SG1846/SG2846/SG3846
CURRENT MODE PWM CONTROLLER
DESCRIPTION
FEATURES
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.
• 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
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.
HIGH RELIABILITY FEATURES - SG1846
♦ Available to MIL-STD - 883
♦ Radiation data available
♦ LMI level "S" processing available
BLOCK DIAGRAM
4/90 Rev 1.1 2/94
LINFINITY Microelectronics Inc.
Copyright 1994
11861 Western Avenue ∞ Garden Grove, CA 92841
(714) 898-8121 FAX: (714) 893-2570
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