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
•
Accurate and Efficient Control of Battery
Charging
•
•
•
•
Controlled Baseline
One Assembly/Test Site
One Fabrication Site
Available in Military (–55°C/125°C)
Temperature Range(1)
•
Average Current Mode Control from Trickle to
Overcharge
•
•
Resistor Programmable Charge Currents
Thermistor Interface Tracks Battery
Requirements Over Temperature
•
•
•
•
Extended Product Life Cycle
Extended Product-Change Notification
Product Traceability
Not to Exceed 185.35-KHz Oscillation
Frequency at 125°C
•
•
Output Status Bits Report on Four Internal
Charge States
Undervoltage Lockout Monitors VCC and
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
1
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.