? semiconductor components industries, llc, 2004 january, 2004 ? rev. 6 1 publication order number: cs5203?3/d cs5203-3 3.0 a, 3.3 v fixed linear regulator the cs5203?3 linear regulator provides 3.3 v reference at 3.0 a with an output voltage accuracy of 1.5%. this regulator is intended for use as a post regulator and microprocessor supply. the fast loop response and low dropout voltage make this regulator ideal for applications where low voltage operation and good transient response are important. the circuit is designed to provide 3.0 a of output current with dropout voltages of less than 1.15 v. the maximum quiescent current is only 10 ma at full load. device protection includes over?current and thermal shutdown. the cs5203?3 is pin compatible with the lt1085 family of linear regulators. the regulator is available in a surface mount d 2 pak?3 package. features ? output current to 3.0 a ? output accuracy to 1.5% over temperature ? dropout voltage (typical) 1.15 v @ 3.0 a ? fast transient response ? fault protection ? current limit ? thermal shutdown figure 1. application diagram cs5203?3 v in v out gnd 100 f 5.0 v 10 f 5.0 v 3.3 v @ 3.0 a 5.0 v d 2 pak?3 dp suffix case 418ab 1 2 3 tab = v out pin 1. gnd 2. v out 3. v in marking diagram cs5203?3 awlyww 1 a = assembly location wl, l = wafer lot yy, y = year ww, w = work week http://onsemi.com see detailed ordering and shipping information in the package dimensions section on page 5 of this data sheet. ordering information
cs5203?3 http://onsemi.com 2 maximum ratings* parameter value unit supply voltage, v in 7.0 v operating temperature range ?40 to +70 c junction temperature 150 c storage temperature range ?60 to +150 c lead temperature soldering: reflow (smd styles only) note 1 230 peak c esd damage threshold (human body model) 2.0 kv 1. 60 second maximum above 183 c *the maximum package power dissipation must be observed. electrical characteristics (c in = 10 f, c out = 22 f tantalum, v out + v dropout < v in < 7.0 v, 0 c t a 70 c, t j +150 c, unless otherwise specified, i full load = 3.0 a) characteristic test conditions min typ max unit fixed output voltage output voltage (notes 2 and 3) v in ? v out = 1.5 v; 0 i out 3.0 a 3.250 (?1.5%) 3.300 3.350 (+1.5%) v line regulation 2.0 v v in ? v out 3.7 v; i out = 10 ma ? 0.02 0.20 % load regulation (notes 2 and 3) v in ? v out = 2.0 v; 10 ma i out 3.0 a ? 0.04 0.4 % dropout voltage (note 4) i out = 3.0 a ? 1.15 1.4 v current limit v in ? v out = 3.0 v 3.1 4.6 ? a quiescent current i out = 10 ma ? 6.0 10 ma thermal regulation (note 5) 30 ms pulse, t a = 25 c ? 0.002 0.020 %/w ripple rejection (note 5) f = 120 hz; i out = 3.0 a; v in ? v out = 3.0 v; v ripple = 1.0 v pp ? 80 ? db thermal shutdown (note 6) ? 150 180 210 c thermal shutdown hysteresis (note 6) ? ? 25 ? c 2. load regulation and output voltage are measured at a constant junction temperature by low duty cycle pulse testing. changes i n output voltage due to temperature changes must be taken into account separately. 3. specifications apply for an external kelvin sense connection at a point on the output pin 1/4o from the bottom of the package . 4. dropout voltage is a measurement of the minimum input/output differential at full load. 5. guaranteed by design, not tested in production. 6. thermal shutdown is 100% functionally tested in production. package pin description package pin number d2pak?3 pin symbol function 1 gnd ground connection. 2 v out regulated output voltage (case). 3 v in input voltage.
