IP6816

TWS Bluetooth Earphone Charging Box SOC

integrated with Qi wireless power reciever
 In-depth customization
1. Features  Flexible and low-cost customized program
 Package: QFN16 (4*4*0.75mm)
 Discharge
 Output capacity: 5V/300mA 2. Applications
 Up to 93%@5V/150mA discharge efficiency
of synchronous switch  TWS Bluetooth Earphone Charging Box
 Built-in power path management supports  Lithium Battery Portable Device
charging and discharging at the same time
 Charge
3. Description
 Max 500mA linear charger, adjustable IP6816 is a multi-functional power management
charging current SOC for total solution on TWS Bluetooth Earphone
 Adjusts charging current automatically to Charging Box. It integrates with Qi wireless power
adapt to different load capacity adapters receiver, 5V-boost converter, lithium battery charging
 Supports 4.20V, 4.30V 4.35V, 4.40V batteries management and battery level indicators.
 Supports wireless power receiver compliant IP6816 is highly integrated with abundant
with Qi functions, which makes the total solution size
 Battery indicators minimized and BOM costed down.
 Built-in 10bits ADC , accurate calculation of The synchronous 5V-boost system of IP6816
battery capacity provides rated 300mA output current with conversion
 Supports 4/3/2/1 LED battery indicator efficiency up to 93%. DC-DC converter operates at
 Low-power dissipation 1.5MHz, and can support low-cost inductors and
 Automatically detect earphone plugged-in/ capacitors.
plugged-out/charger-end, Automatically IP6816’s linear charging system supplies max
enter standby mode 500mA charging current. With the change of IC
 Support detection of earphone temperature and input voltage, IP6816 can
plug-in/plug-out independly automatically adjust the charging current.
 Standby power consumption up to 25ua IP6816 can detects the TWS earphone
minimum plug-in/plug-out in the Chargering Box independently.
 Simplified BOM While the earphone is put in the Chargering Box, it
 Built-in power MOS, only a few peripheral enters the discharging mode automaticaly. When the
devices are needed in the complete charging earphone is fully charged, the Chargering Box
and discharging scheme automatically enters the sleep state, and the standby
 Multiple protection, high reliability current can be reduced to 30uA. The earphone’s
 Output：over current and short circuit charge-end current can be Flexible and customizable,
protection such as 4mA or 8mA.
 Input：over voltage and Battery over charged IP6816 can support 1/2/3/4 LED battery indicator,
protection The built-in 10bits ADC can accurately calculate the
 Over temperature protection Chargering Box’s battery capacity.
 Vin pin can withstand up to 15V(transient IP6816 is packaged with QFN16(4*4*0.75mm).
voltage)
 ESD 4KV

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 IP6816
C7
耳机1

R8
+
C8 BAT
耳机2 -
C1

R9

VOUT

GND
VCC
PH2

LX
VIN

13
15

14
16 D5

17
C9 R10
PH1 BAT
IO2
1 12

KEY VIN R11

2 11 Micro USB
IP6816 D4
QFN16 R4
EN 3 10 LED4
SW
IO1 9 LED3
4
R3
D3
R16
5

D2 R17
LED1

LED2
IO3
IO2

V+
1 BAT+
R2 2 GND
V-
R1 D1 Out 3 EN
Rntc R7
HALL

C2
R12
C3 IO1 VIN
R14
C4 C10
N3
C5 N1 R5 D6 NMOS
NMOS
D9 D7
C6 VIN
NC
N2 R6 D10 D8
NMOS NMOS
C11 N4 R13
R15

Figure1 IP6816 Simplified Application Diagram

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 IP6816
4. Pin Definition

VOUT
GND

VCC
PH2

LX
17

15

14
16

13
PH1 BAT
1 12

KEY VIN
2 11
IP6816
EN QFN16 LED4
3 10

IO1 LED3
4 5 9

8
LED1

LED2
IO3
IO2

Figure 2 IP6816 Pin Assignments

Pin Num Pin Name Description

1 PH1 Earphone 1 negative
2 KEY Key input
3 EN HALL switch output signal , customization individually
4 IO1 Wireless power reception control pin
5 IO2 Wired/wireless charging recognition pin
6 IO3 NTC pin
7 LED1 LED driver pin1
8 LED2 LED driver pin2
9 LED3 LED driver pin3
10 LED4 LED driver pin4
11 VIN 5V input pin
12 VBAT Battery voltage positive pin
13 VCC LDO output pin, connect to 2.2uF inductor
14 LX DCDC switch node
15 VOUT Boost output
16 PH2 Earphone 2 negative
17 GND System ground

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 IP6816
5. IP Series Products List

6. Absolute Maximum Ratings

Parameter Symbol Value Unit
Input Voltage Range VIN -0.3 ~ 15 V
Junction Temperature Range TJ -40 ~ 150 ℃
Storage Temperature Range Tstg -60 ~ 150 ℃
Thermal Resistance
θJA 50 ℃/W
(Junction to Ambient)
ESD (Human Body Model) ESD 4 KV
*Stresses beyond these listed parameter may cause permanent damage to the device.
Exposure to Absolute Maximum Rated conditions for extended periods may affect device reliability.

