BQ24740_07 Datasheet, PDF (1/32 Pages) Texas Instruments – Host-controlled Multi-chemistry Battery Charger with Low Input Power Detect

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bq24740
SLUS736 – DECEMBER 2006
Host-controlled Multi-chemistry Battery Charger with Low Input Power Detect
FEATURES
• NMOS-NMOS Synchronous Buck Converter
with 300 kHz Frequency and >95% Efficiency
• 30-ns Minimum Driver Dead-time and 99.5%
Maximum Effective Duty Cycle
• High-Accuracy Voltage and Current
Regulation
– ±0.5% Charge Voltage Accuracy
– ±3% Charge Current Accuracy
– ±3% Adapter Current Accuracy
– ±2% Input Current Sense Amp Accuracy
• Integration
– Internal Loop Compensation
– Internal Soft Start
• Safety
– Input Overvoltage Protection (OVP)
– Dynamic Power Management (DPM) with
Status Indicator
– Reverse-Conduction Protection Input FET
• Supports Two, Three, or Four Li+ Cells
• 5 – 24 V AC/DC-Adapter Operating Range
• Analog Inputs with Ratiometric Programming
via Resistors or DAC/GPIO Host Control
– Charge Voltage (4-4.512 V/cell)
– Charge Current (up to 10 A, with 10-mΩ
sense resistor)
– Adapter Current Limit (DPM)
• Status and Monitoring Outputs
– AC/DC Adapter Present with
Programmable Voltage Threshold
– Low Input-Power Detect with Adjustable
Threshold and Hysteresis
– DPM Loop Active
– Current Drawn from Input Source
• Battery Discharge Current Sense with No
Adapter, or Selectable Low-Iq mode
• Supports Any Battery Chemistry: Li+, NiCd,
NiMH, Lead Acid, etc.
• Charge Enable
• 10-µA Off-State Current
• 28-pin, 5x5-mm QFN package
APPLICATIONS
• Notebook and Ultra-Mobile Computers
• Portable Data-Capture Terminals
• Portable Printers
• Medical Diagnostics Equipment
• Battery Bay Chargers
• Battery Back-up Systems
DESCRIPTION
The bq24740 is a high-efficiency, synchronous
battery charger with integrated compensation and
system power selector logic, offering low component
count for space-constrained multi-chemistry battery
charging applications. Ratiometric charge current
and voltage programming allows very high regulation
accuracies, and can be either hardwired with
resistors or programmed by the system
power-management microcontroller using a DAC or
GPIOs.
The bq24740 charges two, three, or four series Li+
cells, supporting up to 10 A of charge current, and is
available in a 28-pin, 5x5-mm thin QFN package.
CHGEN
ACN
ACP
LPMD
ACDET
ACSET
LPREF
28 27 26 25 24 23 22
1
21
2
20
3
bq24740
19
4
28 LD QFN
18
5
TOP VIEW
17
6
16
7
15
8 9 10 11 12 13 14
DPMDET
CELLS
SRP
SRN
BAT
SRSET
IADAPT
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 © 2006, Texas Instruments Incorporated