UTC TL1451
LINEAR INTEGRATED CIRCUIT
UTC
UNISONIC TECHNOLOGIES CO., LTD.
1
QW-R103-011,A
DUAL PULSE-WIDTH-MODULATION
CONTROL CIRCUITS
DESCRIPTION
The UTC TL1451 incorporates on a single monolithic chip
all the functions required in the construction of two pulse-
width-modulation (PWM) control circuits. Designed primarily
for power supply control, the TL1451 contains an on-chip 2.5V
regulator, two error amplifiers, an adjustable oscillator, two
dead-time comparators, undervoltage lockout circuitry, and
dual common emitter output transistor circuits.
FEATURES
*Complete PWM Power control Circuitry
*Completely Synchronized Operation
*Internal Undervoltage Lockout Protection
*Wide Supply Voltage Range
*Internal Short-Circuit Protection
*Oscillator Frequency ...500kHz Max
*Variable Dead Time Provides Control Over Total Range
*Internal Regulator Provides a Stable 2.5V Reference Supply
DIP-16
SOP-16
PIN CONFIGURATIONS
CT
RT
1 IN+
1 IN-
1 FEEDBACK
1 DTC
1 OUT
GND
Vcc
2 OUT
2 DTC
2 IN-
SCP
REF
2 IN+
2 FEEDBACK
ERROR
AMPLIFIER
1
ERROR
AMPLIFIER
2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
UTC TL1451
LINEAR INTEGRATED CIRCUIT
UTC
UNISONIC TECHNOLOGIES CO., LTD.
2
QW-R103-011,A
BLOCK DIAGRAM
UTC TL1451
LINEAR INTEGRATED CIRCUIT
UTC
UNISONIC TECHNOLOGIES CO., LTD.
3
QW-R103-011,A
ABSOLUTE MAXIMUM RATINGS
(Unless otherwise noted all is over operating free air temperature
range)
PARAMETER
SYMBOL
VALUE
UNIT
Supply Voltage
V
CC
51
V
Amplifier Input Voltage
V
I
20
V
Collector Output Voltage
V
O
51
V
Collector Output Current
I
O
21
mA
Power Dissipation : TA
25
C
DIP
SOP
1000
500
mW
Operating free-air Temperature Range
T
A
-20 TO 85
C
Storage Temperature Range
Tstg
-65 TO 150
C
Lead Temperature 1.6mm from Case for 10
Sec.
Tcase
260
C
RECOMMENDED OPERATING CONDITIONS
PARAMETER
SYMBOL
VALUE
UNIT
MIN
MAX
Supply Voltage
Vcc
3.6
50
V
Amplifier Input Voltage
Vi
1.05
1.45
V
Collector Output Voltage
Vo
50
V
Collector Output Current(each Transistor)
Io
20
mA
Current into Feedback Terminal
45
A
Feedback Resistor
R
F
100
k
Timing Capacitor
C
T
150
15000
pF
Timing Resistor
R
T
5.1
100
k
Oscillator frequency
1
500
kHz
Operating Free-Air Temperature
T
A
-20
85
C
ELECTRICAL CHARACTERISTICS
(Over recommended operating free-air temperature range,V
CC
=6V,f=200kHz,TA=25
C
,Unless otherwise
specified)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Reference Section
Output Voltage
Io=1mA
2.4
2.5
2.6
V
Output Voltage Change with Temperature
T
A
=-20
C to 25
C
T
A
=25
C to 85
C
-0.1
-0.2
1%
1%
Input Voltage Regulation
Vcc=3.6V to 40V
2
12.5
mV
Output Voltage Regulation
Io=0.1mA to 1mA
1
7.5
mV
Short-Circuit Output Current
Vo=0
3
10
30
mA
Undervoltage Lockout Section
Upper Threshold Voltage (Vcc)
2.72
V
Lower Threshold Voltage (Vcc)
2.6
V
Hysteresis (Vcc)
80
120
mV
Reset Threshold voltage (Vcc)
Io(ref)=0.1mA, T
A
=25
C
1.5
1.9
V
Short-Circuit Protection Control Section
Input Threshold Voltage(SCP)
TA=25
C
0.65
0.7
0.75
V
UTC TL1451
LINEAR INTEGRATED CIRCUIT
UTC
UNISONIC TECHNOLOGIES CO., LTD.
4
QW-R103-011,A
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Standby Voltage(SCP)
No pullup
140
185
230
mV
Latched Input Voltage (SCP)
No pullup
60
120
mV
Input (source) Current
VI=0.7V,T
A
=25
C
-10
-15
-20
A
Comparator Threshold Voltage (FEEDBACK)
1.18
V
Oscillator Section
Frequency
C
T
=330pF, R
T
=10k
200
kHz
Standard deviation of frequency
C
T
=330pF, R
T
=10k
10%
Frequency Change with Voltage
Vcc=3.6V to 40V
1%
Frequency Change with Temperature
TA=-20
C to 25
C
TA=25
C to 85
C
-0.4%
-0.2%
2%
2%
Dead-Time Control Section
Input bias Current (DTC)
1
A
Latch mode (source) Current (DTC)
TA=25
C
-80
-145
A
Latched Input Voltage (DTC)
Io=40
A
2.3
V
Input threshold Voltage at f=10kHz (DTC)
Zero duty cycle
Maximum duty cycle
1.2
2.05
1.45
2.25
V
Error-Amplifier Section
Input Offset Voltage
Vo (FEEDBACK)=1.25V
6
mV
Input Offset Current
Vo (FEEDBACK)=1.25V
100
nA
Input Bias current
Vo (FEEDBACK)=1.25V
160
500
nA
Common-Mode Input Voltage Range
Vcc=3.6V to 40V
1.05 to
1.45
V
Open-loop Voltage Amplification
R
F
=200k
70
80
dB
Unity-gain Bandwidth
1.5
MHz
Common-mode Rejection Ratio
60
80
dB
Positive Output Voltage Swing
Vref-
0.1
V
Negative Output Voltage Swing
1
V
Output (sink) Current (FEEDBACK)
V
ID
=-0.1V,Vo=1.25V
0.5
1.6
mA
Output (source) Current (FEEDBACK)
V
ID
=-0.1V,Vo=1.25V
-45
-70
A
Output Section
Collector off-state Current
Vo=50V
10
A
Output Saturation Voltage
Io=10mA
1.2
2
V
Short-Circuit Output Current
Vo=6V
90
mA
PWM Comparator Section
Input Threshold Voltage at
f=10kHz (FEEDBACK)
Zero duty cycle
Maximum duty cycle
1.2
2.05
1.45
2.25
V
TOTAL DEVICE
Standby Supply Current
Off-state
1.3
1.8
mA
Average Supply Current
R
T
=10k
1.7
2.4
mA
UTC TL1451
LINEAR INTEGRATED CIRCUIT
UTC
UNISONIC TECHNOLOGIES CO., LTD.
5
QW-R103-011,A
TEST CIRCUIT
TIMING DIAGRAM
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