current, 12V Output Output Switching Characteristics 5 TJ = 25°C 3 2 200 180 12 9 6 ENABLE VOLTAGE (V) 160 COUT = 1µF 140 COUT = 10µF 3 SEE APPLICATION SECTION FOR FALL TIME INFORMATION 0 1 CCOUT 0.1F OUT≤≤0.1µF 5 4 8 12 16 20 24 INPUT VOLTAGE (V) 28 120 100 60 20 0 32 10 20 30 40 50 60 70 80 90 TIME (µs) LT1036M/1036C • TPC10 LT1036M/1036C • TPC11 MAIN (12V) OUTPUT 80 40 0 0 0 NOISE (µVRMS) OUTPUT VOLTAGE (V) 15 4 CURRENT (A) Output Voltage Noise 0 100 AUXILIARY OUTPUT 300 3k 10k 1k BANDWIDTH (1 POLE) (Hz) 30k LT1036M/1036C • TPC12 U W U U APPLICATIO S I FOR ATIO General Information The LT1036 is a dual output regulator. The main 12V output is capable of delivering up to 3A of load current and can be shut down with a logic signal. The auxiliary 5V output supplies a minimum of 75mA and is unaffected by the logic signal. The outputs are trimmed to ± 2% initial tolerance and exhibit excellent line and load regulation. The logic control feature makes the LT1036 ideal for many system applications where it is desirable to power-up a portion of the system for a period of time, and then power the system down during a standby operation. Applications such as multiple power supply sequencing, elimination of expensive AC and DC power switches, delayed start applications, switching 12V DC loads, and many others are now easily accomplished. Timing functions, such as delayed power-up or powerdown, can also be performed directly at the enable pin. Because a logic low on the enable pin shuts down the main regulator, feedback from output to enable can be used to generate hysteresis or latching functions. The low quiescent current drain of the LT1036 makes it useful in battery-powered or battery back-up applications. The enable pin can be used as a “low battery” detector or to shut down major portions of system power, allowing memory portions to continue to operate from the auxiliary output. At low output currents, the auxiliary output will regulate with input voltage typically as low as 6.2V, giving maximum battery life. Good design practice with all regulators is to bypass the input and output terminals. A 2µF solid tantalum at the input and at both outputs is suggested. For the applications which follow, the bypass capacitors are still recommended, but for simplicity are not shown on the diagram. It is also recommended that for maximum noise immunity the voltage enable pin be tied high if it is unused. It can be tied directly to VIN, as shown in Figure 1, or to the auxiliary Output. If the enable pin is left open, it will float to a high logic level of approximately 1.6V and the main output regulator will be at 12V. The enable pin is fully protected against input voltages up to 30V, even if the power input voltage is zero. 1036fa 5 LT1036 U W U U APPLICATIO S I FOR ATIO The basic shutdown control circuit uses a direct gate drive or an open collector driver and a pull-up resistor which are tied to VAUX, as shown in Figure 2. 5 VIN + 2 1µF IN OUT LT1036 EN GND 3 AUX 1 VO 12V + 2µF 5V 4 + 2µF be used as the timing current in delayed power-up applications as it is temperature sensitive and varies somewhat from device to device. Instead, a resistor tied to the auxiliary output, the input, or to a logic signal should be used. The timing resistor chosen should provide at least 25µA of current to “swamp out” the effects of the internal current. Main Output Current Voltage Characteristics Figure 1 7.5-20V IN 12V OUT LT1036 EN GND AUX 5V 0A-3A LOAD 0mA–75mA LOAD VAUX LT1036M/1036C • AI02 Figure 2 Driving the Enable Pin The enable pin equivalent schematic is shown in Figure 3. Basically, enable pin current is zero above the threshold and about 1.5µA below the threshold, flowing out of the pin. Standard logic, such as TTL and CMOS, will interface directly to the enable pin, even if the logic output swing is higher than the input voltage (VIN) to the regulator. 