AS2940

AS2940 SIPEX | Alldatasheet

Document overview

• Manufacturer or author: pROVIDED bY alldatasheet.com(free datasheet download site)
• PDF pages: 8

Technical content

Rev. 10/11/00 AS2940 1A Low Dropout Voltage Regulators (PRELIMINARY INFORMATION)

FEATURES

APPLICATIONS

• Output Current 1A • Battery powered Systems
• Internal Short Circuit Current Limit • Cordless Telephones
• Dropout Voltage 0.5V at 1A Output • Automotive Electronics
• Extremely Tight Load and Line Regulation • Portable / Palm Top / Notebook Computers
• Very Low Temperature Coefficient • Portable Consumer Equipment
• Mirror Image Insertion protection • Portable Instrumentation
• Unregulated DC Input Can Withstand -20V Reverse Battery • SMPS Post-Regulator
• and +60V Positive Transients • Voltage Reference
• Direct Replacement For LM2940 Socket PRODUCT DESCRIPTION The AS2940 is a low powered positive voltage regulator. The AS2940 offers 1A output current with dropout voltage of only 0.5V and over temperature dropout is up to 1V. The quiescent current is 30mA at differential output of 5V and output current of 1A. Th e higher quiescent current can be exist when the device is in dropout mode (VIN – VOUT < 3V). Other key additional features of this device includes higher output current, positive transient protection up to 60V (load dump ), and ability to survive an unregulated input voltage transient of -20V below ground (reverse battery). The regulator will automatic ally shut down to protect both the internal circuits and the load. This device also features short circuit and thermal overload protection. The AS2940 is offered in a 3-pin TO-220 and TO-263 package compatible with other 5V regulators. This device offers a variety o f output voltages: 3.3V, 5V and 12V. AS2940 is direct replacement to LM2940.

ORDERING INFORMATION

Oper. Temp. Range AS2940T-X AS2940U-X -40°C to +125°C X= Output Voltage (X = 3.3V, 5.0V) Consult factory for other fixed voltages. PIN CONNECTIONS Top View TO-263-3 (T) AS2940 2 3 Front View TO-220-3 (U) AS2940 123 VIN GND VOUT VIN GND VOUT

Rev. 10/11/00 AS2940 ABSOLUTE MAXIMUM RATINGS ELECTRICAL CHARACTERISTICS VIN = VO + 5V, IO = 1A, CO = 22 µF, unless otherwise specified. Boldface applies over the entire operating temperature range of the indicated device. All other specifications apply for TA = TJ = 25°C. Output Voltage (VO) 5V Units Parameter Conditions Typ AS2940 Limit (Note 5) AS2940 Limit (Note 6) 6.25V < VIN < 26V Output Voltage 5 mA < IO < 1A 5.00 4.85/4.75 5.15/5.25 4.85/4.75 5.15/5.25 V V Line Regulation V O + 2V < VIN < 26V, IO = 5 mA 20 50 40/50 mV Load Regulation 50 mA < IO < 1A AS2940, AS2940/833 AS2940C mV Output Impedance 100 mADC and 20 mArms, f O = 120 Hz mΩ Quiescent Current VO + 2V < VIN < 26V, IO = 5 mA AS2940, AS2940/833 AS2940C mA V IN = VO + 5V IO = 1A 30 45/60 50/ 60 mA Output Noise Voltage

10 Hz - 100 kHz,

IO = 5 mA 150 700/700 µVRMS Ripple Rejection f O = 120 Hz, 1 VRMS, IO = 100 ma AS2940 AS2940C dB MIN f O = 1 kHz, 1 VRMS, IO = 5 mA 60/50 dBMIN Long Term Stability 20 mV/ 1000 Hr I O = 100 mA 110 150/200 150/ 200 mVMAX

Rev. 10/11/00 AS2940 ELECTRICAL CHARACTERISTICS VIN = VO + 5V, IO = 1A, CO = 22 µF, unless otherwise specified. Boldface limits apply over the entire operating temperature range of the indicated device. All other specifications apply for TA = TJ = 25°C. (Continued) Output Voltage (VO) 5V Units Parameter Conditions Typ AS2940 Limit (Note 5) AS2940 Limit (Note 6) 6.25V < VIN < 26V Short Circuit Current (Note 7) 1.9 1.6 1.5/1.3 A Maximum Line Transient RO = 100Ω AS2940, T < 100 ms AS2940/833, T < 20 ms AS2940C, T < 1 ms V Reverse Polarity DC Input Voltage R O = 100Ω AS2940/833, T < 20 ms AS2940C -30 -30 -15/-15 -15 -15/-15 V Reverse Polarity Transient Input Voltage R O = 100Ω AS2940, T < 100 ms AS2940/833, T < 20 ms AS2940C, T < 1 ms -75 -55 -50/-50 -45/-45 -45/-45 V ELECTRICAL CHARACTERISTICS VIN = VO + 5V, IO = 1A, CO = 22 µF, unless otherwise specified. Boldface limits apply over the entire operating temperature range of the indicated device. All other specifications apply for TA = TJ = 25°C. (Continued) Output Voltage (VO) 12V Units Parameter Conditions Typ AS2940 Limit (Note 5) AS2940/883 Limit (Note 6) 13.6V < VIN < 26V Output Voltage 5 mA < IO < 1A 12.00 11.64/11.40 12.36/12.60 11.64/11.40 12.36/12.60 V V Line Regulation V O + 2V < VIN < 26V, IO = 5 mA 20 120 75/120 mV Load Regulation 50 mA < IO < 1A AS2940, AS2940/833 AS2940C 120 mV

