Advanced Monolithic Systems AMS1083 8A LOW DROPOUT VOLTAGE REGULATOR RoHS compliant FEATURES APPLICATIONS • Three Terminal Adjustable or Fixed 1.5V, 2.5V, 2.85V, 3.0V, 3.3V, 3.5V and 5.0V • Output Current of 8A • Operates Down to 1V Dropout • Line Regulation: 0.015% • Load Regulation: 0.1% • TO-220 and TO-263 packages available • High Efficiency Linear Regulators • Post Regulators for Switching Supplies • Microprocessor Supply • Battery Chargers • Constant Current Regulators • Notebook/Personal Computer Supplies • Portable Instrumentation GENERAL DESCRIPTION The AMS1083 series of adjustable and fixed voltage regulators are designed to provide 8A output current and to operate down to 1V input-to-output differential. The dropout voltage of the device is guaranteed maximum 1.5V at maximum output current, decreasing at lower load currents. On-chip trimming adjusts the reference voltage to 1%. Current limit is also trimmed, minimizing the stress under overload conditions on both the regulator and power source circuitry. The AMS1083 devices are pin compatible with older three-terminal regulators and are offered in 3 lead TO-220 package and 3 lead TO-263 (Plastic DD). ORDERING INFORMATION: PACKAGE TYPE 3 LEAD TO-220 AMS1083CT AMS1083CT-1.5 AMS1083CT-2.5 AMS1083CT-2.85 AMS1083CT-3.0 AMS1083CT-3.3 AMS1083CT-3.5 AMS1083CT-5.0 OPERATING JUNCTION 3 LEAD TO-263 AMS1083CM AMS1083CM-1.5 AMS1083CM-2.5 AMS1083CM-2.85 AMS1083CM-3.0 AMS1083CM-3.3 AMS1083CM-3.5 AMS1083CM-5.0 TEMPERATURE RANGE 0 to 125° C 0 to 125° C 0 to 125° C 0 to 125° C 0 to 125° C 0 to 125° C 0 to 125° C 0 to 125° C FRONT VIEW 3 TAB IS OUTPUT 2 1 PIN CONNECTIONS FIXED VERSION 1- Ground 2- VOUT 3- VIN FRONT VIEW ADJUSTABLE VERSION 1- Adjust 2- VOUT 3- VIN Advanced Monolithic Systems, Inc. www.advanced-monolithic.com TAB IS OUTPUT 3 2 1 Phone (925) 443-0722 Fax (925) 443-0723 AMS1083 ABSOLUTE MAXIMUM RATINGS (Note 1) Power Dissipation Input Voltage Operating Junction Temperature Control Section Power Transistor Storage temperature Internally limited 15V 0°C to 125°C 0°C to 150°C - 65°C to +150°C Soldering information Lead Temperature (25 sec) Thermal Resistance TO-220 package TO-263 package 265°C ϕ JA= 50°C/W ϕ JA= 30°C/W * * With package soldering to 0.5in2 copper area over backside ground plane or internal power plane ϕ JA can vary from 20°C/W to >40°C/W depending on mounting technique. ELECTRICAL CHARACTERISTICS Electrical Characteristics at IOUT = 0 mA, and TJ = +25°C unless otherwise specified. Parameter Device Conditions Reference Voltage (Note 2) AMS1083 IOUT = 10 mA 10mA ≤ IOUT ≤ 8A, 1.5V≤ (VIN - VOUT) ≤ 12V 1.238 1.225 1.250 1.250 1.262 1.270 V V Output Voltage (Note 2) AMS1083-1.5 0 ≤ IOUT ≤ 8A , 3V≤ VIN ≤ 12V 1.485 1.470 1.500 1.500 1.515 1.530 V V AMS1083-2.5 0 ≤ IOUT ≤ 8A , 4V≤ VIN ≤ 12V 2.475 2.450 2.500 2.500 2.525 2.550 V V AMS1083-2.85 0 ≤ IOUT ≤ 8A , 4.35V≤ VIN ≤ 12V 2.820 2.790 2.850 2.850 2.880 2.910 V V AMS1083-3.0 0 ≤ IOUT ≤ 8A , 4.5V ≤ VIN ≤ 12V 2.970 2.940 3.000 3.000 3.030 3.360 V V AMS1083-3.3 0 ≤ IOUT ≤ 8A , 4.75V ≤ VIN ≤ 12V 3.267 3.235 3.300 3.300 3.333 3.365 V V AMS1083-3.5 0 ≤ IOUT ≤ 8A, 5V ≤ VIN ≤ 12V 3.465 3.430 3.500 3.500 3.535 3.570 V V AMS1083-5.0 0 ≤ IOUT ≤ 8A , 6.5V ≤ VIN ≤ 12V 4.950 4.900 5.000 5.000 5.050 5.100 V V Line Regulation AMS1083/-1.5/-2.5/2.85/ -3.0/-3.3/-3.5/-5.0 ILOAD = 10 mA , 1.5V≤ (VIN - VOUT) ≤ 12V 0.3 0.6 6 10 mV mV Load Regulation AMS1083 (VIN - VOUT) =3V, 10mA ≤ IOUT ≤ 8A 0.1 0.2 0.3 0.4 % % AMS1083-1.5 VIN = 5V, 0 ≤ IOUT ≤ 8A 3 6 12 20 mV mV AMS1083-2.5 VIN = 5V, 0 ≤ IOUT ≤ 8A 3 6 12 20 mV mV