Texas Instruments TL5001EVM-101, TL5001EVM-102, TL5001EVM-097, TL5001EVM-089, TL5001EVM-087 Datasheet

TL5001, TL5001A PULSE-WIDTH-MODULATION CONTROL CIRCUITS

DComplete PWM Power Control

D3.6-V to 40-V Operation

DInternal Undervoltage-Lockout Circuit

DInternal Short-Circuit Protection

DOscillator Frequency . . . 20 kHz to 500 kHz

DVariable Dead Time Provides Control Over Total Range

D±3% Tolerance on Reference Voltage

(TL5001A)

DAvailable in Q-Temp Automotive

HighRel Automotive Applications Configuration Control / Print Support Qualification to Automotive Standards

description

SLVS084E ± APRIL 1994 ± REVISED OCTOBER 1999

D, JG OR P PACKAGE

(TOP VIEW)

	OUT		1		8			GND
	VCC		2		7			RT
	COMP		3		6			DTC
	FB		4		5			SCP
		FK PACKAGE
			(TOP VIEW)
	NC		OUT	NC	GND			NC
	3	2		1	20			19
NC	4							18	NC
VCC	5							17	RT
NC	6							16	NC

The TL5001 and TL5001A incorporate on a single	COMP	7					15		DTC
	NC	8					14		NC
monolithic chip all the functions required for a
		9	10	11	12		13
pulse-width-modulation (PWM) control circuit.
			FB
Designed primarily for power-supply control, the		NC		NC	SCP			NC
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 0 V to 1.5 V. 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.

The TL5001C and TL5001AC are characterized for operation from ±20°C to 85°C. The TL5001I and TL5001AI are characterized for operation from ±40°C to 85°C. The TL5001Q and TL5001AQ are characterized for operation from ±40°C to 125°C. The TL5001M and TL5001AM are characterized for operation from ±55°C to 125°C.

AVAILABLE OPTIONS

			PACKAGED DEVICES
	TA
		SMALL OUTLINE	PLASTIC DIP	CERAMIC DIP	CHIP CARRIER
		(D)	(P)	(JG)	(FK)
	±20°C to 85°C	TL5001CD	TL5001CP	Ð	Ð
		TL5001ACD	TL5001ACP	Ð	Ð
	±40°C to 85°C	TL5001ID	TL5001IP	Ð	Ð
		TL5001AID	TL5001AIP	Ð	Ð
	±40°C to 125°C	TL5001QD	Ð	Ð	Ð
		TL5001AQD	Ð	Ð	Ð
	±55°C to 125°C	Ð	Ð	TL5001MJG	TL5001MFK
		Ð	Ð	TL5001AMJG	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.

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.

Copyright 1999, Texas Instruments Incorporated

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1

TL5001, TL5001A

PULSE-WIDTH-MODULATION CONTROL CIRCUITS

SLVS084E ± APRIL 1994 ± REVISED OCTOBER 1999

schematic for typical application

				VI
					+
						TPS1101
							VO
						2	+
						VCC
				5	SCP	1
						VO
						COMP 3
				6	TL5001/A
					DTC
						4
				7	RT	FB
						GND
						8
functional block diagram
				VCC		RT	DTC	OUT
					2	7	6	1
						UVLO
						IDT
			1 V	Reference		2.5 V
			1.5 V			1 V
				Voltage
		Error		SCP		OSC	PWM/DTC
							Comparator
		Amplifier	Comparator 1
		+
FB	4	±
COMP	3
						SCP
						Comparator 2
SCP	5
								8
								GND

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TL5001, TL5001A

PULSE-WIDTH-MODULATION CONTROL CIRCUITS

SLVS084E ± APRIL 1994 ± REVISED OCTOBER 1999

detailed description

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:

VO = (1 + R1/R2) (1 V)

		3	COMP	TL5001/A
	Compensation
	Network
	R1	4	FB	±
	VI(FB)
				To PWM
	R2			Comparator
				+
		8	GND	Vref = 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 µA, the total dc load resistance should be 100 kΩ 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 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 0.7 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 is 0% when VDT is 0.7 V or less and 100% when VDT is 1.3 V or greater. Because the triangle wave amplitude is a function of frequency and the source impedance of RT is relatively high (1250 Ω), 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):