Rev. 10/11/00 AS2940 ELECTRICAL CHARACTERISTICS VIN = VO + 5V, IO = 1A, CO = 22 µF, unless otherwise specified. Boldface limits apply over the entire operating temperature range of the indicated device. All other specifications apply for TA = TJ = 25°C. (Continued) Output Voltage (VO) 12V Units Parameter Conditions Typ AS2940 Limit (Note 5) AS2940/833 Limit (Note 6) 13.6V < VIN < 26V Output Impedance 100 mADC and 20 mArms, f O = 120 Hz mΩ Quiescent Current VO +2V < VIN < 26V, IO = 5 mA AS2940, AS2940/883 AS2940C mA V IN = VO + 5V, IO = 1A 30 45/60 50/ 60 mA Output Noise Voltage 10 Hz - 100 kHz, IO = 5 mA 360 1000/1000 µVRMS Ripple Rejection f O = 120 Hz, 1 VRMS, IO = 100 mA AS2940 AS2940C dB f O = 1 kHz, 1 Vrms, IO = 5 mA 52/46 dB Long Term Stability 48 mV/ 1000 Hr I O = 100 mA 110 150/200 150/ 200 mV Short Circuit Current Maximum Line Transient RO = 100Ω AS2940, T < 100 ms AS2940/883, T < 20 ms AS2940C, T < 1 ms V Reverse Polarity DC Input Voltage R O = 100Ω AS2940, AS2940/883 AS2940C -30 -30 -15/-15 -15 -15/-15 V Reverse Polarity Transient Input Voltage R O = 100Ω AS2940, T < 100 ms AS2940/883, T < 20 ms AS2940C, T < 1 ms -75 -55 -50/-50 -45/-45 -45/-45 V

Rev. 10/11/00 AS2940 ELECTRICAL CHARACTERISTICS VIN = VO + 5V, IO =1A, CO = 22 µF, unless otherwise specified. TJ = 25 °C 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 200 400 600 800 1000 OUTPUT CURRENT (mA) INPUT-OUTPUT DIFFERENTIAL (V) Dropout Voltage 500 mA 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 -40 0 40 80 120 160 TEMPERATURE (°C) DROPOUT VOLTAGE (V) Dropout Voltage 1.0 100 mA 1 A 500 mA -40 0 40 80 120 160 TEMPERATURE (°C) QUIESCENT CURRENT (mA) Quiescent Current vs. Temperature 10 mA 1 A 5.08 5.06 5.04 5.02 5.00 4.98 4.96 4.94 4.92 4.90 -40 0 40 80 120 160 TEMPERATURE (°C) OUTPUT VOLTAGE (5V) Output Voltage vs. Temperature 5.10 VIN = VO +5V QUIESCENT CURRENT (mA) Quiescent Current VIN = 14V VO = 5V TJ = 25 °C 180 160 140 120 100 0 5 10 15 20 25 QUIESCENT CURRENT (mA) Quiescent Current 200 30 35 500 mA 100 mA 1 A

Rev. 10/11/00 AS2940 ELECTRICAL CHARACTERISTICS VIN = VO + 5V, IO =1A, CO = 22 µF, unless otherwise specified. -10 -20 -30 - 1 00 1 02 03 04 0 TIME (µµµµs) INPUT VOLTAGE CHANGE (V) Quiescent Current 50 60 ~~ ~~ OUTPUT VOLTAGE DEVIATION (mV) ~~ ~~ - 1 0 0 1 02 03 04 0 TIME (µµµµs) 0.5 1.0 -0.5 -0.4 -0.3 -0.2 -0.1 0.1 0.2 0.3 0.4 0.5 Load Transient Response LOAD CURRENT (A) OUTPUT VOLTAGE DEVIATION (V) VIN = 10V COUT = 22 µF TJ = 25 °C VO = 5V FREQUENCY (Hz) 1 10 100 1k 10k 100k 1M Ripple Rejection RIPPLE REJECTION (dB) VIN = 10V COUT = 22 µF TJ = 10 mA VO = 5V FREQUENCY (Hz) 1 10 100 1k 10k 100k 1M Output Impedance OUTPUT IMPEDANCE (ΩΩΩΩ) VIN = 10V COUT = 22 µF TJ = 50 mA VO = 5V 10.00 5.00 2.00 1.00 0.50 0.20 0.10 0.05 0.02 0.01 AMBIENT TEMPERATURE ( °C) Maximum Power Dissipation (TO-220) POWER DISSIPATION (W) AMBIENT TEMPERATURE ( °C/W) Maximum Power Dissipation (TO-3) POWER DISSIPATION (W) 0 1 02 03 04 05 06 07 08 09 0 1 0 001 0 2 0 3 0 6 0 50 80 70 9040 100 0 0 INFINITE HEAT SINK 10 °C/W HEAT SINK NO HEAT SINK NO HEAT SINK 10 °C/W HEAT SINK INFINITE HEAT SINK AMBIENT TEMPERATURE ( °C) Maximum Power Dissipation (TO-263) (See Note 3) POWER DISSIPATION (W) 0 1 02 03 04 05 06 07 08 09 0 1 0 0 ΘJA = 73 °C/W ΘJA = 50 °C/W ΘJA = 37 °C/W ΘJA = 32 °C/W

