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RT9986A
7-CH DC/DC Converter for DSC
General Description
Features
The RT9986A is a complete power supply solution for
digital still cameras and other handheld devices. It includes
one synchronous step-up DC/DC converter with load
disconnect, one selectable synchronous step-up/stepdown DC/DC converter, two synchronous step-down DC/
DC converters, one synchronous high voltage step-up DC/
DC converter, one inverting DC/DC converter, and one
selectable synchronous high voltage step-up/currentsource for WLED. In addition, the RT9986A also includes
one RTC_LDO, one voltage detector, and one System
Reset. All power MOSFETs are integrated in the RT9986A.
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CH2 Step-Up/Step-Down Auto-Selected by External
Topology
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Preset On/Off Sequence of CH1, CH2, CH3, CH4
(1 → 3 → 4 → 2)
Preset On/Off Sequence of CH5, CH6 (5 → 6)
The RT9986A is designed to fulfill the applications for DSC
as follows :
CH1 is a synchronous step-up output for motor or DSC
system I/O power
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CH2 is a selectable synchronous step-up/step-down
output for motor or DSC system I/O power
CH3 and CH4 are synchronous step-down outputs for DSP
core and memory power supply
CH5 is a synchronous high voltage step-up output for CCD
bias power supply
CH6 is an inverting output for negative CCD bias power
supply
CH7 is a selectable synchronous high voltage step-up/
current source for driving WLED
The selectable step-up/step-down converter can be auto
selected by external component topology. For the
RT9986A, all 7-CHs have built in internal compensation.
The RT9986A also provides a transformerless inverting
converter for supplying CCD power. For the low voltage
synchronous step-up and step down converters, efficiency
can be up to 95%.
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All Channels with Internal Compensation
All Power Switches Integrated
All Step-Up Converter with Load Disconnect
Step-Down DC/DC Converter
` Up to 95% Efficiency
` 100% (max) Duty Cycle
Low Voltage Step-Up DC/DC Converter
` Adjustable Output Voltage
` Up to 95% Efficiency
WLED Driver
` Auto-Selected by External Topology
` Current Source Mode with 30mA DC Current
` Step-Up Mode with LED Open Protection (OVP7)
` Direct PWM Dimming Control
Fixed 2MHz Switching Frequency for CH1/2/3/4,
Fixed 1MHz Switching Frequency for CH5/6/7
Small 32-Lead WQFN Package
RoHS Compliant and Halogen Free
Applications
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Digital Still Camera
PDA
Portable Devices
Marking Information
EZ= : Product Code
EZ=YM
DNN
YMDNN : Date Code
The RT9986A provides comprehensive protection features
including over current protection, thermal shutdown
protection, over voltage protection, overload protection,
and under voltage protection.
DS9986A-00 May 2011
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1
RT9986A
Ordering Information
Pin Configurations
RT9986A
EN56
LX1
PVDD1
BAT
LX6
PVDD2
LX2
EN1234
(TOP VIEW)
Package Type
QW : WQFN-32L 4x4 (W-Type)
Note :
Richtek products are :
`
RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.
`
Suitable for use in SnPb or Pb-free soldering processes.
