Extended
al T Commerci 70˚C -20˚C to ent d Equipm le Handhel for Portab
ING FEATURem ange perature R
August 1996 PREL...
Extended
al T Commerci 70˚C -20˚C to ent d Equipm le Handhel for Portab
ING FEATURem ange perature R
August 1996 PRELIMINARY
ML4895
Synchronous Buck Controller
GENERAL DESCRIPTION
The ML4895 synchronous buck controller has been designed to provide high efficiency DC/DC conversion for portable products. The ML4895 can deliver a user programmable 2.5V to 4V output from input
voltages of 5.9V to 15V. The ML4895 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 Adjustable output synchronous buck (2.5V to 4V) 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 2.5V - 4V
5
GND
– VFB
2
FROM SYSTEM POWER MANAGEMENT
SHDN
4
SLEEP LOGIC
1
ML4895
PIN CONFIGURATION
ML4895 8-Pin SOIC (S08)
VREG VFB ISENSE SHDN 1 ...