®
RT9485
Easy to Use Power Bank Solution (EZPBS
TM
) Integrated
Chip with Switch Charger, MCU, ADC, and Load Switch
General Description
The RT9485 is a high integration and easy to use power
solution for Li-ion power bank and other powered handheld
applications. We call it EZPBS
TM
(Easy to Use Power
Bank Solution). This single chip includes a Switching
Charger with OTG function, MCU, Analog to Digital
Converter (ADC), USBOUT Load Switch, Adapter Detection
with BC1.2, DCP controller and LDO. The battery volume
and the state of charging and discharging can be indicated
by 4LEDs.
Features
System
l
High Accuracy Voltage/Current Regulation
±1%
Charge Voltage Regulation
}
±
±0.1A
Charge Current Regulation
}
±
±3%
Boost Output Voltage Regulation
}
±
l
l
Thermal Shutdown Protection
Applications
l
Power Bank
Ordering Information
RT9485
Package Type
QV : VQFN-32L 4x4 (V-Type)
Lead Plating System
G : Green (Halogen Free and Pb Free)
Note :
Richtek products are :
}
RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
}
Marking Information
AB= : Product Code
AB=YM
DNN
YMDNN : Date Code
Reverse Leakage Protection to Prevent Battery
Drainage
l
Built-in USBOUT DCP Controller
l
Built-in USBOUT Attach/Detach Detection
l
Built-in USBOUT Light Load Detection
l
Built-in Load Switch with Current Regulation
Thermal Regulation and Output Short Current
Protection
l
Built-In Adapter Detection with BC1.2
l
Built-In Accurate ADC to Measure VBAT, VBUS, TS,
IBAT, USBOUT and IUSBOUT
l
Built-In LDO
l
OTP Based MCU
l
4 LED Driver Pin
l
Button Key
Charge Mode
l
Charge Voltage Regulation
l
Charge Current Regulation
l
Minimum Input Voltage Regulation (MIVR)
l
Average Input Current Regulation (AICR)
l
Thermal Regulation
l
VMID Under-Voltage Protection
l
VBUS Over-Voltage Protection
l
Battery Over-Voltage Protection
l
Battery Temperature Protection
Boost Mode
l
OTG Boost Current Up to 3A
l
Battery Under-Voltage Protection
l
VMID Over-Voltage Protection
Copyright
©
2018 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS9485-03 April 2018
www.richtek.com
1
RT9485
Pin Configuration
(TOP VIEW)
BOOT
VMID
LX
LX
PGND
PGND
TP1
TP2
32 31 30 29 28 27 26 25
USBOUT
USBOUT
VHMID
VBUS
VBUS
D-
D+
ISENSP
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
24
23
22
21
20
19
18
17
AGND
33
TP3
TYPE
LED4
LED3
LED2
LED1
RESET
BUTTON
Typical Application Circuit
RT9485
3
C1
1µF/25V
Input Power
Option
4, 5
R1
C2
1µF/25V
R2
DP
Q1
C4
1µF
6 D-
7 D+
32 BOOT
R3
10m
Ω
C5
2.2µF
L1
1µH
C6
10µF
C7
47nF
R10
2
C11
1nF
8 ISENSP
9
ISENSN
10
BATS
+
-
R
NTC
10k
AGND
14, 33 (Exposed Pad)
29, 30
15
VDDA
LED1
LED2
LED3
LX
LED4
BUTTON
RESET
TYPE
19
20
21
22
17
18
23
R8
R9
R4
R5
R6
R7
D1
D2
BAT+
D3
D4
13
C13
10nF
C3
1µF/25V
DM
VBUS
USBOUT
1, 2
C9
22µF/25V x 2
12
C12
10nF
VHMID
VMID
31
C8
22µF/25V x 2
ISENSN
BATS
TS
DM
DP
AGND
VDDA
VDD18V
VQFN-32L 4x4
Output Power
Battery Protect IC
11
TS
26
TP1
25
TP2
24
TP3
16
VDD18V
PGND
27, 28
C10
1µF
Copyright
©
2018 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
2
DS9485-03 April 2018
RT9485
Functional Pin Description
Pin No.
1, 2
3
4, 5
6
7
8
9
10
11
12
13
14,
33 (Exposed Pad)
15
16
17
18
19
20
21
22
23
24
25
26
27, 28
29, 30
31
32
Pin Name
USBOUT
VHMID
VBUS
D-
D+
ISENSP
ISENSN
BATS
TS
DM
DP
AGND
VDDA
VDD18V
BUTTON
RESET
LED1
LED2
LED3
LED4
TYPE
TP3
TP2
TP1
PGND
LX
VMID
BOOT
USB power output.
Internal use only.
VBUS power supply.
