6 Pin Configuration and Functions

Figure 6-1 RTE Package16-Pin WQFNTop View

Table 6-1 Pin Functions

PIN		I/O⁽¹⁾	DESCRIPTION
NAME	NO.	I/O⁽¹⁾	DESCRIPTION
VBUS	1	P	Charger Input Voltage. The internal n-channel reverse block MOSFET (RBFET) is connected between VBUS and PMID with VBUS on source. Place a 2.2uF ceramic capacitor from VBUS to GND and place it as close as possible to IC.
PMID	16	P	Connected to the drain of the reverse blocking MOSFET (RBFET) and the drain of high-side MOSFET (HSFET). Place ceramic 10μF on PMID to GND and place it as close as possible to IC.
SW	13,14	P	Switching node. Connected to output inductor. Internally SW is connected to the source of the n-channel HSFET and the drain of the n-channel LSFET. Connect the 0.047μF bootstrap capacitor from SW to BTST.
BTST	15	P	High-Side FET Driver Supply. Internally, the BTST is connected to the cathode of the internal boost-strap diode. Connect the 0.047μF bootstrap capacitor from SW to BTST.
GND	11,12	P	Ground. Connected directly to thermal pad on the top layer. A single point connection is recommended between power ground and analog ground near the IC GND pins.
REGN	2	P	Low-Side FET driver positive supply output. Connect a 2.2μF ceramic capacitor from REGN to GND. The capacitor should be placed close to the IC.
BAT	10	AI	Battery Voltage Sensing Input. Connect this pin to the positive terminal of the battery pack and the node of inductor output terminal. 10-µF capacitor is recommended to connect to this pin.
TS	7	AI	Battery Temperature Protection Voltage Input. Connect a negative temperature coefficient thermistor (NTC). Program temperature window with a resistor divider from REGN to TS and TS to GND. Charge suspends when TS pin voltage is out of range. When TS pin is not used, connect a 10-kΩ resistor from REGN to TS and a 10-kΩ resistor from TS to GND. It is recommended to use a 103AT-2 thermistor.
ICHG	4	AI	Charge current program input. Connect a 1% resistor RICHG from this pin to ground to program the charge current as ICHG = K_ICHG / R_ICHG (K_ICHG = 40,000). No capacitor is allowed to connect at this pin. When ICHG pin is pulled to ground or left open, the charger stop switching and STAT pin starts blinking.
STAT	3	AO	Charge Status Indication Output. This pin is open drain output. Connect this pin to REGN via a current limiting resistor and LED. The STAT pin indicates charger status as: Charge in progress: STAT pin is pulled LOW Charge completed, charge disabled by EN: STAT pin is OPEN Fault conditions: STAT pin blinks.
VSET	9	AI	Charge Voltage Setting Input. VSET pin sets battery charge voltage. Program battery regulation voltage with a resistor pull-down from VSET to GND: Floating (R > 200kΩ±10%): 4.1V Shorted to GND (R < 510Ω): 4.2V R = 51kΩ ± 10%: 4.35V R = 10kΩ ± 10%: 4.4V The maximum allowed capacitance on this pin is 50pF.
POL	5	AI	This pin must be floating.
EN	6	AI	Device Disable Input. The device is enabled with EN pin floating or pulled low. The device is disabled if EN pin is pulled high.
NC	8	-	No connection. Keep this pin floating or grounded.
Thermal Pad	17	-	Ground reference for the device that is also the thermal pad used to conduct heat from the device. This connection serves two purposes. The first purpose is to provide an electrical ground connection for the device. The second purpose is to provide a low thermal-impedance path from the device die to the PCB. This pad should be tied externally to a ground plane. Ground layer(s) are connected to thermal pad through vias under thermal pad.

(1) AI = Analog input, AO = Analog Output, AIO = Analog input Output, DI = Digital input, DO = Digital Output, DIO = Digital input Output, P = Power