UNISONIC TECHNOLOGIES CO., LTD TL5001 LINEAR INTEGRATED CIRCUIT PULSE-WIDTH-MODULATION CONTROL CIRCUITS DESCRIPTION The UTC TL5001 incorporates on a single monolithic chip all the functions required for a pulse width modulation (PWM) control circuit. Designed primarily for power-supply control, It contains an error amplifier, a regulator, an oscillator, a PWM comparator with a dead-time-control input, undervoltage lockout (UVLO), short-circuit protection (SCP), and an open-collector output transistor. The error-amplifier common-mode voltage ranges from 0V to 1.5V. The noninverting input of the error amplifier is connected to a 1-V reference. Dead-time control (DTC) can be set to provide 0% to 100% dead time by connecting an external resistor between DTC and GND. The oscillator frequency is set by terminating RT with an external resistor to GND. During low Vcc conditions, the UVLO circuit turns the output off until Vcc recovers to its normal operating range. DIP-8 SOP-8 *Pb-free plating product number: TL5001L FEATURES *Complete PWM power control *3.6-V to 40-V operation *Internal under voltage-lockout circuit *Internal short-circuit protection *Oscillator frequency : 20kHz to 500kHz *Variable dead timer provides control over total range ORDERING INFORMATION Ordering Number Normal Lead Free Plating TL5001-D08-T TL5001L-D08-T TL5001-S08-R TL5001L-S08-R TL5001-S08-T TL5001L-S08-T Package Packing DIP-8 SOP-8 SOP-8 Tube Tape Reel Tube TL5001L-D08-R (1)Packing Type (2)Package Type (3)Lead Plating www.unisonic.com.tw Copyright © 2005 Unisonic Technologies Co., Ltd (1) R: Tape Reel, T: Tube (2) D08: DIP-8, S08: SOP-8 (3) L: Lead Free Plating, Blank: Pb/Sn 1 of 13 QW-R103-016,B TL5001 LINEAR INTEGRATED CIRCUIT PIN CONFIGURATION VOUT 1 8 GND VCC 2 7 RT COMP 3 6 DTC FB 4 5 SCP UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 2 of 13 QW-R103-016,B TL5001 LINEAR INTEGRATED CIRCUIT ABSOLUTE MAXIMUM RATINGS OVER OPERATING FREE-AIR TEMPERATURE RANGE (unless otherwise specified)* PARAMETER SYMBOL RATINGS UNIT Supply Voltage (note 1) VCC 41 V Amplifier Input Voltage VI(FB) 20 V Output Voltage VOUT 51 V Output Current IOUT 21 mA Output Peak Current IO(PEAK) 100 mA Continuous Total Power Dissipation See dissipation rating table Operating Ambient Temperature Range TOPR -20 ~ +85 °C Storage Temperature Range TSTG -65 ~ +150 °C Note 1. All voltage values are with respect to the network ground terminal. 2. Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum ratings are stress ratings only and functional device operation is not implied. * 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. DISSIPATION RATING TABLE PACKAGE DIP-8 SOP-8 TA≤25°C POWER RATING 1000mW 725mW DERATING FACTOR ABOVE TA=25°C 8.0mW/°C 5.8mW/°C TA=70°C POWER RATING 640mW 464mW TA=70°C TA=70°C POWER RATING POWER RATING 520mW 200mW 377mW 145mW RECOMMENDED OPERATING CONDITIONS PARAMETER Supply Voltage Amplifier Input Voltage Output Voltage Output Current COMP Source Current COMP dc Load Resistance Oscillator Timing resistor Oscillator Frequency Operating Ambient Temperature Range UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw SYMBOL VCC VI(FB) VOUT IOUT Rt fosc TA MIN 3.6 0 100 15 20 -20 MAX 40 1.5 50 20 45 250 500 85 UNIT V V V mA μA kΩ kΩ kHz °C 3 of 13 QW-R103-016,B TL5001 LINEAR INTEGRATED CIRCUIT ELECTRICAL