Extended
fo
ial T
Commerc
0˚C
-20˚C to 7
ment
eld Equip
Handh
r Portable
NG
FEATUR
e
I
mperature Range
September 1996
PRELIMINARY
ML4894
Synchronous Buck Controller
GENERAL DESCRIPTION
The ML4894 synchronous buck controller has been
designed to provide high efficiency DC/DC conversion for
portable products. The ML4894 can deliver a fixed 5V
output from input voltages of 5.9V to 15V.
The ML4894 drives external P- and N-channel MOSFETs
in a synchronous buck topology, allowing an overall
conversion efficiency of greater than 90% over an output
current range exceeding three decades, with an output
current capability of up to 5A.
The regulator can be disabled via the
SHDN
pin. While
disabled, the output of the regulator is completely
isolated from the circuit’s input supply, and the supply
current is reduced to less than 5µA to help extend battery
life.
FEATURES
s
s
s
s
Regulation to ±3% maximum
Fixed 5V output synchronous buck
Wide input voltage range (5.9V to 15V)
Power conversion efficiencies of >90% over 3 decades
of output current
Integrated antishoot-through logic
Shutdown control provides load isolation and
minimum sleep mode power consumption
Low shutdown current
s
s
s
BLOCK DIAGRAM
8
V
I
N
P DRV
7
+
VIN
5.9V - 15V
1
VREG
BUCK REGULATOR
N DRV
6
BIAS
CIRCUITS
ISENSE
3
VOUT
5V
5
GND
–
VFB
2
TO SYSTEM
POWER
MANAGEMENT
SHDN
4
SLEEP
LOGIC
1
MICRO-LINEAR [ MICRO LINEAR CORPORATION ]