cs5203?3 http://onsemi.com 3 figure 2. block diagram + ? thermal shutdown bandgap reference output current limit error amplifier v in v out gnd typical performance characteristics 0.60 output current (a) t j ( c) figure 3. dropout voltage vs. output current figure 4. output voltage deviation vs. temperature +0.3 0 dropout voltage (v) reference voltage deviation (%) 1.20 1.15 1.10 1.05 1.00 0.95 0.90 0.85 0.80 0.75 0 0.30 0.90 1.20 1.50 1.80 2.10 2.40 2.70 3.00 +0.2 +0.1 0 ?0.1 ?0.2 ?0.3 30 60 90 120 t case = 0 c t case = 125 c t case = 25 c output current (a) figure 5. load regulation vs. output current output voltage deviation (%) 0.16 0 0.12 0.08 0.04 0.00 1.5 3 t case = 0 c t case = 125 c t case = 25 c frequency (hz) figure 6. ripple rejection vs. frequency 85 10 1 ripple rejection (db) 75 65 55 45 35 25 15 10 2 10 3 10 4 10 5 10 6 t case = 25 c i out = 1.0 a (v in ? v out ) = 3.0 v v ripple = 1.0 v pp
cs5203?3 http://onsemi.com 4 time ( s) figure 7. transient response i (a) 0 +200 0 ?200 3 2 1 510 v out (mv) 0 v in = 5.0 v v out = 3.3 v c in = 100 f c out = 10 mf tantalum v in ? v out (v) figure 8. short circuit current vs. v in ? v out i sc (a) 1.0 6 5 4 3 2 1 0 1.5 2.0 2.5 3.0 3.5 applications information the cs5203?3 linear regulator provides a fixed 3.3 v output voltage at currents up to 3.0 a. the regulator is protected against overcurrent conditions and includes thermal shutdown. the cs5203?3 has a composite pnp?npn output transistor and requires an output capacitor for stability. stability considerations the output or compensation capacitor helps determine three main characteristics of a linear regulator: start?up delay, load transient response, and loop stability. the capacitor value and type is based on cost, availability, size and temperature constraints. a tantalum or aluminum electrolytic capacitor is best, since a film or ceramic capacitor with almost zero esr can cause instability. the aluminum electrolytic capacitor is the least expensive solution. however, when the circuit operates at low temperatures, both the value and esr of the capacitor will vary considerably. the capacitor manufacturer's data sheet provides this information. a 22 f tantalum capacitor will work for most applications, but with high current regulators such as the cs5203?3 the transient response and stability improve with higher values of capacitance. the majority of applications for this regulator involve large changes in load current so the output capacitor must supply the instantaneous load current. the esr of the output capacitor causes an immediate drop in output voltage given by: v i esr for microprocessor applications it is customary to use an output capacitor network consisting of several tantalum and ceramic capacitors in parallel. this reduces the overall esr and reduces the instantaneous output voltage drop under transient load conditions. the output capacitor network should be as close to the load as possible for the best results. protection diodes when large external capacitors are used with a linear regulator it is sometimes necessary to add protection diodes. if the input voltage of the regulator gets shorted, the output capacitor will discharge into the output of the regulator. the discharge current depends on the value of the capacitor, the output voltage and the rate at which v in drops. in the cs5203?3 linear regulator, the discharge path is through a large junction and protection diodes are not usually needed. if the regulator is used with large values of output capacitance and the input voltage is instantaneously shorted to ground, damage can occur. in this case, a diode connected as shown in figure 9 is recommended. figure 9. protection diode scheme for large output capacitors v in cs5203?3 v out gnd v out v in c 1 c 2 in4002 (optional)
cs5203?3 http://onsemi.com 5 output voltage sensing since the cs5203?3 is a three terminal regulator, it is not possible to provide true remote load sensing. load regulation is limited by the resistance of the conductors connecting the regulator to the load. for best results the regulator should be connected as shown in figure 10. figure 10. conductor parasitic resistance effects can be minimized with the above grounding scheme for fixed output regulators v in v in v out cs5203?3 conductor parasitic resistance r load r c calculating power dissipation and heat sink requirements the cs5203?3 linear regulator includes thermal shutdown and current limit circuitry to protect the device. high power regulators such as these usually operate at high junction temperatures so it is important to calculate the power dissipation and junction temperatures accurately to ensure that an adequate heat sink is used. the case is connected to v out on the cs5203?3, electrical isolation may be required for some applications. thermal compound should always be used with high current regulators such as these. the thermal characteristics of an ic depend on the following four factors: 1. maximum ambient temperature t a ( c) 2. power dissipation p d (watts) 3. maximum junction temperature t j ( c) 4. thermal resistance junction