SNVS296J December   2006  – June 2016 LP3991

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 Timing Requirements
    7. 6.7 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 Post-Buck Regulator
      2. 7.3.2 Maximum Supply Voltage and Thermal Considerations
    4. 7.4 Device Functional Modes
      1. 7.4.1 Enable Control
  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
        2. 8.2.2.2 Input Capacitor
        3. 8.2.2.3 Output Capacitor
        4. 8.2.2.4 No-Load Stability
        5. 8.2.2.5 Capacitor Characteristics
        6. 8.2.2.6 Power Dissipation
        7. 8.2.2.7 Estimating Junction Temperature
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 DSBGA Mounting
    4. 10.4 DSBGA Light Sensitivity
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 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)(3)
MIN MAX UNIT
IN, OUT pins, voltage to GND –0.3 6.5 V
EN pin, voltage to GND –0.3 (VIN + 0.3) < 6.5 V
Junction temperature 150 °C
Continuous power dissipation(4) 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) All voltages are with respect to the potential at the GND pin.
(3) If Military/Aerospace specified devices are required, contact the Texas Instruments Sales Office/ Distributors for availability and specifications.
(4) Internal thermal shutdown circuitry protects the device from permanent damage.

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) ±200
(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.

6.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)
MIN NOM MAX UNIT
Input voltage 1.65 4 V
Recommended load current 300 mA
Junction temperature –40 125 °C
Ambient temperature, TA(1) –40 85 °C
(1) The maximum ambient temperature (TA-MAX) is a suggested value dependant on the maximum operating junction temperature (TJ-MAX-OP) = 125°C); the maximum power dissipation of the device in the application (PD-MAX), and the junction-to-ambient thermal resistance of the part / package in the application (RθJA), as given by the following equation: TA-MAX = TJ-MAX-OP – (RθJA × PD-MAX).

6.4 Thermal Information

THERMAL METRIC(1) LP3991 UNIT
YZR (DSBGA)
4 PINS
RθJA(2) Junction-to-ambient thermal resistance, High K 189.7 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 0.5 °C/W
RθJB Junction-to-board thermal resistance 112.9 °C/W
ψJT Junction-to-top characterization parameter 8.7 °C/W
ψJB Junction-to-board characterization parameter 112.8 °C/W
(1) For more information about traditional and new thermal metrics, see Semiconductor and IC Package Thermal Metrics.
(2) 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

