UTC-IC TL5001

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.
„
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
Lead Free
TL5001L-D08-T
TL5001L-S08-R
TL5001L-S08-T
Halogen Free
TL5001G-D08-T
TL5001G-S08-R
TL5001G-S08-T
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Copyright © 2012 Unisonic Technologies Co., Ltd
Package
Packing
DIP-8
SOP-8
SOP-8
Tube
Tape Reel
Tube
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QW-R103-016,D
TL5001
„
LINEAR INTEGRATED CIRCUIT
PIN CONFIGURATION
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TL5001
„
LINEAR INTEGRATED CIRCUIT
ABSOLUTE MAXIMUM RATINGS
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.
„
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
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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
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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
UNDERVOLTAGE LOCKOUT
Upper
Threshold Voltage
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
f
IO(SOURCE)
ERROR AMPLIFIER
Input Voltage
Input Bias Current
VIN
II(BIAS)
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
TA= 25°C
TA= 25°C
TA= 25°C
TA= 25°C
0.95
140
-10
RT=100kΩ
-4
-4
-4
V(DT)=1.5V (Note)
Duty cycle=0%
Duty cycle=100%
0.9*IRT
0.5
VCC=3.6V ~ 40V
0
1.5
VO(SW)
GV
IO(SINK)
IO(SOURCE)
VO(SAT)
Off-State Current
IOFF
Short-Circuit Output Current
TOTAL DEVICE
Standby Supply Current (Off state)
Average Supply Current
Note: Output source current at RT
IO(SC)
VI(FB)=1.2V, COMP=1V
VI(FB)=0.8V, COMP=1V
IOUT=10mA
VOUT=50V,Vcc=0
VOUT=50V
VOUT=6V
ISTN-BY
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MAX
VRT
VI(THR)
Positive
Negative
Open-Loop Voltage Amplification
Unity-Gain Bandwidth
Output (sink) Current
Output (source) Current
OUTPUT
Output Saturation Voltage
TYP
VCC=3.6V ~ 40V
TA= -40°C ~ 25°C
TA= -20°C ~ 25°C
TA= 25°C ~ 85°C
Input Threshold Voltage
Output Voltage Swing
MIN
TA= 25°C
No pullup
No pullup
TA= 25°C
Frequency Change with Temperature
Voltage at RT
DEAD-TIME CONTROL
Output (source) Current
TEST CONDITIONS
RT=100kΩ
100
-45
1.00
185
60
-15
1.5
100
15
1
-0.4
-0.4
-0.2
1
V
V
V
mV
1.05
230
120
-20
4
4
4
1.1*IRT
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
mV/V
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
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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
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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 Fig. 1), using the following expression.
VOUT = (1+R1/R2) (1V)
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 Fig. 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.
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TL5001
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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 Fig. 11(VOSC(MAX) and VOSC(MIN) 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 Fig. 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
Fig. 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.
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LINEAR INTEGRATED CIRCUIT
DETAILED DESCRIPTION(Cont.)
SHORT-CIRCUIT PROTECTION (SCP)
The UTC TL5001 includes short-circuit protection (see Fig. 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
scp
Comparator 2
12kΩ
SCP
5
185kΩ
From Error
Amp
1.5V
Q1
scp
Comparator 1
To Output
Drive Logic
VREF=1V
Q2
Fig. 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.
