AIC2511 3A STEP-DOWN PWM CONVERTER FEATURES GENERAL DESCRIPTION Operating Input Voltage From 4.5V to 24V The AIC2511 series are step-down monolithic 3.3V, 5V, 12V and Adjustable Output Version PWM converters for delivering 3A at fixed Adjustable Version Output Voltage Range, 1.25V to 24V ± 4% max Over Line and Load Regulation voltages of 3.3V, 5.0V, 12V and using an external divider to adjust output voltage from 1.25V to 24V with excellent line and load Available in TO-263-5, TO-220-5, TO-220B and TO-252-5 Package regulation. Requires Only 4 External Components. Switching 150KHz Fixed Constant Frequency achievable thus allowing smaller-sized filter Low Power Standby Mode, IQ Typically 80µA components. Internal current limit and thermal shutdown TTL Shutdown Capability. Current Limit Protection. and Thermal frequency circuits overloads. Shutdown The up to provide internal 150KHz protection precise is from reference combined with voltage feedback loop provides optimum output voltage accuracy and fast load 3A Guaranteed Output Load Current transient response. APPLICATIONS Fixed Voltage power supply for LCD Monitor and LCD TV On-Card Switching regulators Simple High Efficiency Step-down regulator TYPICAL APPLICATION CIRCUIT AIC2511 VIN 1 + OUT IN VOUT 2 L1 C1 5 ON/OFF FB D1 4 C2 + CF R1 GND 3 C1: electrolyte capacitor 470uF C2: electrolyte capacitor 220uF CF:refer to table1 D1: SK54 L1:33uH Analog Integrations Corporation R2 R1 short, R2 and CF open for fixed version 3A1, No.1 Li-Hsin Rd. I, Science Park, Hsinchu 300, Taiwan TEL: 886-3-5772500 FAX: 886-3-5772510 www.analog.com.tw DS-2511P-02 071607 1 AIC2511 ORDERING INFORMATION AIC2511- XXXXXXX ORDER NUMBER PACKING TYPE TR: TAPE & REEL TB: TUBE PACKAGE TYPE M5: TO-263-5 T5 : TO-220-5 B5 : TO-220B E5 : TO-252-5 P: Lead Free Commercial OUTPUT VOLTAGE DEFAULT : Adj 33 : 3.3V 50 : 5.0V 12 : 12.0V AIC2511PM5 AIC2511-33PM5 AIC2511-50PM5 AIC2511-12PM5 AIC2511PT5 AIC2511-33PT5 AIC2511-50PT5 AIC2511-12PT5 AIC2511PB5 AIC2511-33PB5 AIC2511-50PB5 AIC2511-12PB5 AIC2511PE5 AIC2511-33PE5 AIC2511-50PE5 AIC2511-12PE5 PIN CONFIGURATION TO-263-5 FRONT VIEW 1: IN 2. OUT 3. GND 4. FB 5. ON/OFF TO-220-5 FRONT VIEW 1: IN 2. OUT 3. GND 4. FB 5. ON/OFF TO-220B FRONT VIEW 1: IN 2. OUT 3. GND 4. FB 5. ON/OFF TO-252-5 1: IN 2. OUT 3. GND 4. FB 5. ON/OFF 12 3 4 5 1 2 3 4 5 1 2 3 4 5 12345 Example: AIC2511-50PM5TR 5.0V Output Version, in Lead Free TO-263-5 Package & Taping & Reel Packing Type AIC2511-33PB5TR 3.3V Output Version, in Lead Free TO-220B Package & Taping & Reel Packing Type 2 AIC2511 ABSOLUTE MAXIMUM RATINGS Supply Voltage 24V FB, ON/OFF Pin Input Voltage -0.3V to 24V Operating Temperature Range -40°C ~ 85°C Storage Temperature Range –65°C ~ 150°C Junction Temperature 125°C Lead Temperature (Soldering 10sec.) 260°C Thermal Resistance Junction to Case TO-263-5, TO-220-5, TO-220B 3°C /W TO-252-5 12.5°C /W Thermal Resistance Junction to Ambient TO-263-5 60°C /W (Assume no ambient airflow, no heatsink) TO-220-5, TO-220B 50°C /W TO-252-5 100°C /W Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. 