CS52015-3 CHERRY | Alldatasheet
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Technical content
Features
n Output Current to 1.5A n Output Accuracy to ±1.5% Over Temperature n Dropout Voltage (typical) 1.05V @ 1.5A n Fast Transient Response n Fault Protection Current Limit Thermal Shutdown Package Options 3L TO-220 Tab (VOUT) CS52015-3 1.5A, 3.3V Fixed Linear Regulator CS52015-3 The CS52015-3 linear regulator pro- vides 1.5A at 3.3V with an output voltage accuracy of ±1.5%. The regulator is intended for use as a post regulator and microprocessor supply. The fast loop response and low dropout voltage make this reg- ulator ideal for applications where low voltage operation and good transient response are important. The circuit is designed to operate with dropout voltages less than 1.4V at 1.5A output current. The maximum quiescent current is only 10mA at full load. Device protec- tion includes overcurrent and ther- mal shutdown. The CS52015-3 is pin compatible with the LT1086 family of linear regulators but has lower dropout voltage. The regulator is available in TO- 220, surface mount D 2, and SOT-223 packages. Application Diagram Consult factory for other fixed output voltage options. CS52015 -3
1 Gnd
OUT (tab) 3V IN
Description
Tab (VOUT) A Company ¨ CS52015-3 VIN Gnd 3.3V @ 1.5A 22mF 5V10 mF VOUT 3L SOT-223 Tab (VOUT) Rev. 2/17/98 Cherry Semiconductor Corporation
2000 South County Trail, East Greenwich, RI 02818
Tel: (401)885-3600 Fax: (401)885-5786 Email: info@cherry-semi.com Web Site: www.cherry-semi.com
Lead Temperature Soldering PACKAGE PIN # PIN SYMBOL FUNCTION PARAMETER TEST CONDITIONS MIN TYP MAX UNIT Electrical Characteristics: CIN = 10µF, COUT = 22µF Tantalum, VOUT + VDROPOUT < VIN < 7V, 0¡C ² TA ² 70¡C, TJ ² +150¡C, unless otherwise specified, Ifull load = 1.5A. Package Pin Description n Fixed Output Voltage Output Voltage V INÐVOUT=1.5V 3.250 3.300 3.350 V (Notes 1 and 2) 0²I OUT²1.5A (-1.5%) (+1.5%) Line Regulation 2V²V INÐVOUT²3.7V; IOUT=10mA 0.02 0.20 % Load Regulation V INÐVOUT=2V; 10mA ²IOUT²1.5A 0.04 0.4 % (Notes 1 and 2) Dropout Voltage (Note 3) I OUT=1.5A 1.05 1.4 V Current Limit V INÐVOUT=3V 1.6 3.1 A Quiescent Current I OUT=10mA 5.0 10.0 mA Thermal Regulation (Note 4) 30ms pulse; T A=25¡C 0.002 0.020 %/W Ripple Rejection f=120Hz; I OUT=1.5A; VINÐVOUT=3V; 80 dB (Note 4) V RIPPLE=1VP-P Thermal Shutdown (Note 5) 150 180 210 ¡C Thermal Shutdown Hysteresis 25 ¡C (Note 5) Note 1: Load regulation and output voltage are measured at a constant junction temperature by low duty cycle pulse testing. Changes in out- put voltage due to temperature changes must be taken into account separately. Note 2: Specifications apply for an external Kelvin sense connection at a point on the output pin 1/4Ó from the bottom of the package. Note 3: Dropout voltage is a measurement of the minimum input/output differential at full load. Note 4: Guaranteed by design, not tested in production. Note 5: Thermal shutdown is 100% functionally tested in production. D2PAK TO-220 SOT-223 1 1 1 Gnd Ground connection 22 2 V OUT Regulated output voltage (case). 33 3 V IN Input voltage
0.75 0.80 0.85 0.90 0.95 1.00 1.05 IOUT (mA) V Drop Out (V) TCASE 0ûC TCASE 125ûC TCASE 25ûC 0 10 130 -0.12 0.10 Output Voltage Deviation (%) TJ (°C) 20 30 40 50 60 70 80 90 100 110 120 0.08 0.06 0.04 0.02 0.00 -0.02 -0.04 -0.06 -0.08 -0.10Dropout Voltage vs Output Current Output Voltage vs. Temperature Error Amplifier Output Current Limit VIN VOUT Gnd Thermal Shutdown Bandgap Typical Performance Characteristics 101 Frequency (Hz) Ripple Rejection (dB) 102 103 104 106105 TCASE = 25°C IOUT = 1.5A (VIN Ð VOUT) = 3V VRIPPLE = 1.0VPP Ripple Rejection vs. Frequency 1.5 2.5 3.0 3.5 1.5 ISC (A) VIN - VOUT (V) 1.7 1.9 2.1 2.3 3.1 3.3 1.0 4.0 2.5 2.7 2.9 3.5 Short Circuit Current vs VIN-VOUT