32 31 30 29 28 27 26 25
FB1
VREF
FB6
VOUT6
FB7
PVDD7
LX7
EN7
1
24
2
23
3
4
5
6
22
21
GND
20
19
33
7
18
8
17
FB2
SYSR
RTCPWR
VDDM
LX5
PVDD5
FB5
RST
9 10 11 12 13 14 15 16
LX4
PVDD4
FB4
VCHK
VNEG
FB3
PVDD3
LX3
Lead Plating System
G : Green (Halogen Free and Pb
Free)
WQFN-32L 4x4
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DS9986A-00 May 2011
RT9986A
Typical Application Circuit
For 2AA
21
C1
1µF
29
VBAT
C2
4.7µF
L5
10µH
VBAT
PVDD1
VDDM
FB1
BAT
20
18 FB5
D1
-7V
C18
10µF x 2
C15
1nF
R11
66.5k
L6
10µH
28 LX6
3
R12
10.5k
C16
0.1µF
2
13
C17
0.1µF
D5
FB6
VREF
FB7
FB2
24
25 EN1234
32 EN56
OFF
12 VCHK
RTCPWR
R14
10k
R15
100k
3.3V
DS9986A-00 May 2011
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23
R3
470k
C6
10µF x 2
R4
150k
LX2 26
L2
2.2µH
LX3 16
FB3
VBAT
C5
4.7µF
PVDD3 15
5V
C7
4.7µF
L3
2.2µH
2.5V
R5
768k
14
C8
10µF
R6
360k
PVDD4 10
LX4 9
8 EN7
ON
VBAT
3.3V
C22
4.7pF
VNEG
7 LX7
6 PVDD7
5
5V
C3
4.7µF
PVDD2 27
R10
26.1k
4 VOUT6
5V
C4
10µF x 2
L1
2.2µH
LX5
C12
27pF
R9
287k
R1
470k
R2
88.7k
LX1 31
19 PVDD5
C13
10µF x 2
1
C21
4.7pF
RT9986A
C14
4.7µF
15V
30
FB4 11
5V or VBAT
C9
10µF
L4
2.2µH
1.8V
R7
470k
C10
10µF
R8
374k
RTCPWR
RST
GND
22
C11
Super Cap
33 (Exposed Pad)
SYSR
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RT9986A
For Li-ion
21
C1
1µF
29
VBAT
C2
4.7µF
L5
10µH
VBAT
PVDD1
VDDM
FB1
BAT
20
L1
2.2µH
LX5
LX2 26
C12
27pF
R9
287k
18 FB5
FB2
L2
2.2µH
D1
-7V
C18
10µF x 2
C15
1nF
L6
10µH
R11
66.5k
28 LX6
3
R12
10.5k
C16
0.1µF
2
13
C17
0.1µF
L7
10µH
VBAT
FB6
VREF
3.3V
C22
10pF
24
PVDD2 27
LX3 16
FB3
PVDD7
RTCPWR
25 EN1234
32 EN56
12
3.3V
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17
23
5V or VBAT
C9
4.7µF
L4
2.2µH
1V
R7
23.2k
C10
10µF
FB7
8 EN7
R15
100k
C8
10µF
R8
93.1k
R13
10
R14
10k
1.8V
R5
470k
R6
374k
FB4 11
5
RTCPWR
VBAT
C7
4.7µF
L3
2.2µH
14
7 LX7
C20
1µF
OFF
VBAT
C6
4.7µF
PVDD3 15
LX4 9
ON
C5
10µF
PVDD4 10
6
D3
D4
R3
470k
R4
150k
VNEG
C19
1µF
D2
VBAT
C4
4.7µF
R10
26.1k
4 VOUT6
5V
C3
10µF x 2
R1
470k
R2
88.7k
LX1 31
19 PVDD5
C13
10µF x 2
1
C21
4.7pF
RT9986A
C14
4.7µF
15V
30
GND
22
C11
Super Cap
33 (Exposed Pad)
VCHK
RST
SYSR
DS9986A-00 May 2011
RT9986A
Timing Diagram
Timing Diagram for CH1 to CH4
VDDM = Max
(BAT, PVDD1)
User define
EN1234
3.5ms
CH1 VOUT
CH3 VOUT
3.5ms
3.5ms
Wait until FB3 < 0.1V
3.5ms
CH4 VOUT
Wait until FB4 < 0.1V
Wait until FB2 < 0.1V
CH2 VOUT
CH5 and CH6 Power Sequence
The power on sequence is :
When EN56 goes high, CH5 will turn on first. After 10ms, CH6 will turn on.
The power off sequence is :
When EN56 goes low, CH6 will turn off first and VOUT6 will be internally pulled to GND.
When VOUT6 > −0.12V, CH6 discharging completes and then CH5 turns off. Finally, the whole IC shuts down.
Power On Sequence : CH5 HV Step-Up 15V → CH6 INV −7V
Power Off Sequence : CH6 INV −7V → CH5 HV Step-Up 15V
EN56
CH5
VOUT
CH6
VOUT
DS9986A-00 May 2011
10ms
Discharge by internal N-MOSFET
Constant Current
Pre-Charge.
10ms
Wait until VOUT6 close to 0V
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RT9986A
Functional Pin Description
Pin No.
Pin Name
Pin Function
1
FB1
Feedback Input Pin of CH1.
2
VREF
1.8V Reference Output Pin.
3
FB6
Feedback Input Pin of CH6.
4
VOUT6
5
FB7
6
PVDD7
7
LX7
8
EN7
Sense Input Pin of CH6 Inverting Output Node.
Feedback input pin of CH7 in step-up mode or current sink pin of CH7 in current
source mode.
