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

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TL5001, TL5001A
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS084E – APRIL 1994 – REVISED OCT OBER 1999
1
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
D
Complete PWM Power Control
D
3.6-V to 40-V Operation
D
D
Internal Short-Circuit Protection
D
Oscillator Frequency . . . 20 kHz to 500 kHz
D
Variable Dead Time Provides Control Over Total Range
D
±3% Tolerance on Reference Voltage (TL5001A)
D
Available in Q-Temp Automotive
HighRel Automotive Applications Configuration Control / Print Support Qualification to Automotive Standards
description
The TL5001 and TL5001A incorporate on a single 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 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 V
CC
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
T
A
SMALL OUTLINE
(D)
PLASTIC DIP
(P)
CERAMIC DIP
(JG)
CHIP CARRIER
(FK)
°
°
TL5001CD TL5001CP
20°C to 85°C
TL5001ACD TL5001ACP
°
°
TL5001ID TL5001IP
40°C to 85°C
TL5001AID TL5001AIP
°
°
TL5001QD
40°C to 125°C
TL5001AQD
°
°
TL5001MJG TL5001MFK
55°C to 125°C
TL5001AMJG TL5001AMFK
The D package is available taped and reeled. Add the suffix R to the device type (e.g., TL5001CDR).
Copyright 1999, Texas Instruments Incorporated
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.
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.
1 2 3 4
8 7 6 5
OUT
V
CC
COMP
FB
GND RT DTC SCP
D, JG OR P PACKAGE
(TOP VIEW)
1920132
17
18
16 15 14
1312119 10
5
4
6 7 8
NC RT NC DTC NC
NC
V
CC
NC
COMP
NC
NC
OUTNCGND
NC
FB
NC
SCP
NC
NC
FK PACKAGE
(TOP VIEW)
TL5001, TL5001A PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS084E – APRIL 1994 – REVISED OCT OBER 1999
2
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
schematic for typical application
TL5001/A
FB
COMP
V
O
DTC
RT
V
I
+
SCP
V
CC
+
TPS1101
GND
8
7
6
5
2
1
3
4
V
O
functional block diagram
GND
8
OUT
SCP
COMP
FB
5
3
4
+
DTC
RT
67
Comparator 2
SCP
PWM/DTC Comparator
OSC
Comparator 1
SCP
Amplifier
Error
UVLO
V
CC
2
1
1 V
1.5 V 1 V
Reference
Voltage
I
DT
2.5 V
TL5001, TL5001A
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS084E – APRIL 1994 – REVISED OCT OBER 1999
3
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
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)
To PWM Comparator
V
ref
= 1 V
4
V
I(FB)
3
+
R2
R1
COMP
FB
Compensation
Network
TL5001/A
GND
8
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 k or more.
oscillator/PWM
The oscillator frequency (f
osc
) can be set between 20 kHz and 500 kHz by connecting a resistor between RT and GND. Acceptable resistor values range from 15 k to 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 (V
DT
), 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 ), 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 (V
osc
max and V
osc
min are the maximum and minimum oscillator levels):
TL5001, TL5001A PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS084E – APRIL 1994 – REVISED OCT OBER 1999
4
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
dead-time control (DTC) (continued)
RDT+ǒRt)
1250
Ǔ
ƪ
DǒV
osc
max – V
osc
minǓ)
V
osc
min
ƫ
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[
IDTR
DT
ǒ
1
–e
ǒ
–tńRDTC
DT
Ǔ
Ǔ
TL5001/A
DTC
C
DT
R
DT
6
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.
TL5001, TL5001A
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS084E – APRIL 1994 – REVISED OCT OBER 1999
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POST OFFICE BOX 655303 DALLAS, TEXAS 75265
short-circuit protection (SCP) (continued)
Q1
12 k
185 k
R
SCP
Q2
SCP Comparator 2
V
ref
= 1 V
SCP Comparator 1
1.5 V
From Error
Amp
C
SCP
To Output Drive Logic
SCP
5
2.5 V
Figure 3. SCP Circuit
The timer operates by charging an external capacitor (C
SCP
), connected between the SCP terminal and ground,
towards 2.5 V through a 185-kΩ resistor (R
SCP
). 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:
V
SCP
+(2.5*0.185
)
ǒ
1*e
–tńt
Ǔ
)
0.185
Where
τ = R
SCPCSCP
The end of the time-out period, t
SCP
, occurs when V
SCP
= 1 V. Solving for C
SCP
yields:
C
SCP
+
12.46 t
SCP
Where
t is in seconds, C in µF.
t
SCP
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.
TL5001, TL5001A PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS084E – APRIL 1994 – REVISED OCT OBER 1999
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POST OFFICE BOX 655303 DALLAS, TEXAS 75265
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Supply voltage, VCC (see Note 1) 41 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Amplifier input voltage, V
I(FB)
20 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output voltage, VO, OUT 51 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output current, I
O
, OUT 21 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output peak current, I
O(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, T
stg
–65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds 260°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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.
NOTE 1: All voltage values are with respect to network ground terminal.
DISSIPATION RATING TABLE
PACKAGE
TA 25°C
POWER RATING
DERATING FACTOR
ABOVE TA = 25°C
TA = 70°C
POWER RATING
TA = 85°C
POWER RATING
TA = 125°C
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, V
CC
3.6 40 V
Amplifier input voltage, V
I(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 k Oscillator timing resistor, R
t
15 250 k
Oscillator frequency, f
osc
20 500 kHz
TL5001C, TL5001AC –20 85
p
p
TL5001I, TL5001AI –40 85
°
Operating ambient temperature, T
A
TL5001Q, TL5001AQ –40 125
°C
TL5001M, TL5001AM –55 125
TL5001, TL5001A
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS084E – APRIL 1994 – REVISED OCT OBER 1999
7
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature range, VCC = 6 V, f
osc
= 100 kHz (unless otherwise noted)
reference
TL5001C, TL5001I TL5001AC, TL5001AI
PARAMETER
TEST CONDITIONS
MIN TYP†MAX MIN TYP†MAX
UNIT
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
All typical values are at TA = 25°C.
undervoltage lockout
TL5001C, TL5001I TL5001AC, TL5001AI
PARAMETER
TEST CONDITIONS
MIN TYP†MAX MIN TYP†MAX
UNIT
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
All typical values are at TA = 25°C.
short-circuit protection
TL5001C, TL5001I TL5001AC, TL5001AI
PARAMETER
TEST CONDITIONS
MIN TYP†MAX MIN TYP†MAX
UNIT
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
All typical values are at TA = 25°C.
oscillator
TL5001C, TL5001I TL5001AC, TL5001AI
PARAMETER
TEST CONDITIONS
MIN TYP†MAX MIN TYP†MAX
UNIT
Frequency Rt = 100 k 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
All typical values are at TA = 25°C.
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