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TL5001, TL5001A

PULSE-WIDTH-MODULATION CONTROL CIRCUITS

SLVS084E ± APRIL 1994 ± REVISED OCTOBER 1999

dead-time control (DTC) (continued)

RDT + Rt ) 1250 D Voscmax ± Voscmin ) Voscmin

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:

V

DT [

I

DT

R

DT

1±e ±t RDTCDT

6

DTC

CDT

RDT

TL5001/A

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 TL5001/A remains off until VDT ≈ 0.7 V, 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 3 V at 25°C) for proper operation. A hysteresis voltage of 200 mV eliminates false triggering on noise and chattering.

short-circuit protection (SCP)

The TL5001/A 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 1.5 V. If the short is removed and the error-amplifier output drops below 1.5 V before time out, normal converter operation continues. If the fault is still present at the end of the time-out period, the timer sets the latching circuit and turns off the TL5001/A output transistor.

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TL5001, TL5001A

PULSE-WIDTH-MODULATION CONTROL CIRCUITS

				SLVS084E ± APRIL 1994 ± REVISED OCTOBER 1999
short-circuit protection (SCP) (continued)
		2.5 V
		RSCP	185 kΩ
CSCP			12 kΩ	SCP
	SCP			Comparator 2
				To Output
5	From Error
				Drive Logic
	Amp		Q1
		SCP		Vref = 1 V
	1.5 V
		Comparator 1
		Q2

Figure 3. SCP Circuit

The timer operates by charging an external capacitor (CSCP), connected between the SCP terminal and ground, towards 2.5 V through a 185-kΩ resistor (RSCP). The circuit begins charging from an initial voltage of approximately 185 mV and times out when the capacitor voltage reaches 1 V. 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 t ) 0.185

Where

τ = RSCPCSCP

The end of the time-out period, tSCP, occurs when VSCP = 1 V. 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 TL5001/A is an open-collector transistor with a maximum collector current rating of 21 mA and a voltage rating of 51 V. 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.

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TL5001, TL5001A

PULSE-WIDTH-MODULATION CONTROL CIRCUITS

SLVS084E ± APRIL 1994 ± REVISED OCTOBER 1999

absolute maximum ratings over operating free-air temperature range (unless otherwise noted)²

Supply voltage, VCC (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . . . . . . . 41 V
Amplifier input voltage, VI(FB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . . . . . . . 20 V
Output voltage, VO, OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . . . . . . . 51 V
Output current, IO, OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . . . . . 21 mA
Output peak current, IO(peak), OUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . . . . 100 mA
Continuous total power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	See Dissipation Rating Table
Operating ambient temperature range, TA: TL5001C, TL5001AC . . . . . . . . . .	. . . . . . . . . . . . ±20°C to 85°C
TL5001I, TL5001AI . . . . . . . . . . . .	. . . . . . . . . . . . ±40°C to 85°C
TL5001Q, TL5001AQ . . . . . . . . . .	. . . . . . . . . . . ±40°C to 125°C
TL5001M, TL5001AM . . . . . . . . . .	. . . . . . . . . . . ±55°C to 125°C
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . ±65°C to 150°C
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . .	. . . . . . . . . . . . . . . . . . . 260°C

²Stresses beyond those listed under ªabsolute maximum ratingsº 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 ªrecommended operating conditionsº is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

NOTE 1: All voltage values are with respect to network ground terminal.

