LM2619MTC Datasheet, PDF (1/16 Pages) National Semiconductor (TI) – 500mA Step-Down DC-DC Converter

August 2003
LM2619MTC
500mA Step-Down DC-DC Converter
General Description
The LM2619MTC 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 LM2619MTC is available in a 14 pin TSSOP package. A
high switching frequency (600kHz) allows use of tiny
surface-mount components.
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 range of 1.5V to 3.6V
n ±2% 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 (Up to 95%) in PWM mode from internal
synchronous rectification
n 100% Maximum Duty Cycle for Lowest Dropout
Features
n 14-pin TSSOP 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
Typical Application Circuits
FIGURE 1. Typical Circuit for 1.8V Output Voltage
20065101
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