The CS52015-3 linear regulator provides a 3.3V output voltage at currents up to 1.5A. The regulator is protected against overcurrent conditions and includes thermal shutdown. The CS52015-3 has a composite PNP-NPN output transistor and requires an output capacitor for stability. A detailed procedure for selecting this capacitor is included in the Stability Considerations section. 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 are based on cost, availabili- ty, size and temperature constraints. A tantalum or alu- minum 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 solu- tion. However, when the circuit operates at low tempera- tures, both the value and ESR of the capacitor will vary considerably. The capacitor manufacturersÕ data sheet pro- vides this information. A 22µF tantalum capacitor will work for most applications, but with high current regulators such as the CS52015-3 the transient response and stability improve with higher val- ues of capacitance. The majority of applications for this regulator involve large changes in load current so the out- put capacitor must supply the instantaneous load current. The ESR of the output capacitor causes an immediate drop in output voltage given by: ÆV = ÆI ´ 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 load transient conditions. The output capacitor network should be as close as possible to the load for the best results. When large external capacitors are used with a linear regu- lator 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 capaci- tor, the output voltage and the rate at which V IN drops. In the CS52015-3 linear regulator, the discharge path is through a large junction and protection diodes are not usu- ally needed. If the regulator is used with large values of output capacitance and the input voltage is instantaneous- ly shorted to ground, damage can occur. In this case, a diode connected as shown in Figure 1 is recommended. Figure 1: Protection diode scheme for large output capacitors. Since the CS52015-3 is a three terminal regulator, it is not possible to provide true remote load sensing. Load regula- tion is limited by the resistance of the conductors connect- ing the regulator to the load. For best results the regulator should be connected as shown in Figure 2. Output Voltage Sensing VOUTVIN CS52015-3 VIN Gnd VOUT IN4002 (optional) Protection Diodes Stability Considerations Typical Performance Characteristics 02 3 4 5 6 750 Voltage Deviation (mV) -100 100 200 Time mS Load Step (mA) 10981 1500 -200 COUT =CIN =22mF Tantalum Transient Response Load Regulation vs. Output Current 0.025 0.000 0.050 0.075 0.100 01 2 Output Current (A) Output Voltage Deviation (%) TCASE = 0°C TCASE = 125°C TCASE = 25°C
Applications Information: continued Figure 2: Conductor parasitic resistance effects can be minimized with the above grounding scheme for fixed output regulators. The CS52015-3 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 CS52015-3, and elec- trical isolation may be required for some applications. Thermal compound should always be used with high cur- rent regulators such as these. The thermal characteristics of an IC depend on the follow- ing four factors: 1. Maximum Ambient Temperature T A (¡C) 2. Power dissipation PD (Watts) 3. Maximum junction temperature TJ (¡C) 4. Thermal resistance junction to ambient RQJA (C/W) These four are related by the equation TJ = TA + PD ´ RQJA (1) The maximum ambient temperature and the power dissi- pation 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)={VIN(max)ÐVOUT(min)}IOUT(max)+VIN(max)IQ (2) where VIN(max) is the maximum input voltage, VOUT(min) is the minimum output voltage, IOUT(max) is the maximum output current, for the application IQ is the maximum quiescent current at IOUT(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 QJA, the total thermal resistance between the junction and the surrounding air. 1. Thermal Resistance of the junction to case, RQJC (¡C/W) 2. Thermal Resistance of the case to Heat Sink, RQCS (¡C/W) 3. Thermal Resistance of the Heat Sink to the ambient air, RQSA (¡C/W) These are connected by the equation: RQJA = RQJC + RQCS + RQSA (3) The value for RQJA is calculated using equation (3) and the result can be substituted in equation (1). The value for RQJC is 3.5ûC/W. For a high current regulator such as the CS52015-3 the majority of the heat is generated in the power transistor section. The value for R QSA depends on the heat sink type, while RQCS depends on fac- tors such as package type, heat sink interface (is an insula- tor and thermal grease used?), and the contact area between the heat sink and the package. Once these calcula- tions are complete, the maximum permissible value of R QJA can be calculated and the proper heat sink selected. For further discussion on heat sink selection, see applica- tion note ÒThermal Management for Linear Regulators.Ó Calculating Power Dissipation and Heat Sink Requirements VOUTVIN CS52015-3 VIN RC RLOAD conductor parasitic resistance
Thermal Data TO-220 D 2PAK SOT-223 RQJC typ 3.5 3.5 15 ûC/W RQJA typ 50 10 - 50* 156 ûC/W *Depending on thermal properties of substrate.RQJA = RQJC + RQCA Part Number Type Description CS52015-3GT3 1.5A, 3.3V output 3 L TO-220 Straight CS52015-3GDP3 1.5A,3.3V output 3 L D 2PAK CS52015-3GDPR3 1.5A, 3.3V output 3 L D 2PAK (tape & reel) CS52015-3GST3 1.5A, 3.3V output 3 Lead SOT-223 CS52015-3GSTR3 1.5A, 3.3V output 3 Lead SOT-223 (tape & reel)
Ordering Information
Rev. 2/17/98 Package Specification PACKAGE THERMAL DATA CS52015-3 © 1999 Cherry Semiconductor Corporation Cherry Semiconductor Corporation reserves the right to make changes to the specifications without notice. Please contact Cherry Semiconductor Corporation for the latest available information. PACKAGE DIMENSIONS IN mm (INCHES)
3 Lead D2PAK (DP)
2.54 (.100) REF 10.31 (.406) 10.05 (.396) 8.53 (.336) 8.28 (.326) 0.91 (.036) 0.66 (.026) 1.40 (.055) 1.14 (.045) 4.57 (.180) 4.31 (.170) 1.68 (.066) 1.40 (.055) 2.74(.108) 2.49(.098) 1.40 (.055) 1.14 (.045) 0.10 (.004) 0.00 (.000) .254 (.010) REF 15.75 (.620) 14.73 (.580) 2.79 (.110) 2.29 (.090)
3 Lead TO-220 (T) Straight
5.33 (.210) 4.83 (.190) 2.79 (.110) 2.29 (.090) 1.02 (.040) 0.63 (.025) 0.56 (.022) 0.38 (.014) 1.40 (.055) 1.14 (.045) 4.83 (.190) 4.06 (.160) 6.17 (.243) REF 1.14 (.045) 1.52 (.060) 1.14 (.045) 1.40 (.055) 2.87 (.113) 5.94 (.234) 14.22 (.560) 13.72 (.540) 2.92 (.115) 2.29 (.090) 9.78 (.385) 10.54 (.415) 3.71 (.146) 3.96 (.156) 14.99 (.590) 14.22 (.560)
3 Lead SOT-223 (ST)
10° MAX 1.30 (.051) 1.10 (.043) 4.60 (.181) 2.30 (.090) 1.05 (.041) 0.85 (.033) 7.30 (.287) 6.70 (.264) 3.30 (.130) 3.70 (.146) 3.15 (.124) 2.95 (.116) 6.70 (.264) 6.30 (.248) 1.70 (.067) 1.50 (.060) 0.10 (.004) 0.02 (.001) 0.85 (.033) 0.65 (.026) 0.35 (.014) 0.25 (.010)