TL3843DR-8

TL284X TI | Alldatasheet

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TL284x, TL384x CURRENT-MODE PWM CONTROLLERS SLVS038E – JANUARY 1989 – REVISED DECEMBER 1999 1POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 /C0068Optimized for Off-Line and dc-to-dc Converters /C0068Low Start-Up Current (<1 mA) /C0068Automatic Feed-Forward Compensation /C0068Pulse-by-Pulse Current Limiting /C0068Enhanced Load-Response Characteristics /C0068Undervoltage Lockout With Hysteresis /C0068Double-Pulse Suppression /C0068High-Current Totem-Pole Output /C0068Internally Trimmed Bandgap Reference /C0068500-kHz Operation /C0068Error Amplifier With Low Output Resistance /C0068Designed to Be Interchangeable With UC2842 and UC3842 Series

description

The TL284x and TL384x series of control integrated circuits provide the features that are necessary to implement off-line or dc-to-dc fixed-frequency current-mode control schemes with a minimum number of external components. Some of the internally implemented circuits are an undervoltage lockout (UVLO), featuring a start-up current of less than 1 mA, and a precision reference trimmed for accuracy at the error amplifier input. Other internal circuits include logic to ensure latched operation, a pulse-width modulation (PWM) comparator (which also provides current-limit control), and a totem-pole output stage designed to source or sink high-peak current. The output stage, suitable for driving N-channel MOSFETs, is low when it is in the off state. Major differences between members of these series are the UVLO thresholds and maximum duty-cycle ranges. Typical UVLO thresholds of 16 V (on) and 10 V (off) on the TLx842 and TLx844 devices make them ideally suited to off-line applications. The corresponding typical thresholds for the TLx843 and TLx845 devices are 8.4 V (on) and 7.6 V (off). The TLx842 and TLx843 devices can operate to duty cycles approaching 100%. A duty-cycle range of 0 to 50% is obtained by the TLx844 and TLx845 by the addition of an internal toggle flip-flop, which blanks the output off every other clock cycle. The TL284x-series devices are characterized for operation from –40°C to 85°C. The TL384x-series devices are characterized for operation from 0°C to 70°C. Copyright  1999, Texas Instruments IncorporatedPRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. COMP NC VFB NC ISENSE NC RT/CT REF NC VCC VC OUTPUT GND POWER GROUND D PACKAGE (TOP VIEW) COMP VFB ISENSE RT/CT REF VCC OUTPUT GND D-8 OR P PACKAGE (TOP VIEW) NC – No internal connection

TL284x, TL384x CURRENT-MODE PWM CONTROLLERS SLVS038E – JANUARY 1989 – REVISED DECEMBER 1999

2 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

(D) SMALL OUTLINE (D-8) PLASTIC DIP (P) CHIP FORM (Y) 0°C to 70°C TL3842D TL3843D TL3844D TL3845D TL3842D-8 TL3843D-8 TL3844D-8 TL3845D-8 TL3842P TL3843P TL3844P TL3845P TL3842Y TL3843Y TL3844Y TL3845Y –40°C to 85°C TL2842D TL2843D TL2844D TL2845D TL2842D-8 TL2843D-8 TL2844D-8 TL2845D-8 TL2842P TL2843P TL2844P TL2845P The D and D-8 packages are available taped and reeled. Add the suffix R to the device type (i.e., TL3842DR or TL3842DR-8). Chip forms are tested at 25°C. functional block diagram † The toggle flip-flop is present only in TL2844, TL2845, TL3844, and TL3845. Pin numbers shown are for the D Package. Internal Bias Vref Good Logic OSC 5-V REF Error Amplifier PWM Latch Current- Sense Comparator

34 V NOM

S R T

TL284x, TL384x CURRENT-MODE PWM CONTROLLERS SLVS038E – JANUARY 1989 – REVISED DECEMBER 1999 3POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 absolute maximum ratings over operating free-air temperature range (unless otherwise noted)† † Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. NOTES: 1. All voltages are with respect to the device GND terminal. 2. Maximum power dissipation is a function of TJ(max), qJA, and TA. The maximum allowable power dissipation at any allowable ambient temperature is PD = (TJ(max) – TA)/qJA. Operating at the absolute maximum TJ of 150°C can impact reliability. 3. The package thermal impedance is calculated in accordance with JESD 51. recommended operating conditions MIN NOM MAX UNIT Supply voltage, VCC and VC‡ 30 V Input voltage, VI, RT/CT 0 5.5 V Input voltage, VI, VFB and ISENSE 0 5.5 V Output voltage, VO , OUTPUT 0 30 V Output voltage, VO , POWER GROUND ‡ –0.1 1 V Supply current, externally limited, ICC 25 mA Average output current, IO 200 mA Reference output current, IO(ref) –20 mA Oscillator frequency, fosc 100 500 kHz Operating virtual junction temperature, TJ 0 125 °C Operating free air temperature T TL284x –40 85 °CO perating free-air temperature, TA TL384x 0 70 °C ‡ These recommended voltages for VC and POWER GROUND apply only to the D package.

