SLUS395K February   2000  – October 2015 UCC2817 , UCC2818 , UCC3817 , UCC3818

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 Reference Section and Error Amplifier
      2. 7.3.2 Zero Power Block
      3. 7.3.3 Multiplier
      4. 7.3.4 Output Overvoltage Protection
      5. 7.3.5 Pin Descriptions
        1. 7.3.5.1  CAI
        2. 7.3.5.2  CAOUT
        3. 7.3.5.3  CT
        4. 7.3.5.4  DRVOUT
        5. 7.3.5.5  GND
        6. 7.3.5.6  IAC
        7. 7.3.5.7  MOUT
        8. 7.3.5.8  OVP/EN
        9. 7.3.5.9  PKLMT
        10. 7.3.5.10 RT
        11. 7.3.5.11 SS
        12. 7.3.5.12 VAOUT
        13. 7.3.5.13 VCC
        14. 7.3.5.14 VFF
        15. 7.3.5.15 VSENSE
        16. 7.3.5.16 VREF
    4. 7.4 Device Functional Modes
      1. 7.4.1 Transition Mode 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 Power Stage
          1. 8.2.2.1.1 LBOOST
          2. 8.2.2.1.2 COUT
        2. 8.2.2.2 Softstart
        3. 8.2.2.3 Multiplier
        4. 8.2.2.4 Voltage Loop
        5. 8.2.2.5 Current Loop
        6. 8.2.2.6 Start Up
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
    1. 9.1 Power Switch Selection
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Capacitor Ripple Reduction
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Related Links
    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

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • DW|16
  • N|16
  • D|16
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)
MIN MAX UNIT
Supply voltage VCC 18 V
Supply current ICC 20 mA
Gate drive current, continuous 0.2 A
Gate drive current 1.2 A
Input voltage, CAI, MOUT, SS 8 V
Input voltage, PKLMT 5 V
Input voltage, VSENSE, OVP/EN 10 V
Input current, RT, IAC, PKLMT 10 mA
Input current, VCC (no switching) 20 mA
Maximum negative voltage, DRVOUT, PKLMT, MOUT –0.5 V
Power dissipation 1 W
TJ Junction temperature –55 150 °C
Tstg Storage temperature –65 150 °C
Tsol Lead temperature (soldering, 10 seconds) 300 °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.

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) ±1500
(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
VCC Input voltage 12 V
VSENSE Input sense voltage 7.5 10 V
Input current for oscillator 1.36 10 mA

6.4 Thermal Information

THERMAL METRIC(1) UCC281x, UCC381x UNIT
SOIC (D) SOIC (DW) PDIP (N) TSSOP (PW)
16 PINS 16 PINS 16 PINS 16 PINS
RθJA Junction-to-ambient thermal resistance 73.9(2) 74.1(2) 49.3(2) 98.9(3) °C/W
RθJC(top) Junction-to-case (top) thermal resistance 33.5 35.5 38.9 30.2(3) °C/W
RθJB Junction-to-board thermal resistance 31.4 38.9 29.4 44.8 °C/W
ψJT Junction-to-top characterization parameter 5.8 9.9 18.9 1.9 °C/W
ψJB Junction-to-board characterization parameter 31.1 38.3 29.2 44.1 °C/W
(1) For more information about traditional and new thermal metrics, For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report.
(2) Specified θja (junction to ambient) is for devices mounted to 5-inch2 FR4 PC board with one ounce copper, where noted. When resistance range is given, lower values are for 5 inch2 aluminum PC board. Test PWB was 0.062-inch thick and typically used 0.635-mm trace widths for power packages and 1.3-mm trace widths for non-power packages with a 100-mil × 100-mil probe land area at the end of each trace.
(3) Modeled data. If value range given for θja, lower value is for 3×3 inch. 1 oz internal copper ground plane, higher value is for 1×1-inch. ground plane. All model data assumes only one trace for each non-fused lead.

