BQ24640 Datasheet, PDF (1/25 Pages) Texas Instruments – High-Efficiency Synchronous Switch-Mode Super Capacitor Charger

bq24640
www.ti.com
SLUSA44 – MARCH 2010
High-Efficiency Synchronous Switch-Mode Super Capacitor Charger
Check for Samples: bq24640
FEATURES
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• Charge Super Capacitor Pack from 2.1V to 26V
• CC–CV Charge Profile from 0V Without
Precharge
• 600kHz NMOS-NMOS Synchronous Buck
Controller
• Over 90% Efficiency for up to 10A Charge
Current
• 5V–28V VCC Input Voltage Range
• Accuracy
– ±0.5% Charge Voltage Regulation
– ±3% Charge Current Regulation
• High Integration
– Internal Loop Compensation
– Internal Digital Soft Start
• Safety
– Input Over-Voltage Protection
– Capacitor Temperature Sensing Hot/Cold
Charge Suspend
– Thermal Shutdown
• Status Outputs
– Adapter Present
– Charger Operation Status
• Charge Enable Pin
• 30ns Driver Dead Time and 99.5% Max
Effective Duty Cycle
• Automatic Sleep Mode for Low Power
Consumption
– <15µA Off-State Super Capacitor Discharge
Current
– <1.5mA Off-State Input Quiescent Current
• Small 3.5 × 3.5 mm² QFN-16 Package
DESCRIPTION
The bq24640 is highly integrated switch-mode super
capacitor charge controller. It offers a constant-
frequency synchronous PWM controller with high
accuracy charge current and voltage regulation, and
charge status monitoring.
The bq24640 charges super capacitor in two phases:
constant current and constant voltage. The charge
starts from down to 0V with current set on ISET pin.
The charge current starts tapering down, when the
voltage on VFB reaches an internal reference,
The bq24640 enters a low-current sleep mode
(<15mA) when the input voltage falls below the output
capacitor voltage.
The bq24640 has an input CE pin to enable and
disable charge; and, the STAT and PG output pins
report charge and adapter status. The TS pin on the
bq24640 monitors the temperature of the capacitor
and suspends charge during HOT/COLD conditions.
PACKAGE
16 15 14
VCC 1
CE ²
STAT 3
OGA
bq24640
QFN-16
TOP VIEW
13
12 ^REGN
11 GND
10 SRP
TS 4
9 SRN
56
7
8
APPLICATIONS
• Memory Backup System
• Industrial UPS system and Power Transient
Buffering
• Bridge Power to Buffer the Battery
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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.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2010, Texas Instruments Incorporated