XL317

XL317 SOP8 1 Features 3 Description • • • • • • • • • • • The XL317 is an adjustable positive voltage regulator capable of supplying 100 mA over a 1.2-V to 37-V output range. The XL317 is easy to use and requires only two external resistors to set the output voltage. Both line and load regulation are better than standard fixed regulators. The XL317 is available packaged in a standard, easy-to-use TO-92 transistor package. 1 • • Adjustable Output Down to 1.2 V 100-mA Output Current Capable of Handling up to 40V VIN Line Regulation Typically 0.01% /V Load Regulation Typically 0.1% /A No Output Capacitor Required (†) Current Limit Constant With Temperature Eliminates the Need to Stock Many Voltages Standard 3-Lead Transistor Package 80-dB Ripple Rejection Available in 3-Pin TO-92, 8-Pin SOIC, or 6-pin DSBGA Packages Output is Short-Circuit Protected See AN-1112 (SNVA009) for DSBGA Considerations The XL317 offers full overload protection. Included on the chip are current limit, thermal overload protection, and safe area protection. Normally, no capacitors are required unless the device is situated more than 6 inches from the input filter capacitors, in which case an input bypass is required. The XL317 uses floating topology and sees only the input-to-output differential voltage, therefore supplies of several hundred volts can be regulated, provided the maximum input-to-output differential is not exceeded. The device makes a simple adjustable switching regulator, a programmable output regulator, or by connecting a fixed resistor between the adjustment and output, the XL317 can be used as a precision current regulator. 2 Applications • • • • • Automotive LED Lighting Battery Chargers Post Regulation for Switching Supplies Constant-Current Regulators Microprocessor Supplies The XL317 is available in a standard 3-pin TO-92 transistor package, the 8-pin SOIC package, and 6pin DSBGA package. The XL317 is rated for operation over a −40°C to 125°C range. Schematic Diagram 4 Device Information(1) PART NUMBER 317 Full output current not available at high input-output voltages †Optional—improves transient response *Needed if device is more than 6 inches from filter capacitors 1 1 PACKAGE BODY SIZE (NOM) TO-92 (3) 4.30 mm × 4.30 mm SOIC (8) 3.91 mm × 4.90 mm DSBGA (6) 1.68 mm × 1.019 mm XL317 SOP8 5 Pin Configuration and Functions LP Plastic Package 3-Pin TO-92 Bottom View D Package 8-Pin SOIC Top View YPB Package 6-Pin DSBGA Top View YPB Package 6-Pin DSBGA Laser Mark Pin Functions PIN NAME TO-92 SOIC DSBGA I/O DESCRIPTION VIN 3 1 C1 I Supply input pin VOUT 2 2, 3, 6, 7 A1 O Voltage output pin Output voltage adjustment pin. Connect to a resistor divider to set VO. ADJ 1 4 B2 I NC — 5, 8 B1, A2, C2 — No connection 2 XL317 SOP8 6 Specifications 6.1 Absolute Maximum Rating (1) (2) MIN Power dissipation MAX Input-output voltage differential −40 Operating junction temperature Lead temperature (soldering, 4 seconds) −55 Storage temperature, Tstg (1) (2) UNIT Internally Limited 40 V 125 °C 260 °C 150 °C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. If Military/Aerospace specified devices are required, contact the Texas Instruments Sales Office/Distributors for availability and specifications. 6.2 ESD Ratings V(ESD) (1) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1) VALUE UNIT ±2000 V JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. Pins listed as ±2000 V may actually have higher performance. 6.3 Recommended Operating Conditions over operating free-air temperature range (unless otherwise noted) Operating temperature MIN MAX UNIT −40 125 °C 6.4 Thermal Information XL317 TO-92 THERMAL METRIC (1) SOIC DSBGA 6 PINS UNIT 3 PINS 0.4-in Leads 0.125-in Leads 8 PINS 180 160 165 290 °C/W RθJC(top) Junction-to-case (top) thermal resistance — 80.6 — — °C/W RθJB Junction-to-board thermal resistance — — — — °C/W ψJT Junction-to-top characterization parameter — 24.7 — — °C/W ψJB Junction-to-board characterization parameter — 135.8 — — °C/W RθJC(bot) Junction-to-case (bottom) thermal resistance — — — — °C/W RθJA (1) Junction-to-ambient thermal resistance For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953. 