Rev. 10/11/00 AS2940 ELECTRICAL CHARACTERISTICS VIN = VO + 5V, IO =1A, CO = 22 µF, unless otherwise specified. Low Voltage Behavior INPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1.0 2.0 3.0 4.0 5.0 IO = 1A TJ = 25 °C VO = 5V Low Voltage Behavior INPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1086420 IO = 1A TJ = 25 °C VO = 8V 12 14 Low Voltage Behavior INPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1291 8630 IO = 1A TJ = 25 °C VO = 9V Low Voltage Behavior INPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1291 8630 IO = 1A TJ = 25 °C VO = 10V Low Voltage Behavior INPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1086420 IO = 1A TJ = 25 °C VO = 12V 12 14 Low Voltage Behavior INPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1291 8630 IO = 1A TJ = 25 °C VO = 15V Output at Voltage Extremes INPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 20100-10-20-30 RL = 100 Ω VO = 5V 30 40 Output at Voltage Extremes INPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 20100-10-20-30 RL = 100 Ω VO = 8V 30 40 Output at Voltage Extremes INPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 20100-10-20-30 RL = 100 Ω VO = 9V 30 40 Output at Voltage Extremes INPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 20100-10-20-30 RL = 100 Ω VO = 10V 30 40 Output at Voltage Extremes INPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 20100-10-20-30 RL = 100 Ω VO = 12V 30 40 Output at Voltage Extremes INPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 20100-10-20-30 RL = 100 Ω VO = 15V 30 40 TEMPERATURE ( °C) Peak Output Current OUTPUT CURRENT (A) 3.0 -40 0 40 80 120 160 1.0 2.0 V IN = 14V Output Capacitor ESR OUTPUT CURRENT (mA) EQUIVALENT SERIES RESISTANCE ( ΩΩΩΩ) 10008006004000 200 0.01 0.1 100 COUT = 22 µF VO = 5V STABLE REGION

Rev. 10/11/00 AS2940 APPLICATION HINTS External Capacitors A minimum capacitance of 22 µF and conditions on ESR (Equivalent Series Resistance) must be met. The minimum value for the capacitance is 22µF and can be increased without limit. However the ESR may cause loop instability if it is too high or too low. The following graph shows the acceptable range for the ESR. If the capacitor does not meet these requirements oscillation can result. ESR is specified only at room temperature. Therefore the designer must ensure the proper behavior of the ESR over the temperat ure range. ESR, for electrolytic capacitor, will increase by about 30X as the temperature is reduced from 25 °C to -40 °C. Aluminum electrolytic capacitors are not well suited for low temperature operation. Solid tantalum capacitors’ ESR are more stable over temperature, but expensive. A cost-effective approach is then to put in pa rallel a solid tantalum and a aluminum electrolytic capacitors in the ratio25/75%. Thermal Consideration Although the AS2940 offers some limiting circuitry for overload conditions, it is n ecessary not to exceed the maximum junction temperature, and therefore to be careful about thermal resistance. The heat flow will follow the lowest resistance path, which is the Junction- to-case thermal resistance. In order to insure the best thermal flow of the component, a proper mounting is required. Note that the case of the device is electrically connected to th e output. In case the case has to be electrically isolated, a thermally conductive sp acer can be used. However do not forget to consider its contribution to thermal resistance. Formulas for calculating the power dissipated in the regulator are the following: I IN = IL + IG P D = (VIN + VOUT) * IL + VIN * IG Where I IN is the input current, I L is the load current, I G is the ground current, P D is the power dissipated, V IN is the input voltage and V OUT is the output voltage. Output Capacitor ESR OUTPUT CURRENT (mA) EQUIVALENT SERIES RESISTANCE ( ΩΩΩΩ) 10008006004000 200 0.01 0.1 100 COUT = 22 µF VO = 5V STABLE REGION