S5ULM2596 Simple Switcher Power Converter Elektronische Bauelemente 150KHz 3A Step-Down Voltage Regulator Description The S5ULM2596 series of regulators are monolithic integrated circuits that provide all active functions for a step-down (buck) switching regulator, capable of driving 3A load with excellent line and load regulation. These devices are available in fixed output voltage of 3.3V,5V,12V and an adjustable output version.Requiring a min. rumber of external components, these regulators are simple to use and include internal frequency components and a fixedfrequency oscillator. The S5ULM2596 series operates at a switching frequency of 150KHz thus allowing smaller sized filter components than what would be needed with lower frequency switching requlators. Available in a standard 5-lead TO-263 package with several different lead bend options. A standard series if inductors are available from several differnet manufactures optimized for use with the S5ULM2596 series.The feature greatly simplifies the design of switching-mode power supplies. Other feature include a guaranteed ± 4% to tolerance on output voltage within specified input voltages and output load condition, and ±15% on the oscillator frequency. External shutdown is included, featuring 80uA(Typ.) standby current. The output switch includes cycle-by-cycle current limiting, as well as thermal shutdown for full protection under fault condition. Features REF. A b L4 c L1 E Millimeter Min. 4.40 0.66 0.00 0.36 2.29 9.80 REF. Max. 4.80 c2 0.91 L2 0.30 B D 0.5 e 2.79 L 10.4 Millimeter Min. Max. 1.25 1.45 1.27 REF. 8.6 9.0 1.70 REF. 14.6 15.8 0˚ 8˚ * High Efficiency * Input Voltage Range Up To 40V * 150KHz Fixed Frequency Oscillator * 3.3V,5V,12V and Adjustable Output Versions * Uses Readily Available Standard Inductors * TTL Shutdown Capability, Low Power Standby Mode * Thermal Shutdown And Current Limit Protection * Guaranteed 3A Output Current * Efficient Per-regulator For Linear Regulators * Requires Only 4 Extermal Components * Adjustable Version Output Voltage Range, 1.2V to 37V ± 4% Max. Over Line And Load Conditions Applications * Positive To Negative Converter * Simple High-Effciency Step-Down (Buck) Regulator * http://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A Any changing of specification will not be informed individual Page 1 of 8 S5ULM2596 Simple Switcher Power Converter Elektronische Bauelemente 150KHz 3A Step-Down Voltage Regulator Typical Application (Fixed Output Voltage Version) GND Description 12V Unregulated DCInput Input DC Typically a large storage capacitor is connected from this pin to ground to insure that the input S5ULM2596-5.0 1.3V 33 tage does not sag below the minimum dropout voltage during the load 1N5824 V higher than220 Vout in order for the device to 680 NC or open= output enable. 680 Block Diagram FEEDBACK Pin Function Pin Name PIN# FUNCTION This is the positive input supply 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 current needed by regulator. Internal switch. The voltage at this pin switches between (+VIN – V SAT) and approximately -0.5V, with a duty cycle of approximately VOUT/V IN. To minimize coupling to sensitive circuit, the PC board copper area connected to this pin should be keep to a minimum. +VIN 1 Output 2 Ground Feedback 3 Circuit ground 4 Senses the regulated output voltage to complete the feedback loop 5 Allows the switching regulator circuit to be shutdown using logic level signals thus dropping the total input supply current to approximately 80 uA. Pulling this pin below a threshold voltage of approximately 1.3V turns the regulator on, and pulling this pin above 1.3V (up to a maximum of 25V) shuts the regulator down. If this shutdown feature is not needed, ON/OFF pin can be wired to the ground pin or it can be left open, in either case the regulator will be in the ON condition. ON/OFF http://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A Any changing of specification will not be informed individual Page 2 of 8 S5ULM2596 Simple Switcher Power Converter Elektronische Bauelemente 150KHz 3A Step-Down Voltage Regulator Absolute Maximum Ratings (Note1) Parameter Ratings 45 -0.3 V +25 -0.3 V +25 -1 Internally Limited -65 ~ +150 +150 2k +260 Maximum Supply Voltage ON/OFF pin input Voltage Feedback pin Voltage Output Voltage