SNVS227H February   2003  – January 2015 LP3872 , LP3875

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 Shutdown (SD)
      2. 7.3.2 Load Voltage Sense
      3. 7.3.3 Short-Circuit Protection
      4. 7.3.4 Low Dropout Voltage
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Active Mode
      3. 7.4.3 ERROR Flag Operation
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Dropout Voltage
      2. 8.1.2 Reverse Current Path
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Power Dissipation and Device Operation
        2. 8.2.2.2 External Capacitors
        3. 8.2.2.3 Selecting a Capacitor
        4. 8.2.2.4 Capacitor Characteristics
          1. 8.2.2.4.1 Ceramic
          2. 8.2.2.4.2 Tantalum
          3. 8.2.2.4.3 Aluminum
        5. 8.2.2.5 Turnon Characteristics for Output Voltages Programmed to 2 V or Less
        6. 8.2.2.6 RFI/EMI Susceptibility
        7. 8.2.2.7 Output Noise
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
  11. 11Device and Documentation Support
    1. 11.1 Related Links
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 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(1)(2)

If Military/Aerospace specified devices are required, contact the Texas Instruments Sales Office/Distributors for availability and specifications.
MIN MAX UNIT
Lead temperature (soldering, 5 sec.) 260 °C
Power dissipation(3) Internally limited
IN pin to GND pin voltage −0.3 7.5 V
Shutdown (SD) pin to GND pin voltage −0.3 7.5 V
OUT pin to GND pin voltage(4), (5) −0.3 6 V
IOUT Short-circuit protected
ERROR pin to GND pin voltage VIN V
SENSE pin to GND pin voltage VOUT V
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, please contact the TI Sales Office/Distributors for availability and specifications.
(3) Internal thermal shutdown circuitry protects the device from permanent damage.
(4) If used in a dual-supply system where the regulator load is returned to a negative supply, the output must be diode-clamped to ground.
(5) The output PMOS structure contains a diode between the IN and OUT pins. This diode is normally reverse biased. This diode will get forward biased if the voltage at the output terminal is forced to be higher than the voltage at the input terminal. This diode can typically withstand 200 mA of DC current and 1 A of peak current.

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

MIN MAX UNIT
VIN supply voltage (1) 2.5 7 V
Shutdown (SD) voltage −0.3 7 V
Maximum operating current (DC) IOUT 1.5 A
Junction temperature –40 125 °C
(1) The minimum operating value for VIN is equal to either [VOUT(NOM) + VDROPOUT] or 2.5 V, whichever is greater.

6.4 Thermal Information

THERMAL METRIC(1) LP3872, LP3875 LP3875 UNIT
NDC (SOT-223) KTT (TO-263) NDH (TO-220)
5 PINS 5 PINS 5 PINS
RθJA Junction-to-ambient thermal resistance 65.2 40.3 32 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 47.2 43.4 43.8
RθJB Junction-to-board thermal resistance 9.9 23.1 18.6
ψJT Junction-to-top characterization parameter 3.4 11.5 8.8
ψJB Junction-to-board characterization parameter 9.7 22 18
RθJC(bot) Junction-to-case (bottom) thermal resistance n/a 1 1.2
(1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.