D- input for adapter detection.
D+ input for adapter detection.
Charging current sensing positive node.
Charging current sensing negative node and connect to battery plus
terminal.
Battery voltage sensing node.
Battery temperature detection pin.
DCP controller DM output.
DCP controller DP output.
Analog ground node. The exposed pad must be soldered to a large PCB
and connected to AGND for maximum power dissipation.
Internal power for analog blocks, put 1µF to GND.
External use LDO output.
Button detection pin.
Reset for internal use. Connect 10kΩ resister to ground.
Current sink output for LED1.
Current sink output for LED2.
Current sink output for LED3.
Current sink output for LED4.
General input pin for select battery charge voltage low is 4.2V and high
is 4.35V.
Test pin. Keep floating. (SCL).
Test pin. Keep floating. (SDA).
Test pin. Keep floating. (INT).
Power ground for switching charger.
Internal switch node to output inductor connection.
Connection point between reverse blocking and high-side.
Bootstrap power node for switching charger.
Pin Function
Copyright
©
2018 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS9485-03 April 2018
www.richtek.com
3
RT9485
Functional Block Diagram
VHMID
VBUS
VDDA
Analog Base
MOS
LDSW
Attach
/Detach
DCP
Control
2.7A SWCHG
3A OTG Controller
PGND
ISENSP
ISENSN
BATS
VDDA
Central Logic
Control
MCU
DP
DM
LED1
LED2
LED3
LED4
BUTTON
TYPE
RESET
TP1
TP2
TP3
VMID
USBOUT
BOOT
LX
TS
AGND
VBAT
D+
D-
Adapter
Detection
VBUS
ADC
IBAT
IUSBOUT
LDO 1.8V
VDD18V
USBOUT
Copyright
©
2018 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
4
DS9485-03 April 2018
RT9485
Operation
The RT9485 is a high integrated IC for Li-Ion battery power
bank. It includes a Switch charger 2.7A, a synchronous
Boost 5V.
Charge Current
Base on thermal regulation function, the charging current
can support up to 2.7A.
VBUS Over-Voltage Protection
If the input voltage (VBUS) is higher than the threshold
voltage VOVP, the internal OVP signal will go high and
the charger will stop charging until VIN is below V
OVP
-
hysteresis.
VMID Over-Voltage Protection
If the internal voltage (VMID) is higher than the threshold
voltage V
OVP
, the internal OVP signal will go high and the
charger will stop charging until VMID is below V
OVP
-
hysteresis.
VMID Under-Voltage Protection
If the internal voltage (VMID) is lower than the threshold
voltage VUVP, the internal VMID_UVP signal will go high
and the system will disable LDSW function in order to
protect system from short-to-ground current damages.
USBOUT SCP
The USBOUT short circuit protection (SCP) function will
prevent system from burning out by monitoring the voltage
drop between LDSW. If the USBOUT is short to ground,
the inrush current will make the VDS voltage too large to
damage chip. The SCP function also reports this condition
to protect chip in time.
Boost OCP
The converter senses the current signal when the high-
side P-MOSFET turns on. As a result, The OCP is cycle
by-cycle current limitation. If the OCP occurs, the converter
holds off the next on pulse until inductor current drops
below the OCP limit.
OTP
The converter has an over-temperature protection.
When the junction temperature is higher than the thermal
shutdown rising threshold, the system will be latched and
the output voltage will no longer be regulated until the
junction temperature drops under the falling threshold.
CC/CV/TR Multi Loop Controller
There are constant current loop, constant voltage loop and
thermal regulation loop to control the charging current.
Base Circuits
Base circuits provide the internal power, VDDA and
reference voltage and bias current.
Buck Regulator for Charging and Boost Regulator
as BOOST
The multi-loop controller controls the operation of charging
process and current supply to the system. It also controls
the circuits as a Boost converter for BOOST applications.
USB Charger Detection
The RT9485 detects USB Charger (Standard Charger Port,
Charging Downstream Port and Dedicated Charger Port)
via D+ and D- pins.
USBOUT Attach/Detach Detection
RT9485 includes an auto attach detection for the power
bank product. The attach detection has a current threshold
which represent an attach condition. When the attach
detection is enable, the USBOUT will generate a 1.6V to
monitor the load current. Once load current is greater than
5µA, the attach flag will be reported until the load current
is removed.
Embedded Micro-Controller
The MCU control the power bank behavior, decide the
operation mode for charging, discharging or relax. MCU
also detects the button press, battery type and control
LED flash function. It is use One Time Programmable (OTP)
memory, the power bank function can flexible adjust for
different application.
Copyright
©
2018 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS9485-03 April 2018
www.richtek.com
5
京公网安备 11010802033920号
EEWORLD
