LM2619_03 Datasheet, PDF (1/15 Pages) National Semiconductor (TI) – 500mA Sub-Miniature Step-Down DC-DC Converter

October 2003
LM2619
500mA Sub-Miniature Step-Down DC-DC Converter
General Description
The LM2619 step down DC-DC converter is optimized for
powering circuits from a single Lithium-Ion cell. It steps down
an input voltage of 2.8V to 5.5V to an output of 1.5V to 3.6V
at up to 500mA. Output voltage is set using resistor feedback
dividers.
The device offers three modes for mobile phones and similar
portable applications. Fixed-frequency PWM mode mini-
mizes RF interference. A SYNC input allows synchronizing
the switching frequency in a range of 500kHz to 1MHz. Low
current hysteretic PFM mode reduces quiescent current to
160µA (typ.). Shutdown mode turns the device off and re-
duces battery consumption to 0.02µA (typ.).
Current limit and thermal shutdown features protect the de-
vice and system during fault conditions.
The LM2619 is available in a 10 bump micro SMD package.
This packaging uses National’s chip-scale micro SMD tech-
nology and offers the smallest possible size. A high switching
frequency (600kHz) allows use of tiny surface-mount com-
ponents.
The device features external compensation to tailor the re-
sponse to a wide range of operating conditions.
Key Specifications
n Operates from a single LiION cell (2.8V to 5.5V)
n Output voltage (1.5V to 3.6V)
n ±1% DC feedback voltage precision
n 500mA maximum load capability
n 600µA typ PWM mode quiescent current
n 0.02µA typ shutdown current
n 600kHz PWM switching frequency
n SYNC input for PWM mode frequency synchronization
from 500kHz to 1MHz
n High efficiency (96% typ at 3.9V_IN, 3.6V_OUT and 200mA)
in PWM mode from internal synchronous rectification
n 100% Maximum Duty Cycle for Lowest Dropout
Features
n Sub-miniature 10-bump thin micro SMD package
n Uses small ceramic capacitors
n 5mV typ PWM mode output voltage ripple(C_OUT = 22µF)
n Internal soft start
n Current overload protection
n Thermal Shutdown
n External compensation
Applications
n Mobile Phones
n Hand-Held Radios
n RF PC Cards
n Wireless LAN Cards
© 2003 National Semiconductor Corporation DS200574
www.national.com