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TL5001
„
LINEAR INTEGRATED CIRCUIT
PARAMETER MEASUREMENT INFORMATION
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TL5001
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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
VCC
SCP
VOUT
COMP
UTC
TL5001
1
C6
0.012μF
RT
4
+
GND
3
DTC
FB
C2
100μF
10V
3.3V
R5
7.50kΩ
1%
R4
5.1kΩ
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
Fig. 5 Step-Down Converter
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TYPICAL CHARACTERISTICS
Oscillator Frequency vs Timing Resistance
Oscillator Frequency vs Ambient Temperature
100
100k
10k
10k
100k
Timing Resistance, RT (
Reference Output Voltage, VREF(V)
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
8 9
10
Reference Output Voltage Fluctuation, VREF (%)
Oscillator Frequency, fOSC (Hz)
1M
98
96
94
92
VCC=6V
90 DT Resistance=100k
RT=100k
88
-50 -25
0
25
50
75
Ambient Temperature, TA(°C)
0.6
0.4
RT=100k
TA=25°C
1.5
1
0.5
10
20
30
40
Power-Supply Voltage, VCC (V)
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VCC=6V
FB and COMP
Connected Together
0
-0.2
-0.4
-0.6
-0.8
-50
-25
0
25
50
75
100
Average Supply Current vs Ambient Temperature
1.3
Average Supply Current, ICC (mA)
2
0
Reference Output Voltage Fluctuation
vs Ambient Temperature
Ambient Temperature, TA (°C)
Average Supply Current vs Power -Supply Voltage
0
100
0.2
Power-Supply Voltage, VCC (V)
Average Supply Current, ICC(mA)
„
LINEAR INTEGRATED CIRCUIT
1.2
1.1
1
0.9
VCC=6V
0.8 DT Resistance=100k
RT=100k
0
-50 -25
0
25
50
75
100
Ambient Temperature, TA (°C)
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1.5
VCC=6V
TA=25°C
1.2
VOSC(MAX)(100% duty cycle)
0.9
0.6
VOSC(MIN)(zero duty cycle)
0.3
0
10k
1M
100k
Error Amplifier Output Voltage
vs Output(Sink)Current
3
10M
2.5
VCC=6V
TA=25°C
VI(FB)=1.2V
2
1.5
1
0.5
0
0
2.5
2
1.5
1
0.5
0
0
240
VCC=6V
TA=25°C
VI(FB)=0.8V
200
180
160
140
120
-50
-25
0
25
50
75
100
Ambient Temperature, TA(°C)
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0.4
0.6
Error Amplifier Output Voltage
vs Ambient Temperature
2.45
2.44
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
VCC=6V
V
I(FB)=1.2V
220
No Load
2.46
2.40
-50
40
80
20
60
100 120
Output(Source)Current, IOUT(uA)
Error Amplifier Open -Loop Gain, GV(dB)
Error Amplifier Output Voltage, VOUT (V)
VO- Error Amplifier Output Voltage -V
Error Amplifier Output Voltage
vs Output(Source)Current
3
0.2
Output(Sink)Current, IOUT (mA)
Oscillator Frequency, fOSC (Hz)
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
-300°
-10
-330°
-20
10k
100k
1M
-360°
10M
Error Amplifier Open -Loop Gain, GV (dB)
1.8
PWM Triangle Wave Amplitude Voltage
vs Oscillator Frequency
Error Amplifier Output Voltage, VOUT(V)
Triancle Wave Amplitude Voltage, PWM (V)
TYPICAL CHARACTERISTICS(Cont.)
Error Amplifier Output Voltage, VOUT (V)
„
LINEAR INTEGRATED CIRCUIT
Frequency, f(Hz)
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LINEAR INTEGRATED CIRCUIT
TYPICAL CHARACTERISTICS(Cont.)
Scp-Time-Output Period vs SCP Capacitance
12
Output Duty Cycle vs DTC Voltage
120
Output Duty Cycle-%
100
tscp-scp Time-Out Period -ms
VCC=6V
TA=25
RT =100Ω
80
60
40
20
0
0
0.5
1
1.5
10
8
6
4
VCC=6V
TA=25
RT =100Ω
DT Resistance =200kΩ
2
0
0
2
DTC Output Current vs RT Output Current
60
80
100 120
Output Saturation Voltage vs Output (Sink) Current
-60
2
Output Saturation Voltage, VCE (V)
DTC Output Current, IO(DT) (μA)
40
Cscp-scp Capacitance -nF
DTC Voltage -V
TA=25
-50 DT Voltage =1.3V
-40
-30
-20
-10
0
20
0
-20
-40 -50
-10
-30
RT Output Current, IOUT (μA)
-60
VCC=6V
TA=25
1.5
1
0.5
0
0
5
10
15
20
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.
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