Advanced Monolithic Systems
FEATURES
• Three Terminal Adjustable or Fixed Voltages 1.5V, 2.5V, 2.85V, 3.0V, 3.3V, 3.5V and 5.0V • Output Current of 3A • Operates Down to 1V Dropout • Load Regulation: 0.1% • Line Regulation: 0.015% • TO-220, TO-263 and TO-252 packages available
AMS1085
3A LOW DROPOUT VOLTAGE REGULATOR
APPLICATIONS
• 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 AMS1085 series of adjustable and fixed voltage regulators are designed to provide 3A output current and to operate The 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 AMS1085 devices are pin compatible with older three-terminal regulators and are offered in 3 lead TO-220 package, 3 and 2 lead TO-263 (Plastic DD) and TO-252 (D PAK) package.
ORDERING INFORMATION:
PACKAGE TYPE 3 LEAD TO-220 AMS1085CT AMS1085CT-1.5 AMS1085CT-2.5 AMS1085CT-2.85 AMS1085CT-3.0 AMS1085CT-3.3 AMS1085CT-3.5 AMS1085CT-5.0 2&3 LEAD TO-263 AMS1085CM AMS1085CM-1.5 AMS1085CM-2.5 AMS1085CM-2.85 AMS1085CM-3.0 AMS1085CM-3.3 AMS1085CM-3.5 AMS1085CM-5.0 TO-252 AMS1085CD AMS1085CD-1.5 AMS1085CD-2.5 AMS1085CD-2.85 AMS1085CD-3.0 AMS1085CD-3.3 AMS1085CD-3.5 AMS1085CD-5.0 OPERATING JUNCTION 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
TO-220 FRONT VIEW TO-252 FRONT VIEW 3 TAB IS OUTPUT 3 2 1 TAB IS OUTPUT 2 1
PIN CONNECTIONS
FIXED VERSION 1- Ground 2- VOUT 3- VIN ADJUSTABLE VERSION 1- Adjust 2- VOUT 3- VIN
2L TO-263 FRONT VIEW 3 2 1 TAB IS OUTPUT
3L TO-263 FRONT VIEW 3 2 1
TAB IS OUTPUT
Advanced Monolithic Systems, Inc.
6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS1085
ABSOLUTE MAXIMUM RATINGS (Note 1)
Power Dissipation Internally limited Input Voltage 15V Operating Junction Temperature Range Control Section 0°C to 125°C Power Transistor 0°C to 150°C Storage temperature - 65°C to +150°C Soldering information Lead Temperature (10 sec) Thermal Resistance TO-220 package TO-263 package TO-252 package 300°C ϕ JA= 50°C/W ϕ JA= 30°C/W * ϕ JA= 100°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
Reference Voltage (Note 2) Output Voltage (Note 2)
Device
AMS1085 AMS1085-1.5 AMS1085-2.5 AMS1085-2.85 AMS1085-3.0 AMS1085-3.3 AMS1085-3.5 AMS1085-5.0
Conditions
IOUT = 10 mA 10mA ≤ IOUT ≤ 3A, 1.5V≤ (VIN - VOUT) ≤ 12V 0 ≤ IOUT ≤ 3A , 3V≤ VIN ≤ 12V 0 ≤ IOUT ≤ 3A , 4V≤ VIN ≤ 12V 0 ≤ IOUT ≤ 3A , 4.35V≤ VIN ≤ 12V 0 ≤ IOUT ≤ 3A , 4.5V ≤ VIN ≤ 12V 0 ≤ IOUT ≤ 3A , 4.75V ≤ VIN ≤ 12V 0 ≤ IOUT ≤ 3A , 5V ≤ VIN ≤ 12V 0 ≤ IOUT ≤ 3A , 6.5V ≤ VIN ≤ 12V ILOAD = 10 mA , 1.5V≤ (VIN - VOUT) ≤ 12V (VIN - VOUT) =3V, 10mA ≤ IOUT ≤ 3A VIN = 5V, 0 ≤ IOUT ≤ 3A VIN = 5V, 0 ≤ IOUT ≤ 3A VIN = 5V, 0 ≤ IOUT ≤ 3A VIN = 5V, 0 ≤ IOUT ≤ 3A VIN = 5V, 0 ≤ IOUT ≤ 3A VIN = 5.25V, 0 ≤ IOUT ≤ 3A VIN = 8V, 0 ≤ IOUT ≤ 3A ∆VOUT , ∆VREF = 1%, IOUT = 3 A (Note 4)
Min
1.238 1.225 1.485 1.470 2.475 2.450 2.82 2.79 2.970 2.940 3.267 3.235 3.465 3.430 4.950 4.900
Typ