7. Recommended Operating Conditions

Parameter Symbol Min. Typ. Max. Unit

Input Voltage VIN, VBUS 4.5 5 6.0 V

Operating Temperature TA 0 -- 70 ℃
*Devices’ performance cannot be guaranteed when working beyond those Recommended Operating
Conditions.

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 IP6816
8. Electrical Characteristics
Unless otherwise specified, TA=25℃，L=1uH
Parameter Symbol Test Conditions Min. Typ. Max. Unit

Charging System

Input Voltage VIN VBAT=3.7V 4.5 5 6.0 V

Input Over Voltage VINOV 10 12 15 V

VIN activation voltage VINOk 3.0 3.2 3.4 V

Input Under Voltage VINUV 4.0 4.2 4.4 V

CV4.2V 4.2V battery 4.15 4.20 4.24 V

CV4.30V 4.3V battery 4.28 4.30 4.34 V

Constant Charge Voltage
CV4.35V 4.35V battery 4.33 4.35 4.4 V

CV4.4V 4.4V battery 4.38 4.40 4.44 V

Charge Stop Current Ivinstop VIN=5V 10 15 20 mA

VIN=5V, VBAT=3.7V,
Charge Current IVIN 260 300 340 mA
Set the charge current=300mA
Trickle Charge Current ITRKL VIN=5v，BAT=2.7v 20 25 30 mA
Trickle Charge Stop
VTRKL 2.9 3 3.1 V
Voltage
Recharge Voltage
VRCH 4.07 4.1 4.13 V
Threshold
Charge Cut-Off Time TEND 20 24 28 Hours
Boost System

BatteryOperation Voltage VBAT 3.0 3.7 4.4 V

Low Power Shutdown
VBATLOW IOUT=200mA 2.9 2.95 3.0 V
Voltage
VBAT=3.7V,VOUT=5.0V,
Switching battery input
IBAT fs=1.5MHz(without LED indicator， 4 6 mA
current
VOUT without load)
VBAT=3.7V @0A 5.0 5.05 5.15 V
DC Output Voltage VOUT
VBAT=3.7V @200mA 4.75 5.00 5.15 V

Output Voltage Ripple ΔVOUT VBAT=3.0V~4.4V 50 100 150 mV

Boost Output Current Ivout VBAT=3.0V~4.4V 0 300 mA

Boost Overcurrent Shut Ishut VBAT=3.0V~4.4V 0.7 0.8 0.9 A

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 IP6816
Down Threshold

Load Overcurrent Detect Duration of output voltage under

TUVD 30 ms
Time 4.2V
Control System

Switch Frequency fs Discharge switch frequency 1.3 1.5 1.6 MHz

PMOS On Resistance 450 mΩ

rDSON
NMOS On Resistance 330 mΩ
VCC = VBAT.
(When no VBAT is connected，only
VBAT-
Vcc Voltage VCC VIN supplys power and the VBAT VABT V
0.1
charger is disabled, then the VCC
is 3.3V)
Battery Input Standby
ISTB1 VIN=0V，VBAT=3.7V 20 27 35 uA
Current
Battery Input Standby VIN=0V，VBAT=3.7V,support hall
ISTB2 30 35 40 uA
Current 2 switch
IO Driving Current IGpio 4 6 8 mA
Light Load Shut Down
TloadD Load current less than 4mA 5 6 8 s
Detect Time
VBAT=3.7V, The load current of
Light Load Shut Down
Iplout both headphones must be less 3 4 5 mA
Current
than Iplout to shut down.
Short Press On Key Wake TOnDebou
100 300 ms
Up Time nce

Long Press On Key Wake

TKeylight 2 3 s
Up Time
Thermal Shut Down
TOTP Rising temperature 130 140 150 ℃
Temperature
Thermal Shut Down
ΔTOTP 30 40 50 ℃
Hysteresis

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 IP6816
9. Function Description

System Diagram

2.2uH
5V
+
-
BAT LX VOUT

VCC

TWS

Boost
LDO Linear
Control
Chager

VIN

V[BAT]
IP6816 PH1

V[VIN]
V[PH1] ADC
V[PH2]
V[IOx] PH2
MCU

IO1
Qi RX
编码
IO2
IO3 GND

LED1 LED2 LED3 LED4 EN KEY

Figure 3 IP6816 Internal System Diagram

Boost

IP6816 integrates a boost dc-dc converter with 5V/300mA output, 1.5MHz switching frequency. To avoid
large rush current causing device failure , it is built in overcurrent, short circuit, overvoltage and over temperature
protection function, ensuring the reliability and stability of system operation. .