3 AIC2511 ELECTRICAL CHARACTERISTICS (TA=25°C, VIN=12V for the 3.3V, 5V and Adjustable version and VIN=24V for the 12V version.) (Note1) PARAMETER TEST CONDITIONS MAX. UNIT 4.5 24 V AIC2511-ADJ (VIN > 4.5V) 1.193 1.267 V AIC2511-33 (VIN > 4.75V) 3.168 3.432 V AIC2511-50 (VIN > 7.0V) 4.800 5.200 V AIC2511-12 (VIN > 15V) 11.52 12.48 V 1.4 V 4 % Input Voltage Fixed Output Voltage MIN. Saturation Voltage TYP. 1.2 Output Voltage Regulation Quiescent Current Internal switch off 5 10 mA Shutdown Quiescent Current ON/OFF= 5V (OFF) 80 200 µA FB bias current VFB=1.3 10 50 nA Output leakage current Vout=-0.9 2 30 mA Logic Input High (Regulator OFF) Logic Input Low (Regulator ON) 2.0 Oscillator Frequency 130 Output Current Limit 3.6 Maximum Duty Cycle 100 Minimum Duty Cycle Efficiency Vo=5V, Io=3A V 150 0.6 V 180 KHz 5.5 A % 0 % 80 % Note 1: Specifications are production tested at TA=25°C. Specifications over the -40°C to 85°C operating temperature range are assured by design, characterization and correlation with Statistical Quality Controls (SQC). 4 AIC2511 TYPICAL PERFORMANCE CHARACTERISTICS 85 90 80 70 75 65 70 60 65 55 50 45 40 35 30 25 VOUT=5.0V version 80 Efficiency (%) Efficiency (%) 85 VOUT=3.3V version 75 Vin=5V Vin=12V 60 55 50 Vin=12V 45 Vin=18V 40 Vin=18V Vin=24V 35 Vin=24V 30 20 25 10 100 1000 10 100 Load current (mA) Fig.1 3.3V version efficiency Fig.2 5V version efficiency 90 95 85 90 VOUT=12.0V version o Case Tempearature ( C) Efficiency (%) 80 75 70 Vin=18V 65 60 Vout=12V 80 85 Vin=24V 55 75 Vout=5.0V 70 65 60 Vout=3.3V 55 50 45 40 50 IOUT=3A TO-263-5 35 30 45 10 100 4 1000 8 12 20 24 Fig.4 Case temperature vs. input voltage 6.8 190 6.4 180 6.0 170 5.6 Current Limit (A) 200 160 150 140 130 120 5.2 4.8 4.4 4.0 3.6 3.2 110 100 -60 16 Input Voltage (V) Load current (mA) Fig.3 12V version efficiency Switching Frequency (kHz) 1000 Load current (mA) -40 -20 0 20 o 40 60 80 TJ( C) Fig.5 Switching Frequency vs. Temperature 100 2.8 -60 -40 -20 0 20 40 60 80 100 Current Limit vs. Temperature Fig.6 Current Limit vs. Temperature 5 AIC2511 TYPICAL PERFORMANCE CHARACTERISTICS (Continued) 1.6 1.5 1.5 1.4 1.4 Saturation Voltage (volt) 1.6 Dropout Voltage (vlot) 1.3 3A 1.2 1.1 1.0 0.9 1A 0.8 0.7 1.3 o -40 C 1.2 o 25 C 1.1 o 100 C 1.0 0.9 0.8 0.7 0.6 0.6 0.5 -60 -40 -20 0 20 40 60 80 100 120 140 0.0 0.5 1.0 1.5 o 2.0 2.5 3.0 3.5 4.0 4.5 Switch Current (A) TJ ( C) Fig.7 Dropout Voltage vs. Temperature Fig.8 Switching Saturation Voltage vs. Switch Current 2.5 5.0 2.0 Minimum Supply Voltage (volt) ON/OFF threshold voltage (volt) 4.8 OFF 1.5 1.0 ON 0.5 4.6 VFB=1.23V 4.4 ILOAD=120mA 4.2 4.0 3.8 3.6 3.4 3.2 3.0 0.0 2.8 -60 -40 -20 0 20 40 60 80 100 120 140 -60 -40 -20 o 0 20 40 60 80 100 120 140 o TJ ( C) TJ ( C) Fig.9 ON/OFF Threshold Voltage vs. Temperature Fig.10 Minimum Operating Supply Voltage vs. Temperature (ADJ only) 2.0 VIN=24V o o -40 C<TJ<125 C 1.5 3A IOUT Current (µA) 0.1A 1.0 0.5 VOUT 100mV/div VIN=12V VOUT=5V 0.0 0 5 10 15 20 25 ON/OFF Pin Voltage (Volt) Fig.11 ON / OFF Pin Current (sinking) vs. Temperature Fig.12 Load transient response 6 AIC2511 TYPICAL PERFORMANCE CHARACTERISTICS (Continued) Fig.13 FB Pin Ripple(CCM) Fig.14 FB Pin Ripple(DCM) BLOCK DIAGRAM SHDN IN 1.23 V Reference 2.6V Regulator ON / OFF FB Current Limit COMP. AMP. COMP. Compensation Latch Driver Circuit OUT 150KHz Thermal OSC Shutdown GND 7 AIC2511 PIN DESCRIPTIONS PIN 1: IN PIN 2: OUT PIN 3: GND Supply voltage input for the IC switching regulator. A suitable input bypass capacitor must be present at this pin to minimize voltage transients and to supply the switching currents needed by the regulator. Internal switch. The voltage at this pin switches between (VIN-VSAT) and approximately -0.5V, with a duty cycle of approximately VOUT/VIN. Ground requires a short, low noise connection to ensure good load regulation. PIN 4: FB Feedback input for fixed-output or adjustable-output version. Connect directly to output for fixed operation version or to a resistor divider for adjustable operation versions. PIN 5: ON / OFF Allows the switching regulator circuit to be shutdown