TL284x, TL384x CURRENT-MODE PWM CONTROLLERS SLVS038E – JANUARY 1989 – REVISED DECEMBER 1999

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electrical characteristics over recommended operating free-air temperature range, VCC = 15 V (see Note 4), RT = 10 kW , CT = 3.3 nF (unless otherwise specified) reference section PARAMETER TEST CONDITIONS TL284x TL384x UNITPARAMETER TEST CONDITIONS MIN TYP † MAX MIN TYP † MAX UNIT Output voltage IO = 1 mA, TA = 25°C 4.95 5 5.05 4.9 5 5.1 V Line regulation VCC = 12 V to 25 V 6 20 6 20 mV Load regulation IO = 1 mA to 20 mA 6 25 6 25 mV Temperature coefficient of output voltage 0.2 0.4 0.2 0.4 mV/°C Output voltage with worst-case variation VCC = 12 V to 25 V,IO = 1 mA to 20 mA 4.9 5.1 4.82 5.18 V Output noise voltage f = 10 Hz to 10 kHz,TA = 25°C 50 50 mV Output-voltage long-term driftAfter 1000 h at TA = 25°C 5 25 5 25 mV Short-circuit output current –30 –100 –180 –30 –100 –180 mA † All typical values are at TA = 25°C. NOTE 4: Adjust VCC above the start threshold before setting it to 15 V. oscillator section PARAMETER TEST CONDITIONS TL284x TL384x UNITPARAMETER TEST CONDITIONS MIN TYP † MAX MIN TYP † MAX UNIT Oscillator frequency (see Note 5) TA = 25°C 47 52 57 47 52 57 kHz Frequency change with supply voltage VCC = 12 V to 25 V 2 10 2 10 Hz/kHz Frequency change with temperature 50 50 Hz/kHz Peak-to-peak amplitude at RT/CT 1.7 1.7 V † All typical values are at TA = 25°C. NOTES: 4. Adjust VCC above the start threshold before setting it to 15 V. 5. Output frequency equals oscillator frequency for the TLx842 and TLx843. Output frequency is one-half oscillator frequency for the TLx844 and TLx845. error-amplifier section PARAMETER TEST CONDITIONS TL284x TL384x UNITPARAMETER TEST CONDITIONS MIN TYP † MAX MIN TYP † MAX UNIT Input bias current –0.3 –1 –0.3 –2 mA Open-loop voltage amplificationVO = 2 V to 4 V 65 90 65 90 dB Gain-bandwidth product 0.7 1 0.7 1 MHz Supply-voltage rejection ratioVCC = 12 V to 25 V 60 70 60 70 dB Output sink current VFB at 2.7 V, COMP at 1.1 V 2 6 2 6 mA High-level output voltage VFB at 2.3 V, R L = 15 kW to GND 5 6 5 6 V † All typical values are at TA = 25°C. NOTE 4: Adjust VCC above the start threshold before setting it to 15 V.