Unless otherwise noted, VEN = 950 mV, VIN = VOUT + 0.5 V, or 1.8 V, whichever is higher, CIN = 1 µF, COUT = 4.7 µF, IOUT = 1 mA. Typical values and limits apply for TA = 25°C. Minimum and maximum limits apply over the full junction temperature range for operation, −40°C to +125°C, unless otherwise specified. (1)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
VIN Input voltage See(2) 1.65 3.6 V
See(3)(4)(5) 4
ΔVOUT Output voltage tolerance VIN = VIN(NOM) to 3.6 V
ILOAD = 1 to 300 mA		 TJ = 25°C –1% 1%
–3% 3%
TJ = –25°C to 85°C –2.5% 2.5%
Line regulation error VIN = VOUT(NOM) 0.5 V to 3.6 V,
IOUT = 1 mA, 0.8 V ≤ VOUT ≤ 2.8 V		 0.05 1 %/V
Load regulation error IOUT = 1 mA to 300 mA 10 60 µV/mA
VDO Dropout voltage(6) 1.8 V ≤ VOUT ≤ 2.5 V IOUT = 150 mA 55 90 mV
IOUT = 300 mA 110 180
VOUT > 2.5 V IOUT = 150 mA 40 80
IOUT = 300 mA 75 160
ILOAD Minimum load current See(7) 0 mA
IQ Quiescent current VEN = 950 mV, IOUT = 0 mA 50 100 µA
VEN = 950 mV, IOUT = 300 mA 120 225
VEN = 0.4 V 0.001 1
ISC Short-circuit current limit VIN = 3.6 V(8) 550 900 mA
IOUT Maximum output current 300 mA
PSRR Power Supply Rejection Ratio(9) ƒ = 1kHz, IOUT = 1 mA to 300 mA 65 dB
en Output noise voltage(9) BW = 10 Hz to 100 kHz,
VIN = 4.2 V, COUT = 4.7 µF		 280 µVRMS
TSHUTDOWN Thermal shutdown Temperature 160 °C
Hysteresis 20
ENABLE CONTROL CHARACTERISTICS
IEN(10) Maximum input current at VEN input VEN = 0 V, VIN = 3.6 V 0.001 µA
VEN = VIN = 3.6 V 3 5.5
VIL Low input threshold VIN = 1.65 V to 3.6 V 0.4 V
VIH High input threshold VIN = 1.65 V to 3.6 V 0.95 V
TIMING CHARACTERISTICS
Transient Response Line transient response |δVOUT| Trise = Tfall = 30 µs(9)
δVIN = 600 mV		 6 mV
(pk - pk)
Load transient response |δVOUT| Trise = Tfall = 1 µs(9) IOUT = 0 mA to 300 mA 140 mV
IOUT = 1 mA to 300 mA 110
IOUT = 300 mA to 1 mA 80
IOUT = 0 mA to 200 mA 110
IOUT = 1 mA to 200 mA 80
IOUT = 200 mA to 1 mA 60
IOUT = 0 mA to 150 mA 100
IOUT = 1 mA to 150 mA 70
IOUT = 150 mA to 1 mA 50
Overshoot on start-up 0% 2%
IIR In-rush current(9) 600 1000 mA
OUTPUT CAPACITANCE
COUT Output capacitor Capacitance(11) VOUT ≥ 1.5 V 2 4.7 µF
VOUT < 1.5 V(12) 1.6 2.2
ESR 5 500 mΩ
(1) All limits are ensured. All electrical characteristics having room-temperature limits are tested during production at TJ = 25°C or correlated using Statistical Quality Control methods. Operation over the temperature specification is ensured by correlating the electrical characteristics to process and temperature variations and applying statistical process control.
(2) All voltages are with respect to the potential at the GND pin.
(3) VIN(MIN) = VOUT(NOM) + 0.5 V or 1.65 V, whichever is greater. (See Figure 19 in DSBGA Light Sensitivity.)
(4) The device operates with input voltages up to 4 V. However special care must be taken in relation to thermal dissipation and the need to derate the maximum allowable ambient temperature.
(5) The maximum ambient temperature (TA-MAX) is a suggested value dependant on the maximum operating junction temperature (TJ-MAX-OP) = 125°C); the maximum power dissipation of the device in the application (PD-MAX), and the junction-to-ambient thermal resistance of the part / package in the application (RθJA), as given by the following equation: TA-MAX = TJ-MAX-OP – (RθJA × PD-MAX).
(6) Dropout voltage is voltage difference between input and output at which the output voltage drops to 100 mV below its nominal value. This parameter is only specified for output voltages above 1.8 V.
(7) The device maintains the regulated output voltage without a load.
(8) Short circuit current is measured with VOUT pulled to 0 V.
(9) This electrical specification is ensured by design.
(10) EN pin has an internal 1.2-MΩ (typical) resistor connected to GND.
(11) The capacitor tolerance must be 30% or better over temperature. The full operating conditions for the application must be considered when selecting a suitable capacitor to ensure that the minimum value of capacitance is always met. Recommended capacitor type is X7R or X5R. (See External Capacitors in Detailed Design Procedure.)
(12) On lower voltage options, 2.2-µF output capacitor may be used but some degradation in load transient (10 -15%) can be expected, compared to a 4.7-µF capacitor.

6.6 Timing Requirements

MIN NOM MAX UNIT
tON Turnon time(1) To 95% Level
VIN(MIN) to 3.6 V, VOUT ≤ 2 V		 100 µs
Turnon time(1) To 95% Level
VIN(MIN) to 3.6 V, VOUT ≥ 2 V		 140
(1) This electrical specification is ensured by design.

6.7 Typical Characteristics

Unless otherwise specified, CIN = 1 µF ceramic, COUT = 4.7 µF ceramic, VIN = VOUT(NOM) + 0.5 V or 1.8 V, whichever is greater, TA = 25°C, VOUT(NOM) = 1.5 V, EN pin is tied to VIN.
LP3991 20110010.png
Figure 1. Output Voltage Change vs Temperature
LP3991 20110012.png
Figure 3. Ground Current vs Load Current
LP3991 20110014.png
Figure 5. Dropout Voltage
LP3991 20110023.png
Figure 7. Enable Characteristics
LP3991 20110025.png
Figure 9. Power Supply Rejection Ratio
LP3991 20110028.png
Figure 11. Noise Density
LP3991 20110009.png
Figure 2. Output Voltage vs Minimum Input Voltage
LP3991 20110011.png
Figure 4. Ground Current vs VIN. ILOAD = 1mA
LP3991 20110015.png
Figure 6. Dropout Voltage vs Output Voltage
LP3991 20110022.png
Figure 8. Short Circuit Current
LP3991 20110026.png
Figure 10. Power Supply Rejection Ratio