• Menu
  • Product
  • Email
  • PDF
  • Order now

  • UCCx808-x Low Power Current Mode Push-Pull PWM

    • SLUS168E Apr   1999  – August 2015 UCC2808-1 , UCC2808-2 , UCC3808-1 , UCC3808-2

      PRODUCTION DATA.  

  • CONTENTS
  • SEARCH
  • UCCx808-x Low Power Current Mode Push-Pull PWM
  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 Electrical Characteristics
    5. 6.5 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 Pin Descriptions
    4. 7.4 Device Functional Modes
      1. 7.4.1 VCC
  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
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Related Links
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    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
  13. IMPORTANT NOTICE

Package Options

Mechanical Data (Package|Pins)
  • D|8
    • MSOI002K
Thermal pad, mechanical data (Package|Pins)
Orderable Information
  • slus168e_oa
  • slus168e_pm
search No matches found.
  • Full reading width
    • Full reading width
    • Comfortable reading width
    • Expanded reading width
  • Card for each section
  • Card with all content

 

DATA SHEET

UCCx808-x Low Power Current Mode Push-Pull PWM

1 Features

  • Dual Output Drive Stages in Push-Pull Configuration
  • 130-μA Typical Starting Current
  • 1-mA Typical Run Current
  • Operation to 1-MHz
  • Internal Soft-Start
  • On-Chip Error Amplifier With 2-MHz Gain Bandwidth Product
  • On-Chip VDD Clamping
  • Output Drive Stages Capable Of 500-mA Peak Source Current, 1-A Peak Sink Current

2 Applications

  • Server and Desktop Power Supplies
  • Telecom Power Supplies
  • DC-DC Converters
  • Switched-Mode Power Supplies

3 Description

The UCCx808-x is a family of BiCMOS push-pull, high-speed, low-power, pulse-width modulators. The UCCx808 contains all of the control and drive circuitry required for offline or DC-to-DC fixed frequency current-mode switching power supplies with minimal external parts count.

The UCCx808-x dual output drive stages are arranged in a push-pull configuration. Both outputs switch at half the oscillator frequency using a toggle flip-flop. The dead time between the two outputs is typically 60 ns to 200 ns depending on the values of the timing capacitor and resistors, thus limiting each output stage duty cycle to less than 50%.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
UCC2808-1
UCC2808-2
UCC3808-1
UCC3808-2		 SOIC (8) 4.90 mm × 3.91 mm
PDIP (8) 9.81 mm × 6.35 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Schematic

UCC2808-1 UCC2808-2 UCC3808-1 UCC3808-2 typ_app_diagram_slus168.gif

4 Revision History

Changes from D Revision (August 2002) to E Revision

  • Removed references to the TSSOP packaging Go
  • Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information section. Go

5 Pin Configuration and Functions

D Package
8-Pin SOIC
Top View
UCC2808-1 UCC2808-2 UCC3808-1 UCC3808-2 po_01_slus168.gif
P Package
8-Pin PDIP
Top View
UCC2808-1 UCC2808-2 UCC3808-1 UCC3808-2 po_02_slus168.gif

Pin Functions

PIN I/O DESCRIPTION
NAME NO.
COMP 1 I/O Output of the error amplifier and the input of the PWM comparator.
CS 3 I Input to the PWM, peak current, and overcurrent comparators.
FB 2 I Inverting input to the error amplifier.
GND 5 — Reference ground and power ground for all functions.
OUTA 7 O Alternating high current output stage.
OUTB 6 O Alternating high current output stage.
RC 4 I Oscillator programming pin.
VDD 8 — Power input connection for this device.

6 Specifications

6.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)
MIN MAX UNIT
Supply voltage (IDD ≤ 10 mA) 15 V
Supply current 20 mA
OUTA/OUTB source current (peak)(2) –0.5 A
OUTA/OUTB sink current (peak)(2) 1.0 A
Analog inputs (FB, CS) – 0.3 V to VDD+0.3 V 6 V
Power dissipation at TA = 25 ° C (N Package) 1 W
Power dissipation at T A = 25 ° C (D Package) 650 mW
Power dissipation at T A = 25 ° C (PW Package) 400 mW
TJ Junction temperature –55 150 °C
Lead temperature (soldering, 10 sec.) 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.
(2) Currents are positive into, negative out of the specified terminal. Consult Packaging Section of the Power Supply Control Data Book (SLUD003) for thermal limitations and considerations of packages.

