TL5001, TL5001A
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS084E – APRIL 1994 – REVISED OCTOBER 1999
1
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
D
Complete PWM Power Control
D
3.6-V to 40-V Operation
D
Internal Undervoltage-Lockout Circuit
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 V
CC
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
(D)
PLASTIC DIP
(P)
CERAMIC DIP
(JG)
CHIP CARRIER
(FK)
20
°
C to 85
°
C
TL5001CD
TL5001CP
—
—
– 20
°
C to 85
°
C
TL5001ACD
TL5001ACP
—
—
40
°
C to 85
°
C
TL5001ID
TL5001IP
—
—
– 40
°
C to 85
°
C
TL5001AID
TL5001AIP
—
—
40
°
C to 125
°
C
TL5001QD
—
—
—
– 40
°
C to 125
°
C
TL5001AQD
—
—
—
55
°
C to 125
°
C
—
—
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)
19
20
1
3
2
17
18
16
15
14
13
12
11
9
10
5
4
6
7
8
NC
RT
NC
DTC
NC
NC
V
CC
NC
COMP
NC
NC
OUT
NC
GND
NC
FB
NC
SCP
NC
NC
FK PACKAGE
(TOP VIEW)
TL5001, TL5001A
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS084E – APRIL 1994 – REVISED OCTOBER 1999
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DALLAS, TEXAS 75265
schematic for typical application
TL5001/A
FB
COMP
VO
DTC
RT
VI
+
SCP
VCC
+
TPS1101
GND
8
7
6
5
2
1
3
4
VO
functional block diagram
GND
8
OUT
SCP
COMP
FB
5
3
4
–
+
DTC
RT
6
7
Comparator 2
SCP
PWM/DTC
Comparator
OSC
Comparator 1
SCP
Amplifier
Error
UVLO
VCC
2
1
1 V
1.5 V
1 V
Reference
Voltage
IDT
2.5 V
TL5001, TL5001A
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS084E – APRIL 1994 – REVISED OCTOBER 1999
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detailed description
voltage reference
A 2.5-V regulator operating from V
CC
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:
V
O
= (1 + R1/R2) (1 V)
To PWM
Comparator
Vref = 1 V
4
VI(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
µ
A, the total dc load resistance should be 100 k
Ω
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
Ω
to 250 k
Ω
. 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 (I
DT
) 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 V
DT
is 0.7 V or less and
100 % when V
DT
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 R
DT
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 OCTOBER 1999
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dead-time control (DTC) (continued)
R
DT
+
Rt
)
1250
D Voscmax – Voscmin
)
Voscmin
Where
R
DT
and R
t
are in ohms, D in decimal
Soft start can be implemented by paralleling the DTC resistor with a capacitor (C
DT
) 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 R
DT
C
DT
TL5001/A
DTC
CDT
RDT
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, R
DT
C
DT
,
should be t
0
/3 to t
0
/5. The TL5001/A remains off until V
DT
≈
0.7 V, the minimum ramp value. C
DT
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 OCTOBER 1999
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short-circuit protection (SCP) (continued)
Q1
12 k
Ω
185 k
Ω
RSCP
Q2
SCP
Comparator 2
Vref = 1 V
SCP
Comparator 1
1.5 V
From Error
Amp
CSCP
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-k
Ω
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) 1
*
e–t
t )
0.185
Where
τ
= R
SCP
C
SCP
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
µ
F.
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 OCTOBER 1999
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DALLAS, TEXAS 75265
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
†
Supply voltage, V
CC
(see Note 1)
41 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Amplifier input voltage, V
I(FB)
20 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output voltage, V
O
, 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, T
A
:
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, 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
µ
A
COMP dc load resistance
100
k
Ω
Oscillator timing resistor, Rt
15
250
k
Ω
Oscillator frequency, fosc
20
500
kHz
TL5001C, TL5001AC
– 20
85
Operating ambient temperature TA
TL5001I, TL5001AI
– 40
85
°
C
Operating ambient temperature, TA
TL5001Q, TL5001AQ
– 40
125
°
C
TL5001M, TL5001AM
– 55
125
TL5001, TL5001A
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS084E – APRIL 1994 – REVISED OCTOBER 1999
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DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature range, V
CC
= 6 V,
f
osc
= 100 kHz (unless otherwise noted)
reference
PARAMETER
TEST CONDITIONS
TL5001C, TL5001I
TL5001AC, TL5001AI
UNIT
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
PARAMETER
TEST CONDITIONS
TL5001C, TL5001I
TL5001AC, TL5001AI
UNIT
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
PARAMETER
TEST CONDITIONS
TL5001C, TL5001I
TL5001AC, TL5001AI
UNIT
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
µ
A
SCP comparator 1 threshold voltage
1.5
1.5
V
† All typical values are at TA = 25
°
C.
oscillator
PARAMETER
TEST CONDITIONS
TL5001C, TL5001I
TL5001AC, TL5001AI
UNIT
PARAMETER
TEST CONDITIONS
MIN
TYP†
MAX
MIN
TYP†
MAX
UNIT
Frequency
Rt = 100 k
Ω
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.
TL5001, TL5001A
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS084E – APRIL 1994 – REVISED OCTOBER 1999
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DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature range, V
CC
= 6 V,
f
osc
= 100 kHz (unless otherwise noted) (continued)
dead-time control
PARAMETER
TEST CONDITIONS
TL5001C, TL5001I
TL5001AC, TL5001AI
UNIT
PARAMETER
TEST CONDITIONS
MIN
TYP†
MAX
MIN
TYP†
MAX
UNIT
Output (source) current
TL5001C
V(DT) = 1.5 V
0.9
×
IRT‡
1.1
×
IRT 0.9
×
IRT‡
1.1
×
IRT
µ
A
Output (source) current
TL5001I
V(DT) = 1.5 V
0.9
×
IRT‡
1.2
×
IRT 0.9
×
IRT‡
1.2
×
IRT
µ
A
Input threshold voltage
Duty cycle = 0%
0.5
0.7
0.5
0.7
V
Input threshold voltage
Duty cycle = 100%
1.3
1.5
1.3
1.5
V
† All typical values are at TA = 25
°
C.
‡ Output source current at RT
error amplifier
PARAMETER
TEST CONDITIONS
TL5001C, TL5001I
TL5001AC, TL5001AI
UNIT
PARAMETER
TEST CONDITIONS
MIN
TYP†
MAX
MIN
TYP†
MAX
UNIT
Input voltage
VCC = 3.6 V to 40 V
0
1.5
0
1.5
V
Input bias current
– 160
– 500
– 160
– 500
nA
Output voltage swing
Positive
1.5
2.3
1.5
2.3
V
Output voltage swing
Negative
0.3
0.4
0.3
0.4
V
Open-loop voltage amplification
80
80
dB
Unity-gain bandwidth
1.5
1.5
MHz
Output (sink) current
VI(FB) = 1.2 V, COMP = 1 V
100
600
100
600
µ
A
Output (source) current
VI(FB) = 0.8 V, COMP = 1 V
– 45
– 70
– 45
– 70
µ
A
† All typical values are at TA = 25
°
C.
output
PARAMETER
TEST CONDITIONS
TL5001C, TL5001I
TL5001AC, TL5001AI
UNIT
PARAMETER
TEST CONDITIONS
MIN
TYP†
MAX
MIN
TYP†
MAX
UNIT
Output saturation voltage
IO = 10 mA
1.5
2