to ground (steady state) Power dissipation Storage Temperature Maximum junction temperature Minimum ESD rating (C=100pF, R=1.5k ) Lead temperature (soldering, 10seconds) Operating Ratings Parameter Ratings -40 TJ +125 4.5 ~ 40 Temperature range Supply Voltage Unit V V V V V Unit V S5ULM2596-3.3 Electrical Characteristics Specifications with standard type face are for TJ=25 Parameter Symbol , and those with boldface type apply over full operating temperature range Conditions System Parameters (Note5) Test Circuit Figure 2 4.75V VIN 40V Output Voltage VOUT 0.2A ILOAD 3A Efficiency VIN=12V, ILOAD=3A (Note4) Min (Note3) Typ (Note4) Max Unit 3.168/3.135 3.3 3.432/3.465 V 73 % S5ULM2596-5.0 Electrical Characteristics Specifications with standard type face are for TJ=25 Parameter Symbol , and those with boldface type apply over full operating temperature range Conditions System Parameters (Note5) Test Circuit Figure 2 7V VIN 40V Output Voltage VOUT 0.2A ILOAD 3A Efficiency VIN=12V, ILOAD=3A (Note4) Min (Note3) Typ (Note4) Max Unit 4.80/4.75 5.0 5.20/5.25 V 80 % S5ULM2596-12 Electrical Characteristics Specifications with standard type face are for TJ=25 Parameter Symbol , and those with boldface type apply over full operating temperature range Conditions System Parameters (Note5) Test Circuit Figure 2 15V VIN 40V Output Voltage VOUT 0.2A ILOAD 3A Efficiency VIN=15V, ILOAD=3A (Note4) Min (Note3) Typ (Note4) Max Unit 11.52/11.40 12 12.48/12.60 V 90 % S5ULM2596 Electrical Characteristics Specifications with standard type face are for TJ=25 Parameter Symbol , and those with boldface type apply over full operating temperature range Conditions System Parameters (Note5) Test Circuit Figure 2 4.5 VIN 40V, 0.2A ILOAD 3A Output Voltage VOUT VOUT=3V, Circuit of Figure 2 Efficiency VIN=12V, ILOAD=3A, VOUT=3V h tp://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A (Note4) Min (Note3) Typ (Note4) Max Unit 1.193/1.180 1.230 1.267/1.280 V 77 % Any changing of specification will not be informed individual Page 3 of 8 S5ULM2596 Simple Switcher Power Converter Elektronische Bauelemente 150KHz 3A Step-Down Voltage Regulator All Output Voltage Version Electrical Characteristics Specifications with standard type face are for TJ=25 , and those with boldface type apply over full operating temperature range. Unless otherwise specified, VIN=12V for the 3.3V, 5.0V and Adjustable versions, VIN=24V for 12V version. ILOAD=0.5A Parameter Symbol Ib Feedback bias current Oscillator frequency Saturation voltage Min Conditions VFB=1.3V (adjustable version only) (Note4) (Note3) Typ (Note4) Max Unit 127/110 10 50/00 nA 150 1.16 173/173 1.4/1.5 kHz V fO VSAT (Note 6) ILOAD=3A (Note 7, 8) - Maximum duty cycle (ON) DC (Note 8) (Note 9) - 100 0 - % Current limit ICL Output leakage current IL Peak Current (Note 7, 8) Output=0V(Note 7, 9) Output=-1V (Note 10) Quiescent current Standby quiescent current IQ 3.6/3.4 - 4.5 2 5 6.9/7.5 50 30 10 A uA mA mA - 80 200/250 uA (OFF) (Note 9) ISTBY ON/OFF pin=5V (OFF)(Note 10) Thermal Resistance JC Junction to Case - 2 - JA Junction to Ambient (Note 11) - 50 - - 1.3 - 2.0 - 0.6 - /W ON/OFF Control Test Circuit Figure 2 ON/OFF pin logic input Threshold Voltage VIH VIL Low (Regulator ON) High (Regulator OFF) ON/OFF pin input IH VLOGIC=2.5V ( Regulator OFF) - 5 15 current IL VLOGIC=0.5V ( Regulator ON) - 0.02 5 V uA Note 1: Absolute Maximum Rating indicate limits beyond which damage to the device may occur. Operating Rating indicate conditions for which the device is intended to be functional, but do not guaranteed specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. Note 2: The human body mode is a 100pF capacitor discharged through a 1.5k Note 3: Typical number are at 25 and represent the most likely norm. resistor into each pin. Note 4: All limits guaranteed at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature limits are 100% production tested. All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality Control (SQC) method. All limits are used to calculate Average Outgoing Quality Level (AOQL). Note 5: External component such as the catch diode, inductor, input and output capacitors, and voltage programming resistor can affect switching regulator system performance. When the G5ELM2596 is used as shutdown in the Figure 1 test circuit, system