LINFINITY SG29125/125A handbook
Contents
1. Junction to Tab Thermal Resistance Junction to Ambient 6 Note 1 Exceeding these values may destroy this part Input Voltage Vp Operating eecee Input Voltage Vp Overvoltage Transient ON OFF Switch 0 0 ecceeeceeeeeeeeeeeeeeseeeeseeees Frapo dae EEEN 26V Storage Temperature Range Tre lt 65 C to 150 C raoa 15V to 60V Operating Junction Temperature T cccceecerereee 150 C i disses 0 3V to Vy SITAE EEEN 4 0 C W Note A Junction Temperature Calculation T T P x 944 ereereetey 55 C wW Note B The above numbers for 6 are maximums for the limiting thermal resistance of the package in a standard mount ing configuration The 6 numbers are meant to be guidelines for the thermal performance of the device pc board system All of the above assume no ambient airflow ON OFF Threshold Voltage OUT Load Current V OUT ELECTRICAL CHARACTERISTICS Low Level Vi Vog iS OFF scceeccececeees High Level Vy Voyz iS ON eee with adequate heatsinking 5 to 1000mA Maximum Line Transient Load Dump V lt 6V 60V max V Input Capacitor Vp to GND cece Note 2 Range over which the device is functional Note 3 During 60V load dump V shall not be less than 4 75V at RECOMMENDED OPERATING CONDITIONS Note 2 amp 3 INPUT Voltage Vg esta eiaa nena OUT 10mA OUT to GND amp Vagt GND iriiri nenen Operating Ambient Temperatur2. 4V l 10mA Pin 4 0 4V lt 26V lt 1000mA 40 C lt T lt 85 C G29125 125A Min Typ Max V W mV mV mV mQ mA mA mA mA uV mV 1000hr RMS 12 90 Rev 1 1 2 94 Copyright 1994 LINFINITY Microelectronics Inc 11861 Western Avenue Garden Grove CA 92841 714 898 8121 FAX 714 893 2570 SG291I25 125A ELECTRICAL CHARACTERISTICS continued G29125 125A Parameter Test Conditions gt Units Min Typ Max Standby Output V Section Output Voltage Note 4 6V lt Vn lt 26V lt 50mA 40 C lt T lt 85 C 4 75 5 0 5 25 vV Line Regulation 6V lt Vp lt 26V 4 50 mV Load Regulation 1mA lt 1 lt 35mA 10 25 mV 1mA lt 1 lt 50mA 25 50 mV Output Impedance 1mA and 1MA 4 100Hz 10kHz 1 Q Quiescent Current I lt 10mA V OFF 12 3 mA Output Noise Voltage 10Hz 100kHz 300 LAS Long Term Stability 20 mV 1000hr Ripple Rejection F 120Hz 66 dB Dropout Voltage lo lt 50mA 0 55 0 7 V Current Limit 50 100 mA Maximum Operational Input Voltage 4 75V lt V lt 6V 60 70 V Note 4 The temperature extremes are guaranteed but not 100 production tested TYPICAL CIRCUIT WAVEFORM sov INPUT 14V VOLTAGE PIN 1 V ov ON OFF 2V SWITCH 0 8V 0 8V 12V 12V 12V 12V 12V OUTPUT 5V VOLTAGE 3 5V PIN 2 V ov ov 5 0V STANDBY 5V VOLTAGE PIN5 V 3 7V SYSTEM TURN LOAD
3. LOW V LINE NOISE Vour THERMAL TURN CONDITION ON DUMP ETC SHORT SHUTDOWN OFF CIRCUIT APPLICATION NOTES The advantages of using a low dropout regulator such as the G29125 125A are the need for less headroom for full regula tion and the inherent reverse polarity protection provided by the PNP output device A typical NPN regulator design requires an input to output differential of approximately two volts minimum This is due to the 2Vbe Vcesat of the NPN Darlington used in the output coupled with the voltage drop across the current limit resistor In contrast the PNP Regulator uses a single series pass transistor with its single Vcesat thus the lower input to output voltage differential or dropout voltage In addition to a low dropout voltage an important advantage of the SG29125 125A series is low quiescent current in the standby mode When the high current or primary regulator is shut off the regulator enters a micropower mode Here all but the most essential circuitry to power the standby output is deactivated This allows the lowest possible quiescent current typical around 1 2mA a vital factor when used in a battery powered system In some applications the regulator output voltage is used not only as a power supply but also as a voltage reference for control systems In such cases not just the temperature stability of the output is important but also the initial accuracy The SG29125 125A fills this need as the