to ambient r ja ( c/w) these four are related by the equation t j t a p d r ja (1) the maximum ambient temperature and the power dissipation are determined by the design while the maximum junction temperature and the thermal resistance depend on the manufacturer and the package type. the maximum power dissipation for a regulator is: p d(max) { v in(max) v out(min) } i out(max) v in(max) i q (2) where: v in(max) is the maximum input voltage, v out(min) is the minimum output voltage, i out(max) is the maximum output current, for the application i q is the maximum quiescent current at i out(max) . a heat sink effectively increases the surface area of the package to improve the flow of heat away from the ic and into the surrounding air. each material in the heat flow path between the ic and the outside environment has a thermal resistance. like series electrical resistances, these resistances are summed to determine r ja , the total thermal resistance between the junction and the surrounding air. 1. thermal resistance of the junction to case, r jc ( c/w) 2. thermal resistance of the case to heat sink, r cs ( c/w) 3. thermal resistance of the heat sink to the ambient air, r sa ( c/w) these are connected by the equation: r ja r jc r cs r sa (3) the value for r ja is calculated using equation (3) and the result can be substituted in equation (1). the value for r jc is 3.5 c/w for a given package type based on an average die size. for a high current regulator such as the cs5203?3 the majority of the heat is generated in the power transistor section. the value for r sa depends on the heat sink type, while r cs depends on factors such as package type, heat sink interface (is an insulator and thermal grease used?), and the contact area between the heat sink and the package. once these calculations are complete, the maximum permissible value of r ja can be calculated and the proper heat sink selected. for further discussion on heat sink selection, see application note athermal management,o document number and8036/d, available through the literature distribution center or via our website at http://onsemi.com. ordering information orderable part number type* package shipping 2 cs5203?3gdp3 3.0 a, 3.3 v output d 2 pak?3 50 units / rail cs5203?3gdpr3 3.0 a, 3.3 v output d 2 pak?3 750 / tape & reel *consult your local sales representative for other package options. 2for information on tape and reel specifications, including part orientation and tape sizes, please refer to our tape and reel packaging specifications brochure, brd8011/d.
cs5203?3 http://onsemi.com 6 package dimensions d 2 pak?3 dp suffix case 418ab?01 issue o for d 2 pak outline and dimensions ? contact factory package thermal data parameter d 2 pak?3 unit r jc typical 3.5 c/w r ja typical 10?50* c/w * depending on thermal properties of substrate. r ja = r jc + r ca on semiconductor and are registered trademarks of semiconductor components industries, llc (scillc). scillc reserves the right to mak e changes without further notice to any products herein. scillc makes no warranty, representation or guarantee regarding the suitability of its products for an y particular purpose, nor does scillc assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including wi thout limitation special, consequential or incidental damages. atypicalo parameters which may be provided in scillc data sheets and/or specifications can and do vary in different application s and actual performance may vary over time. all operating parameters, including atypicalso must be validated for each customer application by customer's technical experts. scillc does not convey any license under its patent rights nor the rights of others. scillc products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the scillc product could create a sit uation where personal injury or death may occur. should buyer purchase or use scillc products for any such unintended or unauthorized application, buyer shall indemnify and hold scillc and its officers, employees, subsidiaries, af filiates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, direct ly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that scillc was negligent regarding the design or manufacture of the part. scillc is an equal opportunity/affirmative action employer. this literature is subject to all applicable copyright laws and is not for resale in any manner. publication ordering information n. american technical support : 800?282?9855 toll free usa/canada japan : on semiconductor, japan customer focus center 2?9?1 kamimeguro, meguro?ku, tokyo, japan 153?0051 phone : 81?3?5773?3850 cs5203?3/d literature fulfillment : literature distribution center for on semiconductor p.o. box 5163, denver, colorado 80217 usa phone : 303?675?2175 or 800?344?3860 toll free usa/canada fax : 303?675?2176 or 800?344?3867 toll free usa/canada email : orderlit@onsemi.com on semiconductor website : http://onsemi.com order literature : http://www.onsemi.com/litorder for additional information, please contact your local sales representative.
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