Texas Instruments bq24720 EVM, Руководство пользователя, Страница: 2 / 34

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1 Introduction
1.1 EVM Features
1.2 General Description
1.3 I/O Description
Introduction
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Evaluation Module For Both bq24720 and bq24721
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High Efficiency NMOS-NMOS Synchronous Buck Charger With User-Selectable 300 kHz or 500 kHz
Frequency
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Battery/Adapter to System Power Selector Function
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SBS-Like SMBus Interface for Control and Status Communications With Host
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Programmable Battery Voltage, Charge Current, and AC Adapter Current via SBS-Like SMBus
Interface
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Battery Pack Voltage Regulation Range up to 19.2 V
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AC Adapter Operating Range 13 V–24 V
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Charge and Adapter Overcurrent Protection
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Charge Peak Current up to 14 A. Charge Average Current up to 7 A
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LED Indication for AC Adaptor Connection, Power Path Conduction, Charge Enable and Alarm Signal
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Test Points for Key Signals Available for Testing Purpose. Easy Probe Hook-up
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Jumpers Available. Easy to Change Connections and Enable (or Disable) Charge
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May Be Used with TI bq2472x SMB Evaluation Software
The bq24720/21 evaluation module is a complete charger module for evaluating a multi-cell synchronous
notebook charge and path selection solution using the bq24720/21 devices. It is designed to deliver up to
9 A of charge current to Li-Ion or Li-Pol applications.
The bq24720/21 has a highly integrated battery charge controller designed to work with external host
commands. The battery voltage, charge current, and other system parameters are programmable via
SBS-like SMBus interface.
The dynamic power management (DPM) function SMBus Interface modifies the charge current depending
on system load conditions, avoiding ac adapter overload.
High accuracy current sense amplifiers enable accurate measurement of either the charge current or the
ac adapter current, allowing termination of nonsmart packs and monitoring of overall system power.
The adapter isolation diode can be bypassed with external an MOSFET using a control signal provided by
the bq24720/21, thus reducing overall power dissipation.
For details, see the bq24720 data sheet ( SLUS668 ) and the bq24721 data sheet ( SLUS683 ).
Jack Description
J1–POS AC adapter, positive output
J1–GND AC adapter, negative output
J2–POS External power supply, positive output
J2–GND External power supply, negative output
J3–REF VREF5 pin (11) output
J3–CHGEN CHGEN pin (1) output
J3–SDA SDA pin (13) output, SMBus data line
J3–SCL SCL pin (14) output, SMBus clock line
J4–ALARM ALARM pin (25) output
J4–IOUT IOUT pin (17) output
J4–GND Ground
2 bq24720/21 EVM (HPA104) for Multi-Cell Synchronous SLUU237 – January 2006
Switch-Mode Charger With System Power Selector and SMBus SBS-Like Interface