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 IP6816
IP6816 Boost Efficiency
n(%)
100
95
90
85 3.1V
80 3.3V
75 3.5V
70
3.7V
65
3.9V
60
4.1V
55
50 4.3V

45
40
0 50 100 150 200 250 300 Iout(mA)

Figure 4 IP6816 Boost Efficiency Curve

Vout(mV)
IP6816 Boost V-I
5300

5100

4900
3.1V
4700 3.3V
4500 3.5V

4300 3.7V
3.9V
4100
4.1V
3900
4.3V
3700

3500
0 50 100 150 200 250 300 Iout(mA)

Figure 5 IP6816 Boost Output V-I Curve

Charge

IP6816 integrates a linear lithium battery charger. When the battery voltage is less than 3V, precharge with
0.1 CC; when the battery voltage is greater than 3V, enter constant current(CC) charging; when the battery voltage
is close to 4.2V/4.3V/4.35V/4.4V, enter constant voltage charging. When the charging is accomplished, once the
battery voltage falls under 4.1V, battery charging stage will be restarted.
IP6816 supports max 500mA charging, with change of the IC temperature and input voltage, IP6816 can

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 IP6816
intelligently adjust charging current.
IP6816 can select the constant current charging current of the battery by connecting different
resistors on the IO2 pin..

2.2uH

BAT LX VOUT

VIN CHARGER
BOOST

Figure6 IP6816 Power Path Diagram

Qi wireless power receive charging

IP6816 supports the Qi protocol wireless charging reception function. The resonant capacitor of the wireless
receiving function needs to be adjusted according to the coil inductance. Please contact INJOINIC Support
Department directly.
When the device is wired charging and put on the wireless charging TX, the IP6816 preferentially uses wired
charging, and the wireless charging receiving function is actively turned off.

Coulombmeter and battery level display

IP6816 has a built-in power algorithm, which can accurately display the remaining battery power according to
the cell capacity.
IP6816 can support 1/2/3/4 LED battery indicator, and the system can automatically identify several LED
modes.

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 IP6816
LED light display mode

D1 100R
LED1
D2 100R
4 LED Mode LED2
D3 100R
LED3
D4 100R
LED4

D1 100R
LED1
D2 100R
3 LED Mode LED2
D3 100R
LED3

LED4 VCC

D1 100R
LED1
D2 100R
2 LED Mode LED2

LED3

LED4 VCC

D1 100R
LED1

1 LED Mode LED2

LED3

LED4 VCC

Figure 7 LED Mode Seleciton Circuit

 4 LED Mode
Discharge
Battery capacity(c)(%) LED1 LED2 LED3 LED4

C≥75% on on on on

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 IP6816
50%≤C＜75% on on on off

25%≤C＜50% on on off off

3%≤C＜25% on off off off

0%＜C＜3% 1Hz blink off off off

Charge
Battery capacity(c)(%) LED1 LED2 LED3 LED4

full on on on on

75%≤C on on on 0.5Hz blink

50%≤C＜75% on on 0.5Hz blink off

25%≤C＜50% on 0.5Hz blink off off

C＜25% 0.5Hz blink off off off

 3 LED Mode
Discharge
Battery capacity(c)(%) LED1 LED2 LED3

C≥66% on on on

33%≤C＜66% on on off

3%≤C＜33% on off off

0%＜C＜3% 1Hz blink off off

Charge
Battery capacity(c)(%) LED1 LED2 LED3

75%≤C on on on

66%≤C＜100% on on 0.5Hz blink

33%≤C＜66% on 0.5Hz blink off

C＜33% 0.5Hz blink off off

 2 LED Mode
state LED1 LED2
charge charging 0.5Hz 闪烁 off
full on off
discharge dischareging off on
low off 1Hz blink

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 IP6816
 1 LED Mode
state LED1
charge charging 0.5Hz blink

full on
discharge dischareging on
low 1Hz blink

NTC

IP6816 support NTC function used for battery temperature detection. NTC pin outputs 20uA
current then detects the voltage on NTC resistance to determine the present battery temperature.