6.5 Electrical Characteristics

TA = 0°C to 70°C for the UCC3817, and TA = −40°C to 85°C for the UCC2817, TA = TJ, VCC = 12 V, RT = 22 kΩ, CT = 270 pF, (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
SUPPLY CURRENT
Supply current, off VCC = (VCC turn-on threshold −0.3 V) 150 300 µA
Supply current, on VCC = 12 V, No load on DRVOUT 2 4 6 mA
UVLO
VCC turn-on threshold (UCCx817) 15.4 16 16.6 V
VCC turn-off threshold (UCCx817) 9.4 9.7 V
UVLO hysteresis (UCCx817) 5.8 6.3 V
Maximum shunt voltage (UCCx817) IVCC = 10 mA 15.4 17 17.5 V
VCC turn-on threshold (UCCx818) 9.7 10.2 10.8 V
VCC turn-off threshold (UCCx818) 9.4 9.7 V
UVLO hysteresis (UCCx818) 0.3 0.5 V
VOLTAGE AMPLIFIER
Input voltage TA = 0°C to 70°C 7.387 7.5 7.613 V
TA = −40°C to 85°C 7.369 7.5 7.631
VSENSE bias current VSENSE = VREF, VAOUT = 2.5 V 50 200 nA
Open loop gain VAOUT = 2 V to 5 V 50 90 dB
High-level output voltage IL = −150 μA 5.3 5.5 5.6 V
Low-level output voltage IL = 150 μA 0 50 150 mV
OVERVOLTAGE PROTECTION AND ENABLE
Over voltage reference VREF +0.48 VREF +0.50 VREF +0.52 V
Hysteresis 300 500 600 mV
Enable threshold 1.7 1.9 2.1 V
Enable hysteresis 0.1 0.2 0.3 V
CURRENT AMPLIFIER
Input offset voltage VCM = 0 V, VCAOUT = 3 V –3.5 0 2.5 mV
Input bias current VCM = 0 V, VCAOUT = 3 V –50 –100 nA
Input offset current VCM = 0 V, VCAOUT = 3 V 25 100 nA
Open loop gain VCM = 0 V, VCAOUT = 2 V to 5 V 90 dB
Common-mode rejection ratio VCM = 0 V to 1.5 V, VCAOUT = 3 V 60 80 dB
High-level output voltage IL = −120 μA 5.6 6.5 6.8 V
Low-level output voltage IL = 1 mA 0.1 0.2 0.5 V
Gain bandwidth product (1) 2.5 MHz
VOLTAGE REFERENCE
Input voltage TA = 0°C to 70°C 7.387 7.5 7.613 V
TA = −40°C to 85°C 7.369 7.5 7.631
Load regulation IREF = 1 mA to 2 mA 0 10 mV
Line regulation VCC = 10.8 V to 15 V, (2) 0 10 mV
Short-circuit current VREF = 0 V –20 –25 –50 mA
OSCILLATOR
Initial accuracy TA = 25°C 85 100 115 kHz
Voltage stability VCC = 10.8 V to 15 V –1% 1%
Total variation Line, temp 80 120 kHz
Ramp peak voltage 4.5 5 5.5 V
Ramp amplitude voltage (peak to peak) 3.5 4 4.5 V
PEAK CURRENT LIMIT
PKLMT reference voltage –15 15 mV
PKLMT propagation delay 150 350 500 ns
MULTIPLIER
IMOUT, high line, low power output current, (0°C to 85°C) IAC = 500 μA, VFF = 4.7 V, VAOUT = 1.25 V 0 –6 –20 µA
IMOUT, high line, low power output current, (–40°C to 85°C) IAC = 500 μA, VFF = 4.7 V, VAOUT = 1.25 V 0 –6 –23 µA
IMOUT, high line, high power output current IAC = 500 μA, VFF = 4.7 V, VAOUT = 5 V –70 –90 –105 µA
IMOUT, low line, low power output current IAC = 150 μA, VFF = 1.4 V, VAOUT = 1.25 V –10 –19 –50 µA
IMOUT, low line, high power output current IAC = 150 μA, VFF = 1.4 V, VAOUT = 5 V –268 –300 –345 µA
IMOUT, IAC limited output current IAC = 150 μA, VFF = 1.3 V, VAOUT = 5 V –250 –300 –400 µA
Gain constant (K) IAC = 300 μA, VFF = 3 V, VAOUT = 2.5 V 0.5 1 1.5 1/V
IMOUT, zero current IAC = 150 μA, VFF = 1.4 V, VAOUT = 0.25 V 0 –2 µA
IAC = 500 μA, VFF = 4.7 V, VAOUT = 0.25 V 0 –2
IMOUT, zero current, (0°C to 85°C) IAC = 500 μA, VFF = 4.7 V, VAOUT = 0.5 V 0 –3 µA
IMOUT, zero current, (–40°C to 85°C) IAC = 500 μA, VFF = 4.7 V, VAOUT = 0.5 V 0 –3.5 µA
Power limit (IMOUT x VFF) IAC = 150 μA, VFF = 1.4 V, VAOUT = 5 V –375 –420 –485 µW
FEED-FORWARD
VFF output current IAC = 300 μA –140 –150 –160 µA
SOFT START
SS charge current –6 –10 –16 µA
GATE DRIVER
Pullup resistance IO = –100 mA to −200 mA 5 12 Ω
Pulldown resistance IO = 100 mA 2 10 Ω
Output rise time CL = 1 nF, RL = 10 Ω, VDRVOUT = 0.7 V to 9.0 V 25 50 ns
Output fall time CL = 1 nF, RL = 10 Ω, VDRVOUT = 9.0 V to 0.7 V 10 50 ns
Maximum duty cycle 93% 95% 99%
Minimum controlled duty cycle At 100 kHz 2%
ZERO POWER
Zero power comparator threshold Measured on VAOUT 0.20 0.33 0.50 V
(1) Ensured by design, not production tested.
(2) Reference variation for VCC < V is shown in Figure 1.

6.6 Typical Characteristics

UCC2817 UCC2818 UCC3817 UCC3818 slus395_typchar_1.gif
Figure 1. Reference Voltage vs Supply Voltage
UCC2817 UCC2818 UCC3817 UCC3818 slus395_typchar_3.gif
Figure 3. Multiplier Output Current vs Voltage Error Amplifier Output
UCC2817 UCC2818 UCC3817 UCC3818 slus395_typchar_5.gif
Figure 5. Multiplier Constant Power Performance
UCC2817 UCC2818 UCC3817 UCC3818 slus395_typchar_2.gif
Figure 2. Reference Voltage vs Reference Current
UCC2817 UCC2818 UCC3817 UCC3818 slus395_typchar_4.gif
Figure 4. Multiplier Gain vs Voltage Error Amplifier Output
UCC2817 UCC2818 UCC3817 UCC3818 slus395_typchar_6.gif
Figure 6. Recommended Minimum Gate Resistance vs Supply Voltage