GS-R12HXXX2 2.5W TO 24W STEP-DOWN SWITCHING REGULATOR FAMILY PRELIMINARY FEATURE ■ MTBF 1 000 000 hours (Tamb=25)C) ■ 2A max output current 35V max input voltage 1.5V max drop-out voltage 3.3V ± 2% reference voltage Remote logic inhibit/enable Synchronization Not-latching overload and short circuit protection Thermal shutdown Fixed or adjustable output No heatsink required ■ ■ ■ ■ ■ ■ ■ ■ ■ ORDERING NUMBER: GS-R12HXXX2 DESCRIPTION The GS-R12HXXX2 series is a family of high efficiency step down switching voltage regulator, designed to replace linear regulators. Based on STM L5973 device, this non isolated family of regulators are suitable for the full spectrum of applications including telecom, industry, computer and distributed power system applications having a widely ranging input voltage. SELECTION CHART Type Ordering Number Output Voltage [V] Input Voltage [V] Output Ripple [mVpp] Efficiency [%] Notes GS-R12H0122 1.235 ± 3% 4.5 ÷ 15 20 68 Fixed output voltage GS-R12H0182 1.8 ± 4% 4.5 ÷ 15 20 72 Fixed output voltage GS-R12H0252 2.5 ± 4% 4.5 ÷ 15 20 76 Fixed output voltage GS-R12H0332 3.3 ± 4% 4.5 ÷ 15 20 82 Fixed output voltage GS-R12H0502 5.0 ± 4% 6.6 ÷ 15 20 85 Fixed output voltage GS-R12H0002 1.235 ÷ 5.0 4.5 ÷ 15 20 68 ÷ 85 Progr. output voltage GS-R24H0332 3.3 ± 4% 16 ÷ 35 20 82 Fixed output voltage October 2003 This is preliminary information on a new product now in development. Details are subject to change without notice. 1/8 GS-R12HXXX2 Type Ordering Number Output Voltage [V] Input Voltage [V] Output Ripple [mVpp] Efficiency [%] Notes GS-R24H0502 5.0 ± 4% 16 ÷ 35 20 85 Fixed output voltage GS-R24H1201.5 12 ± 4% 16 ÷ 35 100 91 Fixed output voltage GS-R24H0001 3.3 ÷ 24 16 ÷ 35 100 ÷ 250 78 ÷ 96 Progr. output voltage ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit DC Input Voltage (for GS-R12HXXX2) 16 V DC Input Voltage (for GS-R24HXXX) 36 V Vi 2/8 Iout Maximum Output Current int. limit V9 INH -0.3 to Vi V V10 Sync -0.3 to 4 V V11 FB 4 V Tstg Storage Temperature Range -40 ÷ 105 °C Top Operating Ambient Temperature -25 ÷ 70 °C Top1 Operating Ambient Temperature with current derating -25 ÷ 85 °C GS-R12HXXX2 CONNECTION DIAGRAM AND MECHANICAL DATA PIN DESCRIPTION Pin Function Description 1 Input GND Return for input voltage source 2 Input GND Return for input voltage source 3 Input GND Return for input voltage source 4 Input + DC input voltage 5 Input + DC input voltage 6 Input + DC input voltage 7 Input + DC input voltage 8 Vref 3.3V reference voltage 9 INH A logical level (active high) disables the device, when it is open an internal pull up disables the device 10 Sync Master/Slave synchronization 11 FB Feedback input, available on adjustable device 12 Vout Regulated output 13 Vout Regulated output 3/8 GS-R12HXXX2 Pin Function Description 14 Vout Regulated output 15 Vout Regulated output 16 Output GND Return for output voltage 17 Output GND Return for output voltage 18 Output GND Return for output voltage ELECTRICAL CHARACTERISTICS All versions (Tamb=25)C, unless otherwise specified.) Symbol Parameter Test Condition Min. Typ. Max. Unit Temperature Stability Vi =Vo + 1.5V Io = 2A IoL Current Limit Vi =4.5 ÷ 15V 2.5 Iq Quiescent Current Vi =12V Io = 0A 1.8 2.5 mA Total Stand-by Quiescent Current Vinh>2.2V 50 100 µA Switching Frequency Vi =12V Io = 1.5A 225 250 275 kHz Reference Voltage Vi =4.5 ÷ 15V Iref =0 ÷ 5mA 3.234 3.3 3.366 V 8 10 30 mA 0.8 V Iqst-by fs Vref Short Circuit Current INH INH Threshold Voltage Device ON Device OFF VFB Feedback voltage SRV Supply Voltage Rejection Rth Thermal Resistance mV/°C Vi =4.5 ÷ 15V Io = 0÷2A A 2.2 1.22 V 1.235 1.25 V mV/V Case to ambient °C/W ELECTRICAL CHARACTERISTICS for GS-R12HXXX2 only (Tamb=25)C, unless otherwise specified.) Symbol 4/8 Parameter Test Condition Io Output Current Vi =4.5 ÷ 15V Vr Ripple Voltage Vi =12V Io = 2A Min. Typ. 0 20 Max. Unit 2 A mVpp GS-R12HXXX2 ELECTRICAL CHARACTERISTICS for GS-R24HXXX only (Tamb=25)C, unless otherwise specified.) Symbol Parameter Test Condition Min. Typ. Max. Unit Io Output