Power Output Pin of CH7.
Switch Node of CH7 in Step-Up Mode. LX7 initial voltage determines CH7
operation mode.
Enable Pin of CH7 and PWM Dimming Signal Input Pin.
9
LX4
Switch Node of CH4.
10
PVDD4
Power Input Pin of CH4.
11
FB4
Feedback Input Pin of CH4.
12
VCHK
Sense Pin of Voltage Detector.
13
VNEG
Output Pin of Negative Regulator.
14
FB3
Feedback Input Pin of CH3.
15
PVDD3
Power Input Pin of CH3.
16
LX3
Switch Node of CH3.
17
RST
Voltage Detector Open Drain Output Pin.
18
FB5
Feedback Input Pin of CH5.
19
PVDD5
Power Output Pin of CH5.
20
LX5
Switch Node of CH5.
21
VDDM
22
RTCPWR
23
SYSR
IC Analog Power Pin.
Internal Control Circuit Power Pin. That must connect to a bypass capacitor for
better noise rejection.
System Reset Open-Drain Output Pin.
24
FB2
Feedback Input Pin of CH2.
25
EN1234
Enable Pin of CH1, CH2, CH3, CH4.
26
LX2
27
PVDD2
28
LX6
Switch Node of CH2.
Power Input Pin for Step-Down of CH2.
Power Output Pin for Step-Up of CH2.
Switch Node of CH6.
29
BAT
Battery Power Pin.
30
31
PVDD1
LX1
Power Output Pin of CH1.
Switch Node of CH1.
32
EN56
Enable Pin of CH5, CH6.
33 (Exposed pad) GND
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Ground. The exposed pad must be soldered to a large PCB and connected to
GND for maximum thermal dissipation.
DS9986A-00 May 2011
RT9986A
Function Block Diagram
VDDM
PVDD5
VDDM
BAT
Body
Diode
Control
UVLO
CH5
C-Mode
Step-Up
PWM
LX5
Soft-Start
BAT
UVLO
VDDI
PVDD1
VDDM
FB5
1.25V
REF
+
VDDM
BAT
Body
Diode
Control
CH1
C-Mode
Step-Up
CH6
Inverting
BAT
LX1
+
LX6
VNEG
FB1
0.8V
REF
VOUT6
PVDD2
VDDM
+
FB6
0.6V
REF
-
1.8V
REF
VREF
Body
Diode
Control
CH2
C-Mode
Step-Up or
Step-Down
VDDM
BAT
LX2
PVDD7
BAT
+
FB2
0.8V
REF
VDDM
PVDD3
+
LX7
Body
Diode
Control
CH7 C-Mode
Step-Up or
Current Source
+
PWM Dimming
+
Mode Selector
FB7
CH3
C-Mode
Step-Down
0.25V
REF
30mA(max.)
LX3
EN7
EN1234
EN56
+
Power On/Off
Sequence Control
Logic Block
FB3
0.8V
REF
VDDM
PVDD4
RTCPWR
CH4
C-Mode
Step-Down
VCHK
RST
Voltage
Detector
LX4
+
VDDM
SYSR
SYS_Reset
GND
DS9986A-00 May 2011
FB2
VDDI
RTC_LDO
W/ Body Diode
Control
FB4
0.8V
REF
RTCPWR
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RT9986A
Absolute Maximum Ratings
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(Note 1)
Supply Input Voltage, VDDM, BAT --------------------------------------------------------------------- −0.3V to 6V
VOUT6 -------------------------------------------------------------------------------------------------------- −10V to 0.3V
LX1, LX2, LX3, LX4 ----------------------------------------------------------------------------------------- −0.3V to 6V
PVDD5, LX5 ------------------------------------------------------------------------------------------------- −0.3V to 24V
PVDD7, LX7 ------------------------------------------------------------------------------------------------- −0.3V to 17V
LX6 ------------------------------------------------------------------------------------------------------------- (BAT − 14V) to (BAT + 0.3V)