CHARACTERISTICS OVER RECOMMENDED OPERATING FREE-AIR TEMPERATURE RANGE (Vcc=6V, fosc=100kHz, all typical values at TA=25°C, unless otherwise noted) PARAMETER Reference Output Voltage Input Regulation SYMBOL VOUT Output Voltage Change with Temperature TEST CONDITIONS MIN TYP MAX UNIT COMP Connected to FB Vcc=3.6V ~ 40V TA= -20°C ~ 25°C TA= 25°C ~ 85°C 0.95 1.05 12.5 10 10 V mV -10 -10 1 2 -1 2 2.1 100 3 2.8 2.55 200 mV/V Undervoltage Lockout Threshold Voltage Upper Lower Reset Hysteresis Short Circuit Protection SCP Threshold voltage SCP Voltage, Latched SCP Voltage, UVLO Standby Input Source Current SCP Comparator 1 Threshold Voltage Oscillator Frequency Standard Deviation of Frequency Frequency Change with Voltage VTHR TA= 25°C No pullup No pullup TA= 25°C f IO(SOURCE) Input Threshold Voltage VI(THR) Error Amplifier Input Voltage Input Bias Current VIN II(BIAS) Positive Negative Open-Loop Voltage Amplification Unity-Gain Bandwidth Output (sink) Current Output (source) Current Output Output Saturation Voltage V(DT)=1.5V -4 -4 -4 VO(SAT) (NOTE) Vcc=3.6V ~ 40V 0 1.5 IOFF Short-Circuit Output Current Total Device Standby Supply Current (Off state) Average Supply Current Note: Output source current at RT IO(SC) IOUT=10mA VOUT=50V,Vcc=0 VOUT=50V VOUT=6V ISTN-BY UNISONIC TECHNOLOGIES CO., LTD Rt=100kΩ 4 4 4 1.1*IRT 0.5 VI(FB)=1.2V, COMP=1V VI(FB)=0.8V, COMP=1V 100 15 1 -0.4 -0.4 -0.2 1 1.05 230 120 -20 (NOTE) GV IO(SINK) IO(SOURCE) 1.00 185 60 -15 1.5 V V V mV 0.9*IRT Duty cycle=0% Duty cycle=100% VO(SW) Off-State Current www.unisonic.com.tw -10 VRT Output (source) Current Output Voltage Swing 0.95 140 Rt=100kΩ Vcc=3.6V ~ 40V TA= -40°C ~ 25°C TA= -20°C ~ 25°C TA= 25°C ~ 85°C Frequency Change with Temperature Voltage at RT Dead-time Control TA= 25°C TA= 25°C TA= 25°C TA= 25°C 100 -45 0.7 1.3 -160 2.3 0.3 80 1.5 600 -70 1.5 1.5 1.5 -500 0.4 2 10 10 40 1 1.4 V mV mV µA V kHz kHz kHz kHz kHz kHz V µA V V nA V V dB MHz µA µA V µA mA 1.5 2.1 mA mA 4 of 13 QW-R103-016,B TL5001 LINEAR INTEGRATED CIRCUIT SCHEMATIC FOR TYPICAL APPLICATION VIN + TSP1101 5 VOUT + 2 VCC SCP VOUT COMP 1 3 UTC TL5001 6 7 DTC FB RT 4 GND 8 FUNCTIONAL BLOCK DIAGRAM RT 7 VCC 2 DTC 6 OUT 1 UVLO IDT 1V 1.5V Error Amplifier + FB 4 3 COMP SCP 2.5V Reference Voltage 1V scp Comparator 1 5 OSC PWM/DTC Comparator scp Comparator 2 8 GND UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 5 of 13 QW-R103-016,B TL5001 LINEAR INTEGRATED CIRCUIT DETAILED DESCRIPTION VOLTAGE REFERENCE A 2.5-V regulator operating from Vcc is used to power the internal circuitry of the TL5001 and as a reference for the error amplifier and SCP circuit. A resistive divider provides a 1-V reference for the error amplifier non-inverting input which typically is within 2% of nominal over the operating temperature range. ERROR AMPLIFIER The error amplifier compares a sample of the dc-to-dc converter output voltage to the 1-V reference and generates an error signal for the PWM comparator. The dc-to-dc converter output voltage is set by selecting the error –amplifier gain (see Figure 1), using the following expression. VOUT=(1+R1/R2) (1V) Compensation Network R1 VI(FB) 3 COMP 4 FB R2 + 8 GND VREF=1V To PWM Comparator Figure 1.Error-Amplifier Gain Setting The error-amplifier output is brought out as COMP for use in compensating the dc-to-dc converter control