15V CMOS can be used to drive the enable pin, even if the regulator is not powered up, without loading the CMOS output. Timing functions, such as delayed power-up or power-down can be implemented with an RC network. The current flowing out of the enable pin should not 70µA 1V ENABLE Following a high to low transition at the enable pin, the main regulator output will begin to drop after a delay of approximately 0.4µs. With no capacitive load, the output will fall to zero in approximately 0.8µs (RL = 4Ω to 100Ω). With a capacitive load, fall time is limited by the RC product of the load and the output capacitance. For light loads (RL >400Ω), the discharge time is controlled by an internal current pull-down of 15mA for output voltages down to 1.5V. Below 1.5V, the pull-down current drops to ≈ 4mA. The DC output voltage in the shutdown mode is approximately 0.12V due to an internal current path in the regulator. (See Figure 4.) The user should note that the output in the low state can only sink about 3mA. If current is forced into the output, the output voltage will rise to 1V at 5mA and about 1.5V at 10mA. With no output capacitor, the rise time of the main output is about 12µs. With an output capacitor, rise time is limited by the short circuit current of the LT1036 and the load capacitance. A 10µF output capacitor slows the output rise time to approximately 80µs. 10 CURRENT FORCED INTO OUTPUT (mA) LT1036M/1036C • AI01 9 VIN = 15V 8 7 6 5 4 TJ = 25°C TJ = –55°C 3 2 TJ = 150°C 1 0 0 0.2 0.4 0.6 0.8 1.0 1.2 OUTPUT VOLTAGE (V) LT1036M/1036C • AI03 Figure 3 1.4 1.6 LT1036M/1036C • AI04 Figure 4 1036fa 6 LT1036 U W U U APPLICATIO S I FOR ATIO Output Current The main output current limits at about 4A for input voltages below 20V. Internal foldback, or “power limiting”, circuitry detects the input-output voltage differential and reduces current limit for input to output voltages exceeding 8V. With 25V input, for instance, short circuit current is reduced to ≈ 0.9A. An additional feature of the LT1036 is that the auxiliary supply does not incorporate, nor is it affected by, thermal shutdown. Any fault condition of the main regulator will not affect the auxiliary output voltage. The following applications circuits will serve to indicate the versatility of the LT1036. U TYPICAL APPLICATIO S Fast Turn-Off, Delayed Turn-On VIN IN Latch-Off with Output Short OUT 12V VIN LT1036 EN * GND IN OUT 12V LT1036 AUX EN GND 68k AUX 0.33µF *CAN BE ANY GATE TYPE 5V + R1 100k C1 LT1036M/1036C • TA02 tON = 0.3 R1C1 LT1036M/1036C • TA01 Delayed Power-Up VIN IN Thermal Cutoff at High Ambient Temperature OUT VIN 12V IN EN GND OUT 5V LT1036 LT1036 AUX EN 5V GND AUX 26.1k C1 tDELAY ≈ 0.4 R1C1 R1 27k tOFF = 58°C tON = 46°C 154k Rt* LT1036M/1036C • TA03 *YELLOW SPRINGS #44008. 