NTE1722
Integrated Circuit
Pulse Width Modulator (PWM) Control Circuit
Description:
The NTE1722 is a high performance pulse width modulator integrated circuit in an 18Lead DIP type
package intended for fixed frequency switching regulators and other power control applications.
Functions included in this IC are a temperature compensated voltage reference, sawtooth oscillator,
error amplifier, pulse width modulator, pulse metering and steering logic, and two high current totem
pole outputs ideally suited for driving the capacitance of power FETs at high speeds.
Additional protective features include soft start and undervoltage lockout, digital current limiting,
double pulse inhibit, adjustable dead time and a data latch for single pulse metering. All digital control
ports art TTL and Bseries CMOS compatible. Active low logic design allows easy wiredOR connec-
tions for maximum flexibility. The versatility of this device enables implementation in singleended
or pushpull switching regulators that are transformerless or transformer coupled.
Features:
D
8.0 to 35 Volt Operation
D
5.0 Volt
1% Trimmed Reference
D
1.0Hz to 400kHz Oscillator Range
D
Dual Source/Sink Current Outputs:
100mA
D
Digital Current Limiting
D
Programmable Dead Time
D
Wide Current Limit Common Mode Range
D
Guaranteed 6 Unit Synchronization
Absolute Maximum Ratings: (Values beyond which damage may occur)
Supply Voltage, V
CC
+40V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Collector Supply Voltage, V
C
+40V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Logic Inputs
0.3 to +5.5V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog Inputs
0.3 to V
CC
V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output Current (Source or Sink), I
O
200mA
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reference Load Current (V
CC
= 40V, Note 1), I
ref
50mA
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Logic Sink Current
15mA
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Dissipation (T
A
= +25
C), P
D
1000mW
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Derate Above 50
C
10mW/
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Dissipation (T
C
= +25
C), P
D
3000mW
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Derate Above 25
C
24mW/
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Junction Temperature, T
J
+
150
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage Temperature Range, T
stg
65
to +150
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermal Resistance, JunctiontoAmbient, R
thJA
100
C/W
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lead Temperature (During Soldering, 10sec), T
L
300
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Note 1. Maximum junction temperature must be observed.
Recommended Operating Conditions:
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
Supply Voltage
V
CC
+8.0
+35
V
Collector Supply Voltage
V
C
+4.5
+35
V
Output Sink/Source Current (Each Output)
I
O
0
100
mA
Reference Load Current
I
ref
0
20
mA
Oscillator Frequency Range
I
ref
0
20
mA
Oscillator Timing Resistor
R
T
2.0
150
k
Oscillator Timing Capacitor
C
T
0.001
20
F
Available Deadtime Range (40kHz)
3.0
50
%
Operating Junction Temperature Range
T
J
0
+125
C
Electrical Characteristics: (V
CC
= 15V, T
J
= 0
to +125
C unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
Referencd Section (I
L
= 0mA unless otherwise specified)
Reference Output Voltage
V
ref
T
J
= +25
C
4.90
5.00
5.10
V
Line Regulation
Reg
line
+8.0V
V
CC
+35V
10
30
mV
Load Regulation
Reg
load
0mA
I
L
20mA
10
50
mV
Temperature Stability
V
ref
/
T
J
10
mV
Total Reference Output Voltage Variation
V
ref
+8.0V
V
CC
+35V,
0mA
I
L
20mA
4.85
5.00
5.15
V
Short Circuit Current
I
SC
V
ref
= 0V, Note 1
25
80
125
mA
Uundervoltage Lockout
Reset Output Voltage
V
ref
= +3.8V
0.2
0.4
V
V
ref
= +4.8V
2.4
4.8
V
Oscillator Section (Note 2)
Initial Accuracy
T
J
= +25
C
3.0
8.0
%
Frequency Stability over Power
Supply Range
f
osc
V
CC
+8.0V
V
CC
+35V
0.5
1.0
%
Frequency Stability over Temperature
f
osc
T
J
T
J
= 0
to +125
C
2.0
%
Minimum Frequency
f
min
R
T
= 150k
, C
T
= 20
F
0.5
Hz
Maximum Frequency
f
max
R
T
= 2k
, C
T
= 0.001
F
400
kHz
Sawtooth Peak Voltage
V
osc(p)
V
CC
= +35V
3.0
3.5
V
Sawtooth Valley Voltage
V
osc(v)
V
CC
= +8V
0.45
0.8
V
Error Amplifier Section (0V
V
CM
+5.2V unless otherwise specified)
Input Offset Voltage
V
IO
R
S
2k
20
10
mV
Input Bias Current
I
IB
350
2000
nA
Input Offset Current
I
IO
35
200
nA
DC Open Loop Gain
A
VOL
R
L
10M
60
72
dB
Note 1. Maximum junction temperature must be observed.
Note 2. f
OSC
= 40kHz (R
T
= 4.12k
1%, C
T
= 0.01
F
1%, R
D
= 0
)
Electrical Characteristics (Cont'd): (V
CC
= 15V, T
J
= 0
to +125
C unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
Error Amplifier Section (Cont'd) (0V
V
CM
+5.2V unless otherwise specified)
High Output Voltage
V
OH
V
Pin1
V
Pin2
+150mV,
I
Source
= 100
A
3.6
4.2
V
Low Output Voltage
V
OL
V
Pin2
V
Pin1
+150mV,
I
Sink
= 100
A
0.2
0.4
V
Common Mode Rejection Ratio
CMRR
R
S
2k
70
94
dB
Power Supply Rejection Ratio
PSRR
+12V
V
CC
+18V
66
80
dB
PWM Comparator Section (Note 2)
Minimum Duty Cycle
DC
min
V
compensation
= +0.4V
0
%
Maximum Duty Cycle
DC
max
V
compensation
= +3.6V
45
49
%
Digital Ports (SYNC, SHUTDOWN, RESET)
Output Voltage, High Logic Level
V
OH
I
source
= 40
A
2.4
4.0
V
Output Voltage, Low Logic Level
V
OL
I
sink
= 3.6mA
0.2
0.4
V
Input Current, High Logic Level
I
IH
V
IH
= +2.4V
125
200
A
Input Current, Low Logic Level
I
IL
V
IL
= +0.4V
225
360
A
Current Limit Comparator Section (0V
V
CM
+12V unless otherwise specified)
Sense Voltage
V
sense
R
S
50
80
100
120
mV
Input Bias Current
I
IB
3
10
A
SoftStart Section
Error Clamp Voltage
Reset = +0.4V
0.1
0.4
V
C
SoftStart Charging Current
I
CS
Reset = +2.4V
50
100
150
A
Output Drivers (Each Output, V
C
= +15Vdc unless otherwise specified)
Output High Level
V
OH
I
source
= 20mA
12.5
13.5
V
I
source
= 100mA
12.0
13.0
V
Output Low Level
V
OL
I
Sink
= 20mA
0.2
0.3
V
I
Sink
= 100mA
1.2
2.0
V
Collector Leakage
I
C(Leak)
V
C
= +40V
50
150
A
Rise Time
t
r
C
L
= 1000pF
0.3
0.6
s
Fall Time
t
f
0.1
0.2
s
Supply Current
I
CC
Shutdown + +0.4V, V
CC
= +35V,
R
T
= 4.12k
18
30
mA
Note 2. f
OSC
= 40kHz (R
T
= 4.12k
1%, C
T
= 0.01
F
1%, R
D
= 0
)
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