loop for stability. Because the amplifier can only source 45µA, the total dc load resistance should be 100kΩ or more. OSCILLATOR/PWM The oscillator frequency (fosc) can be set between 20kHz and 500kHz by connecting a resistor between RT and GND .Acceptable resistor values range from 15 kΩ to 250 kΩ. The oscillator frequency can be determined by using the graph shown in Figure 5. The oscillator output is a triangular wave with a minimum value of approximately 0.7V and a maximum value of approximately 1.3V. The PWM comparator compares the error-amplifier output voltage and the DTC input voltage to the triangular wave and turns the output transistor off whenever the triangular wave is greater than the lesser of the two inputs. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 6 of 13 QW-R103-016,B TL5001 LINEAR INTEGRATED CIRCUIT DETAILED DESCRIPTION(Cont.) DEAD TIME CONTORL (DTC) DTC provides a means of limiting the output-switch duty cycle to a value less than 100%, which is critical for boost and flyback converters. A current source generates a reference current (IDT) at DTC that is nominally equal to the current at the oscillator timing terminal, RT. Connecting a resistor between DTC and GND generates a dead-time reference voltage (VDT), which the PWM/DTC comparator compares to the oscillator triangle wave as described in the previous section. Nominally, the maximum duty cycle is 0% when VDT is 0.7V or less and 100% when VDT is 1.3V or greater. Because the triangle wave amplitude is a function of frequency and the source impedance of RT is relatively high(1250Ω),choosing RDT for a specific maximum duty cycle, D, is accomplished using the following equation and the voltage limits for the frequency in question as found in Figure 11(Voscmax and Voscmin are the maximum and minimum oscillator levels): RDT=(Rt +1250)[D(Vosc max-Vosc min)+Vosc min] Where RDT and Rt are in ohms, D in decimal Soft start can be implemented by paralleling the DTC resistor with a capacitor (CDT) as shown in Figure 2. During soft start, the voltage at DTC is derived by the following equation: VDT≈IDTRDT(1-e(-t/RDTCDT)) 6 DTC CDT RDT UTC TL5001 Figure 2. Soft- Start Circuit If the dc-to-dc converter must be in regulation within a specified period of time, the time constant, RDTCDT, should be t0/3 to t0/5.The UTC TL5001 remains off unit VDT≈0.7V, the minimum ramp value. CDT is discharged every time UVLO or SCP becomes active. UNDERVOLTAGE-LOCKOUT (UVLO) PROTECTION The undervoltage-lockout circuit turns the output transistor off and resets the SCP latch whenever the supply voltage drops too low (approximately 3V at 25℃) for proper operation. A hysteresis voltage of 200mV eliminates false triggering on noise and chattering. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 7 of 13 QW-R103-016,B TL5001 LINEAR INTEGRATED CIRCUIT DETAILED DESCRIPTION(Cont.) SHORT-CIRCUIT PROTECTION (SCP) The UTC TL5001 includes short-circuit protection (see Figure 3), which turns the power switch off to prevent damage when the converter output is shorted. When activated, The SCP prevents the switch from being turned on until the internal latching circuit is reset. The circuit is reset by reducing the input voltage until UVLO becomes active or until the SCP terminal is pulled to ground externally. When a short circuit occurs, the error-amplifier output at COMP rises to increase the power-switch duty cycle in an attempt to maintain the output voltage. SCP comparator 1 starts an RC timing circuit when COMP exceeds 1.5V.If the short is removed and the error-amplifier output drops below 1.5V before time out, normal converter operation continues. If the fault is still present at the end of the time-out period, the time sets the latching circuit and turns off the UTC TL5001 output transistor. 