3 XL317 SOP8 6.5 Electrical Characteristics (1) PARAMETER TEST CONDITIONS Line regulation TJ = 25°C, 3 V ≤ (VIN − VOUT) ≤ 40 V, IL ≤ 20 mA (2) Load regulation TJ = 25°C, 5 mA ≤ IOUT ≤ IMAX Thermal regulation TJ = 25°C, 10-ms Pulse MIN (2) Adjustment pin current change Reference voltage 3 V ≤ (VIN − VOUT) ≤ 40 V (3) 5 mA ≤ IOUT ≤ 100 mA, P ≤ 625 mW Line regulation 3 V ≤ (VIN − VOUT) ≤ 40 V, IL ≤ 20 mA (2) Load regulation 5 mA ≤ IOUT ≤ 100 mA Temperature stability TMIN ≤ TJ ≤ TMAX Minimum load current Current limit RMS output noise, % of VOUT Ripple rejection ratio Long-term stability (1) (2) (3) UNIT 0.01 %/V 0.04 0.1% 0.5% Adjustment pin current 5 mA ≤ IL ≤ 100 mA 3 V ≤ (VIN − VOUT) ≤ 40 V, P ≤ 625 mW TYP MAX 1.2 (2) 0.04 0.2 %/W 50 100 μA 0.2 5 μA 1.25 1.3 V 0.02 0.07 %/V 0.3% 1.5% 0.65% (VIN − VOUT) ≤ 40 V 3.5 5 3 V ≤ (VIN − VOUT) ≤ 15 V 1.5 2.5 100 200 300 25 50 150 3 V ≤ (VIN − VOUT) ≤ 13 V (VIN − VOUT) = 40 V TJ = 25°C, 10 Hz ≤ f ≤ 10 kHz mA mA 0.003% VOUT = 10 V, f = 120 Hz, CADJ = 0 CADJ = 10 μF 65 66 TJ = 125°C, 1000 Hours dB 80 0.3% 1% Unless otherwise noted, these specifications apply: −25°C ≤ Tj ≤ 125°C for the XL317; VIN − VOUT = 5 V and IOUT = 40 mA. Although power dissipation is internally limited, these specifications are applicable for power dissipations up to 625 mW. IMAX is 100 mA. Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to heating effects are covered under the specification for thermal regulation. Thermal resistance of the TO-92 package is 180°C/W junction to ambient with 0.4-inch leads from a PCB and 160°C/W junction to ambient with 0.125-inch lead length to PCB. 4 XL317 SOP8 6.6 Typical Characteristics (Output capacitor = 0 μF unless otherwise noted.) Figure 1. Load Regulation Figure 2. Current Limit Figure 3. Adjustment Current Figure 4. Dropout Voltage Figure 5. Reference Voltage Temperature Stability Figure 6. Minimum Operating Current 5 XL317 SOP8 Typical Characteristics (continued) (Output capacitor = 0 μF unless otherwise noted.) Figure 7. Ripple Rejection Figure 8. Ripple Rejection Figure 9. Output Impedance Figure 10. Line Transient Response Figure 11. Load Transient Response Figure 12. Thermal Regulation 6 XL317 SOP8 7 Detailed Description 7.1 Overview In operation, the XL317 develops a nominal 1.25-V reference voltage, VREF, between the output and adjustment terminal. The reference voltage is impressed across program resistor R1 and, because the voltage is constant, a constant current I1 then flows through the output set resistor R2, giving an output voltage of: (1) Because the 100-μA current from the adjustment terminal represents an error term, the XL317 was designed to minimize IADJ and make it very constant with line and load changes. To do this, all quiescent operating current is returned to the output establishing a minimum load current requirement. If there is insufficient load on the output, the output will rise. Figure 13. Typical Application Circuit for Adjustable Regulator 7.2 Functional Block Diagram 7 XL317 SOP8 8 Application and Implementation 8.1 Application Information The XL317 is a versatile, high-performance, linear regulator with 1% output-voltage accuracy. An output capacitor can be added to further improve transient response, and the ADJ pin can be bypassed to achieve very high ripple-rejection ratios. Its functionality can be used in many different applications that require high performance regulation, such as battery chargers, constant-current regulators, and microprocessor supplies. 8.2 Typical Applications 8.2.1 1.25-V to 25-V Adjustable Regulator Full output current not available at high input-output voltages †Optional—improves transient response *Needed if device is more than 6 inches from filter capacitors Figure 16. 1.25-V to 25-V Adjustable Regulator 8.2.1.1 Design Requirements The device component count is very minimal, employing two resistors as part of a voltage-divider circuit and an output capacitor for load regulation. An input capacitor is needed if the device is more than 6 inches from filter capacitors. An optional bypass capacitor across R2 can also be used to improve PSRR. 8.2.1.2 Detailed Design Procedure The output voltage is set based on the selection of the two resistors, R1 and R2, as shown in Figure 16. For details on capacitor selection, see External Capacitors. 8 XL317 SOP8 98