bq24721

Features:

` High Efficiency NMOS-NMOS Synchronous Buck Converter With User-Selectable 300 kHz or 500 kHz frequency
` SBS-Like ⁽¹⁾ SMBus Interface for Control and Status Communications With Host
` Programmable Battery Voltage, Charge Current, and AC Adapter Current via SBS-Like SMBus Interface
` 0.4% Charge Voltage Regulation Accuracy
` 3% Charge Current Regulation Accuracy
` 3% Adapter Current Regulation Accuracy Dynamic Power Management (DPM)
` 2% Accuracy Integrated Charge and AC Adapter 20x Current Amplifier Output
` Battery Pack Voltage Range 0 V 19.2 V
` AC Adapter Operating Range 8 V 28 V
` 99.5% Max Duty Cycle
` Internal Soft Start
` Integrated 5% 5-V LDO When AC Adapter Applied
` 6-V Drive Supply Voltage for Increased Efficiency
` Reverse Battery to Adapter Discharge Protection
` Battery/Adapter to System Power Selector Function
` Charge and Adapter Overcurrent Protection
` Battery Thermistor Sense, TS, Comparators
` Available in 32-Pin 5x5mm QFN Package




Application

· Portable Notebook Computers
· Portable DVD Players
· Webpads, PC Tablets




Pinout








Specifications

PARAMETER	PIN	VALUE / UNIT
Supply voltage range	ACN, ACP, PVCC, ACDRV, SYNN, SYNP, SRP, SRN , BATDRV, BAT, BYPASS, SYS, VCC	0.3 V to 30 V
	PH	1 V to 30 V
	LODRV, REGN, FBO, EAI, EAO, ISYNSET, CHGEN, TS ,VREF5, ACDET, IOUT, ALARM, SCL, SDA	0.3 V to 7 V
	BTST, HIDRV (with respect to AGND and PGND)	1 V to 36 V
Maximum differential voltage	AGND-PGND	0.3 V to 0.3 V
Maximum difference voltage	ACPACN , SRPSRN, and SYNPSYNN	0.6 V
Maximum voltage with respect to VCC	SRN, SRP, SYNN, SYNP, BAT, PH	20 V to 30 V
Maximum difference voltage	PVCC-BAT, SYSBAT	20 V to 30 V
Operating ambient temperature range (TA)		40 to 85
Maximum junction temperature (TJ_MAX)		150
Storage temperature range (Tstg)		65 to 150

(1) Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

(2) All voltages are with respect to AGND, unless otherwise noted. Currents are positive into, negative out of the specified terminal. Consult Packaging Section of the Databook for thermal limitations and considerations of packages.




Description

The bq24721 is a simple to use, high efficiency synchronous battery pack charger with high level of integration for portable applications. This device implements a high performance analog front-end that easily interfaces to the system power management micro-controller through a simplified SBS-like SMBus interface.

Features of the IRFP150N are:(1)high efficiency NMOS-NMOS synchronous buck converter with user-selectable 300 kHz or 500 kHz frequency; (2)SBS-like SMBus interface for control and status communications with host; (3)programmable battery voltage, charge current, and AC Adapter current via SBS-like smbus interface; (4)0.4% charge voltage regulation accuracy; (5)3% charge current regulation accuracy; (6)3% adapter current regulation accuracy dynamic power management (DPM); (7)2% accuracy integrated charge and AC adapter 20x current amplifier output; (8)battery pack voltage range 0 V 19.2 V.

The absolute maximum ratings of the IRFP150N can be summarized as:(1)maximum differential voltage:0.3 V to 0.3 V:100V;(2)storage temperature range:-65 to 150;(3)maximum difference voltage:0.6 V;(4)maximum voltage with respect to VCC:-20 to 30 V;(5)operating temperature:-40 to 85;(6)maximum difference voltage:-20 to 30 V.Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.The voltage loop regulates the battery voltage to the programmed value, and prevents the voltage from exceeding that value when the battery is connected. The charge current loop regulates the battery charge current to the programmed value, and prevents the charge current from exceeding that value. Through the use of dynamic power management (DPM), the input current loop regulates the battery charge current to the programmed value, and prevents the input current from exceeding that value. The three regulation loops operate independently, yet only require a single loop compensation network.

The bq24721 is a simple to use, high efficiency synchronous battery pack charger with high level of integration for portable applications. This device implements a high performance analog front-end that easily interfaces to the system power management micro-controller through a simplified SBS-like SMBus interface.

The dynamic power management (DPM) function 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 an external MOSFET using a control signal provided by the bq24721, thus reducing overall power dissipation.

Integrated features such as charger soft start, charge overcurrent protection, and IC temperature monitoring provide a second level of protection, in addition to pack and system protection functions.