AMS1083-2.85 VIN = 5V, 0 ≤ IOUT ≤ 8A 3 6 12 20 mV mV AMS1083-3.0 VIN = 5V, 0 ≤ IOUT ≤ 8A 3 6 12 20 mV mV AMS1083-3.3 VIN = 5V, 0 ≤ IOUT ≤ 8A 3 7 15 25 mV mV AMS1083-3.5 VIN = 5.25V, 0 ≤ IOUT ≤ 8A 3 6 15 25 mV mV AMS1083-5.0 VIN = 8V, 0 ≤ IOUT ≤ 8A 5 10 20 35 mV mV AMS1083/-1.5/-2.5/2.85/ -3.0/-3.3/-3.5/-5.0 ∆VOUT , ∆VREF = 1%, IOUT = 8 A (Note 4) 1.3 1.5 V (Notes 2, 3) Dropout Voltage (VIN - VOUT) Advanced Monolithic Systems, Inc. www.advanced-monolithic.com Min Typ Phone (925) 443-0722 Max Units Fax (925) 443-0723 AMS1083 ELECTRICAL CHARACTERISTICS Electrical Characteristics at IOUT = 0 mA, and TJ = +25°C unless otherwise specified. Parameter Device Conditions Min Typ Max Current Limit AMS1083/-1.5/-2.5/2.85/ -3.0/-3.3/-3.5/-5.0 (VIN - VOUT) = 5V 8.00 9.00 10.00 A Minimum Load Current AMS1083 (VIN - VOUT) = 12V (Note 5) 5 10 mA Quiescent Current AMS1083/-1.5/-2.5/2.85/ -3.0/-3.3/-3.5/-5.0 VIN ≤ 12V 5 10 mA Ripple Rejection AMS1083 f =120Hz , COUT = 25µF Tantalum, IOUT = 8A, (VIN-VOUT ) = 3V, CADJ =25µF 60 75 dB AMS1083-1.5 f =120Hz , COUT = 25µF Tantalum, IOUT = 8A, VIN = 4.5V 60 72 dB AMS1083-2.5 f =120Hz , COUT = 25µF Tantalum, IOUT = 8A, VIN = 5.5V 60 72 dB AMS1083-2.85 f =120Hz , COUT = 25µF Tantalum, IOUT = 8A, VIN = 6V 60 72 dB AMS1083-3.0 f =120Hz , COUT = 25µF Tantalum, IOUT = 8A VIN = 6V 60 72 dB AMS1083-3.3 f =120Hz , COUT = 25µF Tantalum, IOUT = 8A VIN = 6.3V 60 72 dB AMS1083-3.5 f =120Hz , COUT = 25µF Tantalum, IOUT = 8A VIN = 6.5V 60 72 dB AMS1083-5.0 f =120Hz , COUT = 25µF Tantalum, IOUT = 8A VIN = 8V 60 68 dB Thermal Regulation AMS1083 TA = 25°C, 30ms pulse Adjust Pin Current AMS1083 10mA ≤ IOUT ≤ 8A , 1.5V≤ (VIN - VOUT) ≤ 12V Adjust Pin Current AMS1083 0.008 10mA ≤ IOUT ≤ 8A , 1.5V≤ (VIN - VOUT) ≤ 12V 0.04 %W 120 µA µA 5 µA 55 0.2 Units Change Temperature Stability % 0.5 Long Term Stability TA =125°C, 1000Hrs RMS Output Noise TA = 25°C , 10Hz ≤ f ≤ 10kHz 0.3 1 0.003 % % (% of VOUT ) Thermal Resistance Junction-to-Case M Package: Control Circuitry/ Power Transistor T Package: Control Circuitry/ Power Transistor 1.5/4.0 1.5/4.0 °C/W °C/W Parameters identified with boldface type apply over the full operating temperature range. Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. For guaranteed specifications and test conditions, see the Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed. Note 2: Line and Load regulation are guaranteed up to the maximum power dissipation of 15W. Power dissipation is determined by the input/output differential and the output current. Guaranteed maximum power dissipation will not be available over the full input/output range. Note 3:See thermal regulation specifications for changes in output voltage due to heating effects. Line and load regulation are measured at a constant junction temperature by low duty cycle pulse testing. Load regulation is measured at the output lead ~1/8” from the package. Note 4: Dropout voltage is specified over the full output current range of the device. Note 5: Minimum load current is defined as the minimum output current required to maintain regulation. When (VIN - VOUT) = 12V the device is guaranteed to regulate if the output current is greater than 10mA. Advanced Monolithic Systems, Inc. www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723 AMS1083 APPLICATION HINTS The AMS1083 series of adjustable and fixed regulators are easy to use and have all the protection features expected in high performance voltage regulators: short circuit protection and thermal shut-down. Pin compatible with older three terminal adjustable