GS-R424

GS-R400 Family 20W TO 140W STEP-DOWN SWITCHING REGULATOR FAMILY FEATURES MTBF in excess of 200,000 hours 4A max output current 46V max input voltage 4V max drop-out voltage Soft start Remote logic inhibit/enable Remote output voltage sense Non-latching overload and short circuit protection Crow-bar output overvoltage protection DESCRIPTION The GS-R400 series is a versatile family of high current, high voltage step-down switching voltage regulators. The integral heatsink allows a large power handling capability and it provides also an effective shielding to minimize EMI. SELECTION CHART Type Ordering Number GS-R405 GS-R412 GS-R415 GS-R424 GS-R405S GS-R400V GS-R400VB Output Voltage (V) 5.1 ± 2% 12.0 ± 4% 15.0 ± 4% 24.0 ± 4% 5.1 ± 2% 5.1 to 40 5.1 to 40 Input Voltage (V) 9 to 46 16 to 46 19 to 46 28 to 46 9 to 46 Vo+4 to 46 Vo+4 to 46 Output Ripple (mVpp) 25 50 65 100 25 25 to 100 25 to 100 Regulation Line (mV/V) 2 5 5 6 2 6 6 Load (mV/A) 20 40 60 90 20 20 to 90 20 to 90 Efficiency Notes (%) 70 80 85 90 70 70 to 90 70 to 90 Reset output Progr. output voltage Progr. output voltage and current. Frequency synchr. Fixed output voltage " " " Note: The line regulation is measured at Iout=1A The load regulation is measured at Vin=Vo+8V and Iout=1 to 3A For VO ≥ 36V and Io = 4A an external heatsink or forced ventilation are required. ABSOLUTE MAXIMUM RATINGS Symbol Vi Irt* Tstg Tcop DC Input Voltage Reset Output Sink Current Storage Temperature Range Operating Case Temperature Range Parameter Value 48 20 – 40 to +105 – 20 to +85 Unit V mA °C °C * GS-R405S only June 1994 1/5 GS-R400 FAMILY CONNECTION DIAGRAM AND MECHANICAL DATA P in 2 GS-R405S only Pin 5,6,7 GS-R400VB only Pin 12 GS-R400V/VB only Dimensions in mm Bottom view PIN DESCRIPTION Pin 1 2 3 4 5 6 7 8 9 10 11 12 Function Inhibit Reset + Input Input GND Oscillator Sync Current limiting Output GND – Sense + Sense + Output Program Description The module is disabled by a high logic level applied to this pin. Reset output (GS-R405S only). DC input voltage. Recommended maximum voltage is 46V. Return for input voltage source. 100kHz oscillator output. To be connected to Sync (pin 6) input if the unit is a master and left open if it is a slave (GS-R400VB only). See fig. 5. Synchronization input. To be connected to the Oscillator output (pin 5) of the master (GSR400VB only). See fig. 5. A resistor (≥ 2.2kΩ) connected from this pin to pin 9 sets the current limiting level (GS-R400VB only). Return for output current path. Internally connected to pin 4. Senses the remote load return. Must be tied to pin 8 when the remote sensing feature is not used. See fig. 1. Senses the remote load high side. Must be tied to pin 11 when the remote load sensing feature is not used. See fig. 1. Regulated DC output voltage. A resistor (≤ 18kΩ) connected between this pin and pin 10 sets the output voltage (GS-R400V and GS-R400VB only). 2/5 GS-R400 FAMILY ELECTRICAL CHARACTERISTICS (TA = 25°C unless otherwise specified) Symbol ∆Vo/∆T Io IoL Iisc fs SVR Vr tss Vinhl Vinhh Iinhh tcb Vrh* Vrl* trd* Vcth ∆Vo Rth Parameter Temperature Stability Output Current Current Limit Average Input Current Switching Frequency Supply Voltage Rejection Ripple Voltage Soft Start Time Low Inhibit Voltage High Inhibit Voltage High Inhibit Input Current Crow-bar Delay Time Reset High Level Reset Low Level Reset Delay Time Crowbar Intervention Threshold Total Remote Sense Compensation Thermal Resistance Case to ambient 5 Irl = 5mA Irl = 10mA 100 Vo•1.25 500 Vinh = 5V 5 5 0.2 0.4 2 Test Conditions Vi = Vo+8V Io = 1A Vi = Vo+8V Vi = Vo+8V Vi = 46V Output Shorted Io = 1A fo = 100Hz Io =1A Io = 2A Vi = Vo+8V 0.2 5 0.1 100 4/12 25/150 10/35 0.8 5.5 500 Min Typ 0.2/1.6 4 8 0.2 Max Unit mv/°C A A A KHz mV/V mVpp ms V V µA µs V V ms V mV °C/W * GS-R405S only USER NOTES Input Voltage The recommended operating maximum DC input voltage is 46V inclusive of the ripple voltage. Remote Sensing The remote voltage sense compensation range is for a total drop of 500mV equally shared between the load connecting wires. It is a good practice to shield the sensing wires to avoid oscillation. Each sense input must be connected to its companion output power pin when the remote sense capability is not used (see fig. 1). Case Grounding The module case is isolated from the electrical circuit of the switching regulator. It can be grounded using the 4 corner pins. The PCB area below the module can be used as an effective sixth side shield against EMI. Thermal Characteristics The case-to-ambient thermal resistance of all the GS-R400 modules is about 5°C/W. This produces a 50°C temperature increase of the module surface for 10W of internal power dissipation. Depending on the ambient temperature and/or on the power dissipation, an additional heatsink or forced ventilation may be required. Input Impedance The module has an internal capacitor connected between the input pins in order to assure PWM stability. This capacitor cannot handle large values of high frequency ripple current and it can be permanently damaged if the primary energy source impedance is not adequate. The use of an external low ESR, high ripple current capacitor located as close the module as possible is recommended. Suitable capacitors should have a RMS current capability of 2.5ARMS with a working voltage of 50 VDC a nd an ESR of 0,1 Ω a t 100 kHz. When space 3/5 GS-R400 FAMILY is a limitation, a 22µF ceramic multilayer capacitor must be connected to the module input pins. Output Voltage Programming The GS-R400V and GS-R400VB output voltage is programmed by using a resistor (see pin function table and fig. 4). The resistor must be located very close the module and the PCB layout must mimimize injected noise. The value of the resistor is calculated by using the following formula:  Vo  –1 kΩ Rv = 2.67   5.1  Vo can be adjusted between 5.1 and 40V. Current Limiting Programming The GS-R400VB current limiting is programmed by using a resistor (see pin function table and fig. 4). Figure 1. Load Connection The value of the resistor is calculated by using the following formula: Ri = [2.2 + (5•Io)] kΩ Module Protection The modules are protected against occasional and permanent short circuits of the output pin to ground, as well as against output current overload. When the output current exceeds the maximum value, the output is automatically disabled. After a fixed time the module starts again in a soft mode. The cycle is repeated until the overload condition is removed. A crowbar output overvoltage protection is activated whenever the output voltage exceeds the nominal output voltage by more than 25%. Figure 2. Remote Inhibit Operation Figure 3. Reset Operation 4/5 GS-R400 FAMILY Figure 4. Voltage and Current Programming Figure 5. Multiple Units Synchronization Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specification mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of SGS-THOMSON Microelectronics. © 1994 SGS-THOMSON Microelectronics – All Rights Reserved SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - China - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco - The Netherlands Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A. 5/5