ETA9741

2A Switching Charger, 2.4A Boost and Fuel Gauge with Single Inductor

DESCRIPTION FEATURES
ETA9741 is a switching Li-Ion battery charger capable of  Bi-Directional Power conversion with Single
delivering 2A of charging current to the battery and also capable Inductor
of delivering up to 5V/2.4A in boost operation, with high efficiency  Automatic Mode Switching
in both charging mode and boost mode. It also includes a fuel  Switching Charger
gauge system for power indication. For charging, it uses a  5V Synchronous Boost
proprietary control scheme that eliminates the current sense  Up to 96% Efficiency
resistor for conventional constant current control, maximizing  2A charging current and 2.4A discharging
efficiency, reducing charging time and reducing costs. It can also  No-Battery detection
output a 5V voltage in the reversed direction by boosting from the  No External Sense resistor
battery. It only needs a single inductor to provide power bi-  4 LEDs Fuel gauge
directionally with a proprietary automatic mode detect and  Button Controlled
switch scheme. ETA9741 is an ideal all-in-one solution for battery
charging and discharge applications, such as power banks, smart
phones, and tablets with only one USB port that can be used for APPLICATIONS
charging battery function.  Tablet, MID
 Smart Phone
ETA9741 is suitable for charging a 4.2V Li-ion battery. And ETA9741  Power Bank
is in ESOP8 package.

TYPICAL APPLICATION

ORDERING INFORMATION PART No. PACKAGE TOP MARK Pcs/Reel

ETA9741E8A ESOP8 ETA9741 4000

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ETA9741

PIN CONFIGURATION ABSOLUTE MAXIMUM RATINGS

(Note: Exceeding these limits may damage the device. Exposure to absolute maximum
rating conditions for long periods may affect device reliability.)

OUT, SW Voltage ..........................................................–0.3V to 6V

All Other Pin Voltage ..................................................–0.3V to 6V
SW to ground current……………………..…………...Internally limited
Operating Temperature Range …………………....…–40°C to 85°C
Storage Temperature Range ……..……….………….–55°C to 150°C
Thermal Resistance JA Jc
ESOP8 …………………………………………...10……………50............ °C/W
Lead Temperature (Soldering, 10ssec) ……………………….260°C
ESD HBM (Human Body Mode) …………….………………..………….2KV
ESD MM (Machine Mode) ……………………..………………………….200V

ELECTRICAL CHACRACTERISTICS
(VIN = 5V, unless otherwise specified. Typical values are at TA = 25oC.)

PARAMETER CONDITIONS MIN TYP MAX UNITS

BUCK MODE
USB Range 4.5 5.5 V
USB UVLO Voltage Rising, Hys=500mV 4.5 V
Switcher Enable, Switching 5 mA
USB Operating Current as BUCK
Switcher Enable, No Switching 800 μA
BATTERY CHARGER
Battery CV Voltage IBAT =0mA, default 4.17 4.21 4.25 V
Charger Restart Threshold From DONE to Fast Charge -160 mV
Battery Pre-Condition Voltage VBAT Rising Hys=250mV 2.8 V
Pre-Condition Charge Current 200 mA
Fast Charge Current 2 A
Charge Termination Current 200 mA
Charge Termination Blanking time 16 S
BOOST MODE
BATT Ok Threshold Rising, HYS=0.4 V 3.2 V
Output Voltage Range Iout=0 5.05 5.1 5.15 V
Quiescent Current At BATT Vbat=3.6V 80 μA
Switching Frequency VIN<4.3V 550 650 750 KHz
Inductor Peak Current Limit 5.0 A
Maximum Duty Cycle 90 %
High side Pmos Rdson ISW =500mA 75 mΩ
Low side Nmos Rdson ISW =500mA 70 mΩ

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ETA9741
PARAMETER CONDITIONS MIN TYP MAX UNITS
Short Circuit Hiccup Current 3.8 A
On Time 45
Short Circuit Hiccup Timer ms
Off Time 2000
o
Charging Thermal Regulation threshold 85 C
o o
Thermal Shutdown Rising, Hys=20 C 150 C

PIN DESCRIPTION

PIN # NAME DESCRIPTION

1 SW Inductor Connection. Connect an inductor Between SW and the regulator output
2 LED1 Fuel gauge LED1, LED2 connection pin
3 LED2 Fuel gauge LED3, LED4 connection pin
4 LED3 Fuel gauge LED1, LED2, LED3, LED4 connection pin
5 Button Push Button pin. When the push button is pushed, LED 4 LEDs Fuel gauge are lighted.
6 BAT Battery pin. Connect a Battery to this pin, and with a bypass capacitor 10uF.
7 OUT Output pin. Bypass with a 22uF or larger ceramic capacitor closely between this pin
and GND
8 PGND Power Ground Pin
9 / Exposed Pad AGND Analog Ground Pin

TYPICAL CHARACTERISTICS
(Vin=5V, TA=250C, unless otherwise specified)
100%
2.5
99%
VIN=5V,ICHARGER=2.2A VIN=5V,ICHARGER=2.2A
98%
2
97%
96%
Icharger (A)
Efficiency

1.5
95%
94% 1
93%
92% 0.5
91%
90% 0
2 2.5 3 3.5 4 4.5 0 1 2 3 4 5
Iout (A) Vout (V)

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