FAN5235

Features:

•Synchronous rectification
•±1% precision internal reference
•>90% efficiency
•Input and output voltage feedback
•5.4V to 24V input voltage range
•Internally set 300kHz ±15% oscillator
•5V and 3.3V Main outputs switch out of phase
•5V-ALWAYS and 3.3V-ALWAYS outputs
•Adjustable boost converter for 12V
•Boost converter slaved to 5V Main
•Input UVLO
•Outputs OVP of Buck Converters
•Precision current limit option for 5V, 3.3V Main
•Power Good Voltage Monitor


Application

•Notebook PCs and PDAs
•Hand-held portable instruments


Pinout




Specifications

</table

Parameter	Conditions	Min.	Typ.	Max.	Units
VIN		-0.3		27	V
SW, ISEN Pins,SDWN Pin		-0.3		27	V
CPUMP, HSD Pins		-0.3		33	V
SDN, VFB, V_always pins		-0.3		6.5	V
CPUMP to SW pins, and all other pins		-0.3		6.5	V
The sum of the load currents on pins 2 and 6 must not exceed 60mA total

Description

The FAN5235 is a high efficiency and high precision DC/DC controller for notebook converters. Utilization of both input and output voltage feedback in a current-mode control allows for fast and stable loop response over a wide range of input and output voltage variations. The two main regulators switch out of phase to minimize input ripple current.
Current sense based on MOSFET Rdson gives maximum efficiency, while also permitting use of a sense resistor for high accuracy. An externally adjustable boost converter can be set to generate 12V.
The FAN5235 is available in a 24-pin QSOP package, and in a 24-pin TSSOP package.