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  • TL317 100-mA 3-Terminal Adjustable Positive Voltage Regulator

    • SLVS004I April   1979  – August 2016 TL317

      PRODUCTION DATA.  

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  • TL317 100-mA 3-Terminal Adjustable Positive Voltage Regulator
  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristic
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagrams
    3. 7.3 Feature Description
      1. 7.3.1 NPN Darlington Output Drive
      2. 7.3.2 Programmable Feedback
    4. 7.4 Device Functional Modes
      1. 7.4.1 Normal Operation
      2. 7.4.2 Operation With Low Input Voltage
      3. 7.4.3 Operation in Light Loads
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Adjustable Voltage Regulator
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curve
      2. 8.2.2 0-V to 30-V Regulator Circuit
      3. 8.2.3 Regulator Circuit With Improved Ripple Rejection
      4. 8.2.4 Precision Current-Limiter Circuit
      5. 8.2.5 Tracking Preregulator Circuit
      6. 8.2.6 Slow-Turnon 15-V Regulator Circuit
      7. 8.2.7 50-mA Constant-Current Battery-Charger Circuit
      8. 8.2.8 Current-Limited 6-V Charger
      9. 8.2.9 High-Current Adjustable Regulator
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information
  13. IMPORTANT NOTICE

Package Options

Mechanical Data (Package|Pins)
  • D|8
    • MSOI002K
  • PW|8
    • MPDS568
  • LP|3
    • MSOT002D
  • PS|8
    • MSOP001A
Thermal pad, mechanical data (Package|Pins)
  • PS|8
    • QFND376
Orderable Information
  • slvs004i_oa
  • slvs004i_pm
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DATA SHEET

TL317 100-mA 3-Terminal Adjustable Positive Voltage Regulator

1 Features

  • Output Voltage Range Adjustable From
    1.25 V to 32 V When Used With an External
    Resistor Divider
  • Output Current Capability of 100 mA
  • Input Regulation Typically 0.01% Per
    Input-Voltage Change
  • Output Regulation Typically 0.5%
  • Ripple Rejection Typically 80 dB

2 Applications

  • Power Supplies
  • Portable Devices
  • Computing and Servers
  • Telecommunications
  • HVAC: Heating, Ventilation, and Air Conditioning
  • Desktop PC
  • Digital Signage
  • Programmable Logic Controller
  • Appliances

    • Functional Block Diagram

    TL317 fbd.gif

3 Description

The TL317 is an adjustable three-terminal positive-voltage regulator capable of supplying 100 mA over an output-voltage range of 1.25 V to 32 V. It is exceptionally easy to use and requires only two external resistors to set the output voltage.

This regulator offers full overload protection available only in integrated circuits. Included on the chip are current-limiting and thermal-overload protection. All overload-protection circuitry remains fully functional, even when ADJUSTMENT is disconnected. Normally, no capacitors are required unless the device is situated far from the input filter capacitors, in which case an input bypass is required. An optional output capacitor can be added to improve transient response. ADJUSTMENT can be bypassed to achieve very high ripple rejection.

In addition to replacing fixed regulators, the TL317 regulator is useful in a wide variety of other applications. Because the regulator is floating and sees only the input-to-output differential voltage, supplies of several hundred volts can be regulated as long as the maximum input-to-output differential is not exceeded. Its primary application is that of a programmable output regulator, but by connecting a fixed resistor between ADJUSTMENT and OUTPUT, this device can be used as a precision current regulator. Supplies with electronic shutdown can be achieved by clamping ADJUSTMENT to ground, programming the output to 1.25 V, where most loads draw little current.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
TL317D SOIC (8) 4.90 mm × 3.90 mm
TL317PW TSSOP (8) 4.30 mm × 3.00 mm
TL317PS SOP (8) 6.20 mm × 5.30 mm
TL317LP TO-92 (3) 4.83 mm × 3.68 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

4 Revision History

Changes from H Revision (September 2011) to I Revision

  • Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information sectionGo
  • Deleted Ordering Information table, see POA at the end of the datasheet.Go

Changes from G Revision (September 2009) to H Revision

  • Changed datasheet format from QuickSilver to DocZoneGo
  • Changed low end output voltage range from 1.2 V to 1.25Go
  • Added MIN value of 2.5 V for VI – VO parameter in the Recommended Operating Conditions tableGo

5 Pin Configuration and Functions

D Package
8-Pin SOIC
Top View
PW Package
8-Pin TSSOP
Top View
PS Package
8-Pin SOP
Top View
LP Package
3-Pin TO-92
Top View
TL317 po_lp3.png

Pin Functions

PIN I/O DESCRIPTION
NAME SOIC TSSOP SOP TO-92
ADJUSTMENT 4 4 6 3 — Supply reference voltage
INPUT 1 1 1 1 I Input supply voltage
NC 5, 8 2, 3, 5, 7, 8 2, 3, 4, 5, 7 — — No internal connection
OUTPUT 2, 3, 6, 7 6 8 2 O Output voltage, output terminals are all internally connected.