using logic level signals thus dropping the total input supply current to approximately 80µA. Drive it high to disable the reference, control circuitry and internal switches. Drive low or connect to GND for normal operation. APPLICATION INFORMATION Thermal considerations The AIC2511 is available with TO-220-5, TO220B, TO-263-5 and TO-252-5 packages. The TO-220-5 and TO-220B packages need a heat sink in most conditions. The TO-263-5 and TO252-5 packages are designed to be soldered to the copper on a printed circuit board. The printed circuit board is the heat sink for TO-263-5 and TO-252-5 packages and other heat components, such as inductors and diodes. The size of the heat sink depends on the power loss of AIC2511 and the ambient temperature. The power loss of AIC2511 is determined by input voltage, output voltage and load current. The Fig.4 represents the curve of the AIC2511 case temperature in different conditions. The curve shows the AIC2511 temperature rises above ambient temperature for a 3A load with different input and output voltage. The values of the temperature rise, which are affected by factors such as sink size, heat produced from heat components, and etc., may be different from those in Fig.8 depending on the conditions of the application. According to the equation 1, as the power loss or ambient temperature is rising the heat sink size must be increased to decrease the thermal resistance ( Rθ jA ) so that the junction temperature does not over 125۫ C. An appropriate increase of heat sink size may result in a normalranged junction temperature. PD = T j − TA Rθ jA As junction temperature rises to its temperature protect point, the AIC2511 will stop working. Output voltage drops to zero until the junction temperature decreases to a normal range. 8 AIC2511 APPLICATION INFORMATION (Continued) Components Selection Inductor The inductor selection depends on the operating frequency of the AIC2511. The ripple current ∆IL interrelates with inductor value. A lower inductor value gets a higher ripple current. Besides, a higher VIN or VOUT can also get the same result. The inductor value can be calculated as the following formula. ⎛ V ⎞ 1 L= VOUT ⎜⎜1 − OUT ⎟⎟ (f )(∆IL ) VIN ⎠ ⎝ Users can define the acceptable ∆IL to gain a suitable inductor value. Diode The diode current rating must be higher than 1.3 times maximum load current. Also, if the power supply needs to resist a continuous output short, the diode should have a current ration equal to the maximum current limit of the AIC2511. The reverse voltage rating of the diode should be higher than 1.25 times input voltage and the diode must be fast. The reverse recovery time of the diode is short. Capacitor The selection of output capacitor depends on the suitable ripple voltage. Lower ripple voltage corresponds to lower ESR (Equivalent Series Resistor) of output capacitor. Typically, once the ESR is satisfied with the ripple voltage, the value of capacitor is adequate for filtering. The formula of ripple voltage is as below: ⎛ 1 ⎞ ⎟ ∆VOUT = ∆IL ⎜⎜ ESR + 8fC OUT ⎟⎠ ⎝ The typical input capacitor is 470uF. But as the temperature decreases, the input capacitor needs to increase to stabilize the circuit. Assume the input voltage is 12V, output voltage is 5V and maximum load current is 3A. The output ripple must be smaller than 2% of output voltage Inductor selection L= = ⎛ V 1 VOUT ⎜⎜1 − OUT ( f )(∆I L ) V IN ⎝ ⎞ ⎟⎟ ⎠ 1 5⎞ ⎛ × 5 × ⎜1 − ⎟ = 32.4uH 150k × 0.6 ⎝ 12 ⎠ Here, the delta IL is 0.6A. So we choose 33uH inductor. Output capacitor selection ⎛ 1 ∆VOUT = ∆I L ⎜⎜ ESR + 8 fC