regulators, these devices offer the advantage of a lower dropout voltage, more precise reference tolerance and improved reference stability with temperature. D1 AMS1083 IN OUT ADJ VIN Stability CADJ 10µF The circuit design used in the AMS1083 series requires the use of an output capacitor as part of the device frequency compensation. The addition of 150µF aluminum electrolytic or a 22µF solid tantalum on the output will ensure stability for all operating conditions. When the adjustment terminal is bypassed with a capacitor to improve the ripple rejection, the requirement for an output capacitor increases. The value of 22µF tantalum or 150µF aluminum covers all cases of bypassing the adjustment terminal. Without bypassing the adjustment terminal smaller capacitors can be used with equally good results. To ensure good transient response with heavy load current changes capacitor values on the order of 100µF are used in the output of many regulators. To further improve stability and transient response of these devices larger values of output capacitor can be used. Protection Diodes Unlike older regulators, the AMS1083 family does not need any protection diodes between the adjustment pin and the output and from the output to the input to prevent over-stressing the die. Internal resistors are limiting the internal current paths on the AMS1083 adjustment pin, therefore even with capacitors on the adjustment pin no protection diode is needed to ensure device safety under short-circuit conditions. Diodes between the input and output are not usually needed. Microsecond surge currents of 50A to 100A can be handled by the internal diode between the input and output pins of the device. In normal operations it is difficult to get those values of surge currents even with the use of large output capacitances. If high value output capacitors are used, such as 1000µF to 5000µF and the input pin is instantaneously shorted to ground, damage can occur. A diode from output to input is recommended, when a crowbar circuit at the input of the AMS1083 is used. Normal power supply cycling or even plugging and unplugging in the system will not generate current large enough to do any damage. The adjustment pin can be driven on a transient basis ±25V, with respect to the output without any device degradation. As with any IC regulator, none the protection circuitry will be functional and the internal transistors will break down if the maximum input to output voltage differential is exceeded. Advanced Monolithic Systems, Inc. VOUT R1 + COUT 150µF R2 Overload Recovery When the power is first turned on, as the input voltage rises, the output follows the input, permitting the regulator to start up into heavy loads. During the start-up, as the input voltage is rising, the input-to-output voltage differential remains small, allowing the regulator to supply large output currents. A problem can occur with a heavy output load when the input voltage is high and the output voltage is low, when the removal of an output short will not permit the output voltage to recover. The load line for such a load may intersect two points on the output current curve. In this case, there are two stable output operating points for the regulator. With this double intersection, the power supply may need to be cycled down to zero and brought up again to make the output recover. Ripple Rejection The ripple rejection values are measured with the adjustment pin bypassed. The impedance of the adjust pin capacitor at the ripple frequency should be less than the value of R1 (normally 100Ω to120Ω) for a proper bypassing and ripple rejection approaching the values shown. The size of the required adjust pin capacitor is a function of the input ripple frequency. If R1=100Ω at 120Hz the adjust pin capacitor should be 25µF. At 10kHz only 0.22µF is needed. The ripple rejection will be a function of output voltage, in circuits without an adjust pin bypass capacitor. The output ripple will increase directly as a ratio of the output voltage to the reference voltage (VOUT / VREF ). Output Voltage The AMS1083 series develops a 1.25V reference voltage between the output and the adjust terminal. Placing a resistor between these two terminals causes a constant current to flow through R1 and down through R2 to set the overall output voltage. www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723 AMS1083 APPLICATION HINTS This current is normally the specified minimum load current of 10mA. Because IADJ is very small and constant it represents a small error and it can usually be ignored. AMS1083 IN OUT ADJ VIN VOUT VREF R1 IADJ 50µA R2 VOUT = VREF (1+ R2/R1)+IADJR2 Figure 1. Basic Adjustable Regulator Load Regulation True remote load sensing it is not possible to provide, because the AMS1083 is a three terminal device. The resistance of the wire connecting the regulator to the load will limit the load regulation. The data sheet specification for load regulation is measured at the bottom of the package. Negative side sensing is a true Kelvin connection, with the bottom of the output divider returned to the negative side of the load. The best load regulation is obtained when the top of the resistor divider R1 is connected directly to the case not to the load. If R1 were connected to the load, the effective resistance between the regulator and the load would be: RP x ( R2+R1 ) , R1 VIN AMS1083 IN OUT ADJ RP = Parasitic Line Resistance Connected as shown, RP is not multiplied by the divider ratio. Using 16-gauge wire the parasitic line resistance is about 0.004Ω per foot, translating to 4mV/ft at 1A load current. It is important to keep the positive lead between regulator and load as short as possible and use large wire or PC board traces. Thermal Considerations The AMS1083 series have internal power and thermal limiting circuitry designed to protect the device under overload conditions. However maximum junction temperature ratings should not be exceeded under continuous normal load conditions. Careful consideration must be given to all sources of thermal resistance from junction to ambient, including junction-to-case, case-to-heat sink interface and heat sink resistance itself. To ensure safe operating temperatures and reflect more accurately the device temperature, new thermal resistance specifications have been developed. Unlike older regulators with a single junction-to-case thermal resistance specification, the data section for these new regulators provides a separate thermal resistance and maximum junction temperature for both the Control Section and the Power Transistor. Calculations for both temperatures under certain conditions of ambient temperature and heat sink resistance and to ensure that both thermal limits are met. Junction-to-case thermal resistance is specified from the IC junction to the bottom of the case directly below the die. This is the lowest resistance path for the heat flow. In order to ensure the best possible thermal flow from this area of the package to the heat sink proper mounting is required. Thermal compound at the case-to-heat sink interface is recommended. A