SGLS318A November   2005  – November 2015 UC2854B-EP

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Multiply/Square and Divide
      2. 8.3.2 Voltage Amplifier
      3. 8.3.3 Current Amplifier
      4. 8.3.4 Miscellaneous
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1  Switching Frequency
        2. 9.2.2.2  Inductor Selection
        3. 9.2.2.3  Output Capacitor
        4. 9.2.2.4  Switch and Diode
        5. 9.2.2.5  Current Sensing
        6. 9.2.2.6  Peak Current Limit
        7. 9.2.2.7  Multiplier Set-up
        8. 9.2.2.8  Feedforward Voltage
        9. 9.2.2.9  Multiplier Input Current
        10. 9.2.2.10 Oscillator Frequency
        11. 9.2.2.11 Current Error Amplifier Compensation
        12. 9.2.2.12 Voltage Error Amplifier Compensation
        13. 9.2.2.13 Feedforward Voltage Divider Filter Capacitors
        14. 9.2.2.14 Design Procedure Summary
      3. 9.2.3 Application Curve
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Community Resources
    2. 12.2 Trademarks
    3. 12.3 Electrostatic Discharge Caution
    4. 12.4 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

7 Specifications

7.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)
MIN MAX UNIT
VCC Supply voltage 22 V
Input voltage VSENSE, VRMS, ISENSE MOUT 11 V
PKLMT 5 V
IGTDRV GTDRV current, continuous 0.5 A
IGTDRV GTDRV current, 50% duty cycle 1.5 A
Input current RSET, IAC, PKLMT, ENA 10 mA
TJ Junction temperature −55 150 °C
Tsol Lead temperature, 1.6 mm (1/16 inch) from case for 10 seconds 300 °C
Tstg Storage temperature −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.

7.2 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.

7.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)
MIN MAX UNIT
VCC Supply voltage 10 20 V
TJ Operating junction temperature −55 125 °C

7.4 Thermal Information

THERMAL METRIC(1) UC2854B-EP UNIT
DW (SOIC)
16 PINS
HIGH LOW
RθJA Junction-to-ambient thermal resistance (2) 36.9 38.4 °C/W
RθJC Junction-to-case thermal resistance 73.1 111.6 °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953.
(2) RθJA values are based on zero air flow.

7.5 Electrical Characteristics

over operating free-air temperature range (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
OVERALL
Supply current, off CAO = 0 V, VAO = 0 V, VCC = VUVLO − 0.3 V 250 400 µA
Supply current, on 12 18 mA
VCC turn-on threshold voltage 8 10.5 11.3 V
VCC turn-off threshold voltage 9 10 12 V
VCC clamp IVCC = IVCC(on) + 5 mA 18 20 22 V
VOLTAGE AMPLIFIER
Input voltage 2.9 3 3.1 V
VSENSE bias current −500 −25 500 nA
Open loop gain 2 V ≤ VOUT ≤ 5 V 70 100 dB
VOH High-level output voltage ILOAD = −500 µA 6 V
VOL Low-level output voltage ILOAD = 500 µA 0.3 0.5 V
ISC Output short-circuit current VOUT = 0 V 1.5 3.5 mA
Gain bandwidth product(1) fIN = 100 kHz, 10 mVP−P 1 MHz
CURRENT AMPLIFIER
Input offset voltage VCM = 0 V, TA = 25°C −4 0 mV
VCM = 0 V, overtemperature −5.5 0
Input bias current, ISENSE VCM = 0 V −500 500 nA
Open loop gain 2 V ≤ VOUT ≤ 6 V 80 110 dB
VOH High-level output voltage ILOAD = −500 µA 8 V
VOL Low-level output voltage ILOAD = 500 µA 0.3 0.5 V
ISC Output short-circuit current VOUT = 0 V 1.5 3.5 mA
CMRR Common mode rejection range −0.3 5 V
Gain bandwidth product(1) fIN = 100 kHz, 10 mVP−P 3 5 MHz
REFERENCE
Output voltage IREF = 0 mA, TA = 25°C 7.4 7.5 7.6 V
IREF = 0 mA 7.35 7.5 7.65
Load regulation 1 mA ≤ IREF ≤ 10 mA 0 8 20 mV
Line regulation 12 V ≤ VCC ≤ 18 V 0 14 25 mV
ISC Short circuit current VREF = 0 V 25 35 60 mA
OSCILLATOR
Initial accuracy TA = 25°C 85 100 115 kHz
Voltage stability 12 V ≤ VCC ≤ 18 V 1%
Total variation Line, temperature 80 120 kHz
Ramp amplitude (peak-to-peak) 4.9 5.9
Ramp valley voltage 0.8 1.3 V
ENABLE/SOFT-START/CURRENT LIMIT
Enable threshold voltage 2.35 2.55 2.90 V
Enable hysteresis VFAULT = 2.5 V 500 600 mV
Enable input bias current VENA = 0 V −2 −5 µA
Propagation delay to disable time(1) Enable overdrive = 100 mV 300 ns
Soft-start charge current VSS = 2.5 V 10 14 24 µA
Peak limit offset voltage −15 15 mV
Peak limit input current VPKLMT = −0.1 V −200 −100 µA
Peak limit propagation delay time(1) 150 ns
MULTIPLIER
Output current, IAC limited IAC = 100 µA, VRMS = 1 V, RSET = 10 kΩ −220 −200 −170 µA
Output current, zero IAC = 0 µA, RSET = 10 kΩ −2 −0.2 2 µA
Output current, power limited VRMS = 1.5 V, VA = 6 V −230 −200 −170 µA
Output current VRMS = 1.5 V, VA = 2 V −22 µA
VRMS = 1.5 V, VA = 5 V −156
VRMS = 5 V, VA = 2 V −2
VRMS = 5 V, VA = 5 V −14
Gain constant(2) VRMS = 1.5 V, VA = 6 V, TA = 25°C −1.1 −1 −0.9 A/A
GATE DRIVER
VOH High-level output voltage IOUT = −200 mA, VCC = 15 V 12 12.8 V
VOL Low-level output voltage IOUT = 200 mA 1 2.2 V
IOUT = 10 mA 300 500 mV
Low-level UVLO voltage IOUT = 50 mA, VCC = 0 V 0.9 1.5 V
Output rise time(1) CLOAD = 1 nF 35 ns
Output fall time(1) CLOAD = 1 nF 35 ns
Output peak current(1) CLOAD = 10 nF 1 A
(1) Ensured by design. Not production tested.
(2) Gain constant. UC2854B-EP eq_K_gls318.gif
UC2854B-EP derating_graph_sgls318.gif Figure 1. Wirebond Operating Life Derating Chart

7.6 Typical Characteristics

UC2854B-EP gr_001_sgls318.gif
Figure 2. Gate Drive Timing vs Load Capacitance
UC2854B-EP gr_003_sgls318.gif
Figure 4. Multiplier Gain Constant vs Supply Current
UC2854B-EP gr_005_sgls318.gif
Figure 6. Current Amplifier Gain vs Frequency
UC2854B-EP gr_007_sgls318.gif
Figure 8. Oscillator Frequency vs Limit Set Resistance and Timing Capacitance
UC2854B-EP gr_002_sgls318.gif
Figure 3. Gate Drive Maximum Duty Cycle vs Oscillator Charging Resistance
UC2854B-EP gr_004_sgls318.gif
Figure 5. Multiplier Gain Constant vs Supply Current
UC2854B-EP gr_006_sgls318.gif
Figure 7. Voltage Amplifier Gain vs Frequency