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Электронный компонент: TL494

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2000 Fairchild Semiconductor International
www.fairchildsemi.com
Rev. 5.0
Features
Internal regulator provides a stable 5V reference supply
trimmed to 5%
Uncommitted output TR for 200mA sink or source
current
Output control for push-pull or single-ended operation
Variable duty cycle by dead time control (pin 4) Complete
PWM control circuit
On-chip oscillator with master or slave operation
Internal circuit prohibits double pulse at either output
Description
The TL494 is used for the control circuit of the PWM
switching regulator. The TL494 consists of 5V reference
voltage circuit, two error amplifiers, flip flop, an output con-
trol circuit, a PWM comparator, a dead time comparator and
an oscillator. This device can be operated in the switching
frequency of 1 KHz to 300 KHz.
16-DIP
16-SOP
1
1
Internal Block Diagram
TL494
SMPS Controller
TL494
2
Absolute Maximum Ratings
Parameter
Symbol
Value
Unit
Supply Voltage
V
CC
42
V
Collector Supply Voltage
V
C
42
V
Output Current
I
O
250
mA
Amplifier Input Voltage
V
IN
V
CC
+ 0.3
V
Power Dissipation (T
A
= 25
C)
P
D
1 (TL494CN)
0.9 (TL494CD)
W
Operating Temperature Range
T
OPR
0 ~ +70
C
Storage Temperature Range
T
STG
-65 ~ + 150
C
TL494
3
Electrical Characteristics
(V
CC
= 20V, f = 10KHz, T
A
= 0
C to + 70
C, unless otherwise specified)
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Unit
REFERENCE SECTION
 Reference Output Voltage
V
REF
I
REF
= 1mA
4.75
5.0
5.25
V
Line Regulation
V
REF
V
CC
= 7V to 40V
-
2.0
25
mV
Temperature Coefficient of V
REF
V
REF
/
T
T
A
= 0
C to 70
C
-
0.01
0.03
%/
C
Load Regulation
V
REF
I
REF
= 1mA to 10mA
-
1.0
15
mV
Short-Circuit Output Currnet
I
SC
V
REF
= 0V
10
35
50
mA
OSCILLATOR SECTION
 Oscillation Frequency
f
C
T
= 0.01
F, R
T
= 12K
-
10
-
KHz
Frequency Change with Temperature
f/
T
C
T
= 0.01
F, R
T
= 12K
-
-
2
%
DEAD TIME CONTROL SECTION
 Input Bias Current
I
BIAS
V
CC
= 15V, 0V
V
4
5.25V
-
-2.0
-10
A
Maximum Duty Cycle
D
(MAX)
V
CC
= 15V, V
4
= 0V
O.C Pin = V
REF
45
-
-
%
Input Threshold Voltage
V
ITH
Zero Duty Cycle
-
3.0
3.3
V
Max. Duty Cycle
0
-
-
ERROR AMP SECTION
 Input Offset Voltage
V
IO
V
3
= 2.5V
-
2.0
10
mV
Input Offset Current
I
IO
V
3
= 2.5V
-
25
250
mA
Input Bias Current
I
BIAS
V
3
= 2.5V
-
0.2
1.0
A
Common Mode Input Voltage
V
CM
7V
V
CC
40V
-0.3
-
V
CC
V
Open-Loop Voltage Gain
G
VO
0.5V
V
3
3 .5V
70
95
-
dB
Unit-Gain Bandwidth
BW
-
-
650
-
KHz
PWM COMPARATOR SECTION
 Input Threshold Voltage
V
ITH
Zero Duty Cycle
-
4
4.5
V
Input Sink Currnet
I
SINK
V
3
=0.7V
-0.3
-0.7
-
mV
OUTPUT SECTION
 Output Saturation Voltage
Common Emitter
V
CE(SAT)
V
E
= 0, I
C
= 200mA
-
1.1
1.3
V
Common Collector
V
CC(SAT)
V
C
= 15V, I
E
= -200mA
-
1.5
2.5
Collector Off-State Currnet
I
C(OFF)
V
CC
= 40V, V
CE
= 40V
-
2
100
A
Emitter Off-State Current
I
E(OFF)
V
CC
= V
C
= 40V, V
E
= 0
-
-
-100
TOTAL DEVICE
 Supply Current
I
CC
Pin 6 = V
REF
, V
CC
= 15V
-
6
10
mA
OUTPUT SWITCHING CHARACTERISTIC
 Rise Time
t
R
-
-
-
-
-
Common Emitter
-
-
-
100
200
ns
Common Collector
-
-
-
100
200
Fall Time
t
F
-
-
-
-
-
Common Emitter
-
-
-
25
100
ns
Common Collector
-
-
-
40
100
TL494
4
Typical Application
Pulse Width Modulated Step-down Converter
TL494
TL494
5
Mechanical Dimensions
Package
#1
#8
#9
#16
6.40
0.20
7.62
0.300
2.54
0.100
0.252
0.008
0~15
0.25
+0.10
0.05
0.010
+0.004
0.002
3.30
0.30
0.130
0.012
3.25
0.20
0.128
0.008
19.40
0.20
0.764
0.008
19.80
0.780
MAX
5.08
0.200
0.38
0.014
MAX
MIN
0.81
0.032
()
0.46
0.10
0.018
0.004
0.059
0.004
1.50
0.10
16-DIP
TL494
6
Mechanical Dimensions
(Continued)
Package
0.70
0.20
0.0275
0.008
#1
#8
#9
#16
9.90
0.20
0.39
0.008
1.27
0.050
5.72
0.225
1.55
0.10
0.061
0.004
0.05
0.002
6.00
0.30
0.236
0.012
3.95
0.20
0.156
0.008
10.30
0.405
MAX
0~8
0.51
0.020
()
1.80
0.071
MAX0.10
MAX0.004
MAX
MIN
+
0.10
-0.05
0.20
+
0.004
-0.002
0.008
+
0.10
-0.05
0.406
+
0.004
-0.002
0.016
16-SOP
TL494
7
Ordering Information
Product Number
Package
Operating Temperature
TL494CN
16 DIP
0 ~ + 70
C
TL494CD
16 SOP
TL494
7/12/00 0.0m 001
Stock#DSxxxxxxxx
2000 Fairchild Semiconductor International
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which, (a) are intended for surgical implant into the body,
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perform when properly used in accordance with
instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of the
user.
2. A critical component in any component of a life support
device or system whose failure to perform can be
reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
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