SNVS099I May   1999  – October 2016 LM2991

PRODUCTION DATA.  

  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 Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 ON/Off Pin
      2. 7.3.2 Forcing The Output Positive
      3. 7.3.3 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operation with VOUT(TARGET) -5 V ≥ VIN > -26 V
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 External Capacitors
          1. 8.2.2.1.1 Input Capacitor
          2. 8.2.2.1.2 Output Capacitor
        2. 8.2.2.2 Ceramic Bypass Capacitors
        3. 8.2.2.3 Minimum Load
        4. 8.2.2.4 Setting The Output Voltage
        5. 8.2.2.5 Power Dissipation
        6. 8.2.2.6 Estimating Junction Temperature
      3. 8.2.3 Application Curves
      4. 8.2.4 Additional Application Circuits
  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 Device Support
      1. 11.1.1 Device Nomenclature
    2. 11.2 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Community Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

6 Specifications

6.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)(2)
MIN MAX UNIT
Input voltage –26 0.3 V
Power dissipation(3) Internally limited
Storage temperature, 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.
(2) If Military/Aerospace specified devices are required, contact the Texas Instruments Sales Office/Distributors for availability and specifications.
(3) The maximum power dissipation is a function of TJ(MAX), RθJA, and TA. The maximum allowable power dissipation at any ambient temperature is PD = (TJ(MAX) − TA)/RθJA. If this dissipation is exceeded, the die temperature will rise above 125°C, and the LM2991 will eventually go into thermal shutdown at a TJ of approximately 160°C. Refer to Thermal Shutdown for more details.

6.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2000 V
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.

6.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)(1)
MIN NOM MAX UNIT
Junction temperature, TJ –40 125 °C
ON/OFF pin 0 5 V
Maximum input voltage (operational) –26 V
(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.

6.4 Thermal Information

THERMAL METRIC(1) LM2991 UNIT
TO-263 (KTT) TO-220 (NDH)(2) TO-220 (KC)(2)
5 PINS 5 PINS 5 PINS
RθJA(3) Junction-to-ambient thermal resistance, High-K 27.8 54.4 56.4 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 41.4 30.1 40.0 °C/W
RθJB Junction-to-board thermal resistance 10.9 33.2 38.6 °C/W
ψJT Junction-to-top characterization parameter 6.0 11.6 12.8 °C/W
ψJB Junction-to-board characterization parameter 10.6 36.2 35.3 °C/W
RθJC(bot) Junction-to-case (bottom) thermal resistance 0.7 0.5 0.6 °C/W
(1) For more information about traditional and new thermal metrics, see Semiconductor and IC Package Thermal Metrics.
(2) The TO-220 package is vertically mounted in center of a JEDEC High-K test board (JESD 51-7) with no additional heat sink attached. This is a through-hole package; this is NOT a surface-mount package.
(3) Thermal resistance value RθJA is based on the EIA/JEDEC High-K printed circuit board defined by JESD51-7 - High Effective Thermal Conductivity Test Board for Leaded Surface Mount Packages.

6.5 Electrical Characteristics

VIN = −10 V, VOUT = −3 V, IOUT = 1 A, COUT = 47 μF, R1 = 2.7 kΩ, TJ = 25°C, unless otherwise specified.
PARAMETER TEST CONDITIONS MIN TYP(1) MAX UNIT
Reference voltage 5 mA ≤ IOUT ≤ 1 A –1.234 –1.210 –1.186 V
5 mA ≤ IOUT ≤ 1 A, VOUT – 1 V ≥ VIN > −26 V
−40°C ≤ TJ ≤ 125°C		 –1.27 –1.15 V
Output voltage (VOUT) –2 –3 V
VIN = −26 V –24 –25 V
Line regulation IOUT = 5 mA, VOUT −1 V > VIN > −26 V 0.004 0.04 %/V
Load regulation 50 mA ≤ IOUT ≤ 1 A 0.04% 0.4%
Dropout voltage IOUT = 0.1 A, ΔVOUT ≤ 100 mV 0.1 0.2 V
IOUT = 0.1 A, ΔVOUT ≤ 100 mV
−40°C ≤ TJ ≤ 125°C		 0.3
IOUT = 1 A, ΔVOUT ≤ 100 mV 0.6 0.8 V
IOUT = 1 A, ΔVOUT ≤ 100 mV
−40°C ≤ TJ ≤ 125°C		 1
Quiescent current IOUT ≤ 1 A 0.7 mA
IOUT = 1 A, −40°C ≤ TJ ≤ 125°C 5
Dropout quiescent current VIN = VOUT, IOUT ≤ 1 A 16 50 mA
Ripple rejection Vripple = 1 VRMS,
ƒripple = 1 kHz, IOUT = 5 mA		 50 60 dB
Output noise 10 Hz to 100 kHz, IOUT = 5 mA 200 450 µV
ON/OFF input voltage VOUT: ON 1.2 V
VOUT: ON −40°C ≤ TJ ≤ 125°C 0.8
VOUT: OFF 1.3 V
VOUT: OFF, −40°C ≤ TJ ≤ 125°C 2.4
ON/OFF input current VON/OFF = 0.8 V, VOUT: ON 0.1 10 µA
VON/OFF = 2.4 V, VOUT: OFF 40 100
Output leakage current VIN = −26 V, VON/OFF = 2.4 V, VOUT = 0 V 60 250 µA
Current limit VOUT = 0 V 1.5 2 A
(1) Typicals are at TJ = 25°C and represent the most likely parametric norm.

6.6 Typical Characteristics

LM2991 1126013.png
Figure 1. Dropout Voltage
LM2991 1126015.png
Figure 3. Output Voltage
LM2991 1126017.png
Figure 5. Quiescent Current
LM2991 1126021.png
Figure 7. Maximum Output Current
LM2991 1126023.png
Figure 9. Output Impedance
LM2991 1126025.png
Figure 11. Adjust Pin Current
LM2991 1126027.png
Figure 13. Maximum Power Dissipation (TO-220)
LM2991 1126014.png
Figure 2. Normalized Output Voltage
LM2991 1126016.png
Figure 4. Output Noise Voltage
LM2991 1126018.png
Figure 6. Maximum Output Current
LM2991 1126022.png
Figure 8. Ripple Rejection
LM2991 1126024.png
Figure 10. ON/OFF Control Voltage
LM2991 1126026.png
Figure 12. Low Voltage Behavior
LM2991 D001_SNVS099.gif
Figure 14. Maximum Power Dissipation (DDPAK/TO-263)