performance will be as shown in system parameters section of Electrical Characteristics. Note 6: The switching frequency is reduced when the second stage current limit is activated. The amount of reduction is determined by the severity of current over-load. Note 7: No diode, inductor or capacitor connected to output pin. Note 8: Feedback pin removed from output and connected to 0V to force the output transistor switch ON. Note 9: Feedback pin removed from output and connected to 12V for the Adjustable, 3.3V and 5V versions, and 15V for the 12V version, to force the output transistor switch OFF. Note 10: VIN=40V. Note 11: Junction to ambient thermal resistance (no external heat sink) for To-220 package mounted vertically, with the leads soldered to a 2 printed circuit board with (1 oz.) copper area of approximately 1 in . http://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A Any changing of specification will not be informed individual Page 4 of 8 S5ULM2596 Elektronische Bauelemente Simple Switcher Power Converter 150KHz 3A Step-Down Voltage Regulator Typical Performance Characteristics (circuit of Figure 2) http://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A Normalized Output Voltage Line Regulator Efficiency Switch Saturation Voltage Switch Current Limit Dropout Voltage Any changing of specification will not be informed individual Page 5 of 8 S5ULM2596 Elektronische Bauelemente Simple Switcher Power Converter 150KHz 3A Step-Down Voltage Regulator Description GND Typically a large storage capacitor is connected from this pin to ground to insure that the input 1.3V or open= output enable. tage does not sag below the minimum dropout voltage during the load V higher than Vout in order for the device to NC Operating Quiescent Current Shutdown Quiescent Current Minimum Operating Supply Voltage ON/OFF Threshold Voltage ON/OFF Pin Current (Sinking) Switching Frequency http://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A Any changing of specification will not be informed individual Page 6 of 8 S5ULM2596 Elektronische Bauelemente Feedback Pin Bi Simple Switcher Power Converter 150KHz 3A Step-Down Voltage Regulator as Current /div Horizontal Time Base: 2 s Continuous Mode Switching Waveforms Horizontal Time Base: 2 s Discontinuous Mode Switching Waveforms /div Horizontal Time Base: /div Horizontal Time Base: 100 s Load Transient Response for Continuous Mode Horizontal Time Base: 200 s/div h tp://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A Load Transient Response for Discontinuous Mode Any changing of specification will not be informed individual Page 7 of 8 S5ULM2596 Elektronische Bauelemente Simple Switcher Power Converter 150KHz 3A Step-Down Voltage Regulator Test Circuit and layout Guidelines As in any switching regulator, layout is very important. Rapidly switching currents associated with wiring inductance generate voltage transients which can cause problems. For minimal inductance and ground loops, the wires indicated by heavy lines should be wide printed circuit traces and should be kept as short as possible. For best results, external components should be located as close to the switcher IC as possible using ground plane construction or single point grounding. If open core inductors are used, special care must be taken as to the location and positioning of this type of inductor. Allowing the inductor flux to intersect sensitive feedback, IC groundpath and COUT wiring can cause problems. When using the Adjustable version, special care must be taken as to the location of the feedback resistors and the associated wiring. Physically locate both resistors near the IC, and route the wiring away from the inductor, especially an open core type of inductor. S5ELM2596 Cin-- 470uF, 50V, Aluminum Electrolytic Cout-- 220uF, 25V Aluminum Electrolytic D1-- 5A, 40V Schottky Rectifer, 1N5825 L1-- 68uH S5ELM2596 Vout=VREF*(1+R2/R1) Where VREF=1.23V R2=R1*(Vout/VREF-1) Select R1 to be approximately 1k , use a 1% resistor for best stability. Cin-- 470uF, 50V, Aluminum Electrolytic Cout-- 220uF, 35V Aluminum Electrolytic D1-- 5A, 40V Schottky Rectifer, 1N5825 L1-- 68uH Figure 2 Standard http://www.SeCoSGmbH.com/ 01-Jun-2002 Rev. A Test Circuits and Layout Guides Any changing of specification will not be informed individual Page 8 of 8