LM2772 Datasheet, PDF (1/16 Pages) National Semiconductor (TI) – Low-Ripple Switched Capacitor Step-Down Regulator

LM2772
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SNVS486A – DECEMBER 2006 – REVISED MARCH 2007
LM2772 Low-Ripple Switched Capacitor Step-Down Regulator
Check for Samples: LM2772
FEATURES
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•2 Low-Noise Fixed Frequency Operation
• 1.2V Output Voltage
• 3% Output Voltage Regulation
• Li-Ion (3.6V) to 1.2V with 80% Efficiency
• Very Low Output Ripple: 8mV @ 150mA
• Output Currents up to 150mA
• 2.7V to 5.5V Input Voltage Range
• Shutdown Disconnects Load from V_IN
• 1.1MHz Switching Frequency
• No Inductors…Small Solution Size
• Short Circuit and Thermal Protection
• SON-10 Package (3mm × 3mm × 0.8mm)
APPLICATIONS
• DSP, Memory, and Microprocessor Power
Supplies
• Mobile Phones and Pagers
• Portable Electronic Devices
DESCRIPTION
The LM2772 is a switched capacitor step-down regulator that produces a 1.2V output. It is capable of supplying
loads up to 150mA with 3% output voltage regulation over line, load, and temperature. The LM2772 operates
with an input voltage from 3.0V to 5.5V, accommodating 1-cell Li-Ion batteries and chargers.
The LM2772 utilizes a highly efficient regulated multi-gain charge pump. Pre-regulated 1.1MHz fixed-frequency
switching results in very low ripple and noise on both the input and the output. When output currents are low, the
part automatically switches to a low-ripple PFM regulation mode to maintain high efficiency over the entire load
range.
The LM2772 is available in National’s 10-pad Leadless Leadframe No-Pullback Package (SON-10).
Typical Application Circuit
V_IN = 3.0V to 5.5V
V_IN
C_IN
1 µF
V_OUT
V_OUT: 1.2V
I_OUT up to 150 mA
C_OUT
4.7 µF
GND
C1+
LM2772
C1
High: ON
1 µF
Low: Shutdown
EN
C1-
C3+
C2+
C3
1 µF
C2
1 µF
C3-
C2-
Capacitors: 1 µF - TDK C1005X5R0J105K
4.7 µF - TDK C1608X5R0J475K
or equivalent
Figure 1. LM2772 Efficiency vs.
Low-Dropout Linear Regulator (LDO) Efficiency
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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.
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