IL494-02 1

TECHNICAL DATA
PWM Control Circuit
IL494
The IL494 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
IL494 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 output-control function. The architecture of the
IL494 prohibits the possibility of either output being pulsed twice
during push-pull operation.
FEATURE






PIN ASSIGNMENT
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
ORDERING INFORMATION
Device
Operating
Temperature Range
IL494N
IL494D
IL494DT
TA = -20 to 85 C
for all packages
Package
Plastic
DIP-16
SOP-16
SOP-16
Shipping
Tube
Tube
Tape& Reel
FUNCTION TABLE
Output Control
Grounded
At Vref
Output Function
Single-ended or Parallel Output
Normal Push-Pull Operation
LOGIC DIAGRAM
2011, February, Rev. 02
IL494
MAXIMUM RATINGS
Symbol
VCC
Parameter
Supply Voltage
Value
Unit
41
V
VI
Amplifier Input Voltage
VCC +0.3
V
VO
Collector Output Voltage
41
V
Collector Output Current
250
mA
-65 to +150
C
Tstg
Storage Temperature
* Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device.
These are stress ratings only and functional operation of the device at these or any other conditions beyond those
indicated under “recommended operating conditions” is not implied.
Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
RECOMMENDED OPERATING CONDITIONS
Symbol
VCC
Parameter
Supply Voltage
Min
Max
Unit
7
40
V
-0.3
VCC - 2
V
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
K
1
300
KHz
-20
+85
C
Oscillator Frequency
TA
Operating Free-Air Temperature
2011, February, Rev. 02
IL494
ELECTRICAL CHARACTERISTICS (Temperature -20  85C, VCC = 15 V, f=10 kHz))
Symbol
Parameter
Test Conditions
Min
Max
Unit
4.90
5.10
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 F, RT=12 k
fOSC
Standard deviation of
frequency (Note 2)
All values of VCC, CT, RT, TA
Constant
15
%
fOSC(V)
Frequency change with
voltage
VCC= 7 V to 40 V,
TA=25C
10
%
fOSC(T)
Frequency change with
temperature
CT=0.01 F, RT=12 k
TA= -20C to 85C
2
%
-10
A
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
A
Common-mode input
VCC= 7 V to 40 V
voltage range
Avol
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
2011, February, Rev. 02
IL494
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
A
IE(off)
Emitter off-state current
VCC=VC=40 V, VE=0
-100
A
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
ICCA
Standby supply current
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
 (xn - x)2
n=1
=
N–1
2011, February, Rev. 02
IL494
Typical Application
Pulse Width Modulated Step-down Converter
2011, February, Rev. 02
IL494
Parameter Measurement Information
1.
Dead time and Feedback Control
2.
Error Amplifier Characteristics
3.
Common-Emitter Configuration
4.
Emitter-Follower Configuration
2011, February, Rev. 02
IL494
Typical Performance Curves
FIGURE 1 – OSCILLATOR FREQUENCY vs.
TIMING RESISTANCE
FIGURE 2 – OPEN LOOP VOLTAGE GAIN AND
PHASE vs. FREQUENCY
FIGURE 3 – PERCENT DEAD TIME
vs.OSCILLATOR FREQUENCY
FIGURE 4 – PERCENT DUTY CYCLE vs.
DEAD-TIME CONTROL VOLTAGE
2011, February, Rev. 02
IL494
FIGURE 5 – EMITTER-FOLLOWER
CONFIGURATION OUTPUT-SATURATION
VOLTAGE vs. EMITTER CURRENT
FIGURE 6 – COMMON-EMITTER
CONFIGURATION OUTPUT-SATURATION
VOLTAGE vs. COLLECTOR CURRENT
FUGURE 7 – STANDBY-SUPPLY CURRENT
vs. SUPPLY VOLTAGE
2011, February, Rev. 02
IL494
2011, February, Rev. 02