6 Specifications

6.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)
MIN MAX UNIT
Input-to-output differential voltage, Vl – VO 35 V
Operating virtual-junction temperature, TJ 150 °C
Storage temperature range, Tstg –65 150 °C
(1) 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.

6.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2000 V
Charged-device model (CDM), per JEDEC specification JESD22-C101(2) ±1000(3)
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
(3) Tested on PW package.

6.3 Recommended Operating Conditions

MIN NOM MAX UNIT
VI – VO Input-to-output voltage differential 2.5 35 V
IO Output current 2.5 100 mA
TJ Operating virtual-junction temperature TL317C 0 125 °C
TL317 –40 125 °C

6.4 Thermal Information

THERMAL METRIC(1) TL317 UNIT
D (SOIC) PW (TSSOP) PS (SOP) LP (TO-92)
8 PINS 8 PINS 8 PINS 3 PINS
RθJA Junction-to-ambient thermal resistance 109.9 170 115.3 157.9 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 58.8 51 67.1 81.6 °C/W
RθJB Junction-to-board thermal resistance 58.5 101.5 64.4 — °C/W
ψJT Junction-to-top characterization parameter 12.5 3.7 27.7 25.4 °C/W
ψJB Junction-to-board characterization parameter 57.9 99.1 63.5 137.1 °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report.

6.5 Electrical Characteristics

over recommended operating virtual-junction temperature range (unless otherwise noted)(1)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Input voltage regulation(2) VI – VO = 5 V to 35 V TJ = 25°C 0.01% 0.02% V
IO = 2.5 mA to 100 mA 0.02% 0.05%
Ripple regulation VO = 10 V, f = 120 Hz 65 dB
VO = 10 V,
10-µF capacitor between
ADJUSTMENT and ground		 66 80
Output voltage regulation VI = 5 V to 35 V,
IO = 2.5 mA to 100 mA,
TJ = 25°C		 VO ≤ 5 V 25 mV
VO ≥ 5 V 5 mV/V
VI = 5 V to 35 V,
IO = 2.5 mA to 100 mA		 VO ≤ 5 50 mV
VO ≥ 5 V 10 mV/V
Output voltage change with temperature TJ = 0°C to 125°C 10 mV/V
Output voltage long-term drift After 1000 hours at TJ = 125°C and VI – VO = 35 V 3 10 mV/V
Output noise voltage f = 10 Hz to 10 kHz, TJ = 25°C 30 µV/V
Minimum output current to maintain regulation VI – VO = 35 1.5 2.5 mA
Peak output current VI – VO ≤ 35 V 100 200 mA
ADJUSTMENT current 50 100 µA
Change in ADJUSTMENT current VI – VO = 2.5 V to 35 V, IO = 2.5 mA to 100 mA 0.2 5 µA
Reference voltage
(output to ADJUSTMENT)		 IO = 2.5 mA to 100 mA, VI − VO = 5 V to 35 V,
P ≤ rated dissipation		 1.2 1.25 1.3 V
(1) Unless otherwise noted, these specifications apply for the following test conditions: VI – VO = 5 V and IO = 40 mA. Pulse-testing techniques must be used that maintain the junction temperature as close to the ambient temperature as possible. All characteristics are measured with a 0.1-µF capacitor across the input and a 1-µF capacitor across the output.
(2) Input voltage regulation is expressed here as the percentage change in output voltage per 1-V change at the input.

6.6 Typical Characteristic

TL317 D002_SLVS004_DropoutVoltage.gif Figure 1. Dropout Voltage vs Load Current (TJ = 25°C)

7 Detailed Description

7.1 Overview

The TL317 device is an adjustable three-terminal positive-voltage regulator capable of supplying up to 100 mA over an output-voltage range of 1.25 V to 32 V. It requires only two external resistors to set the output voltage. The TL317 device is versatile in its applications, including uses in programmable output regulation and local on-card regulation. Also, by connecting a fixed resistor between the ADJUSTMENT and OUTPUT terminals, the TL317 device can function as a precision current regulator. An optional output capacitor can be added to improve transient response. The ADJUSTMENT terminal can be bypassed to achieve very high ripple-rejection ratios, which are difficult to achieve with standard three-terminal regulators.

7.2 Functional Block Diagrams

TL317 fbd.gif Figure 2. Equivalent Schematic
TL317 schematic_lvs004.gif
All component values shown are nominal
Figure 3. Detailed Schematic

7.3 Feature Description

7.3.1 NPN Darlington Output Drive

NPN Darlington output topology provides naturally low output impedance and an output capacitor is optional.

7.3.2 Programmable Feedback

An internal amplifier with 1.25-V offset input at the ADJUSTMENT terminal provides easy output voltage or current (not both) programming. For current regulation applications, a single resistor whose resistance value is 1.25 V / IO and power rating is greater than (1.25 V)2 / R must be used. For voltage regulation applications, two resistors set the output voltage as described in Adjustable Voltage Regulator.

