ZHCSEO7C October   2015  – January 2017 LM27761

PRODUCTION DATA.  

  1. 特性
  2. 应用
  3. 说明
  4. 修订历史记录
  5. Pin Configuration and Functions
  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. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Undervoltage Lockout
      2. 7.3.2 Input Current Limit
      3. 7.3.3 PFM Operation
      4. 7.3.4 Output Discharge
      5. 7.3.5 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Enable Mode
  8. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application - Regulated Voltage Inverter
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 Charge-Pump Voltage Inverter
        3. 8.2.2.3 Negative Low-Dropout Linear Regulator
        4. 8.2.2.4 Power Dissipation
        5. 8.2.2.5 Output Voltage Setting
        6. 8.2.2.6 External Capacitor Selection
          1. 8.2.2.6.1 Charge-Pump Output Capacitor
          2. 8.2.2.6.2 Input Capacitor
          3. 8.2.2.6.3 Flying Capacitor
          4. 8.2.2.6.4 LDO Output Capacitor
      3. 8.2.3 Application Curves
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11器件和文档支持
    1. 11.1 器件支持
      1. 11.1.1 开发支持
        1. 11.1.1.1 使用 WEBENCH® 工具创建定制设计
    2. 11.2 接收文档更新通知
    3. 11.3 社区资源
    4. 11.4 商标
    5. 11.5 静电放电警告
    6. 11.6 Glossary
  12. 12机械、封装和可订购信息

Specifications

Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)(2)
MIN MAX UNIT
Ground voltage, VIN to GND or GND to VOUT 5.8 V
EN (GND − 0.3 V) (VIN + 0.3 V)
Continuous output current, CPOUT and VOUT 300 mA
TJMAX(3) 150 °C
Storage temperature, Tstg –65 150 °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 . Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
If Military/Aerospace specified devices are required, contact the TI Sales Office/Distributors for availability and specifications.
The maximum power dissipation must be de-rated at elevated temperatures and is limited by TJMAX (maximum junction temperature), TA (ambient temperature) and RθJA (junction-to-ambient thermal resistance). The maximum power dissipation at any temperature is: PDissMAX = (TJMAX – TA)/RθJA up to the value listed in the Absolute Maximum Ratings.

ESD Ratings

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

Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)
MIN MAX UNIT
Operating ambient temperature, TA –40 85 °C
Operating junction temperature, TJ –40 125 °C
Operating input voltage, VIN 2.7 5.5 V
Operating output current, IOUT 0 250 mA

Thermal Information

THERMAL METRIC(1) LM27761 UNIT
WSON (DSG)
8 PINS
RθJA Junction-to-ambient thermal resistance 67.7 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 89.9 °C/W
RθJB Junction-to-board thermal resistance 37.6 °C/W
ψJT Junction-to-top characterization parameter 2.4 °C/W
ψJB Junction-to-board characterization parameter 38 °C/W
RθJC(bot) Junction-to-case (bottom) thermal resistance 9.4 °C/W
For more information about traditional and new thermal metrics, see Semiconductor and IC Package Thermal Metrics.

Electrical Characteristics

Typical limits apply for TA = 25°C, and minimum and maximum limits apply over the full temperature range. Unless otherwise specified, VIN = 5 V and values for C1 to C4 are as shown in the 典型应用.
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Iq Supply current Open circuit, no load 370 600 µA
ISD Shutdown supply current 7 12 µA
ƒSW Switching frequency VIN = 3.6 V 1.7 2 2.3 MHz
RNEG Output resistance to CPOUT VIN = 5.5 V 2 Ω
VDO LDO dropout voltage ILOAD = 100 mA, VOUT = −5 V 30 mV
PSRR Power supply rejection ratio ILOAD = 80 mA, VCPOUT = −5 V 35 dB
VN Output noise voltage ILOAD = 80 mA, 10 Hz to 100 kHz 20 µVRMS
VFB Feedback pin reference voltage 1.202 1.22 1.238 V
VOUT Adjustable output voltage 5.5 V ≥ VIN ≥ 2.7 V –5 –1.5 V
Load regulation 0 to 250 mA, VOUT = −1.8 V 4.6 µV/mA
Line regulation 5.5 V ≥ VIN ≥ 2.7 V, ILOAD = 50 mA 1.5 mV/V
VIH Enable pin input voltage high 5.5 V ≥ VIN ≥ 2.7 V 1.2 V
VIL Enable pin input voltage low 5.5 V ≥ VIN ≥ 2.7 V 0.4 V
UVLO Undervoltage lockout VIN falling 2.6 V
VIN rising 2.4

Typical Characteristics

Unless otherwise specified, TA = 25°C, VIN = 5 V, and values for C1 to C4 are as shown in the 典型应用.
LM27761 D001_SNVSA85.gif
Figure 1. Output Voltage Ripple vs Output Current
LM27761 D015_SNVSA85.gif
EN = 1 ILOAD = 0 mA
Figure 3. Quiescent Current
LM27761 D006_SNVSA85.gif
VIN = 3 V VOUT = –1.8 V
R1 = 237 kΩ R2 = 500 kΩ
Figure 5. Load Regulation
LM27761 D011_SNVSA85.gif
VIN = 5 V VOUT = –3.3 V
R1 = 856 kΩ R2 = 500 kΩ
Figure 7. Load Regulation
LM27761 wvfrm02_output_voltage_ripple_5p0v_snvsa85.png
VIN = 5.5 V VOUT = –5 V IOUT = 250 mA
Figure 9. Output Voltage Ripple
LM27761 wvfrm04_enable_low_snvsa85.png
Figure 11. Enable Low
LM27761 D012_SNVSA85.gif
VOUT = –1.8 V IOUT = 50 mA
R1 = 237 kΩ R2 = 500 kΩ
Figure 13. Line Regulation
LM27761 D014_SNVSA85.gif
VOUT = –1.8 IOUT = 250 mA R1 = 237 kΩ R2 = 500 kΩ
Figure 15. Line Regulation
LM27761 D002_SNVSA85.gif
VOUT = –1.8 V IOUT = 100 mA
Figure 2. Output Voltage Ripple vs Input Voltage
LM27761 D016_SNVSA85.gif
EN = 0
Figure 4. Shutdown Current
LM27761 D007_SNVSA85.gif
VIN = 5.5 V VOUT = –5 V
R1 = 1.54 MΩ R2 = 500 kΩ
Figure 6. Load Regulation
LM27761 wvfrm01_output_voltage_ripple_1p8v_snvsa85.png
VIN = 3 V VOUT = –1.8 V IOUT = 250 mA
Figure 8. Output Voltage Ripple
LM27761 wvfrm03_enable_high_snvsa85.png
Figure 10. Enable High
LM27761 D008_SNVSA85.gif
Figure 12. LDO Dropout Voltage vs IOUT
LM27761 D013_SNVSA85.gif
VOUT = –1.8 V IOUT = 100 mA
R1 = 237 kΩ R2 = 500 kΩ
Figure 14. Line Regulation