2.5V RSCP CSCP 12kO SCP 5 185kO From Error Amp 1.5V scp Comparator 2 Q1 scp Comparator 1 To Output Drive Logic VREF=1V Q2 Figure 3.SCP Circuit The timer operates by charging an external capacitor (Cscp),connected between the SCP terminal and ground, towards 2.5V through a 185kΩ resistor (Rscp).The circuit begins charging from an initial voltage of approximately 185mV and times out when capacitor voltage reaches 1V.The output of SCP comparator 2 then goes high, turns on Q2,and latches the timer circuit. The expression for setting the SCP time period is derived from the following equation: Vscp =(2.5-0.185)(1-e-t/τ)+0.185 Where ι=RscpCscp The end of the time-out period, tscp, occurs when Vscp=1V. Solving for Cscp yields: Cscp=12.46*tscp Where t is in seconds, C in µF tscp must be much longer (generally 10 to 15 times) than the converter start-up period or the converter will not start. OUTPUT TRANSISTOR The output of the UTC TL5001 is an open-collector transistor with a maximum collector current rating of 21mA and a voltage rating of 51V.The output is turned on under the following conditions: the oscillator triangle wave is lower than both the DTC voltage and the error-amplifier output voltage, the UVLO circuit is inactive, and the short-circuit protection circuit is inactive. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 8 of 13 QW-R103-016,B TL5001 LINEAR INTEGRATED CIRCUIT PARAMETER MEASUREMENT INFORMATION COMP 2.3V 1.5V DTC OSC PWM/DTC Comparator OUT scp Comparator 1 1V scp SCP Timing Period 0V scp Comparator 2 VCC 3V NOTE A:The waveforms show timing characteristics for an intermittent short circuit and a longer short circuit that is sufficient to activate SCP. Figure 4. PWM Timing Diagram UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 9 of 13 QW-R103-016,B TL5001 LINEAR INTEGRATED CIRCUIT APPLICATION INFORMATION VIN 5V C1 100μF 10V R1 470Ω + Q1 TPS1101 GND L1 20μH C3 0.1μF CR1 MBRS140T3 2 C4 1μF + C4 0.1μF R2 56kΩ R3 43kΩ 5 6 7 V CC SCP VOUT COMP UTC TL5001 1 FB 4 + GND 3 DTC RT C2 100μF 10V 3.3V C6 0.012μF R4 5.1kΩ R5 7.50kΩ 1% R7 2.0kΩ C7 0.0047μF R6 3.24kΩ 1% GND 8 Partial Bill of Materials: Q1 L1 C1 C2 CR1 TPS1101 Texas Instruments CTX20-1 or Coiltronics 23 turns of #28 wire on Micrometals No. T50-26B core TPSD 107M010R0100 AVX TPSD 107M010R0100 AVX MBRS 140T3 Motorola NOTES: A. Frequency = 200KHz B. Duty cycle = 90% max C. Soft-start time constant (TC) = 5.6ms D. SCP TC = 70msA Figure 5. Step-Down Converter UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 10 of 13 QW-R103-016,B TL5001 LINEAR INTEGRATED CIRCUIT TYPICAL CHARACTERISTICS Oscillator Frequency vs Timing Resistance 100k 100k Timing Resistance, Rt (Ω) 1M Reference Output Voltage vs Power -Supply Voltage 2 1.8 TA=25°C FB and COMP Connected Together 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 0 1 2 3 4 5 6 7 Oscillator