Other Pins ---------------------------------------------------------------------------------------------------- −0.3V to 6V
Power Dissipation, PD @ TA = 25°C
WQFN 32L 4x4 ---------------------------------------------------------------------------------------------- 3.590W
Package Thermal Resistance (Note 2)
WQFN 32L 4x4, θJA ---------------------------------------------------------------------------------------- 27.8°C/W
WQFN 32L 4x4, θJC ---------------------------------------------------------------------------------------- 7°C/W
Junction Temperature -------------------------------------------------------------------------------------- 150°C
Lead Temperature (Soldering, 10 sec.) ---------------------------------------------------------------- 260°C
Storage Temperature Range ----------------------------------------------------------------------------- −65°C to 150°C
ESD Susceptibility (Note 3)
HBM (Human Body Mode) ------------------------------------------------------------------------------- 2kV
MM (Machine Mode) --------------------------------------------------------------------------------------- 200V
Recommended Operating Conditions
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(Note 4)
VDDM --------------------------------------------------------------------------------------------------------- 2.7V to 5.8V
Junction Temperature Range ----------------------------------------------------------------------------- −40°C to 125°C
Ambient Temperature Range ----------------------------------------------------------------------------- −40°C to 85°C
Electrical Characteristics
(VDDM = VBAT = 3.3V, TA = 25°C, unless otherwise specified)
Parameter
Supply Input Voltage
BAT Startup Voltage
BAT UVLO Threshold
BAT UVLO Hysteresis
Symbol
Test Conditions
VST
BAT Falling
Min
Typ
Max
Unit
1.5
---
-1.3
0.2
----
V
V
V
VDDM OVP Threshold
VDDM OVP Hysteresis
VDDM Rising
5.85
--
6
−0.25
6.15
--
V
V
VDDM UVLO Threshold
VDDM UVLO Hysteresis
VDDM Rising
2.2
--
2.4
0.3
2.6
--
V
V
All EN pins = 0, VBAT = 3.3V
--
10
20
μA
Non switching, VEN1234 = 3.3V
--
--
800
μA
Non switching, VEN1234 = 3.3V
--
--
800
μA
VEN1234 = 3.3V
--
--
800
μA
Supply Current
Shutdown Supply Current
IOFF
(IBAT + IVDDM)
CH1 Synchronous Step-Up Supply
IQ1
Current into VDDM
CH2 Synchronous Step-Up or
I
Step-Down Supply Current into VDDM Q2
CH3 Synchronous Step-Down Supply
Current into VDDM
IQ3
To be continued
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DS9986A-00 May 2011
RT9986A
Parameter
CH4 Synchronous Step-Down
Supply Current into VDDM
CH5 Synchronous Step-Up Supply
Current into VDDM
CH6 (Inverting)
Supply Current into VDDM
CH7 (WLED) in Step-Up Mode
Supply Current into VDDM
CH7 (WLED) in Current Source
Mode Supply Current into VDDM
Oscillator
Symbol
Test Conditions
Min
Typ
Max
Unit
IQ4
Non switching, VEN1234 = 3.3V
--
--
800
μA
IQ5
Non switching, VEN56 = 3.3V
--
--
800
μA
IQ6
Non switching, VEN56 = 3.3V
--
--
800
μA
IQ7b
Non switching, VEN7 = 3.3V
--
--
800
μA
IQ7c
VEN7 = 3.3V, VLX7 = 0V
--
--
800
μA
1800
2000
