SI9138 Datasheet, PDF (1/14 Pages) Vishay Siliconix – Multi-Output, Individual On/Off Control Power-Supply Controller

New Product
Si9138
Vishay Siliconix
Multi-Output, Individual On/Off Control Power-Supply Controller
FEATURES
D Up to 95% Efficiency
D "3% Total Regulation (Line, Load and Temperature)
D 5.5-V to 30-V Input Voltage Range
D 3.3-V, 5-V, and Adjustable 5- to 12-V Outputs
D Individual ON/OFF Control for 3.3 V and 5 V
D 300-kHz Low-Noise Fixed Frequency Operation
D Precision 3.3-V Reference Output
D 5-V/30-mA Linear Regulator Output
D High Efficiency Pulse Skipping Mode Operation at Light Load
D Only Three Inductors RequiredNo Transformer
D LITTLE FOOT^R Optimized Output Drivers
D Internal Soft-Start
D Minimal External Control Components
D 28-Pin SSOP Package
D Output Overvoltage Protection
D Output Undervoltage Shutdown
D Power-Good Output (RESET)
APPLICATIONS
D Notebook and Subnotebook Computers
D PDAs and Mobile Communicators
D Portable Display
D Multimedia Set-Top Box
D Telecommunications Infrastructure
D Network Equipment
D Distributed Power Conversion
DESCRIPTION
The Si9138 is a current-mode PWM and PSM converter
controller, with two synchronous buck controllers (3.3 V and
5 V) and an adjustable Buck-Boost controller whose output
can be set between 5 and 12 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 includes
on-board pre-programmed 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 Si9138 is available in a 28-pin SSOP package and
specified to operate over the extended commercial (0_C to
90_C) temperature range.
FUNCTIONAL BLOCK DIAGRAM
V_IN
(5.5 V to 30 V)
V_L
(5.0 V)
+3.3 V/6 A
5-V
Linear
Regulator
3.3-V
SMPS
3.3-V
Voltage
Reference
5-V
SMPS
V_REF
(+3.3 V)
+5 V/6 A
5- to 12-V SMPS
Programmable
V_BUCK-BOOST
+5- to +12-V/500 mA
Adjustable
ON3
ON5
Document Number: 71446
S-20642—Rev. B, 13-May-02
Logic Control Power_Good
RESET
(Power_Good)
www.vishay.com
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