4707 dey road liverpool, n.y. 13088 m.s.kennedy corp. (315) 701-6751 features: 5101 high current, low dropout voltage regulator extremely compact 10 pin flatpack with metal base extremely low dropout voltage: 350mv @ 1.5 amps available in adjustable version only ttl level enable pin: zero current shutdown mode reverse battery and load dump protection low ground current: 22ma typical at full load 1% guaranteed accuracy output current to 1.5 amps mil-prf-38534 and 38535 certified facility description: the msk 5101 voltage regulator is available in the adjustable output configuration only. the ultra low dropout specifica- tion is due to the utilization of a super pnp output pass transistor with monolithic technology. dropout voltages of 350mv at 1.5 amps are typical in this configuration, which drives efficiency up and power dissipation down. the device also offers a ttl/cmos compatible on/off enable function. the msk 5101 is packaged in a space efficient 10 pin ceramic flatpack with a built in metal base. equivalent schematic typical applications pin-out information high efficiency, high current linear regulators constant voltage/current regulators system power supplies switching power supply post regulators battery powered equipment nc enable vin a vin b nc vout a vout b nc adj nc 1 2 3 4 5 6 7 8 9 10 msk5101-00 base the base of the package is electrically connected to ground. 1 8548-43 rev. j 2/13
input voltage (100ms 1%d.c.) input voltage enable voltage output current storage temperature range lead temperature (10 seconds soldering) operating temperature msk5101 msk5101h -20v to +60v 26v -0.3v to 26v 3.5a v inp v in v en i out t st t ld t j electrical specifications absolute maximum ratings -65c to +150c 300c -40c to +85c -55c to +125c 1 2 3 4 5 6 7 8 notes: output decoupled to ground using 10 f minimum capacitor unless otherwise specified. this parameter is guaranteed by design but need not be tested. typical parameters are representative of actual device performance but are for reference only. all output parameters are tested using a low duty cycle pulse to maintain t j = t c . industrial grade shall be tested to subgroups 1 and 4 unless otherwise specified. military grade devices ('h' suffix) shall be 100% tested to subgroups 1,2,3 and 4. subgroup 1,4 subgroup 2 subgroup 3 due to current limit, maximum output current may not be available at all values of v in -v out and temperatures. see typical performance curves for clarification. continuous operation at or above absolute maximum ratings may adversly effect the device performance and/or life cycle. t c =+25c t j =+125c t a =-55c 2 8 8548-43 rev. j 2/13
application notes heat sink selection: to select a heat sink for the msk 5101, the following formula for convective heat flow may be used. governing equation: tj = pd x (r jc + r cs + r sa) + ta where: tj = junction temperature pd = total power dissipation r jc = junction to case thermal resistance r cs = case to heat sink thermal resistance r sa = heat sink to ambient thermal resistance ta = ambient temperature regulator protection: the msk 5101 is fully protected against reversed input polar- ity, overcurrent faults, overtemperature conditions (pd) and tran- sient voltage spikes of up to 60v. if the regulator is used in dual supply systems where the load is returned to a negative supply, the output voltage must be diode clamped to ground. output capacitor: the output voltage ripple of the msk 5101 voltage regulator can be minimized by placing a filter capacitor from the output to ground. the optimum value for this capacitor may vary from one application to the next, but a minimum of 10 f is recom- mended for optimum performance. transient load response can also be improved by placing a capacitor directly across the load. load connections: in voltage regulator applications where very large load currents are present, the load connection is very important. the path connecting the output of the regulator to the load must be extremely low impedance to avoid affecting the load regulation specifications. any impedance in this path will form a voltage divider with the load. the msk 5101 requires a minimum of 10ma of load current to stay in regulation. enable pin: the msk 5101 voltage regulator is equipped with a ttl com- patible enable pin. a ttl high level on this pin activates the internal bias circuit and powers up the device. a ttl low level on this pin places the controller in shutdown mode and the device draws approximately 10 a of quiescent current. if the enable function is not used, simply connect the enable pin to the input. msk5101-00 output adjustment: the diagram below illustrates proper adjustment technique for the output voltage. the series resistance of r1+r2 should be selected to pass the minimum regulator output current require- ment of 10ma. first, the power dissipation must be calculated as follows: power dissipation = (vin - vout) x iout next, the user must select a maximum junction temperature. the maximum allowable junction temperature is 125c. the equation may now be rearranged to solve for the required heat sink to ambient thermal resistance (r sa). example: an msk 5101 is configured for vin=+5v and vout=+3.3v. iout is a continuous 1a dc level. the ambient temperature is +25c. the maximum desired junction temperature is 125c. r jc = 6c/w and r cs = 0.5c/w typically. power dissipation = (5v - 3.3v) x (1a) solve for r sa: r sa = 125c - 25c - 6c/w - 0.5c/w in this example, a heat sink with a thermal resistance of no more than 52c/w must be used to maintain a junction temperature of no more than 125c. 1.7w = 1.7 watts device soldering/case connection: the msk 5101 is a highly thermally conductive device, and the thermal path from the package base to the internal junctions is very short. standard surface mount techniques should be used when soldering the device into a circuit board. the external heat sink/pad needs to be connected to ground because the base of the msk 5101 is also electrically connected to ground. the user is urged to keep this in mind when designing the printed circuit board for the msk 5101. there should be no printed circuit traces making contact with the base of the device except for ground. the ground plane can be used to pull heat away from the device. 3 = 52.3c/w 8548-43 rev. j 2/13
typical performance curves 4 8548-43 rev. j 2/13
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. please visit our website for the most recent revision of this datasheet. mechanical specifications m.s. kennedy corp. 4707 dey road, liverpool, new york 13088 phone (315) 701-6751 fax (315) 701-6752 www.mskennedy.com note: all dimensions are 0.010 inches unless otherwise labeled. esd triangle indicates pin 1. msk5101-00 h ordering information screening blank=industrial; h=mil-prf-38534 class h output voltage 00=adjustable general part number 5 weight= 0.3 grams typical 8548-43 rev. j 2/13
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