Complete PWM Power Control to 40-V Operation Internal Undervoltage-Lockout Circuit Internal Short-Circuit Protection Oscillator Frequency. 20 kHz to 500 kHz Variable Dead Time Provides Control Over Total Range �3% Tolerance on Reference Voltage (TL5001A) Available in Q-Temp Automotive HighRel Automotive Applications Configuration Control / Print Support Qualification to Automotive Standardsdescription
The TL5001 and TL5001A incorporate on a single 14 NC monolithic chip all the functions required for a pulse-width-modulation (PWM) control circuit. Designed primarily for power-supply control, the TL5001/A 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 TL5001A has a typical reference voltage tolerance of �3% compared to �5% for the TL5001.
The error-amplifier common-mode voltage ranges from 1.5 V. The noninverting input of the error amplifier is connected a 1-V reference. Dead-time control (DTC) can be set to provide 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. The TL5001C and TL5001AC are characterized for operation from to 85�C. The TL5001I and TL5001AI are characterized for operation from to 85�C. The TL5001Q and TL5001AQ are characterized for operation from to 125�C. The TL5001M and TL5001AM are characterized for operation from to 125�C.
AVAILABLE OPTIONS PACKAGED DEVICES TA SMALL OUTLINE (D) TL5001QD TL5001AQD PLASTIC DIP (P) TL5001IP TL5001AIP CERAMIC DIP (JG) TL5001MJG TL5001AMJG CHIP CARRIER (FK) TL5001MFK TL5001AMFK
The D package is available taped and reeled. Add the suffix R to the device type (e.g., TL5001CDR). 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.
On products compliant to MIL-PRF-38535, all parameters are tested unless otherwise noted. On all other products, production processing does not necessarily include testing of all parameters.
PRODUCTION 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.
voltage reference A 2.5-V regulator operating from VCC is used to power the internal circuitry of the TL5001 and TL5001A and as a reference for the error amplifier and SCP circuits. A resistive divider provides a 1-V reference for the error amplifier noninverting 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: (1 V)
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 45 �A, the total dc load resistance should k or more. oscillator/PWM The oscillator frequency (fosc) can be set between 20 kHz and 500 kHz by connecting a resistor between RT and GND. Acceptable resistor values range from 250 k. 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 0.7 V and a maximum value of approximately 1.3 V. 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. dead-time control (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 0 % when VDT V or less and 100 % when VDT V or greater. Because the triangle wave amplitude is a function of frequency and the source impedance RT is relatively high (1250 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):