thermally conductive spacer can be used, if the case of the device must be electrically isolated, but its added contribution to thermal resistance has to be considered. RP PARASITIC LINE RESISTANCE R1* RL R2* *CONNECT R1 TO CASE CONNECT R2 TO LOAD Figure 3. Connections for Best Load Regulation Advanced Monolithic Systems, Inc. www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723 AMS1083 TYPICAL PERFORMANCE CHARACTERISTICS Dropout Voltage 0 1 2 3 4 5 6 7 8 OUTPUT CURRENT (A) 9 10 ∆I = 8A 0.05 0 -0.05 -0.10 -0.15 -0.20 -50 -25 Ripple Rejection RIPPLE REJECTION (dB) VRIPPLE≤ 0.5VP-P 60 (VIN-VOUT) ≥ 3V 50 40 (VIN-VOUT)≥VDROPOUT 30 20 IOUT=IFULL LOAD 10 0 100 1k 10k FREQUENCY (Hz) 80 70 60 fR =20kHz VRIPPLE≤ 0.5VP-P 50 40 30 20 -0.2 ~ ~ VOUT = 10V VIN = 13V PRELOAD = 100mA 6 4 2 0 0 50 TIME (µs) 100 INPUT OUTPUT VOLTAGE DEVIATION (V) DEVIATION (mV) LOAD OUTPUT VOLTAGE CURRENT (A) DEVIATION (V) 0 CIN = 1µF COUT = 10µF TANTALUM 8 6 4 2 4 6 0 2 8 10 12 14 INPUT/OUTPUT DIFFERENTIAL (V) Maximum Power Dissipation* Line Transient Response CADJ = 0 -0.4 ~ ~ 8 10 0 0 0.4 0.6 0.8 1.0 0.2 OUTPUT CURRENT (0 TO I FULL LOAD) 100k 150 100 100 90 CADJ = 0 50 80 0 70 -50 -100 -150 14 0 25 50 75 100 125 150 TEMPERATURE (° C) Short-Circuit Current fR = 120Hz VRIPPLE≤ 3VP-P Load Transient Response 0.2 -2.0 -50 -25 12 10 0 0.6 0.4 -1.0 0 25 50 75 100 125 150 TEMPERATURE (° C) 100 90 RIPPLE REJECTION (dB) VRIPPLE≤ 3VP-P 0 Ripple Rejection vs. Current 80 70 1.0 SHORT-CIRCUIT CURRENT (A) 0 2.0 OUTPUT VOLTAGE CHANGE (%) TJ =150° C Temperature Stability 0.10 ~ ~ VOUT = 10V IIN = 0.2A CIN = 1µF TANTALUM COUT = 10µF TANTALUM ~ ~ 13 POWER (W) MINIMUM INPUT/OUTPUT DIFFERENTIAL (V) TJ =25° C 1 OUTPUT VOLTAGE DEVIATION (%) Load Regulation 2 60 50 40 30 20 10 0 12 0 100 TIME (µs) 200 50 60 70 80 90 100 110 120 130 140 150 CASE TEMPERATURE (° C) *AS LIMITED BY MAXIMUM JUNCTION TEMPERATURE Advanced Monolithic Systems, Inc. www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723 AMS1083 TYPICAL PERFORMANCE CHARACTERISTICS (Continued) Adjust Pin Current (Adjustable only) 10 100 9 90 8 ADJUST PIN CURRENT ( µA) MINIMUM OPERATING CURRENT (mA) Minimum Operating Current (Adjustable only) TJ = 150° C 7 6 TJ = 25° C 5 4 3 2 1 0 0 2 4 6 8 10 12 14 INPUT/OUTPUT DIFFERENTIAL (V) 80 70 60 50 40 30 20 10 0 -50 -25 0 25 50 75 100 125 150 TEMPERATURE (° C) PACKAGE DIMENSIONS inches (millimeters) unless otherwise noted. 3 LEAD TO-220 PLASTIC PACKAGE (T) 0.147-0.155 (3.734-3.937) DIA 0.390-0.415 (9.906-10.541) 0.165-0.180 (4.191-4.572) 0.045-0.055 (1.143-1.397) 0.230-0.270 (5.842-6.858) 0.570-0.620 (14.478-15.748) 0.460-0.500 (11.684-12.700) 0.330-0.370 (8.382-9.398) 0.980-1.070 (24.892-27.178) 0.218-0.252 (5.537-6.401) 0.520-0.570 (13.208-14.478) 0.090-0.110 (2.286-2.794) 0.028-0.038 (0.711-0.965) 0.050 (1.270) TYP 0.013-0.023 (0.330-0.584) 0.095-0.115 (2.413-2.921) T (TO-220) AMS DRW# 042193 Advanced Monolithic Systems, Inc. www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723 AMS1083 PACKAGE DIMENSIONS inches (millimeters) unless otherwise noted (Continued). 3 LEAD TO-263 PLASTIC DD (M) 0.060 (1.524) TYP 0.390-0.415 (9.906-10.541) 0.335-0.380 (8.50-9.65) 0.165-0.180 (4.191-4.572) 0.045-0.055 (1.143-1.397) 0.004 +0.008 -0.004 (0.102 +0.203 ) -0.102 0.595-0.615 (15.113-15.621) 0.095-0.115 (2.413-2.921) 0.059 (1.499) TYP 0.090-0.110 (2.286-2.794) Advanced Monolithic Systems, Inc. 0.050 (1.270) TYP 0.050±0.012 (1.270±0.305) 0.013-0.023 (0.330-0.584) www.advanced-monolithic.com M (DD3) AMS DRW# 042191 Phone (925) 443-0722 Fax (925) 443-0723