6.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2500 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 MAX UNIT
VDD Supply Voltage UCCx808-1 13 14 V
UCCx808-2 5 14
TJ Junction Temperature UCC2808-x –40 85 °C
UCC3808-x 0 70

6.4 Electrical Characteristics

TA = 0°C to 70°C for the UCC3808-x, –40°C to 85°C for the UCC2808-x and –55°C to 125°C for the UCC1808-x, VDD = 10 V(6), 1-μF capacitor from VDD to GND, R = 22 kΩ , C = 330 pF, TA = TJ , (unless otherwise specified)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
OSCILLATOR SECTION
Oscillator frequency 175 194 213 kHz
Oscillator amplitude/VDD(1) 0.44 0.5 0.56 V/V
ERROR AMPLIFIER SECTION
Input voltage COMP = 2 V 1.95 2 2.05 V
Input bias current –1 1 μ A
Open-loop voltage gain 60 80 dB
COMP sink current FB = 2.2 V, COMP = 1 V 0.3 2.5 mA
COMP source current FB = 1.3 V, COMP = 3.5 V –0.25 –0.5 mA
PWM SECTION
Maximum duty cycle Measured at OUTA or OUTB 48% 49% 50%
Minimum duty cycle COMP = 0 V 0%
CURRENT SENSE SECTION
Gain(2) 1.9 2.2 2.5 V/V
Maximum input signal COMP = 5 V (3) 0.45 0.5 0.55 V
CS to output delay COMP = 3.5 V, CS from 0 to 600 mV 100 200 ns
CS source current –200 nA
Over current threshold 0.7 0.75 0.8 V
COMP to CS offset CS = 0 V 0.35 0.8 1.2 V
OUTPUT SECTION
OUT low level I = 100 mA 0.5 1 V
OUT high level I = – 50 mA, VDD – OUT 0.5 1 V
Rise time CL = 1 nF 25 60 ns
Fall time CL = 1 nF 25 60 ns
UNDERVOLTAGE LOCKOUT SECTION
Start threshold UCCx808-1 (6) 11.5 12.5 13.5 V
UCCx808-2 4.1 4.3 4.5
Minimum operating voltage after start UCCx808-1 7.6 8.3 9 V
UCCx808-2 3.9 4.1 4.3
Hysteresis UCCx808-1 3.5 4.2 5.1 V
UCCx808-2 0.1 0.2 0.3
SOFT-START SECTION
COMP rise time FB = 1.8 V, rise from 0.5 V to 4 V 3.5 20 ms
OVERALL SECTION
Start-up current VDD < start threshold 130 260 µA
Operating supply current FB = 0 V, CS = 0 V (5)(6) 1 2 mA
VDD zener shunt voltage IDD = 10 mA (4) 13 14 15 V
(1) Measured at RC. Signal amplitude tracks VDD.
(2) Gain is defined by: UCC2808-1 UCC2808-2 UCC3808-1 UCC3808-2 equation_01_slus168.gif0 v VCS v 0.4 V
(3) Parameter measured at trip point of latch with FB at 0 V.
(4) Start threshold and Zener shunt threshold track one another.
(5) For UCCx808 – 1, set VDD above the start threshold before setting at 10 V
(6) Does not include current in the external oscillator network.

6.5 Typical Characteristics

UCC2808-1 UCC2808-2 UCC3808-1 UCC3808-2 graph_01_slus168.gif
Figure 1. Frequency vs Timing Resistor
UCC2808-1 UCC2808-2 UCC3808-1 UCC3808-2 graph_03_slus168.gif
Figure 3. CS Offset vs Temperature
UCC2808-1 UCC2808-2 UCC3808-1 UCC3808-2 graph_02_slus168.gif
Figure 2. IDD vs Oscillator Frequency

 
Texas Instruments

© Copyright 1995-2025 Texas Instruments Incorporated. All rights reserved.
Submit documentation feedback | IMPORTANT NOTICE | Trademarks | Privacy policy | Cookie policy | Terms of use | Terms of sale