●SI-8000S Series SI-8000S Series Full-Mold, Separate Excitation Switching Type ■Features • • • • • • • • Compact full-mold package (equivalent to TO220) Output current: 3.0A High efficiency: 79 to 91% Requires only 4 external components Phase correction and output voltage adjustment performed internally Built-in reference oscillator (60kHz) Built-in overcurrent and thermal protection circuits Built-in soft start circuit (output ON/OFF control) ■Applications • Power supplies for telecommunication equipment • Onboard local power supplies ■Lineup Part Number SI-8033S SI-8050S SI-8090S SI-8120S SI-8150S VO(V) 3.3 5.0 9.0 12.0 15.0 IO(A) 3.0 ■Absolute Maximum Ratings Parameter DC Input Voltage Power Dissipation Symbol Ratings VIN 43* Unit V PD1 18(With infinite heatsink) W PD2 1.5(Without heatsink, stand-alone operation) W Junction Temperature Tj +125 °C Storage Temperature Tstg –40 to +125 °C SW Terminal Applied Reverse Voltage VSW –1 V Thermal Resistance(junction to case) Rth(j-c) 5.5 °C/W *SI-8033S: 35V ■Recommended Operating Conditions Parameter Ratings Symbol Unit SI-8033S SI-8050S SI-8090S SI-8120S SI-8150S 5.5 to 28 7 to 40 12 to 40 15 to 40 18 to 40 DC Input Voltage Range VIN Output Current Range IO 0 to 3.0 A Tjop –30 to +125 °C Operating Junction Temperature Range 80 V ●SI-8000S Series ■Electrical Characteristics (Ta=25°C) Ratings Parameter Symbol SI-8000S *1 VO Output Voltage SI-8000SS Conditions SI-8033S Conditions Conditions typ. max. min. 3.17 3.30 3.43 4.80 5.00 5.20 8.55 9.00 9.45 3.234 3.30 3.366 4.90 5.00 5.10 8.73 9.00 9.27 Conditions Temperature Coefficient of Output Voltage VIN=25V, IO=1.0A 79 84 88 90 91 VIN=15V, IO=1.0A VIN=20V, IO=1.0A VIN=21V, IO=1.0A VIN=24V, IO=1.0A VIN=25V, IO=1.0A 60 60 60 60 60 VIN=15V, IO=1.0A VIN=20V, IO=1.0A VIN=21V, IO=1.0A VIN=24V, IO=1.0A VIN=25V, IO=1.0A 40 50 60 60 Overcurrent Protection IS1 10 100 120 130 % kHZ 130 mV VIN=10 to 30V, IO=1.0A VIN=15 to 30V, IO=1.0A VIN=18 to 30V, IO=1.0A VIN=21 to 30V, IO=1.0A 30 10 40 10 40 10 40 10 40 mV VIN=15V, IO=0.5 to 1.5A VIN=20V, IO=0.5 to 1.5A VIN=21V, IO=0.5 to 1.5A VIN=24V, IO=0.5 to 1.5A VIN=25V, IO=0.5 to 1.5A ±0.5 ±0.5 ±1.0 ±1.0 ±1.0 45 45 –45 45 45 f=100 to 120HZ f=100 to 120HZ f=100 to 120HZ f=100 to 120HZ f=100 to 120HZ 3.1 3.1 Conditions Starting Current 80 VIN=8 to 28V, IO=1.0A ∆VO/∆Ta Conditions V VIN=24V, IO=1.0A RREJ Ripple Rejection 11.50 12.00 12.50 14.25 15.00 15.75 VIN=21V, IO=1.0A ∆VOLOAD Load Regulation Unit typ. max. VIN=20V, IO=1.0A 25 Conditions SI-8150S typ. max. min. VIN=15V, IO=1.0A ∆VOLINE Line Regulation SI-8120S typ. max. min. f Switching Frequency SI-8090S typ. max. min. η Efficiency SI-8050S min. VIN=15V 3.1 VIN=20V 3.1 VIN=21V 3.1 VIN=24V mV/°C dB A VIN=25V *1: "S" may be indicated to the right of the Sanken logo. ■Outline Drawing (unit: mm) φ 3.2±0.2 4.2±0.2 ±0.2 2.8 Part Number Lot Number (2.0) (8.0) +0.2 0.85 –0.1 (4.6) 0.95±0.15 +0.2 0.45 –0.1 P1.7±0.7×4=6.8±0.7 3.9±0.7 5.0±0.6 2.6±0.1 (17.9) 16.9±0.3 4.0±0.2 7.9±0.2 0.5 ±0.2 10.0 (4.3) 8.2±0.7 Plastic Mold Package Type Flammability: UL94V-0 Weight: Approx. 2.3g q w e r VIN SWOUT GND VOS t S.S 1 2 3 4 5 Forming No. 1101 81 ●SI-8000S Series ■Block Diagram VIN 1 2 SWOUT OCP Reg. OSC Reset Drive Comp. TSD 4 VOS Amp. VREF 5 S.S. 3 GND ■Standard External Circuit VIN L1 2 1 VIN SI-8000S + VO SWOUT D1 + C2 C1 VOS S.S GND 5 3 C1,2 : 1000µF L1 : 150µH D1 : RK46(Sanken) 4 GND GND ■Ta-PD Characteristics PD=VO•IO 20 Power Dissipation PD (W) Infinite heatsink 15 With Silicon Grease Heatsink: Aluminum 200×200×2mm (2.3°C/W) 100×100×2mm 10 (5.2°C/W) 75×75×2mm (7.6°C/W) 5 Without heatsink 0 –25 0 25 50 75 100 125 Ambient Operating Temperature Ta (°C) 100 –1 ηχ –VF•IO 1– VO VIN The efficiency depends on the input voltage and the output current. Thus, obtain the value from the efficiency graph on page 83 and substitute the percentage in the formula above. VO : Output voltage VIN : Input voltage IO : Output current ηx : Efficiency (%) VF : Diode forward voltage 0.5V(RK46) Thermal design for D1 must be considered separately. 