SLVS038J January   1989  – October 2024 TL2842 , TL2843 , TL2844 , TL2845 , TL3842 , TL3843 , TL3844 , TL3845

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Pulse-by-Pulse Current Limiting
      2. 6.3.2 Error Amplifier With Low Output Resistance
      3. 6.3.3 High-Current Totem-Pole Output
    4. 6.4 Device Functional Modes
      1. 6.4.1 Shutdown Technique
      2. 6.4.2 Slope Compensation
  8. 7 Application and Implementation
    1. 7.1 Typical Application
      1. 7.1.1 Design Requirements
      2. 7.1.2 Detailed Design Procedure
        1. 7.1.2.1 Current-Sense Circuit
        2. 7.1.2.2 Error-Amplifier Configuration
        3. 7.1.2.3 Oscillator Section
      3. 7.1.3 Application Curve
    2. 7.2 Power Supply Recommendations
    3. 7.3 Layout
      1. 7.3.1 Layout Guidelines
        1. 7.3.1.1 Feedback Traces
        2. 7.3.1.2 Input/Output Capacitors
        3. 7.3.1.3 Compensation Components
        4. 7.3.1.4 Traces and Ground Planes
      2. 7.3.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Receiving Notification of Documentation Updates
    2. 8.2 Support Resources
    3. 8.3 Trademarks
    4. 8.4 Electrostatic Discharge Caution
    5. 8.5 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • D|14
  • D|8
  • P|8
Thermal pad, mechanical data (Package|Pins)
Orderable Information

5.5 Electrical Characteristics

over operating free-air temperature range, VCC = 15 V(1), RT = 10 kΩ, CT = 3.3 nF (unless otherwise noted)
PARAMETERTEST CONDITIONS(2)TL284xTL384xUNIT
MINTYP(2)MAXMINTYP(2)MAX
Reference Section
Output voltageIO = 1 mA, TA = 25°C4.9555.054.955.1V
Line regulationVCC = 12 V to 25 V620620mV
Load regulationIO = 1 mA to 20 mA625625mV
Temperature coefficient of output voltage0.20.40.20.4mV/°C
Output voltage with worst-case variationVCC = 12 V to 25 V, IO = 1 mA to 20 mA4.95.14.825.18V
Output noise voltagef = 10 Hz to 10 kHz, TA = 25°C5050µV
Output-voltage long-term driftAfter 1000 h at TA = 25°C525525mV
Short-circuit output current–30–100–180–30–100–180mA
Oscillator Section
Oscillator frequency(3)TA = 25°C475257475257kHz
Frequency change with supply voltageVCC = 12 V to 25 V210210Hz/kHz
Frequency change with temperature5050Hz/kHz
peak-to-peak amplitude at RT/CT1.71.7V
Error-Amplifier Section
Feedback input voltageCOMP at 2.5 V2.452.502.552.422.502.58V
Input bias current–0.3–1–0.3–2µA
Open-loop voltage amplificationVO = 2 V to 4 V65906590dB
Gain-bandwidth product0.710.71MHz
Supply-voltage rejection ratioVCC = 12 V to 25 V60706070dB
Output sink currentVFB, at 2.7 V, COMP at 1.1 V2626mA
Output source currentVFB, at 2.3 V, COMP at 5 V–0.5–0.8–0.5–0.8mA
Hihg-level output voltageVFB, at 2.3 V, RL = 15 kΩ to GND5656V
Low-level output voltageVFB, at 2.7 V, RL = 15 kΩ to GND0.71.10.71.1V
Current-sense Section
Voltage amplificationSee(4)(5)2.8533.132.8533.15V/V
Current-sense comparator thresholdCOMP at 5 V, see(4)0.911.10.911.1V
Supply-voltage rejection ratioVCC = 12 V to 25 V, see(4)7070dB
Input bias current–2–10–2–10µA
Delay time to output150300150300ns
Output Section
High-level output voltageIOH = –20 mA1313.51313.5V
IOH = –200 mA1213.51313.5
Low-level output voltageIOH = 20 mA0.10.40.10.4V
IOH = 200 mA1.52.21.52.2
Rise timeCL = 1 nF, TA = 25°C2515025150ns
fall timeCL = 1 nF, TA = 25°C2515025150ns
Undervoltage-Lockout Section
Start threshold voltageTLx842, TLx84415161714.51617.5V
TLx843, TLx8457.88.497.88.49
Minimum operating voltage after startupTLx842, TLx844910118.51011.5V
TLx843, TLx84577.68.277.68.02
Pulse-Width-Modulator Section
Maximum duty cycleTLx842, TLx84392%97%100%92%97%100%
TLx844, TLx84546%48%50%46%48%50%
Minimum duty cycle0%0%
Supply Voltage
Start-up current0.510.51mA
Operating supply currentVFB and ISENSE at 0 V11171117mA
Limiting voltageICC = 25 mA3939V
(1) Adjust VCC above the start threshold before setting it to 15 V.
(2) All typical values are at TA = 25°C.
(3) Output frequency equals oscillator frequency for the TLx842 and TLx843. Output frequency is one-half the oscillator frequency for the TLx844 and TLx845.
(4) These parameters are measured at the trip point of the latch, with VFB at 0 V.
(5) Voltage amplification is measured between ISENSE and COMP, with the input changing from 0 V to 0.8 V.