UC2909-EP

www.ti.com

SLUSA72 – JULY 2010

SWITCHMODE LEAD-ACID BATTERY CHARGER

Check for Samples: UC2909-EP

1

FEATURES

SUPPORTS DEFENSE, AEROSPACE,

AND MEDICAL APPLICATIONS

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Accurate and Efficient Control of Battery

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Controlled Baseline

Charging

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One Assembly/Test Site

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Average Current Mode Control from Trickle to

•

One Fabrication Site

Overcharge

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Available in Military (–55°C/125°C)

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Resistor Programmable Charge Currents

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Thermistor Interface Tracks Battery

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Extended Product Life Cycle

Requirements Over Temperature

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Extended Product-Change Notification

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Output Status Bits Report on Four Internal

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Product Traceability

Charge States

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Not to Exceed 185.35-KHz Oscillation

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Undervoltage Lockout Monitors VCC and

Frequency at 125°C

VREF

(1)

Additional temperature ranges available - contact factory

DESCRIPTION

The UC2909 controls lead acid battery charging with a highly efficient average current mode control loop. This

chip combines charge state logic with average current PWM control circuitry. Charge state logic commands

current or voltage control depending on the charge state. The chip includes undervoltage lockout circuitry to

insure sufficient supply voltage is present before output switching starts. Additional circuit blocks include a

differential current sense amplifier, a 1.5% voltage reference, a –3.9-mV/°C thermistor linearization circuit,

voltage and current error amplifiers, a PWM oscillator, a PWM comparator, a PWM latch, charge state decode

bits, and a 100-mA open collector output driver.

FUNCTION BLOCK DIAGRAM

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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas

Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

PRODUCTION DATA information is current as of publication date.

Copyright © 2010, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.