4. internal bandgap reference is trimmed allowing a typical output voltage tolerance of 1 12 90 Rev1 1 2 94 Copyright 1994 LINFINITY Microelectronics Inc 11861 Western Avenue Garden Grove CA 92841 714 898 8121 FAX 714 893 2570 SG291I25 125A APPLICATION HINTS EXTERNAL CAPACITORS To stabilize the outputs and prevent oscillation perhaps by many volts external capacitors are required The minimum recom mended value for the output capacitors is 10uF although the actual size and type will likely vary according to the particular application e g operating temperature range and load Another consideration is the effective series resistance ESR of the capacitor Capacitor ESR will vary by manufacturer Conse quently some evaluation may be required to determine the minimum value of the output capacitors Generally worst case occurs at the maximum load and minimum ambient temperature The size of the output capacitor can be increased to any value above the minimum One possible advantage of this would be to maintain the output voltage during brief periods of negative input transients The output capacitors chosen should be rated for the full range of ambient temperature over which the circuit will be exposed and expected to operate For example many aluminum type electro lytic capacitors will freeze at 30 C The effective capacitance is reduced to zero in such a situation Capacitors rated for 40 C oper
5. 4 893 2570 12 90 Rev 1 1 2 94 Copyright 1994
6. ASG 29125fH A LINFINITY MICROELECTRONICS LOW DROPOUT DUAL REGULATOR DESCRIPTION The SG29125 125A is a dual 12V 5V positive voltage regulator One output is a high current up to 1000 mA regulator that can be turned on or off by a high impedance low current TTL compatible switch The second or standby output remains on regardless The on off switch not only shuts off the high current output but actually puts the IC in a micropower mode making possible a low quiescent current This unique character istic coupled with an extremely low dropout 55V for output current of 10mA makes the SG29125 125A well suited for power systems that require standby memory The G29125 125A includes other features which were originally designed for automotive applications These include protection from reverse battery installations and double battery jumps The high current regulator has overvoltage shutdown to protect both the internal circuitry and the load during line transients such as load dump 60V In addition the high current regulator design also has built in protection for short circuit and thermal overload During these fault conditions of the primary regulator the standby regulator will continue to power its load The SG29125 is the 12 volt 5 version of a family of dual regulators with a standby output voltage of 5V Other high current outputs of 5 and 8 2 volts are available Also available is the SG29125A which offers an improved output vol
7. ENT OUTPUT STANDBY SG29125 125A STUT FIGURE 1 Disabling Standby Output to Eliminate C3 The high current regulated output features fault protection against overvoltage as well as a thermal shutdown feature Ifthe input voltage rises above 33V load dump the high current output shuts down automatically The internal circuitry is thus protected and the IC is able to survive higher voltage transients than might otherwise be expected The thermal shutdown of the high current output effectively guards against overheating of the die since this section of the IC is the principle source of power dissipation on the chip ON OFF SWITCH The ON OFF pin is a high impedance low current switch that controls the main output voltage pin 2 This is directly compat ible with all 5 volt logic families For use with open collector logic outputs a 100K resistor from this pin to a 5V supply such as Pin 5 is required CONNECTION DIAGRAM amp ORDERING INFORMATION See Note Below Ambient i Package Part No Temperature Range Connection Diagram 5 PIN TO 220 PLASTIC SG29125P 40 C to 85 C 5 STANBY OUTPUT P PACKAGE SG29125AP 40 C to 85 C 5 lt 4 ONOFF SWITCH tL _ 3 GROUND GND 2 OUTPUT VOLTAGE Vou 1 INPUT VOLTAGE Vn Note 1 All parts are viewed from the top LINFINITY Microelectronics Inc 11861 Western Avenue Garden Grove CA 92841 4 714 898 8121 FAX 71
