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

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Operates from a single LiION cell (2.8V to 5.5V)

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Output voltage range of 1.5V to 3.6V

2% DC feedback voltage precision

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500mA maximum load capability

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600µA typ PWM mode quiescent current

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0.02µA typ shutdown current

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600kHz PWM switching frequency

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SYNC input for PWM mode frequency synchronization

from 500kHz to 1MHz

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High efficiency (Up to 95%) in PWM mode from internal

synchronous rectification

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100% Maximum Duty Cycle for Lowest Dropout

Features

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14-pin TSSOP package

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Uses small ceramic capacitors

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5mV typ PWM mode output voltage ripple(C

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Internal soft start

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Current overload protection

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Thermal Shutdown

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External compensation

Applications

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Mobile Phones

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Hand-Held Radios

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RF PC Cards

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Wireless LAN Cards

Typical Application Circuits

20065101

FIGURE 1. Typical Circuit for 1.8V Output Voltage

August 2003

© 2003 National Semiconductor Corporation

DS200651

www.national.com

PrintDate=2003/08/20 PrintTime=18:54:04 801627bc ds200651_p Rev. No. 1.25

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