2200
kHz
CH7 in Step-Up mode
900
1000
1100
kHz
CH1 Maximum Duty Cycle (Step-Up)
VFB1 = 0.75V
80
83
86
%
CH2 Maximum Duty Cycle (Step-Up)
CH2 Maximum Duty Cycle
(Step-Down)
CH3 Maximum Duty Cycle
(Step-Down)
CH4 Maximum Duty Cycle
(Step-Down)
CH5 Maximum Duty Cycle (Step-Up)
VFB2 = 0.75V
80
83
86
%
VFB2 = 0.75V
--
--
100
%
VFB3 = 0.75V
--
--
100
%
VFB4 = 0.75V
--
--
100
%
VFB5 = 1.15V
91
93
97
%
CH6 Maximum Duty Cycle (Inverting)
VFB6 = 0.7V
91
93
97
%
CH7 Maximum Duty Cycle (Step-Up)
VFB7 = 0.15V
91
93
97
%
0.788
0.8
0.812
V
1.237
1.25
1.263
V
0.59
0.6
0.61
V
0.237
0.25
0.263
V
28.5
30
31.5
mA
--
--
0.3
V
1.782
1.8
1.818
V
0μA < I REF < 200μA
--
--
10
mV
VPVDD1 = 3.3V
--
200
300
VPVDD1 = 3.3V
VPVDD2 = 3.3V
-2.2
--
150
3
200
250
4
300
VPVDD2 = 3.3V
--
150
250
CH1, 2, 3, 4 Operation Frequency
fOSC
CH5, 6, 7 Operation Frequency
fOSC2
Feedback, Regulation Voltage
Feedback Regulation Voltage @
FB1, FB2, FB3, FB4
Feedback Regulation Voltage @ FB5 VFB5
Feedback Regulation Voltage @ FB6
VFB6
(Inverting)
Feedback Regulation Voltage @ FB7 VFB7
Output Current (CS Mode)
Dropout Voltage @ FB7 (CS Mode)
VREF Output Voltage
VLX7 = 0V
VREF
VREF Load Regulation
Power Switch
CH1 On-Resistance
P-MOSFET
N-MOSFET
CH1 Current Limitation (Step-Up)
P-MOSFET
CH2 On Resistance
N-MOSFET
RDS(ON)1
ILIM1
RDS(ON)2
mΩ
A
mΩ
CH2 Current Limitation (Step-Down)
ILIM2_D
1.2
1.6
2
A
CH2 Current Limitation (Step-Up)
ILIM2_U
2.2
3
4
A
To be continued
DS9986A-00 May 2011
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9
RT9986A
Parameter
CH3 On Resistance
Symbol
P-MOSFET
N-MOSFET
CH3 Current Limitation (Step-Down)
CH4 On Resistance
P-MOSFET
N-MOSFET
CH4 Current Limitation (Step-Down)
CH5 On Resistance
P-MOSFET
N-MOSFET
CH5 Current Limitation of
N-MOSFET
CH6 On Resistance of P-MOSFET
CH6 Current Limitation of
P-MOSFET
P-MOSFET
CH7 On Resistance
N-MOSFET
CH7 Current Limitation of
N-MOSFET
Protection
Over Voltage Protection of PVDD1
and PVDD2
Over Voltage Protection of PVDD5
Min
Typ
Max
VPVDD3 = 3.3V
--
300
400
VPVDD3 = 3.3V
--
300
400
1.2
1.6
2
VPVDD4 = 3.3V
--
300
400
VPVDD4 = 3.3V
--
300
400
1.2
1.6
2
A
VPVDD5 = 16V
--
0.8
1
VPVDD5 = 3.3V
--
0.6
0.8
Ω
0.9
1.2
1.6
A
RDS(ON)6
--
0.5
0.7
Ω
I LIM6
1
1.5
2
A
VPVDD7 = 10V
--
3
--
VPVDD7 = 3.3V
--
0.9
1.1
0.6
0.8
1
A
5.85
6
6.15
V
20
21
22
V
--
−13
--
V
14.3
15
16
V
--
VBAT
−0.8V
--
V
0.35
0.4
0.45
V
0.5
0.6
0.7
V
1.1
1.2
1.3
V
0.65
0.7
0.75
V
1.05
1.1
1.15
V
0.69
0.74
0.79
V
--
100
--
ms
1.3
--
--
--
--
0.4
RDS(ON)3
Test Conditions
I LIM3
RDS(ON)4
I LIM4
RDS(ON)5
I LIM5
RDS(ON)7
I LIM7
Over Voltage Protection of VOUT6
Over Voltage Protection of PVDD7
(Step-Up Mode)
CH1, CH2 Step-Up Under Voltage
Protection of PVDD1 and PVDD2
At VFBx < 0.4V after soft-start
ends
At VFB5 < 0.6V after soft-start
ends
At VFB6 > 1.2V after soft-start
end
At VFBx < 0.7V after fault delay
(100ms)
At VFB5 < 1.1V after fault delay
(100ms)
At VFB6 > 0.74V after fault
delay (100ms)
CH1/2/3/4 Under Voltage Protection
CH5 Under Voltage Protection
CH6 Under Voltage Protection
