Current Mode PWM Controller 2.5V/1.5V/1.24V to 20V 1A 28-Pin SSOP T/R

The Si9139 is a current-mode PWM and PSM converter controller, with two synchronous buck controllers and an adjustable Buck-Boost controller whose output can be set between 1.24 V and 20 V with an external resistor divider. Designed for portable devices, it offers a total of five power outputs (three tightly regulated dc/dc converter outputs, a precision 3.3-V reference and a 5-V LDO output) and individually controlled power-up sequencing, power-good signal with delay, internal frequency compensation networks and automatic boot-strapping. It requires minimum external components and is capable of achieving conversion efficiencies approaching 95%.The Si9139 is available in a 28-pin SSOP package and specified to operate over the extended commercial (-40°C to 85°C) temperature range.

• 50-W, Triple Output DC-DC-Controller
• Up to 95% Efficiency
• 3% Total Regulation (Line, Load and Temperature)
• 4.5-V to 30-V Input Voltage Range
• Two Fixed 1.5-V, 1.8-V, 2.0-V, 2.2-V, 2.5-V, 2.8-V, 3.3-V, and One Adjustable 1.24- to 20-V Outputs
• Individual ON/OFF Controls
• 300-kHz Low-Noise Fixed Frequency Operation
• 3.3-V Reference Output
• 5-V/30-mA Linear Regulator Output
• High Efficiency Pulse Skipping Mode Operation at Light Load
• Only Three Inductors Required – No Transformer
• LITTLE FOOT® Optimized Output Drivers
• Internal Soft-Start
• Minimal External Control Components
• 28-Pin SSOP Package
• Output Overvoltage Protection
• Output Undervoltage Shutdown
• Power-Good Output (RESET)