Extended
al T Commerci 70˚C -20˚C to ent d Equipm le Handhel for Portab
ING FEATURem ange perature R
September 1996 P...
Extended
al T Commerci 70˚C -20˚C to ent d Equipm le Handhel for Portab
ING FEATURem ange perature R
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
VIN
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
ML4894
PIN CONFIGURATION
ML4894 8-Pin SOIC (S08)
VREG VFB ISENSE SHDN 1 2 3 4 TOP VIEW 8 7 6 5 VIN P DRV N DRV GN...