SG1846/SG2846/SG3846
CURRENT MODE PWM CONTROLLER
DESCRIPTION
The SG1846 family of control ICs provides all of the necessary
features to implement fixed frequency, current mode control
schemes while maintaining a minimum external parts count. The
superior performance of this technique can be measured in im-
proved line regulation, enhanced load response characteristics,
and a simpler, easier-to-design control loop. Topological advan-
tages include inherent pulse-by-pulse current limiting capability,
automatic symmetry correction for push-pull converters, and the
ability to parallel “power modules” while maintaining equal current
sharing.
Protection circuitry includes built-in under-voltage lockout and
programmable current limit in addition to soft start capability. A
shutdown function is also available which can initiate either a
complete shutdown with automatic restart or latch the supply off.
Other features include fully latched operation, double pulse sup-
pression, deadtime adjust capability, and a ±1% trimmed bandgap
reference.
FEATURES
•
Automatic feed forward compensation
•
Programmable pulse by pulse current limiting
•
Automatic symmetry correction in push-pull
configuration
•
Enhanced load response characteristics
•
Parallel operation capability for modular power
systems
•
Differential current sense amplifier with wide
common mode range
•
Double pulse suppression
•
200mA totem-pole outputs
•
± 1% bandgap reference
•
Under-voltage lockout
•
Soft-start capability
•
Shutdown capability
•
500KHz operation
HIGH RELIABILITY FEATURES - SG1846
♦
Available to MIL-STD - 883
♦
Radiation data available
♦
LMI level "S" processing available
BLOCK DIAGRAM
Rev 1.1a
3.21.2005
Copyright
©
1994
1
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FAX: (714) 893-2570
Microsemi Inc.
MICROSEMI [ MICROSEMI CORPORATION ]