30kΩ at 25°C LT1036M/1036C • TA04 Power Supply Turn-On Sequencing VIN IN OUT LT1036 EN GND IN AUX OUT LT1036 R2 EN GND AUX C2 R1 C1 t1 = 0.4 R1C1 t2 = 0.15 R2C2 LT1036M/1036C • TA05 1036fa 7 LT1036 U TYPICAL APPLICATIO S First-On, Last-Off Sequencing VIN IN OUT LT1036 “FIRST ON” EN GND AUX IN 12V First-On, First-Off Sequencing OUT 12V VIN IN OUT LT1036 “FIRST ON” EN GND AUX LT1036 EN 5V GND AUX 5V R1 10k R4 150k R5 150k + 5V ON EN OFF OFF tON (1) = 100ms tON (2) = 200ms ON GND AUX 5V R2 4.7k R5 1k + R1 1k 100µF 50µF 12V R6 150k R3 1k R3 1k OUT LT1036 R4 150k R2 2.2k tON (1) = 50ms tON (2) = 150ms IN 12V LT1036M/1036C • TA06 LT1036M/1036C • TA07 Line Dropout Detector TO FILTERED RAW DC IN TRIP SET OUT 12V AUX 5V AUXILIARY LT1036 18k 500k TO SECONDARY OF AC POWER TRANSFORMER EN 8 0.1µF 4N46 GND 3 2k 3.3k – 7 LT1011 1N4148(4) 2 + DROPOUT SIGNAL 1 4 3k LT1036M/1036C • TA08 Low Dissipation Regulator 27k 1k 1N4003 3.9k LT1035 LT1036 VOUT VIN AUX 6000µF 4 2 GND + 12V OUTPUT 10µF – 4 12V GND AUX 5V COUPLER “ON” = OUTPUT “ON” OUTPUT CONTROL LOGIC 150k + OUT 3 R 2 LT1011 COMPARATOR 1 EN 1 10.5k 1000pF 8 EN 5 + IN LT1036 15.5V 1mH* VIN 17.5VDC TO 30VDC 7 VIN 3.5V DC UNDER ALL CONDITIONS 2N6667 1k Optocoupled Output Control 3 5k 5k *DALE TD-5 THIS CIRCUIT IS DESIGNED TO REDUCE POWER DISSIPATION IN THE LT1036 OVER A 90VAC–140VAC INPUT RANGE SELECT R DEPENDING UPON THE ON-RESITANCE OF THE OPTOCOUPLER LT1036M/1036C • TA10 LT1036M/1036C • TA09 1036fa 8 LT1036 W W SCHE ATIC DIAGRA VIN 5 Q38 860 800 6k 3k Q36 Q37 Q31 Q33 Q32 D2 7V Q35 Q28 Q29 8k D1 5k Q23 Q27 Q24 10k 2k 5k 430 Q13 Q2 Q1 Q12 AUX OUTPUT 3k D5 8k 5k 115 1.3k 900 Q3 2k Q7 Q8 Q30 Q11 Q25 20pF D3 6.5V Q10 20 Q5 0.03Ω 10pF 4Ω 4 50 750 Q4 4k Q26 30 pF 15pF Q34 Q9 20pF MAIN OUTPUT 500 1.2k 10k 1 Q22 4.8k 8k Q21 Q6 7k Q16 Q20 Q15 2.1k 12k 20.4k Q19 Q14 2k Q18 400 2.9k Q39 Q17 10k 100k 500 GND 3 2 ENABLE LT1036M/1036C • SD01 1036fa 9 LT1036 U PACKAGE DESCRIPTIO T Package 5-Lead Plastic TO-220 (Standard) (Reference LTC DWG # 05-08-1421) 0.390 – 0.415 (9.906 – 10.541) 0.165 – 0.180 (4.191 – 4.572) 0.147 – 0.155 (3.734 – 3.937) DIA 0.045 – 0.055 (1.143 – 1.397) 0.230 – 0.270 (5.842 – 6.858) 0.460 – 0.500 (11.684 – 12.700) 0.570 – 0.620 (14.478 – 15.748) 0.330 – 0.370 (8.382 – 9.398) 0.620 (15.75) TYP 0.700 – 0.728 (17.78 – 18.491) SEATING PLANE 0.152 – 0.202 0.260 – 0.320 (3.861 – 5.131) (6.60 – 8.13) 0.095 – 0.115 (2.413 – 2.921) 0.155 – 0.195* (3.937 – 4.953) 0.013 – 0.023 (0.330 – 0.584) BSC 0.067 (1.70) 0.028 – 0.038 (0.711 – 0.965) 0.135 – 0.165 (3.429 – 4.191) * MEASURED AT THE SEATING PLANE T5 (TO-220) 0399 1036fa 10 LT1036 U PACKAGE DESCRIPTIO K Package 4-Lead TO-3 Metal Can (Reference LTC DWG # 05-08-1311) 0.320 – 0.350 (8.13 – 8.89) 0.760 – 0.775 (19.30 – 19.69) 0.060 – 0.135 (1.524 – 3.429) 0.420 – 0.480 (10.67 – 12.19) 0.038 – 0.043 (0.965 – 1.09) 1.177 – 1.197 (29.90 – 30.40) 0.470 TP P.C.D. 0.655 – 0.675 (16.64 – 19.05) 0.151 – 0.161 (3.84 – 4.09) DIA 2 PLC 0.167 – 0.177 (4.24 – 4.49) R 72° 18° 0.490 – 0.510 (12.45 – 12.95) R K4(TO-3) 1098 OBSOLETE PACKAGE 1036fa 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 LT1036 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1573 UltraFast Transient Response Low Dropout Regulator PNP Driver, Up to 5A VIN=2.8 to 10V, VOUT = 1.265V, Dropout Voltage = 350mV-Ext PNP V@IOUT, IQ = 1.7mA, Shutdown Current = 200µA, S8 Package. Requires External PNP Transistor. LT1764/A 3A, Low Noise, Fast Transient Response, LDO VIN = 2.7 to 20V, VOUT = 1.21V, Dropout Voltage = .34V@IOUT, IQ = 1mA, Shutdown Current < 1µA, DD, TO220-5 Packages. Low Noise < 40µVRMS PK-PK. "A" Version Stable with Ceramic Capacitors. LT3150 Fast Transient Response Low Dropout Regulator MOSFET Driver, Up to 10A VIN = 1.4 to 10V, VOUT = 1.23V, Dropout Voltage = 150mV Ext FET @IOUT, IQ = 12mA, GN-16 Package. Intgr LT1613 Boost, Drives Low Cost N-Channel MOSFETs, Fast Transient Response. 1036fa 12 Linear Technology Corporation LW/TP 0902 1K REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 1985