The NTE1721 and NTE1723 are pulse width modulator control鈥揷ircuits designed to offer improved
performance and lowered external parts count when implemented for controlling all types of switching
power supplies. The no鈥揷hip +5.1V reference is trimmed to
of the errror amplifier includes the reference voltage, thus eliminating the need for external divider
resistors. A sync input to the oscillator enables multiple units to be slaved or a single unit to be syn-
chronized to an external system clock. A wide range of dead time can be programmed by a single
and the Discharge pins. These devices also feature a built鈥搃n
soft鈥搒tart circuitry, requiring only an external timing capacitor. A shutdown pin controls both the soft鈥?/div>
start circuitry and the output stages, provided instantaneous turn鈥搊ff through the PWM latch with
pulsed shutdown, as well as soft鈥搒tart recycle with longer shutdown commands. The under voltage
lockout inhibits the outputs and the changing of the soft鈥搒tart capacitor when V
CC
is below nominal.
The output stages are totem鈥損ole design capable of sinking and sourcing in excess of 200mA. The
output stages of the NTE1721 features NOR logic resulting in a low output for an off state while the
NTE1723 utilizes OR logic which gives a high output when off.
Features:
D
8V to 35V Operation
D
+5.1V
鹵1%
Trimmed Reference
D
100Hz to 400kHz Oscillator Range
D
Separate Oscillator Sync Pin
D
Adjustable Dead Time Control
D
D
D
D
Input Undervoltage Lockout
Latching PWM to Prevent Multiple Pulses
Pulse鈥揵y鈥揚(yáng)ulse Shutdown
Dual Source/Sink Outputs:
鹵400mA
Peak
Absolute Maximum Ratings:
(Note 1)
Supply Voltage, V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +40V
Collector Supply Voltage, V
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +40V
Logic Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 鈥?.3V to +5.5V
Analog Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 鈥?.3V to V
CC
Output Current, Source or Sink, I
O
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
鹵500mA
Reference Output Current, I
ref
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50mA
Oscillator Charging Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5mA
Power Dissipation (T
A
= +25擄C), P
D
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1000mW
Derate Above 50擄C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10mW/擄C
Power Dissipation (T
C
= +25擄C), P
D
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2000mW
Derate Above 25擄C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16mW/擄C
Operating Junction Temperature, T
J
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +150擄C
Storage Temperature Range, T
stg
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 鈥?5擄 to +125擄C
Thermal Resistance, Junction鈥搕o鈥揂mbient, R
thJA
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100擄C/W
Thermal Resistance, Junction鈥搕o鈥揅ase, R
thJC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60擄C/W
Lead Temperature (During Soldering, 10sec), T
L
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +300擄C
Note 1 Values beyond which damage may occur
1
2
3
4