6.5 Electrical Characteristics

Unless otherwise specified: TJ = 25°C, VIN = VO(NOM) + 1 V, IL = 10 mA, COUT = 10 µF, VSD = 2 V.
PARAMETER TEST CONDITIONS MIN(1) TYP(2) MAX(1) UNIT
VOUT Output voltage tolerance (3) VOUT +1 V ≤ VIN ≤ 7 V, 10 mA ≤ IL ≤ 1.5 A –1.5% 0% 1.5%
VOUT +1 V ≤ VIN ≤ 7 V, 10 mA ≤ IL ≤ 1.5 A, –40°C ≤ TJ ≤ 125°C –3% 3%
ΔVOL Output voltage line regulation (3) VOUT + 1 V ≤ VIN ≤ 7 V 0.02%
VOUT + 1 V ≤ VIN ≤ 7 V, –40°C ≤ TJ ≤ 125°C 0.06%
ΔVO/ ΔIOUT Output voltage load regulation (3) 10 mA ≤ IL ≤ 1.5 A 0.06%
10 mA ≤ IL ≤ 1.5 A, –40°C ≤ TJ ≤ 125°C 0.12%
VIN - VOUT Dropout voltage (4) IL = 150 mA 38 50 mV
IL = 150 mA, –40°C ≤ TJ ≤ 125°C 60
IL = 1.5 A 380 450
IL = 1.5 A, –40°C ≤ TJ ≤ 125°C 550
IGND Ground pin current in normal operation mode IL = 150 mA 5 9 mA
IL = 150 mA,–40°C ≤ TJ ≤ 125°C 10
IL = 1.5 A 6 14
IL = 1.5 A, –40°C ≤ TJ ≤ 125°C 15
IGND Ground pin current in shutdown mode VSD ≤ 0.3 V 0.01 10 µA
–40°C ≤ TJ ≤ 85°C 50
IO(PK) Peak output current VOUT ≥ VO(NOM) – 4% 1.8 A
SHORT CIRCUIT PROTECTION
ISC Short-circuit current 3.2 A
SHUTDOWN INPUT
VSDT Shutdown threshold Output = High VIN V
Output = High, –40°C ≤ TJ ≤ 125°C 2
Output = Low 0
Output = Low, –40°C ≤ TJ ≤ 125°C 0.3
TdOFF Turnoff delay IL = 1.5 A 20 µs
TdON Turnon delay IL = 1.5 A 25 µs
ISD SD input current VSD = VIN 1 nA
ERROR FLAG
VT Threshold See(5) 10%
See(5), –40°C ≤ TJ ≤ 125°C 5% 16%
VTH Threshold hysteresis See(5) 5%
See(5), –40°C ≤ TJ ≤ 125°C 2% 8%
VEF(Sat) ERROR flag saturation Isink = 100 µA 0.02 V
Isink = 100 µA, –40°C ≤ TJ ≤ 125°C 0.1
Td Flag reset delay 1 µs
Ilk ERROR flag pin leakage current 1 nA
Imax ERROR flag pin sink current VError = 0.5 V 1 mA
AC PARAMETERS
PSRR Ripple rejection VIN = VOUT + 1 V, COUT = 10 µF
VOUT = 3.3 V, f = 120 Hz		 73 dB
VIN = VOUT + 0.5 V, COUT = 10 µF
VOUT = 3.3 V, f = 120 Hz		 57
ρn(l/f) Output noise density f = 120 Hz 0.8 µV
en Output noise voltage BW = 10 Hz – 100 kHz, VOUT = 2.5 V 150 µV (rms)
BW = 300 Hz – 300 kH, VOUT = 2.5 V 100
(1) Limits are specified by testing, design, or statistical correlation.
(2) Typical numbers are at 25°C and represent the most likely parametric norm.
(3) Output voltage line regulation is defined as the change in output voltage from the nominal value due to change in the input line voltage. Output voltage load regulation is defined as the change in output voltage from the nominal value due to change in load current. The line and load regulation specification contains only the typical number. However, the limits for line and load regulation are included in the output voltage tolerance specification.
(4) Dropout voltage is defined as the minimum input to output differential voltage at which the output drops 2% below the nominal value. Dropout voltage specification applies only to output voltages of 2.5 V and above. For output voltages below 2.5 V, the dropout voltage is nothing but the input to output differential, because the minimum input voltage is 2.5 V.
(5) ERROR Flag threshold and hysteresis are specified as percentage of regulated output voltage. See ERROR Flag Operation.

6.6 Typical Characteristics

Unless otherwise specified: TJ = 25°C, COUT = 10 µF, CIN = 10 µF, SD pin is tied to VIN, VOUT = 2.5 V, VIN = VO(NOM) + 1 V, IL = 10 mA
20063360.gifFigure 1. Dropout Voltage vs Output Load Current
20063355.gifFigure 3. Shutdown IQ vs Junction Temperature
20063354.gifFigure 2. Ground Current vs Output Voltage
IL = 1.5 A
20063357.gifFigure 4. Errorflag Threshold vs Junction Temperature
20063358.gifFigure 5. DC Load Reg. vs Junction Temperature
20063361.gifFigure 7. Noise vs Frequency
20063359.gifFigure 6. DC Line Regulation vs Temperature