TL284x, TL384x CURRENT-MODE PWM CONTROLLERS SLVS038E – JANUARY 1989 – REVISED DECEMBER 1999 5POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 electrical characteristics over recommended operating free-air temperature range, VCC = 15 V (see Note 4), RT = 10 kW , CT = 3.3 nF (unless otherwise specified) (continued) current-sense section PARAMETER TEST CONDITIONS TL284x TL384x UNITPARAMETER TEST CONDITIONS MIN TYP † MAX MIN TYP † MAX UNIT Voltage amplification See Notes 6 and 7 2.85 3 3.13 2.85 3 3.15 V/V Current-sense comparator thresholdCOMP at 5 V, See Note 6 0.9 1 1.1 0.9 1 1.1 V Supply-voltage rejection ratio VCC = 12 V to 25 V,See Note 6 70 70 dB Input bias current –2 –10 –2 –10 mA Delay time to output 150 300 150 300 ns † All typical values are at TA = 25°C. NOTES: 4. Adjust VCC above the start threshold before setting it to 15 V. 6. These parameters are measured at the trip point of the latch, with VFB at 0 V. 7. Voltage amplification is measured between ISENSE and COMP, with the input changing from 0 V to 0.8 V. output section PARAMETER TEST CONDITIONS TL284x TL384x UNITPARAMETER TEST CONDITIONS MIN TYP † MAX MIN TYP † MAX UNIT High level output voltage IOH = –20 mA 13 13.5 13 13.5 VHigh-level output voltage IOH = –200 mA 12 13.5 12 13.5 V Low level output voltage IOL = 20 mA 0.1 0.4 0.1 0.4 VLow-level output voltage IOL = 200 mA 1.5 2.2 1.5 2.2 V Rise time C L = 1 nF, TA = 25°C 50 150 50 150 ns Fall time C L = 1 nF, TA = 25°C 50 150 50 150 ns † All typical values are at TA = 25°C. NOTE 4: Adjust VCC above the start threshold before setting it to 15 V. undervoltage-lockout section PARAMETER TL284x TL384x UNITPARAMETER MIN TYP † MAX MIN TYP † MAX UNIT Start threshold voltage TLx842, TLx844 15 16 17 14.5 16 17.5 VStart threshold voltage TLx843, TLx845 7.8 8.4 9 7.8 8.4 9 V Minimum operating voltage after startup TLx842, TLx844 9 10 11 8.5 10 11.5 VMinimum operating voltage after startup TLx843, TLx845 7 7.6 8.2 7 7.6 8.2 V † All typical values are at TA = 25°C. NOTE 4: Adjust VCC above the start threshold before setting it to 15 V. pulse-width-modulator section PARAMETER TL284x TL384x UNITPARAMETER MIN TYP † MAX MIN TYP † MAX UNIT Maximum duty cycle TLx842, TLx843 95% 97% 100% 95% 97% 100% Ma ximum duty cycle TLx844, TLx845 46% 48% 50% 46% 48% 50% Minimum duty cycle 0 0 † All typical values are at TA = 25°C. NOTE 4: Adjust VCC above the start threshold before setting it to 15 V.

TL284x, TL384x CURRENT-MODE PWM CONTROLLERS SLVS038E – JANUARY 1989 – REVISED DECEMBER 1999

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electrical characteristics over recommended operating free-air temperature range, VCC = 15 V (see Note 4), RT = 10 kW , CT = 3.3 nF (unless otherwise specified) (continued) supply voltage PARAMETER TEST CONDITIONS TL284x TL384x UNITPARAMETER TEST CONDITIONS MIN TYP † MAX MIN TYP † MAX UNIT Start-up current 0.5 1 0.5 1 mA Operating supply current VFB and ISENSE at 0 V 11 17 11 17 mA Limiting voltage ICC = 25 mA 34 34 V † All typical values are at TA = 25°C. NOTE 4: Adjust VCC above the start threshold before setting it to 15 V. electrical characteristics, VCC = 15 V (see Note 4), RT = 10 kW , CT = 3.3 nF, TA = 25°C (unless otherwise specified) reference section PARAMETER TEST CONDITIONS TL384xY UNITPARAMETER TEST CONDITIONS MIN TYP MAX UNIT Output voltage IO = 1 mA 5 V Line regulation VCC = 12 V to 25 V 6 mV Load regulation IO = 1 mA to 20 mA 6 mV Temperature coefficient of output voltage 0.2 mV/°C Output noise voltage f = 10 Hz to 10 kHz 50 mV Output-voltage long-term drift After 1000 h at TA = 25°C 5 mV Short-circuit output current –100 mA NOTE 4: Adjust VCC above the start threshold before setting it to 15 V. oscillator section PARAMETER TEST CONDITIONS TL384xY UNITPARAMETER TEST CONDITIONS MIN TYP MAX UNIT Oscillator frequency (see Note 5) 52 kHz Frequency change with supply voltage VCC = 12 V to 25 V 2 Hz/kHz Frequency change with temperature 5 Hz/kHz Peak-to-peak amplitude at RT/CT 1.7 V NOTES: 4. Adjust VCC above the start threshold before setting it to 15 V. 5. Output frequency equals oscillator frequency for the TLx842 and TLx843. Output frequency is one-half oscillator frequency for the TLx844 and TLx845.