OUT ⎝ ⎞ ⎟⎟ < 100mV ⎠ We choice the capacitor value: ESR=0.12, capacitance=220uF ⎛ 1 ⎞ ⎟ = 74mV < 100mV ⇒ ∆VOUT = ∆I L ⎜⎜ ESR + 8 fCOUT ⎟⎠ ⎝ The full load is 3A and delta IL is 0.6A, so the diode current rating must be higher than 3.6A. CF Capacitor for adj version As using the AIC2511 adj version, the CF capacitor is required to provide additional stability. In different condition, the CF capacitor must be changed to make the circuit stable. Output Input Voltage (V) Voltage (V) R1 (Ω) R2 (Ω) CF (pF) 1.8 7 36k 82k 1000 4 12 180k 82k 360 6 12 180k 47k 360 8 15 180k 33k 360 10 18 150k 22k 470 15 25 110k 10k 560 Table 1 Example 9 AIC2511 PHYSICAL DIMENSIONS (unit: mm) TO-263-5 A c2 S Y M B O L H D L1 E TO-263-5L MILLIMETERS A 4.06 4.83 A1 0.00 0.25 b 0.51 0.99 c 0.38 0.74 1.65 c2 1.14 D 8.38 9.65 E 9.65 10.67 e A A e SEE VIEW B b c WITH PLATING BASE METAL SECTION A-A MAX. MIN. 1.70 BSC H 14.61 L 1.78 2.79 L1 -- 1.68 0.25 BSC L3 q 15.88 0° 8° θ L VIEW B SEATING PLANE A1 L3 GAUGE PLANE Note: 1. Refer to JEDEC TO-263BA. 2. Dimension "E" does not include mold flash, protrusions or gate burrs. Mold flash, protrusion or gate burrs shall not exceed 6 mil per side . 3. Dimension "D" does not include inter-lead flash or protrusions. 4. Controlling dimension is millimeter, converted inch dimensions are not necessarily exact. 10 AIC2511 PHYSICAL DIMENSIONS(Continued) (unit: mm) TO-220B A E E1 S Y M B O L F d E1 D φ TO-220B MILLIMETERS MIN. MAX. A 4.318 4.826 A1 4.250 4.550 A2 8.250 8.550 b 0.690 0.940 C 0.304 0.530 3.556(REF) D D1 D1 b e1 9.300 2.743(REF) d L1 L e 8.480 E 9.906 10.44 E1 4.953 5.220 φ 3.708 3.962 e 1.524 2.032 e1 6.604 7.112 F 1.143 1.397 L 9.880 10.64 L1 9.090 9.850 C A1 A2 Note : Controlling dimension is millimeter, converted inch dimensions are not necessarily exact. 11 AIC1595 PHYSICAL DIMENSIONS(Continued) (unit: mm) TO-220-5L E A E1 S Y M B O L F d E1 L D1 D φ e b TO-220-5L MILLIMETERS MIN. MAX. A 4.064 4.826 A1 2.032 2.921 b 0.635 1.016 C 0.304 0.460 D 3.429 3.683 D1 7.620 9.398 d 2.620 2.870 E 9.779 10.668 E1 4.953 5.220 φ 3.708 3.962 e 1.524 2.032 F 1.143 1.397 L 13.589 14.351 C A1 Note : Controlling dimension is millimeter, converted inch dimensions are not necessarily exact. 12 AIC1595 PHYSICAL DIMENSIONS(Continued) (unit: mm) TO-252-5 A E L3 H D e S Y M B O L c2 b3 A A TO-252-5L MILLIMETERS MAX. MIN. A 2.19 2.38 A1 0.00 0.13 b 0.51 0.71 b3 4.32 5.46 c 0.46 0.61 c2 0.46 0.89 D 5.33 6.22 E 6.35 e 6.73 1.27 BSC SEE VIEW B H 9.40 10.41 b L 1.40 1.78 c WITH PLATING BASE METAL SECTION A-A L1 2.67 REF L2 0.51 BSC L3 0.89 2.03 θ 0° 8° θ GAUGE PLANE SEATING PLANE L1 A1 L2 L VIEW B Note: 1. Refer to JEDEC TO-252AD and AB. 2. Dimension "E" does not include mold flash, protrusions or gate burrs. Mold flash, protrusion or gate burrs shall not exceed 6 mil per side . 3. Dimension "D" does not include inter-lead flash or protrusions. 4. Controlling dimension is millimeter, converted inch dimensions are not necessarily exact. Note: Information provided by AIC is believed to be accurate and reliable. However, we cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AIC product; nor for any infringement of patents or other rights of third parties that may result from its use. We reserve the right to change the circuitry and specifications without notice. Life Support Policy: AIC does not authorize any AIC product for use in life support devices and/or systems. Life support devices or systems are devices or systems which, (I) are intended for surgical implant into the body or (ii) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 13