General Description
The uP1586 is a dual synchronous buck controller with
5V/3.3V 100mA LDOs for notebook system power supply
solution.
The uP1586 supports high efficiency, fast transient
response and provides a combined POK signal. The
ultrasonic mode maintains the switching frequency above
audio frequency, which eliminates noise in audio
applications. The proprietary RCOTTM technology provides
fast transient response and high noise immunity.
The uP1586 has internal soft-start to control the inrush
current. Other features include overcurrent protection,
overvoltage protection, power-up sequencing, power OK
output, and thermal shutdown. The uP1586 is available
in the space saving package VQFN4x4-24L, specified from
-40OC to 85OC.

Features
† Wide Input Voltage Range: 6V to 26V
† Two Synchronous Buck Controllers
„ Dual Fixed 5V/3.3V Outputs or Adjustable from
2V to 5.5V
„ Selectable PWM, DEM and USM in Light Load
„ Internal Soft-start and Soft-Discharge
„ RCOTTM (Robust Constant On-Time) Control
Architecture
„ 4500ppm/OC RDS(ON) Current Sensing
† 100mA 5V/3.3V LDO with Switches
† Secondary FB Input Maintains Charge Pump
Voltage (uP1586R)
† 2V + 1% Reference Voltage Output
† Power OK Indicator
† OVP/UVP/OCP/OTP
† VQFN4x4-24L
† RoHS Compliant and Halogen Free

Applications
† Notebook and Subnotebook System Power
Supplies
† 3-4 Cell Li-Ion Battery-Power Devices
† Dual Output Supplies for DSP, Memory, Logic
and Microprocessor