A4401KL-T Datasheet, PDF (1/17 Pages) Allegro MicroSystems – Automotive Quasi-Resonant Flyback Control IC

A4401
Automotive Quasi-Resonant Flyback Control IC
Features and Benefits
▪ Multiple output regulator
▪ 7 to 40 V input supply
▪ Low EMI conducted and radiated emissions
▪ Adaptive quasi-resonant turn on/off control
▪ Minimal number of external components
▪ Enable input which can be driven with respect to the
battery voltage
Package: 8-pin narrow SOIC (suffix L)
Description
This device provides all the necessary control functions to
provide the power rails for driving a vacuum fluorescent
display (VFD) using minimal external components. The power
supply is based on a quasi-resonant, discontinuous flyback
converter, operating near the critical conduction boundary. A
novel adaptive turn-on control scheme is used to optimize the
turn-on and turn-off phase of the MOSFET, to reduce EMI
emissions while minimizing switching losses.
The converter is self-oscillating, operating at switching
frequencies depending on the input voltage, load, and external
components. An onboard linear regulator that is powered
directly from the battery provides the housekeeping supply,
avoiding the need for complex bias supplies.
Internal diagnostics provide comprehensive protection
against overloads, input undervoltage, and overtemperature
conditions.
The A4401 is supplied in an 8-pin narrow SOIC package
(suffix L), which is lead (Pb) free, with 100% matte-tin
leadframe plating.
Approximate Scale 1:1
Typical Application
+V_BAT
VIN
VFD
ECU
LX
A4401
GD
0V
ISS
EN
0V
GND
VA
COMP
A4401-DS, Rev. 2