TL284x, TL384x CURRENT-MODE PWM CONTROLLERS SLVS038E – JANUARY 1989 – REVISED DECEMBER 1999 7POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 electrical characteristics, VCC = 15 V (see Note 4), RT = 10 kW , CT = 3.3 nF, TA = 25°C (unless otherwise specified) (continued) error-amplifier section PARAMETER TEST CONDITIONS TL384xY UNITPARAMETER TEST CONDITIONS MIN TYP MAX UNIT Feedback input voltage COMP at 2.5 V 2.50 V Input bias current –0.3 mA Open-loop voltage amplification VO = 2 V to 4 V 90 dB Gain-bandwidth product 1 MHz Supply-voltage rejection ratio VCC = 12 V to 25 V 70 dB Output sink current VFB at 2.7 V, COMP at 1.1 V 6 mA Output source current VFB at 2.3 V, COMP at 5 V –0.8 mA High-level output voltage VFB at 2.3 V, R L = 15 kW to GND 6 V Low-level output voltage VFB at 2.7 V, R L = 15 kW to GND 0.7 V NOTE 4: Adjust VCC above the start threshold before setting it to 15 V. current-sense section PARAMETER TEST CONDITIONS TL384xY UNITPARAMETER TEST CONDITIONS MIN TYP MAX UNIT Voltage amplification See Notes 6 and 7 3 V/V Current-sense comparator threshold COMP at 5 V, See Note 6 1 V Supply-voltage rejection ratio VCC = 12 V to 25 V, See Note 6 70 dB Input bias current –2 mA Delay time to output 150 ns NOTES: 4. Adjust VCC above the start threshold before setting it to 15 V. 6. These parameters are measured at the trip point of the latch, with VFB at 0 V. 7. Voltage amplification is measured between ISENSE and COMP, with the input changing from 0 V to 0.8 V. output section PARAMETER TEST CONDITIONS TL384xY UNITPARAMETER TEST CONDITIONS MIN TYP MAX UNIT High level output voltage IOH = –20 mA 13.5 VHigh-level output voltage IOH = –200 mA 13.5 V Low level output voltage IOL = 20 mA 0.1 VLow-level output voltage IOL = 200 mA 1.5 V Rise time C L = 1 nF 50 ns Fall time C L = 1 nF 50 ns NOTE 4: Adjust VCC above the start threshold before setting it to 15 V. undervoltage-lockout section PARAMETER TL384xY UNITPARAMETER MIN TYP MAX UNIT Start threshold voltage TL3842Y , TL3844Y 16 VStart threshold voltage TL3843Y , TL3845Y 8.4 V Minimum operating voltage after startup TL3842Y , TL3844Y 10 VMinimum operating voltage after startup TL3843Y , TL3845Y 7.6 V NOTE 4: Adjust VCC above the start threshold before setting it to 15 V.

TL284x, TL384x CURRENT-MODE PWM CONTROLLERS SLVS038E – JANUARY 1989 – REVISED DECEMBER 1999

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electrical characteristics, VCC = 15 V (see Note 4), RT = 10 kW , CT = 3.3 nF, TA = 25°C (unless otherwise specified) (continued) pulse-width-modulator section PARAMETER TL384xY UNITPARAMETER MIN TYP MAX UNIT Maximum duty cycle TL3842Y , TL3843Y 97% Ma ximum duty cycle TL3844Y , TL3845Y 48% NOTE 4: Adjust VCC above the start threshold before setting it to 15 V. supply voltage PARAMETER TEST CONDITIONS TL384xY UNITPARAMETER TEST CONDITIONS MIN TYP MAX UNIT Start-up current 0.5 1 mA Operating supply current VFB and ISENSE at 0 V 11 17 mA Limiting voltage ICC = 25 mA 34 V NOTE 4: Adjust VCC above the start threshold before setting it to 15 V.

TL284x, TL384x CURRENT-MODE PWM CONTROLLERS SLVS038E – JANUARY 1989 – REVISED DECEMBER 1999

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APPLICATION INFORMATION

C T – Timing Capacitance – nF 100 0.4

0.1 Dead Time –

VCC = 15 V R T ≥ 5 kW TA = 25°C TIMING RESISTANCE vs FREQUENCY Figure 5 W 100 1 k 10 k 100 k 1 M f - Frequency - Hz R T– Timing Resistance – k 100 VCC = 15 V TA = 25°C C T = 22 nF C T = 47 nF C T = 100 nF C T = 10 nF C T = 4.7 nF C T = 22 nF C T = 1 nF open-loop laboratory test fixture In the open-loop laboratory test fixture shown in Figure 6, high peak currents associated with loads necessitate careful grounding techniques. Timing and bypass capacitors should be connected close to the GND terminal in a single-point ground. The transistor and 5-kW potentiometer sample the oscillator waveform and apply an adjustable ramp to the ISENSE terminal. 2N2222 4.7 kW 1 kW Error Amplifier Adjust 4.7 kW 5 kW ISENSE Adjust R T 100 kW COMP VFB ISENSE RT/CT REF OUTPUT GND VCC 0.1 mF 0.1 mF REF VCC OUTPUT GND 1 kW , 1 W A C T TL284x TL384x DUT Figure 6. Open-Loop Laboratory Test Fixture

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