-'l-Micro Linear
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GENERAL DESCRIPTION
The ML4862 is a complete solution for DC to DC
conversion and power management in multi-cell battery
powered portable computers and instruments. Several
advanced techniques are incorporated in the IC for the
highest possible systems efficiency.
The 5.0V and 3.3V main regulators in the ML4862 each
control a synchronously rectified buck regulator, using
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N-channel MOSFETs. This allows high conversion
efficiencies (90% or greater). Bias for all N-channel
MOSFETs in the system as well as the input for the 12V
regulator for programming EEPROMs comes from an
auxiliary winding on the buck regulator choke.
The ML4862 also contains 3 outputs to drive external N-
channel MOSFETs to power down disk drives and memory
under control of external logic. Automatic switch-over to
battery operation is also provided when the charger is
removed. A IlPower 5V linear regulator and low battery
indicator are provided for the power monitoring logic.
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Battery Power ControllC
FEATURES
• Two synchronously rectified, 100kHz buck regulators
for 5V and 3.3V outputs
Regulation to ±3% maximum; provides 2% PCMClA
switch matrix margin
Low cost all N-channel MOSFET switching
• Three logic to N-channel gate drive translators for
power management
• IlPower SV standby linear regulator to run power
management logic
• Output and logic for N-channel MOSFET to disconnect
battery when charger is connected
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12V auxiliary output available with On/Off Control for
E2 memory programming
• low battery detect comparator
• Wide input voltage range (5V to 20V)
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DIAGRAM
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MICRO-LINEAR [ MICRO LINEAR CORPORATION ]