82 ●SI-8000S Series ■Typical Characteristics Rise Characteristics(SI-8050S) 10 Load Regulation(SI-8050S) Ta=25°C 100 5.10 Efficiency η (%) 3A 0A 1A 4 80 Output Voltage VO (V) VIN=40V 6 Ta=25°C 5.15 90 8 IO= Output Voltage VO (V) Efficiency Characteristics(SI-8050S) *Load=C.C Ta=25°C 20V 10V 7V 70 60 5.05 VIN=40V 20V 5.00 10V 7V 4.95 2 50 0 0 2 4 6 8 10 0 12 0 0.5 Input Voltage VIN (V) 1.5 2.0 2.5 0 0 3.0 0.5 100 Overcurrent Protection Characteristics(SI-8050S) 5.15 10 5.10 8 1.0 1.5 Ta=25°C 2.5 3.0 Thermal Protection Characteristics(SI-8050S) 10 (VIN=20V,IO=1A) 5.00 4.95 f Output Voltage VO (V) 70 6 4 2 40V 5.05 VO 8 VIN=7V η 80 Output Voltage VO (V) Output Voltage VO (V) (VIN=20V,IO=0A) 90 60 2.0 Output Current IO (A) Output Current IO (A) Temperature Characteristics(SI-8050S) Efficiency η (%) Frequency f (kHz) 1.0 6 4 TSD OFF TSD ON 2 20V 0 –50 –25 0 25 50 75 0 0 0 100 1 2 3 4 5 0 50 6 Output Current IO (A) Ambient Temperature Ta (°C) 75 100 125 150 175 200 Ambient Temperature Ta (°C) Note on Thermal Protection: The thermal protection circuit is intended for protection against heat during instantaneous shortcircuiting. Its operation is not guaranteed for shortcircuiting over extended periods of time. Rise Characteristics(SI-8120S) *Load=C.C Ta=25°C Efficiency Characteristics(SI-8120S) Efficiency η (%) 15V 80 70 60 =0 A 10 IO 5 1A Output Voltage VO (V) 12.2 24V 15 Ta=25°C 12.3 VIN=40V 90 20 Load Regulation(SI-8120S) Ta=25°C 100 Output Voltage VO (V) 25 12.1 VIN=40V 24V 12.0 15V 11.9 50 3A 0 0 5 10 15 20 Input Voltage VIN (V) 25 30 0 0 0.5 1.0 1.5 2.0 Output Current IO (A) 2.5 3.0 0 0 0.5 1.0 1.5 2.0 2.5 3.0 Output Current IO (A) 83 ●SI-8000S Series Caution 1. Selecting External Components (1) Choke coil L1 To maintain the stable operation of the regulator, choke coil L1 should be selected appropriately. When selecting choke coil L1, consider the following: a) Suitable for a switching regulator Do not use a coil as a noise filter because it generates excess heat. b) Appropriate inductance The greater the inductance of the choke coil, the smaller the output ripple voltage. However, the size of the coil increases large as the inductance increases. If the inductance is low, a greater peak current flows to the IC and loss increases. This is not favorable for stable operation. The standard external circuit shows reference inductance values suitable for stable operation. However, the appropriate inductance may also be calculated as follows: (VIN–VO)•VO L= ∆IL•VIN•f Where, deltaIL indicates the ripple current of the choke coil that is roughly set as follows: • If the working output current is close to the maximum rating (3 A) of SI-8000S Ripple current = output current × 0.2 to 0.3 • If the working output current is about 1.0A or less Ripple current = output current × 0.3 to 0.4 c) Satisfying the rated current The rated current of a choke coil must be greater than the maximum load current. Note that the inductance decreases drastically and an excess current flows if the load current exceeds the rated current of the coil. d) Good DC current superposition characteristics The current flowing through a choke coil is a triangular waveform current superimposed on a DC current equal to the load current. The coil inductance decreases as the load current increases. In general, the coil can be used until the inductance drops to 50% of the rated value. Use this as the reference value for selection. (2) Input capacitor C1 Input capacitor C1 operates as a bypass capacitor in the input circuit. When selecting input capacitor C1, consider the following: a) The breakdown voltage is higher than the maximum input voltage. b) Satisfies the allowable ripple current Exceeding the ratings of this capacitor or using it without derating may reduce its service life and also cause the regulator to malfunction. Therefore, an input capacitor with a sufficient margin should be selected. With the SI-8000S Series, the effective ripple current Irms flowing to the input capacitor can be calculated approximately as follows: VO × IO Irms 1.2 × VIN (3) Output capacitor C2 Output capacitor C2 operates as a smoothing capacitor for switching output. The output ripple voltage from the regulator is determined by the product of the pulsating current part ∆IL (=C2 chargedischarge current) of the choke coil current and the equivalent series resistance ESR of the output capacitor C2. Vrip=∆IL•C2ESR Therefore, a capacitor of low equivalent series