HIGH-PERFORMANCE CURRENT-MODE PWM CONTROLLERS

www.DataSheet4U.com TL284xB, TL384xB HIGH-PERFORMANCE CURRENT-MODE PWM CONTROLLERS www.ti.com SLVS610A – AUGUST 2006 – REVISED SEPTEMBER 2006 FEATURES • • • • • • • • Low Start-Up Current (<0.5 mA) Trimmed Oscillator Discharge Current Current Mode Operation to 500 kHz Automatic Feed-Forward Compensation Latching PWM for Cycle-by-Cycle Current Limiting Internally Trimmed Reference With Undervoltage Lockout High-Current Totem-Pole Output Undervoltage Lockout With Hysteresis Double-Pulse Suppression D (SOIC) OR P (PDIP) PACKAGE (TOP VIEW) COMP VFB ISENSE RT/CT 1 2 3 4 8 7 6 5 VREF VCC OUTPUT GND D (SOIC) PACKAGE (TOP VIEW) COMP NC VFB NC ISENSE NC RT/CT 1 2 3 4 5 6 7 14 13 12 11 10 9 8 VREF NC VCC VC OUTPUT GND POWER GROUND NC − No internal connection DESCRIPTION/ORDERING INFORMATION The TL284xB and TL384xB 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. Internally implemented circuits include an undervoltage lockout (UVLO) and a precision reference that is trimmed for accuracy at the error amplifier input. Other internal circuits include logic to ensure latched operation, a pulse-width modulation (PWM) comparator that 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. The TL284xB and TL384xB series are pin compatible with the standard TL284x and TL384x with the following improvements. The start-up current is specified to be 0.5 mA (max), while the oscillator discharge current is trimmed to 8.3 mA (typ). In addition, during undervoltage lockout conditions, the output has a maximum saturation voltage of 1.2 V while sinking 10 mA (VCC = 5 V). 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 TLx842B and TLx844B devices make them ideally suited to off-line applications. The corresponding typical thresholds for the TLx843B and TLx845B devices are 8.4 V (on) and 7.6 V (off). The TLx842B and TLx843B devices can operate to duty cycles approaching 100%. A duty-cycle range of 0% to 50% is obtained by the TLx844B and TLx845B by the addition of an internal toggle flip-flop, which blanks the output off every other clock cycle.The TL284xB-series devices are characterized for operation from –40°C to 85°C. The TL384xB-series devices are characterized for operation from 0°C to 70°C. 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. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2006, Texas Instruments Incorporated TL284xB, TL384xB HIGH-PERFORMANCE CURRENT-MODE PWM CONTROLLERS SLVS610A – AUGUST 2006 – REVISED SEPTEMBER 2006 www.ti.com ORDERING INFORMATION TA PACKAGE (1) ORDERABLE PART NUMBER TL2842BP PDIP – P Tube of 50 TL2843BP TL2844BP TL2845BP Tube of 75 Reel of 2500 Tube of 75 SOIC – D (8 pin) –40°C to 85°C Reel of 2500 Tube of 75 Reel of 2500 Tube of 75 Reel of 2500 Tube of 75 Reel of 2500 Tube of 75 SOIC – D (14 pin) Reel of 2500 Tube of 75 Reel of 2500 Tube of 75 Reel of 2500 TL2842BD-8 TL2842BDR-8 TL2843BD-8 TL2843BDR-8 TL2844BD-8 TL2844BDR-8 TL2845BD-8 TL2845BDR-8 TL2842BD TL2842BDR TL2843BD TL2843BDR TL2844BD TL2844BDR TL2845BD TL2845BDR TL3842BP PDIP – P Tube of 50 TL3843BP TL3844BP TL3845BP Tube of 75 Reel of 2500 Tube of 75 SOIC – D (8 pin) 0°C to 70°C Reel of 2500 Tube of 75 Reel of 2500 Tube of 75 Reel of 2500 Tube of 75 Reel of 2500 Tube of 75 SOIC – D (14 pin) Reel of 2500 Tube of 75 Reel of 2500 Tube of 75 Reel of 2500 (1) TL3842BD-8 TL3842BDR-8 TL3843BD-8 TL3843BDR-8 TL3844BD-8 TL3844BDR-8 TL3845BD-8 TL3845BDR-8 TL3842BD TL3842BDR TL3843BD TL3843BDR TL3844BD TL3844BDR TL3845BD TL3845BDR TOP-SIDE MARKING TL2842BP TL2843BP TL2844BP TL2845BP 2842B 2843B 2844B 2845B TL2842B TL2843B TL2844B TL2845B TL3842BP TL3843BP TL3844BP TL3845BP 3842B 3843B 3844B 3845B TL3842B TL3843B TL3844B TL3845B Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are available at www.ti.com/sc/package. 