LP3905 Datasheet, PDF (1/24 Pages) National Semiconductor (TI) – Power Management Unit For Low Power Handheld Applications

LP3905
www.ti.com
SNVS374D – JUNE 2006 – REVISED MAY 2013
LP3905 Power Management Unit For Low Power Handheld Applications
Check for Samples: LP3905
FEATURES
1
• Two Buck Regulators for Powering High
Current Processor Functions or Peripheral
Devices
• Two Linear Regulators for Powering Internal
Processor Functions and I/Os
• One Enable Pin for Buck1 and Linear
Regulators 1 and 2
• Separate Enable Pin for Buck2
• Thermal and Current Overload Protection
• Small 14–Pin WSON Package (4x4mmx0.8mm)
APPLICATIONS
• Baseband Processors
• Peripheral Processor (Video, Audio)
• I/O Power
• FPGA Power
DESCRIPTION
LP3905 is a multi-functional Power Management Unit,
optimized for low power handheld applications. This
device integrates two 600mA DC-DC buck regulators
and two 150mA linear regulators. Fixed and
adjustable buck output versions are available. The
LP3905 additionally features two enable pins for the
device output control and is offered in an WSON
package.
KEY SPECIFICATIONS
Buck Regulators
• Fixed and Adjustable Voltage Options, Range
1.0V to 3.3V⁽¹⁾
• Up to 90% Efficiency
• Auto-Switching PFM-PWM Mode and Fixed
PWM Mode
• 2MHz PWM Fixed Switching Frequency (Typ)
• 600mA Output Current
• ±4% Output Voltage Accuracy Over Temp
• Internal SoftStart
• 2.2µH Inductor, 10µF Input and Output Caps
Linear Regulators
• Output Options in the Range 1.5V to 3.3V⁽¹⁾
• 13.5µV_rms Output Voltage Noise
• PSRR - 70dB @ 1kHz
• ±3% Output Voltage Accuracy Over Full Line
and Load Regulation
• 0mA to 150mA Output Current
• C_in = 1.0µF, C_out = 0.47µF for 100mA O/P
• C_in = 1.0µF, C_out = 1.0µF for 150mA O/P
• 80mV Dropout Voltage
(1) Fixed output voltage devices can be customized to fit system
requirements. Please contact Texas Instruments Sales Office.
Typical Application Circuit
Enable 1
LDO2
Output
VSupply
LDO1
Output
Enable 2
0.47 PF
1.0 PF
0.47 PF
LDO GND
LP3905
EN2
FB2
TGND
GND_B2
LDO2
SW2
Vin2
Vin1
LDO1
SW1
GND
GND_B1
EN1
FB1
SGND
2.2 PH
2.2 PH
10 PF
10 PF
10 PF
BUCK GND
Buck2
Output
VSupply
Buck1
Output
Figure 1. Typical Application Circuit – 14-Pin WSON Package
1
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2006–2013, Texas Instruments Incorporated