DISSIPATION RATING TABLE

	PACKAGE	TA ≤ 25°C	DERATING FACTOR	TA = 70°C	TA = 85°C	TA = 125°C
		POWER RATING	ABOVE TA = 25°C	POWER RATING	POWER RATING	POWER RATING
	D	725 mW	5.8 mW/°C	464 mW	377 mW	145 mW
	FK	1375 mW	11.0 mW/°C	880 mW	715 mW	275 mW
	JG	1050 mW	8.4 mW/°C	672 mW	546 mW	210 mW
	P	1000 mW	8.0 mW/°C	640 mW	520 mW	200 mW

recommended operating conditions

			MIN	MAX	UNIT
	Supply voltage, VCC		3.6	40	V
	Amplifier input voltage, VI(FB)		0	1.5	V
	Output voltage, VO, OUT			50	V
	Output current, IO, OUT			20	mA
	COMP source current			45	µA
	COMP dc load resistance		100		kΩ
	Oscillator timing resistor, Rt		15	250	kΩ
	Oscillator frequency, fosc		20	500	kHz
		TL5001C, TL5001AC	± 20	85
	Operating ambient temperature, TA	TL5001I, TL5001AI	± 40	85	°C
		TL5001Q, TL5001AQ	± 40	125
		TL5001M, TL5001AM	± 55	125

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TL5001, TL5001A

PULSE-WIDTH-MODULATION CONTROL CIRCUITS

SLVS084E ± APRIL 1994 ± REVISED OCTOBER 1999

electrical characteristics over recommended operating free-air temperature range, VCC = 6 V, fosc = 100 kHz (unless otherwise noted)

reference

	PARAMETER	TEST CONDITIONS	TL5001C, TL5001I			TL5001AC, TL5001AI			UNIT
			MIN	TYP²	MAX	MIN	TYP²	MAX
	Output voltage	COMP connected to FB	0.95	1	1.05	0.97	1	1.03	V
	Input regulation	VCC = 3.6 V to 40 V		2	12.5		2	12.5	mV
		TA = ± 20°C to 25°C (C suffix)	± 10	± 1	10	± 10	± 1	10
	Output voltage change with temperature	TA = ± 40°C to 25°C (I suffix)	± 10	± 1	10	± 10	± 1	10	mV/V
		TA = 25°C to 85°C	± 10	± 2	10	± 10	± 2	10
	² All typical values are at T = 25°C.
	A
	undervoltage lockout

	PARAMETER	TEST CONDITIONS	TL5001C, TL5001I		TL5001AC, TL5001AI			UNIT
			MIN	TYP² MAX	MIN	TYP²	MAX
	Upper threshold voltage	TA = 25°C		3		3		V
	Lower threshold voltage	TA = 25°C		2.8		2.8		V
	Hysteresis	TA = 25°C	100	200	100	200		mV
	Reset threshold voltage	TA = 25°C	2.1	2.55	2.1	2.55		V
	² All typical values are at T = 25°C.
	A
	short-circuit protection

	PARAMETER	TEST CONDITIONS	TL5001C, TL5001I			TL5001AC, TL5001AI			UNIT
			MIN	TYP²	MAX	MIN	TYP²	MAX
	SCP threshold voltage	TA = 25°C	0.95	1.00	1.05	0.97	1.00	1.03	V
	SCP voltage, latched	No pullup	140	185	230	140	185	230	mV
	SCP voltage, UVLO standby	No pullup		60	120		60	120	mV
	Input source current	TA = 25°C	±10	±15	±20	±10	±15	±20	µA
	SCP comparator 1 threshold voltage			1.5			1.5		V
	² All typical values are at T = 25°C.
	A
	oscillator

	PARAMETER	TEST CONDITIONS	TL5001C, TL5001I			TL5001AC, TL5001AI			UNIT
			MIN	TYP²	MAX	MIN	TYP²	MAX
	Frequency	Rt = 100 kΩ		100			100		kHz
	Standard deviation of frequency			15			15		kHz
	Frequency change with voltage	VCC = 3.6 V to 40 V		1			1		kHz
		TA = ± 40°C to 25°C	± 4	± 0.4	4	± 4	± 0.4	4	kHz
	Frequency change with temperature	TA = ± 20°C to 25°C	± 4	± 0.4	4	± 4	± 0.4	4	kHz
		TA = 25°C to 85°C	± 4	± 0.2	4	± 4	± 0.2	4	kHz
	Voltage at RT			1			1		V
	² All typical values are at T = 25°C.
	A

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