7.4 Device Functional Modes

7.4.1 Normal Operation

The device OUTPUT pin sources current necessary to make the OUTPUT pin 1.25 V greater than the ADJUSTMENT pin to provide output regulation

7.4.2 Operation With Low Input Voltage

The device requires 2.5 V of headroom (VI – VO) to regulate the OUTPUT. With less headroom, the OUTPUT voltage of the device may be below the desired setpoint.

7.4.3 Operation in Light Loads

The device passes its bias current to the OUTPUT pin. The load or feedback must consume this minimum current for regulation or the output may be too high. The minimum current require to regulate is provided in the Electrical Characteristics, so the series resistance used to set the output voltage is recommended to be VO / IMIN to ensure regulation at all times.

8 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.

8.1 Application Information

The flexibility of the TL317 allows it to be configured to take on many different functions in DC power applications.

8.2 Typical Applications

8.2.1 Adjustable Voltage Regulator

TL317 app1_lvs004.gif Figure 4. Adjustable Voltage Regulator

8.2.1.1 Design Requirements

  • R1 and R2 are required to set the output voltage.
  • C1 is recommended, particularly if the regulator is not in close proximity to the power-supply filter capacitors. A 0.1-µF ceramic or 1-µF tantalum capacitor provides sufficient bypassing for most applications, especially when adjustment and output capacitors are used.
  • Use of an output capacitor, C2, improves transient response, but is optional.

8.2.1.2 Detailed Design Procedure

VO is calculated as shown in Equation 1. IADJ is typically 50 µA and negligible in most applications.

Power dissipation for linear regulators is calculated as shown in Equation 2. IADJ is typically 50 µA and negligible in most applications, so a typical way to calculate power dissipation for linear regulators is simplified to Equation 3.

Equation 1. VO = VREF (1 + R2 / R1) + (IADJ × R2)
Equation 2. P = (VI - VO) × IO + (VI - VADJ) × IADJ
Equation 3. P = (VI - VO) × IO

8.2.1.3 Application Curve

TL317 adjustment_voltage.gif Figure 5. Line Regulation

8.2.2 0-V to 30-V Regulator Circuit

VO is calculated as shown in Equation 4, where Vref equals the difference between OUTPUT and ADJUSTMENT voltages (approximately 1.25 V).

Equation 4. TL317 lm317l_appeqn.gif
TL317 app2_lvs004.gif Figure 6. 0-V to 30-V Regulator Circuit Schematic

8.2.3 Regulator Circuit With Improved Ripple Rejection

  • Protection diode D1 is recommended if C2 is used. The diode provides a low-impedance discharge path to prevent the capacitor from discharging into the output of the regulator
  • Use of an output capacitor, C2, improves transient response, but is optional.
TL317 app3_lvs004.gif Figure 7. Regulator Circuit With Improved Ripple Rejection Schematic

8.2.4 Precision Current-Limiter Circuit

The use of the TL317 in this configuration limits the output current to Ilimit shown in Figure 8.

TL317 app4_lvs004.gif Figure 8. Precision Current-Limiter Circuit

8.2.5 Tracking Preregulator Circuit

This application keeps a constant voltage across the second TL317 in the circuit.

TL317 app5_lvs004.gif Figure 9. Tracking Preregulator Circuit Schematic

8.2.6 Slow-Turnon 15-V Regulator Circuit

The capacitor C1, in combination with the PNP transistor, helps the circuit to slowly start supplying voltage. In the beginning, the capacitor is not charged. Therefore, output voltage starts at VC1+ VBE + 1.25 V = 0 V + 0.65 V + 1.25 V = 1.9 V. As the capacitor voltage rises, VOUT also rises at the same rate. When the output voltage reaches the value determined by R1 and R2, the PNP is turned off.

TL317 app6_lvs004.gif Figure 10. Slow-Turnon 15-V Regulator Circuit Schematic

8.2.7 50-mA Constant-Current Battery-Charger Circuit

The current limit operation mode can be used to trickle charge a battery at a fixed current. ICHG = 1.25 V / 24 Ω. VI must be greater than VBAT + 4.25 V (1.25 V [VREF] + 3 V [headroom]).

Power dissipation through resistor R1 is calculated as shown in Equation 5, so a resistor with the appropriate power rating must be chosen for this application.

Equation 5. P(R1) = IO2 × R1[Ω]
TL317 app7_lvs004.gif Figure 11. 50-mA Constant-Current Battery-Charger Circuit

8.2.8 Current-Limited 6-V Charger

As the charge current increases, the voltage at the bottom resistor increases until the NPN starts sinking current from the adjustment pin. The voltage at the adjustment pin drops, and consequently the output voltage decreases until the NPN stops conducting.

TL317 app8_lvs004.gif Figure 12. Current-Limited 6-V Charger Schematic

8.2.9 High-Current Adjustable Regulator

The NPNs at the top of the schematic allow higher currents at VOUT than the LM317 can provide, while still keeping the output voltage at levels determined by the adjustment pin resistor divider of the LM317.

TL317 app9_lvs004.gif
A. Minimum load current is 30 mA.
B. Optional capacitor improves ripples rejection.
Figure 13. High-Current Adjustable Regulator Schematic

 
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