CH1/2/3/4 Over Load Protection
CH5 Over Load Protection
CH6 Over Load Protection
Protection Fault Delay
Unit
mΩ
A
mΩ
Ω
Control
Logic-High
EN1234, EN56, EN7
Input Threshold Voltage Logic-Low
LX7 Input Threshold
Voltage
V
Logic-High
High to Select Step-Up Mode
1
--
--
Logic-Low
Low to Select CS Mode
--
0.25
--
--
2
6
μA
--
32
--
ms
EN1234, EN56, EN7 Sink Current
EN7 Low Time for Shutdown
t SHDN
V
To be continued
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DS9986A-00 May 2011
RT9986A
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
125
160
--
°C
--
20
--
°C
0.709
0.72
0.731
V
SYSR, FB2 Hysteresis
--
40
--
mV
SYSR Rising Delay Time
--
10
--
ms
Thermal Protection
Thermal Shutdown
TSD
Thermal Shutdown Hysteresis
ΔTSD
System Reset
SYSR, FB2 Regulation Threshold
for SYSR to go low
SYSR Sink Capability
VSYSR = 0.5V
4
--
--
mA
Voltage Detector
Voltage Detector Reset Threshold
(VCHK < Threshold Æ RST = L)
Voltage Detector Reset Hysteresis
VCHK Falling
1.57
1.6
1.63
V
--
16
--
mV
Standby Current
VVCHK = 3V
--
2
4
μA
35
55
75
ms
RST Rising Delay Time
RST Sink Capability
RTC LDO
VRST = 0.5V, VVCHK = 1.5V
4
--
--
mA
Standby Current
Regulated Output Voltage @
RTCPWR
Max Output Current (Current Limit)
VDDM = 4.2V
--
5
8
μA
IOUT = 0mA
3.1
3.2
3.3
V
VDDM = 4.2V
60
130
200
mA
IOUT = 50mA
--
--
1000
IOUT = 10mA
--
--
150
IOUT = 3mA
--
--
60
Dropout Voltage
mV
Note 1. Stresses listed as the above “Absolute Maximum Ratings” may cause permanent damage to the device. These are for
stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the operational
sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may
remain possibility to affect device reliability.
Note 2. θJA is measured in natural convection at TA = 25°C on a high-effective thermal conductivity four-layer test board of JEDEC
51-7 thermal measurement standard. The measurement case position of θJC is on the exposed pad of the package.
Note 3. Devices are ESD sensitive. Handling precaution is recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
DS9986A-00 May 2011
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11
RT9986A
Typical Operating Characteristics
CH1 Step-Up Efficiency vs. Output Current
CH1 Step-Up Efficiency vs. Output Current
100
100
90
90
VBAT
VBAT
VBAT
VBAT
VBAT
VBAT
70
60
50
=
=
=
=
=
=
VBAT
VBAT
VBAT
VBAT
VBAT
VBAT
80
4.5V
4.2V
3.9V
3.6V
3.3V
3V
Efficiency (%)
Efficiency (%)
80
40
30
20
70
60
50
40
30
10
VOUT = 5V, L = 2.2μH, COUT = 10μF x 2
VOUT = 3.3V, L = 2.2μH, COUT = 10μF x 2
0
0
10
100
10
1000
100
Output Current (mA)
CH2 Step-Down Efficiency vs. Output Current
100
100
90
90
VBAT
VBAT
VBAT
VBAT
VBAT
VBAT
VBAT
70
60
50
40
=
=
=
=
=
=
=
80
3.6V
3.3V
3V
2.7V
2.5V
2.2V
1.8V
Efficiency (%)
80
1000
Output Current (mA)
CH2 Step-Up Efficiency vs. Output Current
Efficiency (%)
3V
2.7V
2.5V
2.2V
2V
1.8V
20
10
30
20
VBAT
VBAT
VBAT
VBAT
VBAT
VBAT
70
60
50
40
=
=
=
=
=
=
3.4V
3.7V
3.9V
4.2V
4.5V
5V
30
20
10
10
VOUT = 5V, L = 2.2μH, COUT = 10μF x 2
0
VOUT = 3.3V, L = 2.2μH, COUT = 10μF