Current Vi =16 ÷ 35V for GS-R24H0332 ---------------------GS-R24H0502 0 2 A Io Output Current Vi =16 ÷ 35V for GS-R24H1201.5 0 1.5 A Io Output Current Vi =16 ÷ 35V for GS-RH0001 0 1-2 A Vr Ripple Voltage Vi =24V Io = 2A for GS-R24H0332 --------------------- -GS-R24H0502 20 mVpp Vr Ripple Voltage Vi =24V Io = 2A for GS-R24H1201.5 100 mVpp Vr Ripple Voltage Vi =24V Io = 2A for GS-R24H0001 100250 mVpp USER NOTES Input Voltage The recommended operating maximum DC Input Voltage is 15V inclusive of ripple voltage. Reference voltage No capacitor is required for stability. Inhibit function The inhibit feature allows to put in stand-by mode the device. With INH pin 9 higher than 2.2V the device is disabled and the power consumption is reduced to less than 100µA. With INH pin lower than 0.8V, the device is enabled. If the INH pin is left floating, an internal pull up ensures that the voltage at the pin reaches the inhibit threshold and the device is disabled. The pin is also Vcc compatible. Multiple units synchronization Using more than one unit on the same circuit, it is possible to synchronize the switching frequency, connecting all pin 10 together (see figure 3). The unit with higher frequency becomes the master. Current protection The device has two current limit protections, pulse by pulse and frequency fold back. The current is sensed through a resistor and if reaches the threshold, the on time is reduced and consequently the output voltage too. Since the minimum switch ON time (necessary to avoid false overcurrent signal) is not enough to obtain a sufficiently low duty cycle at 250 Hz, the output current, in strong overcurrent or short circuit conditions, could increase again. For this reason the switching frequency is also reduced, so keeping the inductor current under its maximum threshold. 5/8 GS-R12HXXX2 The frequency depends on the feedback voltage. As the feedback voltage decreases (due to the reduced duty cycle), the switching frequency decrease too. Thermal shutdown The shutdown block generates a signal that turns off the power stage if the temperature of the internal chip goes higher than a fixed internal threshold (150 ºC). The sensing element of the chip is very close to the PDMOS area, so ensuring an accurate and fast temperature detection. An hysteresis of approximately 20ºC avoids that the devices turns on and off continuously. Thermal Characteristics Output voltage programming (GS-R12H0002 only) The GS-R12H0002 output voltage is 5.05V ±4%, to reduce this value connect a resistor between pin 11 (FB) and pin 12 (Vout). The resistor must be located very close to the proper pins, to minimize the injected noise (see figure 1). The resistor value is calculated using the following formula: Rv=[(Vout-1.235)*10.2]/(5.05-Vout) --[kOhm] Vout can be adjusted between 1.235V (Rv=0 Ohm) and 5.05V (Rv=open) Loop compensation (GS-R12H0002 only) If required by particular load conditions, it is possible to change the feedback loop compensation, adding an external capacitor between pin 11 (FB) and pin 12 (Vout), which will act as speed up (see figure 2). ADDITIONAL FEATURES AND PROTECTIONS Feedback disconnection In case of feedback disconnection, the duty cycle increases versus the maximum allowed value, bringing the output voltage close to the input supply. THis condition could destroy the load. To avoid this dangerous condition, the device is turned off if the internal feedback pin remains floating. Output overvoltage protection The overvoltage protection, OVP, is realized by using an internal comparator, which input is connected to the feedback, that turns off the power stage when the OVP threshold is reached. This threshold is typically 30% higher than the feedback voltage. 6/8 GS-R12HXXX2 Figure 1 Figure 2 Figure 3 7/8 GS-R12HXXX2 Information furnished is believed to be accurate and reliable. However, STMicroelectronics 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 STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics. 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