resistance ESR should be selected to reduce the output ripple voltage. It is recommended to select a low-impedance capacitor intended for use with switching regulators as C2. (4) Diode D1 Use a Schottky barrier diode for D1. If you use a general rectifier diode or fast recovery diode, the IC may be damaged. (Sanken RK46 recommended) 2. Notes on Pattern Design (1) Large current line Since a large current flows through the bold lines in the standard external circuit make the pattern as wide and as short as possible. L1 VIN 1 SI-8000S + C1 3 4 C2 + D1 GND 100% VOUT 2 GND Inductance (2) Input capacitor Place the input capacitor C1 and output capacitor C2 as close to the IC as possible. Since a large current flows through the lead wires of the input and output capacitors to charge and discharge them quickly, minimize the lead wire length. The pattern around the capacitors should also be minimized. 50% Load current IO (max.) C1. C2. e) Less noise A drum-type open magnetic core coil can affect peripheral circuits with noise because the flux passes outside the coil. To avoid this problem, use a toroidal, EI, or EE type open magnetic core coil. C1. C2. + Example of bad pattern 84 + Example of good pattern ●SI-8000S Series (3) Sensing terminal Output voltage sensing terminal VOS should be connected as close to output capacitor C2 as possible. If the terminal is far from the capacitor, the decreasing regulation and increasing switching ripple may result in abnormal oscillation. 3. Variable Output Voltage The output voltage can be increased by connecting a resistor to VOS terminal No. 4. (There is no way of decreasing the voltage) (1) Variable output voltage with single external resistor L Example of basic pattern VO' 2 SI-8000S SI-8000S REX IVS L 1 5 3 C2 VS 4 D1 GND + VOUT C1 The output voltage adjustment resistance REX is calculated as follows: VO'–VS REX= IVS VS : Set output voltage of product VO' : Adjusted output voltage IVS : Inflow current to Vs terminal C2 GND VIN Top view (with part names) Applications 1. Soft Start Connecting a capacitor to terminal no. 5 permits a soft start at poweron. Delay time Td and rise time Ts can roughly be calculated as shown below. (However, the values may slightly vary in an actual application.) If the capacitance of C3 is increased, it takes longer to discharge C3 after VIN is turned off. Therefore, it is recommended to set the value within 10µF. When not using the soft start function, keep terminal no. 5 open. 0.7×C3 T d= (sec) 20×10–6 4.845×C3 Ts= (sec) VIN×20×10–6 SI-8000S 5 * The temperature characteristics of output voltage worsen because the value REX is not compensated for temperature. The Vs value fluctuates by up to ±20% depending on the IC product. Since the output voltage fluctuates more, a semi-fixed resistor is necessary for accurate output voltage adjustment. If Vs and REX are constant, the range of output voltage fluctuation can be expressed as follows: VO'–VS ∆VO'(%)=±20• VO' ∆VO':Adjusted output voltage (2) Variable output voltage with two external resistors L SI-8000S 3 VIN VO 2 IREX1 REX1 VS 4 C2 IVS REX2 GND S. S. C3 VO Td TS 2. Output ON/OFF control Output can be turned on and off by using the soft start terminals. Set the soft start terminal voltage to VSSL (0.2V typ.) or less to stop output. To switch the potential at the soft start terminals, drive the open collector of the transistor. Since the discharge current from C3 flows to the ON/OFF control transistor, limit the current for protection. The SS terminal is pulled up to the power supply in the IC and no external voltage can be applied. SI-8000S 5 SI-8000S 5 S. S. S. S. C3 ON/OFF S. S + ON/OFF The output voltage adjustment resistances REX1 and REX2 are calculated as follows: VO'–VS REX1= S•IVS VS REX2= (S-1)•IVS S:Stability factor Bypassing the current to REX2 improves the temperature characteristics and voltage fluctuation ranges more than the method of (1). Stability factor S indicates the ratio of REX1 to Vs terminal inflow current. Increasing the S value improves the fluctuations of the temperature characteristics and output voltage. (Usually 5 to 10) If the Vs and REX values are constant, the output voltage fluctuation range can be calculated as follows: ±20 VO'–VS ∆VO'(%)= • S VO' 85