4707 dey road liverpool, n.y. 13088 (315) 701-6751 features: mil-prf-38534 qualified 138/139 class c high power operational amplifier iso-9001 certified by dscc 1 2 3 4 -vcc comp 1 output drive current sense 8 7 6 5 inverting input non-inverting input comp 2 +vcc m.s.kennedy corp. msk139 pin-out information typical applications low cost high voltage operation: 150v ultra low quiescent current: 4.0 ma typ. high output current: 5a min. no second breakdown monolithic mos technology external compensation for optimum gain-bandwidth MSK138 description: the msk 138 is a high power class "c" mosfet operational amplifier ideally suited for high power amplification and magnetic deflection applications. with a total supply voltage rating of 150 volts and 5a of available output current, the msk 138 is also an excellent low cost choice for motor drive circuits. the mosfet output frees the msk 138 from secondary breakdown limitations and power dissipation is kept to a minimum with a quiescent current rating of only 4.0ma. the msk 138 is packaged in a hermetically sealed 8 pin power dip which has two external compensation pins. for applications requiring heat sinking, the msk 139 is available with bolt down tabs and is otherwise identical to the msk 138 (see mechanical specifications). equivalent schematic pa audio magnetic deflection motor drive noise cancellation dc power regulators rev. a 7/00 1
4 150v 5a 16v vcc 150c total supply voltage output current (within s.o.a.) input voltage (differential) input voltage (common mode) junction temperature -65c to +150c 300c -55c to +125c -40c to +85c 1.0c/w absolute maximum ratings t st t ld t c r th v cc i out v ind v in t j storage temperature lead temperature case operating temperature (MSK138b/139b) (MSK138/139) thermal resistance (dc) junction to case electrical specifications 2 v in =0v v in =0v v in =0v v in =0v v cm =0v (dc) v cm =30vdc 10khz bw i out =5a peak v out =max v out =80v pp 10v step a v =+1v/v c c =68pf c c =open f=15hz max. 75 6 10 50 15 100 50 - - - - - - - - - - - group a subgroup - 1 1 2,3 1 1,3 2 - - - - 4 4 - - - - 4 static supply voltage range input offset voltage offset voltage drift offset voltage vs vcc input bias current input impedance input capacitance common mode rejection noise output output voltage swing output current power bandwidth settling time to 0.1% capacitive load transfer characteristics slew rate open loop voltage gain min. 15 - - - - - - - - 90 - 40 5 - - 10 - 94 max. 75 8 15 - 15 100 - - - - - - - - - - - - typ. 50 4 5 10 8 20 - 10 5 106 10 42 5.5 66 2 - 27 106 units v ma mv v/c v/v pa na w pf db v rms v a khz s nf v/s db MSK138b/139b MSK138/139 2 parameter 4 test conditions 1 quiescent current 4 4 4 4 4 4 9 4 3 4 4 4 11 11 1 2 3 4 5 6 7 8 9 unless otherwise noted c c =10pf, r c =1.0k w , v cc = 50vdc. derate maximum supply voltage 0.5v/c below t c =+25c. no derating is needed above t c =25c. a v =-10v/v measured in false summing junction circuit. devices shall be capable of meeting the parameter, but need not be tested. typical parameters are for reference only. industrial grade devices shall be tested to subgroups 1 and 4 unless otherwise requested. military grade devices ('b' suffix) shall be 100% tested to subgroups 1,2,3 and 4. subgroup 5 and 6 testing available upon request. subgroup 1,4 t c =+25c subgroup 2,5 t c =+125c subgroup 3,6 t a =-55c parameter is specified with the output above the deadband near zero volts notes: min. 15 - - - - - - - - 90 - 40 5 - - 10 - 94 typ. 50 4 5 10 8 20 - 10 5 106 10 42 5.5 66 2 - 27 106 9 rev. a 7/00 2
application notes current limit (see typical connection diagram) a value of current limit resistance can be calculated as fol- lows: where: r cl is the current limit resistor value i cl is the current limit 0.05 i cl is the voltage dropped in the current limit path across internal impedances other than the actual current limit resistor 0.83 volts is the voltage drop that must be developed across the current limit connections to activate the current limit circuit the maximum practical value of current limit resistance is 16 ohms. the current limit resistor will decrease available output voltage swing in the following manner: v r is the reduction in output voltage swing due to the current limit resistor. it is recommended the user limit output current to a value as close to the required output current as possible, without clipping output voltage swing. current limit will vary with case temperature. refer to the typical performance curves to predict current limit drift. if current limit is not required replace the resistor with a short. safe operating area (soa) the mosfet output stage of this power operational ampli- fier has two distinct limitations: 1. the current handling capability of the die metallization. 2. the junction temperature of the output mosfet's. note: the output stage is protected against transient flyback. however, for protection against sustained, high energy flyback, external fast-recovery reverse biased diodes should be connected from the output to ground. v r =i o r cl * r cl =(0.83 - (0.05 i cl )) / i cl * * stability the msk 138/139 has sufficient phase margin when com- pensated for unity gain to be stable with capacitive loads of at least 10nf. however, it is recommended that the parallel sum of the input and feedback resistor be 1000 ohms or less for closed loop gains of ten or less to minimize phase shift caused by the r-c network formed by the input resistor, feedback re- sistor and input capacitance. the user can tailor the perfor- mance of the msk 138/139 to their application using the ex- ternal compensation pins. the graphs of small signal gain and phase as well as the graphs of slew rate and power response demonstrate the effect of various forms of compensation. the compensation capacitor must be rated at 150 volts working voltage if maximum power supply voltages are used. the com- pensation resistor and capacitor lead lengths must be kept as short as possible to minimize spurious oscillations. a high quality npo capacitor is recommended for the compensation capaci- tor. an effective method of checking amplifier stability is to apply the worst case capacitive load to the output of the ampli- fier and drive a small signal square wave across it. if overshoot is less than 25%, the system will typically be stable. input protection input protection circuitry within the msk 138/139 will clip differential input voltages greater than 16 volts. the inputs are also protected against common mode voltages up to the supply rails as well as static discharge. there are 300 ohm current limiting resistors in series with each input. these resistors may become damaged in the event the input overload is capable of driving currents above 1ma. if severe overload conditions are expected, external input current limiting resistors are recom- mended. typical connection diagram the msk 138/139 output is biased for class "c" operation to yield ultra low quiescent current. a small amount of cross- over distortion will be present under heavy load conditions. the user must verify that this condition will not affect circuit performance. applications requiring a high degree of linearity near the zero point with minimum distortion should use the msk 148/149. class "c" performance rev. a 7/00 3
typical performance curves rev. a 7/00 4
ordering information screening level mechanical specifications part number esd triangle indicates pin 1. all dimensions are 0.010 inches unless otherwise labeled. the information contained herein is believed to be accurate at the time of printing. msk reserves the right to make changes to its products or specifications without notice, however, and assumes no liability for the use of its products. m.s. kennedy corp. 4707 dey road, liverpool, new york 13088 phone (315) 701-6751 fax (315) 701-6752 www.mskennedy.com MSK138 MSK138b msk139 msk139b industrial military-mil-prf-38534 industrial military-mil-prf-38534 MSK138 msk139 rev. a 7/00 5
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