1.250 1.250 1.500 1.500 2.500 2.500 2.850 2.850 3.000 3.000 3.300 3.300 3.500 3.500 5.000 5.000 0.3 0.6 0.1 0.2 3 6 3 6 3 6 3 6 3 7 3 6 5 10 1.3
Max
1.262 1.270 1.515 1.530 2.525 2.550 2.88 2.91 3.300 3.360 3.333 3.365 3.535 3.570 5.050 5.100 10 10 .03 .04 12 20 12 20 12 20 12 20 15 25 15 25 20 35 1.5
Units
V V V V V V V V V V V V V V V mV mV % % mV mV mV mV mV mV mV mV mV mV mV mV mV mV V
Line Regulation Load Regulation (Notes 2, 3)
AMS1085/-1.5/-2.5/-2.85/ -3.0/-3.3/-3.5/-5.0 AMS1085 AMS1085-1.5 AMS1085-2.5 AMS1085-2.85 AMS1085-3.0 AMS1085-3.3 AMS1085-3.5 AMS1085-5.0
Dropout Voltage (VIN - VOUT)
AMS1085/-1.5/-2.5/-2.85/ -3.0/-3.3/-3.5/-5.0
Advanced Monolithic Systems, Inc.
6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS1085
ELECTRICAL CHARACTERISTICS
Electrical Characteristics at IOUT = 0 mA, and TJ = +25°C unless otherwise specified. Parameter
Current Limit Minimum Load Current Quiescent Current Ripple Rejection
Device
AMS1085/-1.5/-2.5/-2.85/ -3.0/-3.3/-3.5/-5.0 AMS1085 AMS1085/-1.5/-2.5/-2.85/ -3.0/-3.3/-3.5/-5.0 AMS1085 AMS1085-1.5 AMS1085-2.5 AMS1085-2.85 AMS1085-3.0 AMS1085-3.3 AMS1085-3.5 AMS1085-5.0
Conditions
(VIN - VOUT) = 5V (VIN - VOUT) = 12V (Note 5) VIN ≤ 12V f =120Hz , COUT = 25µF Tantalum, IOUT = 3A, (VIN-VOUT ) = 3V, CADJ =25µF f =120Hz , COUT = 25µF Tantalum, IOUT = 3A, VIN = 4.5V f =120Hz , COUT = 25µF Tantalum, IOUT = 3A, VIN = 5.5V f =120Hz , COUT = 25µF Tantalum, IOUT = 3A, VIN = 6V f =120Hz , COUT = 25µF Tantalum, IOUT = 3A VIN = 6V f =120Hz , COUT = 25µF Tantalum, IOUT = 3A VIN = 6.3V f =120Hz , COUT = 25µF Tantalum, IOUT = 3A VIN = 6.5V f =120Hz , COUT = 25µF Tantalum, IOUT = 3A VIN = 8V TA = 25°C, 30ms pulse 10mA ≤ IOUT ≤ 3A , 1.5V≤ (VIN - VOUT) ≤ 12V 10mA ≤ IOUT ≤ 3A , 1.5V≤ (VIN - VOUT) ≤12V
Min
3.00
Typ
3.50 5 5
Max
4.00 10 10
Units
A mA mA dB dB dB dB dB dB dB dB
60 60 60 60 60 60 60 60
75 72 72 72 72 72 72 68 0.008 55 120 0.2 0.5 5 0.04
Thermal Regulation Adjust Pin Current Adjust Pin Current Change Temperature Stability Long Term Stability RMS Output Noise (% of VOUT ) Thermal Resistance Junction-to-Case
AMS1085 AMS1085 AMS1085
%W µA µA µA %
TA =125°C, 1000Hrs TA = 25°C , 10Hz ≤ f ≤ 10kHz M Package: Control Circuitry/ Power Transistor T Package: Control Circuitry/ Power Transistor
0.3 0.003
1
% %
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.
6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS1085
APPLICATION HINTS
The AMS1085 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 shutdown. 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. Stability The circuit design used in the AMS1085 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 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 AMS1085 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 AMS1085 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 AMS1085 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, wit
