AS2842/D-8, UC3842 ASTEC Current Mode PWM Controller 8pin SOIC Quantity:

Description

Current Mode PWM Controller, 8pin soic, UC3842,
Mfr:
ASTEC
Part:
AS2842/D-8
Quantity:
10 piecee
cut tape
-
ESD Static Shield Pkg.
Description
The AS2842 family of control ICs provide pin-for-pin replacement of the
industry standard UC3842 series of devices. The devices are
redesigned to provide significantly improved tolerances in power supply
manufacturing. The 2.5 V reference has been trimmed to 1.0% toler-
ance. The oscillator discharge current is trimmed to provide guaranteed
duty cycle clamping rather than specified discharge current. The circuit
is more completely specified to guarantee all parameters impacting
power supply manufacturing tolerances.
In addition, the oscillator and flip-flop sections have been enhanced to
provide additional performance. The R T /C T pin now doubles as a syn-
chronization input that can be easily driven from open collector/open
drain logic outputs. This sync input is a high impedance input and can
easily be used for externally clocked systems. The new flip-flop topolo-
gy allows the duty cycle on the AS2844/5 to be guaranteed between 49
and 50%. The AS2843/5 requires less than 0.5 mA of start-up current
over the full temperature range.
Features:
2.5 V bandgap reference trimmed to 1.0%
•
and temperature-compensated
Extended temperature range from –40 to
•
105°C
AS2842/3 oscillations trimmed for precision
•
duty cycle clamp
AS2844/5 have exact 50% max duty cycle
•
clamp
Advanced oscillator design simplifies
•
synchronization
Improved specs on UVLO and hysteresis
•
provide more predictable start-up and
shutdown
Improved 5 V regulator provides better AC
•
noise immunity
Guaranteed performance with current sense
•
pulled below ground
Over-temperature shutdown
Please email if you have any questions.