0
10
100
1000
10
Output Current (mA)
100
90
90
70
60
50
40
=
=
=
=
=
=
=
80
2.7V
3V
3.3V
3.6V
3.9V
4.2V
4.5V
Efficiency (%)
VBAT
VBAT
VBAT
VBAT
VBAT
VBAT
VBAT
1000
CH4 Step-Down Efficiency vs. Output Current
100
80
100
Output Current (mA)
CH 3 Step-Down Efficiency vs. Output Current
Efficiency (%)
=
=
=
=
=
=
30
VBAT
VBAT
VBAT
VBAT
VBAT
VBAT
VBAT
70
60
50
40
30
=
=
=
=
=
=
=
1.8V
2.5V
3V
3.3V
3.6V
4.2V
4.5V
20
20
10
VOUT = 1.8V, L = 2.2μH, COUT = 10μF
10
VOUT = 1V, L = 2.2μH, COUT = 10μF
0
0
10
100
Output Current (mA)
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12
1000
10
100
1000
Output Current (mA)
DS9986A-00 May 2011
RT9986A
CH5 Step-Up Efficiency vs. Output Current
90
90
70
60
50
40
30
20
10
VOUT
VBAT = 4.5V
VBAT = 4.2V
VBAT = 3.9V
VBAT = 3.6V
VBAT = 3.3V
VBAT = 3V
VBAT = 2.7V
VBAT = 2.5V
VBAT = 2.2V
VBAT = 2V
= 16V, L = 10μH, COUT = 10μF x 2
0
0.001
Inverting Efficiency (%)
100
80
Efficiency (%)
CH6 Inverting Efficiency vs. Output Current
100
80
70
60
50
40
30
20
10
VOUT
0
0.01
0.1
VBAT = 4.2V
VBAT = 3.9V
VBAT = 3.6V
VBAT = 3.3V
VBAT = 3V
VBAT = 2.7V
VBAT = 4.5V
VBAT = 2.5V
VBAT = 2.2V
VBAT = 2V
= −8V, L = 10μH, COUT = 10μF x 2
1
10
Output Current (A)
100
Output Current (mA)
CH7 Efficiency vs. Input Voltage
CH1 Step-Up Output Voltage vs. Output Current
100
5.20
90
5.15
Output Voltage (V)
Efficiency (%)
80
70
60
50
40
30
VBAT = 3V
5.10
5.05
VBAT = 4.5V
5.00
4.95
4.90
20
4.85
10
IOUT = 25mA, L = 10μH, COUT = 1μF
VOUT = 5V
0
4.80
1.8
2.1
2.4
2.7
3
3.3
3.6
3.9
4.2
4.5
0
100
Input Voltage (V)
CH1 Step-Up Output Voltage vs. Output Current
300
400
500
600
CH2 Step-Up Output Voltage vs. Output Current
5.10
3.35
VBAT = 1.8V
5.08
Output Voltage (V)
3.33
Output Voltage (V)
200
Output Current (mA)
VBAT = 3.2V
3.31
3.29
VBAT = 3V
5.06
VBAT = 4.2V
5.04
5.02
3.27
VOUT = 3.3V
VOUT = 5V
5.00
3.25
0
100
200
300
400
Output Current (mA)
DS9986A-00 May 2011
500
600
0
100
200
300
400
500
600
Output Current (mA)
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13
RT9986A
CH2 Step-Down Output Voltage vs. Output Current
CH3 Step-Down Output Voltage vs. Output Current
1.830
3.36
1.825
Output Voltage (V)
Output Voltage (V)
3.34
VBAT = 4.5V
VBAT = 5V
3.32
3.30
3.28
1.820
1.815
VBAT = 3V
VBAT = 4.5V
1.810
1.805
VOUT = 3.3V
3.26
VOUT = 1.8V
1.800
0
100
200
300
400
500
0
600
100
200
Output Current (mA)
400
500
600
Output Current (mA)
CH4 Step-Down Output Voltage vs. Output Current
CH5 Step-Up Output Voltage vs. Output Current
16.3
1.006
1.004
16.2
Output Voltage (V)
Output Voltage (V)
300
VBAT = 4.5V
VBAT = 2.7V
VBAT = 3V
1.002
1.000
0.998
0.996
VBAT = 3.4V
VBAT = 4.5V
16.1
16.0
15.9
0.994
VOUT = 16V
VOUT = 1V
15.8
0.992
0
100
200
300
400
500
0
600
20
40
60
80
100
Output Current (mA)
Output Current (mA)
Power On Sequence
CH6 Inverting Efficiency vs. Output Current
Output Voltage (V)
-8.190
VBAT = 2.7V
VBAT = 3.4V
VBAT = 4.5V
-8.195
VOUT_CH1
(5V/Div)
VOUT_CH2
(2V/Div)
-8.200
-8.205
VOUT = −8V
VOUT_CH3
(2V/Div)
VOUT_CH4
(2V/Div)
VBAT = 3.7V
-8.210
0
20
40
60
80