Frequency, fosc(Hz) Vcc=6V DT Resistance=Rt TA =25°C 10k 10k Reference Output Voltage, VREF(V) 100 8 9 10 Reference Output Voltage Fluctuation, VREF (%) Oscillator Frequency, fosc (Hz) 1M 98 96 94 92 Vcc=6V 90 DT Resistance=100kΩ Rt=100kΩ 88 -50 -25 0 25 50 75 Ambient Temperature, TA(°C) 0.6 0.4 Average Supply Current vs Power -Supply Voltage Aver age Supply Current, Icc (mA) Average Supply Current, Icc(mA) 1 0.5 30 10 20 Power-Supply Voltage, Vcc (V) 40 UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw Vcc=6V FB and COMP Connected Together 0 -0.2 -0.4 -0.6 -0.8 -50 1.3 1.5 0 Reference Output Voltage Fluctuation vs Ambient Temperature -25 0 25 50 75 100 Ambient Temperature, TA (°C) Rt=100kΩ TA=25°C 0 100 0.2 Power-Supply Voltage, Vcc (V) 2 Oscillator Frequency vs Ambient Temperature Average Supply Current vs Ambient Temperature 1.2 1.1 1 0.9 Vcc=6V 0.8 DT Resistance=100kΩ Rt=100kΩ 0 -50 -25 0 25 50 75 100 Ambient Temperature, TA (°C) 11 of 13 QW-R103-016,B TL5001 LINEAR INTEGRATED CIRCUIT 1.2 Voscmax(100% duty cycle ) 0.9 0.6 Vosc min(zero duty cycle ) 0.3 0 10k 1M 100k 1 0.5 0 0 0.2 0.4 0.6 Error Amplifier Output Voltage vs Output(Source)Current Error Amplifier Output Voltage vs Ambient Temperature 1.5 1 Vcc=6V TA=25°C VI (FB)=0.8V 2.46 2.45 180 160 140 -25 0 25 50 75 100 Ambient Temperature, TA(°C) UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 2.43 2.42 2.41 Vcc=6V VI(FB)=0.8V No Load -25 0 25 50 75 100 Ambient Temperature, TA(°C) Error Amplifier Output Voltage vs Ambient Temperature 200 2.44 2.40 -50 40 80 100 120 20 60 Output(Source)Current, IoUT(uA) Vcc=6V 220 VI (FB)=1.2V No Load 120 -50 1.5 Output(Sink)Current, IoUT (mA) 2 0 0 2 Oscillator Frequency, fosc (Hz) 2.5 0.5 Vcc=6V TA=25°C 2.5 VI (FB)=1.2V 10M Vo- Error Amplifier Output Voltage -V 3 240 Error Amplifier Output Voltage, VoUT (V) Vcc=6V TA=25°C Error Amplifier Output Voltage vs Output(Sink)Current Error Amplifier Open-Loop Gain and Phase Shift vs Frequency 40 -180° Vcc=6V TA=25°C 30 -210° -240° 20 Gv 10 -270° 0 Φ -10 -20 10k -300° -330° 100k 1M -360° 10M Error Amplifier Open -Loop Gain, Gv (dB) 1.5 3 Error Amplifier Output Voltage, VOUT(V) 1.8 PWM Triangle Wave Amplitude Voltage vs Oscillator Frequency Er ror Amplifier Open -Loop G ain, Gv(dB) Error Amplifier Output Voltage, VoUT (V) Triancle Wave Amplitude Voltage, PWM (V) TYPICAL CHARACTERISTICS(Cont.) Frequency, f(Hz) 12 of 13 QW-R103-016,B TL5001 LINEAR INTEGRATED CIRCUIT TYPICAL CHARACTERISTICS(Cont.) Output Duty Cycle vs DTC Voltage 120 Output Duty Cycle-% tscp-scp Time-Out Per iod -ms Vcc=6V TA =25℃ Rt =100Ω 100 80 60 40 20 0 0 0.5 1 1.5 10 8 6 4 0 0 2 Output S aturation Voltage, VCE (V) DTC Output Current, Io(DT) (µA) 2 TA=25℃ -50 DT Voltage =1.3V -40 -30 -20 -10 -10 -20 -30 -40 -50 RT Output Current, IoUT (µA) 20 40 60 80 100 120 Cscp-scp Capacitance -nF DTC Output Current vs RT Output Current 0 0 Vcc=6V TA=25℃ Rt =100Ω DT Resistance =200kΩ 2 DTC Voltage -V -60 Scp-Time-Output Period vs SCP Capacitance 12 -60 1.5 Output Saturation Voltage vs Output (Sink) Current Vcc=6V TA =25℃ 1 0.5 0 -50 -25 0 25 50 75 100 Output(Sink)Current, Io(SINK) (mA) UTC assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all UTC products described or contained herein. UTC products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 13 of 13 QW-R103-016,B