2 Submit Documentation Feedback www.ti.com TL284xB, TL384xB HIGH-PERFORMANCE CURRENT-MODE PWM CONTROLLERS SLVS610A – AUGUST 2006 – REVISED SEPTEMBER 2006 FUNCTIONAL BLOCK DIAGRAM VCC 7 34 V NOM GND 5 − + UVLO EN 5-V VREF 8 VREF 2.5 V VREF Good Logic RT/CT 4 OSC T Error Amplifier VFB COMP ISENSE 2 1 3 + − 2R R R 1V CurrentSense Comparator Internal Bias 6 OUTPUT S PWM Latch A. Pin numbers shown are for the 8-pin D package. Submit Documentation Feedback 3 TL284xB, TL384xB HIGH-PERFORMANCE CURRENT-MODE PWM CONTROLLERS SLVS610A – AUGUST 2006 – REVISED SEPTEMBER 2006 www.ti.com Absolute Maximum Ratings (1) (2) over operating free-air temperature range (unless otherwise noted) MIN Low impedance source VCC VI ICC IO IO(sink) θJA Supply voltage Analog input voltage range Supply current Output current Error amplifier output sink current Package thermal impedance (3) (4) Output energy TJ Tstg Tlead (1) (2) (3) (4) Virtual junction temperature Storage temperature range Lead temperature Soldering, 10 s –65 D package P package Capacitive load 8 pin 14 pin ICC < 30 mA VFB and ISENSE –0.3 MAX 30 Self limiting 6.3 30 ±1 10 97 86 85 5 150 150 300 µJ °C °C °C °C/W V V mA A mA UNIT 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. All voltages are with respect to the device GND terminal. Maximum power dissipation is a function of TJ(max), θJA, and TA. The maximum allowable power dissipation at any allowable ambient temperature is PD = (TJ(max) – TA)/θJA. Operating at the absolute maximum TJ of 150°C can impact reliability. The package thermal impedance is calculated in accordance with JESD 51-7. Recommended Operating Conditions MIN VCC VI VO ICC IO IO(ref) fosc TJ (1) Supply voltage Input voltage Output voltage Supply current, externally limited Average output current Reference output current Oscillator frequency Operating free-air temperature TL284xB TL384xB –40 0 100 VCC VC (1) RT/CT VFB and ISENSE OUTPUT POWER GROUND (1) 0 0 0 –0.1 NOM MAX 30 30 5.5 5.5 30 1 25 200 –20 500 85 70 UNIT V V V mA mA mA kHz °C The recommended voltages for VC and POWER GROUND apply only to the 14-pin D package. 4 Submit Documentation Feedback www.ti.com TL284xB, TL384xB HIGH-PERFORMANCE CURRENT-MODE PWM CONTROLLERS SLVS610A – AUGUST 2006 – REVISED SEPTEMBER 2006 Reference Section Electrical Characteristics VCC = 15 V (1), RT = 10 kΩ, CT = 3.3 nF, over recommended operating free-air temperature range (unless otherwise specified) PARAMETER Output voltage Line regulation Load regulation Average temperature coefficient of output voltage Output voltage, worst-case variation Output noise voltage Short-circuit output current (1) (2) Adjust VCC above the start threshold before setting it to 15 V. All typical values are at TJ = 25°C. VCC = 12 V to 25 V, IO = 1 mA to 20 mA f = 10 Hz to 10 kHz, TJ = 25°C –30 4.9 50 5 –100 25 –180 –30 TEST CONDITIONS IO = 1 mA, TJ = 25°C VCC = 12 V to 25 V IO = 1 mA to 20 mA TL284xB MIN 4.95 TYP (2) 5 6 6 0.2 MAX 5.05 20 25 0.4 5.1 4.82 50 5 –100 25 –180 MIN 4.9 TL384xB TYP (2) 5 6 6 0.2 MAX 5.1 20 25 0.4 5.18 UNIT V mV mV mV/°C V µV mV mA Output-voltage long-term drift After 1000 h at TJ = 25°C Oscillator Section (1) Electrical Characteristics VCC = 15 V (2), RT = 10 kΩ, CT = 3.3 nF, over recommended operating free-air temperature range (unless otherwise specified) PARAMETER TEST CONDITIONS TJ = 25°C, RT = 62 kΩ, CT = 1 nF, Min = 225 kHz, Max = 275 kHz TJ = Full range Voltage stability Temperature stability Amplitude Discharge current (1) (2) (3) Peak to peak TJ = 25°C, RT/CT = 2 V RT/CT = 2 V 7.8 7.5 VCC = 12 V to 25 V TL284xB MIN 49 48 0.2 5 1.7 8.3 8.8 8.8 7.8 7.6 TYP (3) 52 MAX 55 56 1 MIN 49 48 0.2 5 1.7 8.3 8.8 8.8 TL384xB TYP (3) 52 MAX 55 56 1 % % V mA UNIT Initial accuracy kHz Output frequency equals oscillator frequency for the TL3842B and TL3843B. Output frequency is one-half the oscillator frequency for the TL3844B and TL3845B. Adjust VCC above the start threshold before setting it to 15 V. All typical values are at TJ = 25°C. Submit Documentation Feedback 5 TL284xB, TL384xB HIGH-PERFORMANCE CURRENT-MODE PWM CONTROLLERS SLVS610A – AUGUST 2006 – REVISED SEPTEMBER 2006 www.ti.com Error-Amplifier Section Electrical Characteristics VCC = 15 V (1), RT = 10 kΩ, CT = 3.3 nF, over recommended operating free-air temperature range (unless otherwise specified) PARAMETER Feedback input voltage Input bias current Open-loop voltage amplification Gain-bandwidth product Supply-voltage rejection ratio VCC = 12 V to 25 V Output sink current Output source current High-level output voltage Low-level output voltage (1) (2) VFB = 2.7 V, COMP = 1.1 V VFB = 2.3 V, COMP = 5 V VFB = 2.3 V, RL = 15 kΩ to GND VFB = 2.7 V, RL = 15 kΩ to GND VO = 2 V to 4 V 65 0.7 60 2 –0.5 5 TEST CONDITIONS COMP = 2.5 V TL284xB MIN 2.45 TYP (2) 2.5 –0.3 90 1 70 6 –0.8 6 0.7 1.1 MAX 2.55 –1 65 0.7 60 2 –0.5 5 MIN 2.42 TL384xB TYP (2) 2.