8. ation must be used in order to maintain regulator stability at that temperature Tantalum capacitors satisfy this requirement STANDBY OUTPUT The SG29125 125A differs from most fixed voltage regulators in that it is equipped with two regulator outputs instead of one The additional output is intended for use in systems requiring standby memory circuits While the high current regulator output can be controlled with the ON OFF pin described below the standby remains on under all conditions as long as sufficient input voltage is applied to the IC Thus memory and other circuits powered by this output remain unaffected by positive line transients thermal shutdown etc The standby regulator circuit is designed so that the quiescent current to the IC is very low lt 1 5mA when the other regulator output is off If the standby output is not required it can be disabled This is accomplished by connecting a resistor from the standby output to the supply voltage thereby also eliminating the requirement for a more expensive output capacitor to prevent unwanted oscilla tions The resistor value depends upon the minimum input voltage expected for a given system Since the standby output is shunted with an internal 5 6V zener the current through the external resistor should be sufficient to bias internal resistors up to this point Approximately 60A will suffice resulting in a 10k external resistor for most applications Figure 1 HIGH CURR
9. e Range T G29125 125A TERRENA 13V to 26V Reverse Polarity D C Input Voltage Vn Vo 2 0 6V 160 load sacs dervessicasansininmisnccasactons 15V max mene 0 8V max Reverse Polarity Transient Input Voltage Vn 50V max EET 2 0V min 1 duty cycle T lt 100ms V 2 9V 16Q load Output Capacitor with ESR of 1Q max 10uF min 40 C to 85 C Unless otherwise specified these specifications apply for the operating ambient temperature of T 25 C Vn 14V 500mA for Vur and 10mA for V and are for DC characteristics only Low duty cycle pulse testing techniques are used which maintains junction and case temperatures equal to the ambient temperature Parameter Voltage Output V Output Voltage Note 4 Line Regulation Load Regulation Output Impedance Quiescent Current Output Noise Voltage Long Term Stability Ripple Rejection Dropout Voltage Current Limit Maximum Operational Input Voltage Maximum Line Transient ON OFF Switch l ON OFF Switch l Test Conditions 13V lt V SG29125 SG29125A 13V lt Va lt 16V l 5MA 13V lt V lt 26V 5mA 5mA lt l lt 1000mA 500mA and 10mA 100Hz 10kHz lt 10mA No Load on Standby 500mA No Load on Standby i Uo 0 750mA No Load on Standby 220mA 10MA Vn Vour 200mMV 10Hz 100kHz F 120Hz 500mA 1000mA Double Battery Vo lt 13V 10mA Pin 4 2
10. tage tolerance of 2 They are available in the plastic TO 220 power package and are designed to function over the automotive ambient temperature range of 40 C to 85 C SG291I25 125A FEATURES e 2 Internally Trimmed Output e Two regulated outputs e Output current in excess of 1000mA Low quiescent current standby regulator Input output differential less than 0 6V at 0 5A Reverse battery protection 60V load dump protection 50V reverse transient protection Short circuit protection Internal thermal overload protec tion Available in plastic TO 220 ON OFF switch for high current output TYPICAL APPLICATION CIRCUIT Required if regulator is located far from power supply filter INPUT VOLTAGE T Required for stability May be increased without OQ bound Capacitor must be rated to operate at the minimum temperature expected for the regulator system L Gir 0 1uF G29125 125A OUTPUT VOLTAGE 3 i 12V 1000mA OVERVOLTAGE THERMAL SHUTDOWN ON OFF SWITCH O REGULATOR for output voltage only BIAS 1 23V REFERENCE 5V STANDBY STANDBY OUTPUT REGULATOR 5V 50mA GROUND LINFINITY Microelectronics Inc 11861 Western Avenue Garden Grove CA 92841 1 714 898 8121 FAX 714 893 2570 12 90 Rev 1 1 2 94 Copyright 1994 SG29125 125A ABSOLUTE MAXIMUM RATINGS THERMAL DATA P Package Thermal Resistance Junction to Case 6
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LINFINITY SG29125/125A handbook