SL494CN
SMPS Controller
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
16-DIP
16-SOP
SL494CN
SL494CNS
Description
The
SL494CN
is used for the control circuit of the PWM switching regulator. The
SL494CN
consists of 5V reference
voltage circuit, two error amplifiers, a flip flop, an output control circuit, a PWM comparator, a dead time comparator
and an oscillator. This device can be operated in the switching frequency of 1kHz to 300kHz.
Internal Block Diagram
www.slkormicro.com
1
SL494CN
Absolute Maximum Ratings
Parameter
Supply Voltage
Collector Supply Voltage
Output Current
Amplifier Input Voltage
Power Dissipation (T
A
= 25°C)
Operating Temperature Range
Storage Temperature Range
Symbol
V
CC
V
C
I
O
V
IN
P
D
T
OPR
T
STG
Value
41
41
250
V
CC
+0.3
1 (SL494CN)
0.9 (SL494CNS)
0 ~ +70
-65 ~ +150
Unit
V
V
mA
V
W
°C
°C
www.slkormicro.com
2
SL494CN
Electrical Characteristics
(V
CC
= 20V, f = 10kHz, T
A
= 0°C to +70°C, unless otherwise specified)
Parameter
REFERENCE SECTION
Reference Output Voltage
Line Regulation
Temperature Coefficient of V
REF
Load Regulation
Short-Circuit Output Current
OSCILLATOR SECTION
Oscillation Frequency
Frequency Change with Temperature
DEAD TIME CONTROL SECTION
Input Bias Current
Maximum Duty Cycle
Input Threshold Voltage
ERROR AMP SECTION
Input Offset Voltage
Input Offset Current
Input Bias Current
Common Mode Input Voltage
Open-Loop Voltage Gain
Unit-Gain Bandwidth (Note1)
PWM COMPARATOR SECTION
Input Threshold Voltage
Input Sink Current
OUTPUT SECTION
Output Saturation Voltage
Common Emitter
Common Collector
Collector Off-State Current
Emitter Off-State Current
TOTAL DEVICE
Supply Current
OUTPUT SWITCHING CHARACTERISTICS
Rise Time
Common Emitter
Common Collector
Fall Time
Common Emitter
Common Collector
t
R
-
-
t
F
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
100
100
-
25
40
-
200
200
-
100
100
-
ns
-
ns
I
CC
Pin 6 = V
REF
, V
CC
= 15V
-
6
10
mA
V
CE(SAT)
V
CC(SAT)
I
C(OFF)
I
E(OFF)
V
E
= 0, I
C
= 200mA
V
C
= 15V, I
E
= -200mA
V
CC
= 40V, V
CE
= 40V
V
CC
= V
C
= 40V, V
E
= 0
-
-
-
-
1.1
1.5
2
-
1.3
2.5
100
-100
V
µA
V
ITH
I
SINK
Zero Duty Cycle
V
3
=0.7V
-
-0.3
4
-0.7
4.5
-
V
mV
V
IO
I
IO
I
BIAS
V
CM
G
VO
BW
V
3
= 2.5V
V
3
= 2.5V
V
3
= 2.5V
7V
≤
V
CC
≤
40V
0.5V
≤
V
3
≤3
.5V
-
-
-
-
-0.3
70
-
2.0
25
0.2
-
95
650
10
250
1.0
V
CC
-
-
mV
mA
µA
V
dB
kHz
I
BIAS
D
(MAX)
V
ITH
V
CC
= 15V, 0V≤V
4
≤5.25V
V
CC
= 15V, V
4
= 0V
O.C Pin = V
REF
Zero Duty Cycle
Max. Duty Cycle
-
45
-
0
-2.0
-
3.0
-
-10
-
3.3
-
µA
%
V
f
∆f/∆T
C
T
= 0.01µF, R
T
= 12kΩ
C
T
= 0.01µF, R
T
= 12kΩ
-
-
10
-
-
2
kHz
%
V
REF
∆V
REF
∆V
REF
/∆T
∆V
REF
I
SC
I
REF
= 1mA
V
CC
= 7V to 40V
T
A
= 0°C to 70°C
I
REF
= 1mA to 10mA
V
REF
= 0V
4.75
-
-
-
10
5.0
2.0
0.01
1.0
35
5.25
25
0.03
15
50
V
mV
%/°C
mV
mA
Symbol
Conditions
Min.
Typ.
Max.
Unit
www.slkormicro.com
3
SL494CN
Typical Application
Pulse Width Modulated Step-down Converter
V
I
=10V to 40V
KSA1010
1mH,2A
Vo=5V
Io=1A
47Ω
150Ω
0.1uF
1MΩ
50uF
10V
5.1kΩ
12
Vcc
11
C2
8
C1
3
COMP INPUT
-2
V
REF
14
5.1kΩ
- 15
5.1kΩ
+1
+16
150Ω
D.T GND E1
9
4
7
+
50uF
50V
E2
10
O.C
13
R
T
6
C
T
5
+
+
47kΩ
50uF
10V
0.001uF
GND
0.1
www.slkormicro.com
4
SL494CN
Mechanical Dimensions
Package
16-DIP
0.81
)
0.032
#16
6.40
±0.20
0.252
±0.008
#1
(
19.80
MAX
0.780
19.40
±0.20
0.764
±0.008
#8
#9
7.62
0.300
3.25
±0.20
0.128
±0.008
0.38
0.014 MIN
5.08
MAX
0.200
3.30
±0.30
0.130
±0.012
0~15
°
0.25
–0.05
0.010
–0.002
+0.004
+0.10
www.slkormicro.com
5
2.54
0.100
0.46
±0.10
0.018
±0.004
1.50
±0.10
0.059
±0.004
电子工程世界
电源技术
