SLS SL494N

SL494
PWM Control Circuit
The SL494 incorporates on a single monolithic chip all the
functions required in the construction of a pulse-width-modulation
control circuit. Designed primarily for power supply control, the SL494
contains an on-chip 5-volt regulator, two error amplifiers, adjustable
oscillator, dead-time control comparator, pulse-steering flip-flop, and
output-control circuitry. The uncommitted output transistors provide
either common-emitter or emitter-follower output capability. Push-pull
or single-ended output operation may be selected through the outputcontrol function. The architecture of the IL494 prohibits the possibility
of either output being pulsed twice during push-pull operation.
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Complete PWM Power Control Circuitry
Uncommitted Outputs for 200 mA Sink or Source
Output Control Selects Single-Ended or Push-Pull Operation
Internal Circuitry Prohibits Double Pulse at Either Output
Internal Regulator Provides a Stable 5 V Reference Supply
Variable Dead-Time Provides Control Over Total Range
FUNCTION TABLE
Output Control
Grounded
At Vref
Output Function
Single-ended or Parallel Output
Normal Push-Pull Operation
LOGIC DIAGRAM
SLS
System Logic
Semiconductor
ORDERING INFORMATION
SL494N Plastic
SL494D SOIC
TA = -20°C to 85° C
for all packages
PIN ASSIGNMENT
SL494
MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
41
V
VCC +0.3
V
VCC
Supply Voltage
VI
Amplifier Input Voltage
VO
Collector Output Voltage
41
V
Collector Output Current
250
mA
-65 to +150
°C
Tstg
Storage Temperature
RECOMMENDED OPERATING CONDITIONS
Symbol
Parameter
Min
Max
Unit
7
40
V
-0.3
VCC - 2
V
VCC
Supply Voltage
VI
Amplifier Input Voltage
VO
Collector Output Voltage
40
V
Collector Output Current (Each Transistor)
200
mA
Current Into Feed back Terminal
0.3
mA
CT
Timing Capacitor
0.47
10.000
nF
RT
Timing Resistor
1.8
500
KΩ
1
300
KHz
-20
+85
°C
Oscillator Frequency
TA
Operating Free-Air Temperature
SLS
System Logic
Semiconductor
SL494
ELECTRICAL CHARACTERISTICS (Temperature -20 ∼ 85°C, VCC = 15 V, f=10 kHz))
Symbol
Parameter
Test Conditions
Min
Max
Unit
4.75
5.25
V
Reference Section
Vref
Output Voltage
IO=1 mA
Vregin
Output regulation
VCC=7 V to 40 V, TA=25°C
25
mV
Vregout
Input regulation
IO=1 to 10 mA, TA=25°C
15
mV
∆Vref
Output Voltage change with
temperature
TA= -20°C to 85°C
1
%
ISC
Short-circuit output current
(Note 1)
Vref=0
50
mA
14
KHz
Oscillator Section
fOSC
Frequency
CT=0.01 µF, RT=12 kΩ
δfOSC
Standard deviation of
frequency (Note 2)
All values of VCC, CT, RT, TA
Constant
15
%
δfOSC(∆V)
Frequency change with
voltage
VCC= 7 V to 40 V,
TA=25°C
10
%
δfOSC(∆T)
Frequency change with
temperature
CT=0.01 µF, RT=12 kΩ
TA= -20°C to 85°C
2
%
-10
µA
6
Dead Time Control Section
IIB(2T)
Input bias current (pin 4)
VI= 0 to 5.25 V
DCmax
Maximum duty cycle, each
output
VI(pin 4)=0 V
VTHD
Input threshold voltage
Zero duty cycle
(pin 4)
Maximum duty cycle
45
%
3.3
V
0
Error Amp Section
VIO
Input offset voltage
VO(pin 3)=2.5 V
10
mV
IIO
Input offset current
VO(pin 3)=2.5 V
250
nA
IIB
Input bias current
VO(pin 3)=2.5 V
1
µA
Common-mode input
VCC= 7 V to 40 V
voltage range
A vol
fb
CMRR
Open-loop voltage
amplification
LOW
-0.3
HIGH
VCC - 2
∆VO=3 V, VO=0.5 to 3.5 V
Unity-gain bandwidth
V
70
dB
100
kHz
Common-mode rejection ratio
VCC=40 V, TA=25°C
65
dB
IO
Output sink current (pin 3)
VID=-15 mV to -5 V,
VO(pin 3)=0.7 V
0.3
mA
IO+
Output source current
(pin 3)
VID=15 mV to 5 V,
VO(pin 3)=3.5 V
-2
mA
SLS
System Logic
Semiconductor
SL494
ELECTRICAL CHARACTERISTICS (Temperature -20 ∼ 85°C, VCC = 15 V, f=10 kHz))
Symbol
Parameter
Test Conditions
Min
Max
Unit
4.5
V
PWM Comparator Section
VTHP
II
Input threshold voltage
(pin 3)
Zero duty cycle
Input sink current (pin 3)
VO(pin 3)=0.7 V
0.3
mA
Switching Characteristics
trc
Output voltage rise time
Common-emitter configuration
200
ns
tfc
Output voltage fall time
Common-emitter configuration
100
ns
trf
Output voltage rise time
Emitter-follower configuration
200
ns
tff
Output voltage fall time
Emitter-follower configuration
100
ns
Output Section
IC(off)
Collector off-state current
VCE=40 V, VCC=40 V
100
µA
IE(off)
Emitter off-state current
VCC=VC=40 V, VE=0
-100
µA
VSAT
Collectoremitter
Commonemitter
VE=0, IC=200 mA
1.3
V
saturation
voltage
Emitterfollower
VC=15 V, IE=-200 mA
2.5
VI=Vref
3.5
mA
mA
IOCH
Output control input current
Total Device
ICC
Standby supply current
ICCA
Average supply current
All other inputs &
VCC=15 V
10
outputs open
VCC=40 V
15
V(pin 4)=2 V
17
mA
Notes: 1. Duration of the short circuit should not exceed one second.
2. Standard deviation is a measure of the statistical disribution about the mean as derived from the formula
N
∑ (x - x)
2
n
n=1
σ =
N-1
SLS
System Logic
Semiconductor