6
IO3

R7 Rntc
82K 100k@25度
B=3950

Figure8 NTC circuit

Under charging state:
Voltage on NTC resistance is higher than 1.3V meaning the battery temperature is under 0 centigrade, then
stop charging the battery;
Voltage on NTC resistance is lower than 0.5V meaning the battery temperature is above 50 centigrade,
then stop charging the battery;
Under discharging state:
Voltage on NTC resistance is higher than 1.47V meaning the battery temperature is under -15 centigrade,
stop discharging;
Voltage on NTC resistance is lower than 0.44V meaning the battery temperature is above 55 centigrade,
stop discharging.
If NTC function is not required in the scheme, the IO3 pin shall be connected 51K to GND. IO3 pin shall not
float, otherwise abnormal charging and discharging may be caused.

plug-in/plug-out detection

Once detecting the insertion of the earphone, the IP6816 wakes up from the standby mode and turns on the
boost 5V to charge the earphone, eliminating the button operation and supporting the buttonless mold solution.
The IP6816 supports light-load auto standby function. When the earphone’s load current on PH1 and PH2 are less
than 4mA for 16 seconds, IP6816 will automatically enter standby mode. In the standby mode, the VOUT pin
voltage has three configurations: 5V, VBAT, and 2.4V. The standard standby VOUT output voltage is 2.4V, and other

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 IP6816
specifications need to be customized separately.
When the earphones are charged end, the IP6816 will enter standby mode and the VOUT output will change
to 2.4V. In this case,in order to make the earphones also enter power-saved mode, You need to adjust the
resistance R8/R9 on PH1/PH2. Taking PH1 as an example, the adjustment method is as follows:
1. R8 default resistance is 100K
2. If IP6816 can enters standby mode , but the earphone cannot enter the standby mode, then gradually
reduce the R8.
3. If IP6816 can enters standby , but it can not be waked up by the earphone’s plug-in, then gradually increase
the R8.
4. Repeat steps 2/3 until you find a suitable resistor R8, which makes IP6816 can enter standby mode, and
the earphone can enter stanby mode,and IP6816 can be waked up by the plug-in of earphone.

VOUT

Earphone1

PH1

R8

NMOS1

Figure9 IP6816 Earphone Standby Resistance Adjustment Diagram

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 IP6816
10. Typical Application Diagram
C7 4.7uF
耳机1

R8
C8 +
C1 BAT
耳机2 10uF -
2.2uH 2.2uF
R9 VOUT

GND
VCC
PH2

LX VIN

13
15

14
D5
16

17
C9 R10
10uF IO2 1K
PH1 BAT
1 12
R11
KEY
2 11 VIN D4 5.1K Micro USB
IP6816 100%
QFN16 R4
EN LED4
3 10

IO1 4 9 LED3
SW
R3 D3
R16 75%
10K
5

D2 R17 51R
50% 1 BAT+
LED1

LED2
IO3
IO2

V+
R2 V- 2 GND

Out 3 EN
Rntc R7 R1 D1
25% HALL

C2 AC1
R12
C3 C10 IO1 VIN AC2
R14
C4 22nF N3 R18
R5 D6 2.2R N5 D9 D7
C5 N1 NMOS
NMOS 1K 10V NMOS
C6 VIN
NC R6
N2
NMOS 5.1K N6
NMOS D10 D8
N4 NMOS
C11 R13 R19
22nF AC1 2.2R
R15
1. Adjust R1/2/3/4 according to the LED light brightness. AC2
2. When NTC function is supported, R7=82K , Rntc=100K@25°C, B=3950.
When NTC function is not supported, R7=51K , Rntc is floating.
3. Please adjust R8/R9 according to different Bluetooth earphone solutions
4. N1/N2/N3/N4 are withstand voltage 20V NMOS, transient current maximum 5A, constant current 1A
5. D5/D7/D8/D9/D10 are Schottky diode, constant current 1A
6. D6 is 10V Zener Diode
7. C2/C3/C4/C5 value should be according to different coil inductance values
8. R12/R14/R13/R15 value should be according to different coil inductance values
9. If Hall element is supported, R16 requires NC
10.The D9/D10 can be replaced with NMOS (N5/N6) in the red dashed box to improve wireless charging
efficiency and reduce heat

Figure10 IP6816 Typical Application Diagram

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 IP6816
11. Package

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 IP6816

12. Mark description

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 IP6816
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