100
Time (2.5ms/Div)
Output Current (mA)
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14
DS9986A-00 May 2011
RT9986A
Power On Sequence
Power Off Sequence
VOUT_CH1
(5V/Div)
VOUT_CH5
(10V/Div)
VOUT_CH2
(2V/Div)
VOUT_CH6
(5V/Div)
VOUT_CH3
(2V/Div)
VOUT_CH4
(2V/Div)
VBAT = 3.7V
VBAT = 3.7V
Time (1ms/Div)
Time (5ms/Div)
Power Off Sequence
CH1 Output Voltage Ripple
VOUT_CH5
(10V/Div)
LX1
(2V/Div)
VOUT_CH6
(5V/Div)
VOUT_CH1_ac
(10mV/Div)
VBAT = 3.7V, VOUT = 5V,
IOUT = 400mA, L = 2.2μH, COUT = 10μF x 2
VBAT = 3.7V
Time (2.5ms/Div)
Time (500ns/Div)
CH2 Output Voltage Ripple
CH3 Output Voltage Ripple
LX2
(2V/Div)
LX3
(2V/Div)
VOUT_CH2_ac
(2mV/Div)
VOUT_CH3_ac
(5mV/Div)
VBAT = 3.7V, VOUT = 3.3V,
IOUT = 400mA, L = 2.2μH, COUT = 10μF
Time (500ns/Div)
DS9986A-00 May 2011
VBAT = 3.7V, VOUT = 1.8V,
IOUT = 400mA, L = 2.2μH, COUT = 10μF
Time (500ns/Div)
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15
RT9986A
CH5 Output Voltage Ripple
CH4 Output Voltage Ripple
LX4
(2V/Div)
LX5
(10V/Div)
VOUT_CH4_ac
(5mV/Div)
VOUT_CH5_ac
(10mV/Div)
VBAT = 3.7V, VOUT = 1V,
IOUT = 400mA, L = 2.2μH, COUT = 10μF
VBAT = 3.7V, VOUT = 16V,
IOUT = 30mA, L = 10μH, COUT = 10μF
Time (500ns/Div)
Time (1μs/Div)
CH6 Output Voltage Ripple
CH1 Load Transient Response
LX6
(10V/Div)
IOUT
(100mA/Div)
VOUT_CH6_ac
(10mV/Div)
V OUT_CH1_ac
(100mV/Div)
VBAT = 3.7V, VOUT = −8V,
IOUT = 50mA, L = 10μH, COUT = 10μF x 2
VBAT = 3.7V, VOUT = 5V,
IOUT = 0 to 300mA, L = 2.2μH, COUT = 10μF x 2
Time (1μs/Div)
Time (1ms/Div)
CH2 Load Transient Response
CH3 Load Transient Response
IOUT
(100mA/Div)
IOUT
(100mA/Div)
V OUT_CH2_ac
(50mV/Div)
V OUT_CH3_ac
(50mV/Div)
VBAT = 3.7V, VOUT = 3.3V,
IOUT = 0 to 300mA, L = 2.2μH, COUT = 10μF
Time (1ms/Div)
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16
VBAT = 3.7V, VOUT = 1.8V,
IOUT = 0 to 300mA, L = 2.2μH, COUT = 10μF
Time (1ms/Div)
DS9986A-00 May 2011
RT9986A
CH5 Load Transient Response
CH4 Load Transient Response
IOUT
(20mA/Div)
IOUT
(100mA/Div)
V OUT_CH4_ac
(20mV/Div)
V OUT_CH5_ac
(50mV/Div)
VBAT = 3.7V, VOUT = 1V,
IOUT = 0 to 300mA, L = 2.2μH, COUT = 10μF
Time (1ms/Div)
VBAT = 3.7V, VOUT = 16V,
IOUT = 10 to 30mA, COUT = 10μF
Time (1ms/Div)
CH6 Load Transient Response
IOUT
(20mA/Div)
V OUT_CH6_ac
(20mV/Div)
VBAT = 3.7V, VOUT = −8V,
IOUT = 15 to 50mA, COUT = 10μF x 2
Time (1ms/Div)
DS9986A-00 May 2011
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17
RT9986A
Application Information
The RT9986A is a multiple output power supply system
for digital still cameras and other small handheld devices.
It includes six DC/DC converters as well as one WLED
driver, one RTC LDO, one voltage detector, and one
system reset. The WLED works in either current source
mode or step-up mode.
CH1 : Step-up synchronous current mode DC/DC converter
with internal power MOSFETs and compensation network.
The P-MOSFET body can be controlled to disconnect the
load.
CH2 : Step-up or step-down synchronous current mode
DC/DC converter with internal power MOSFETs and
compensation network. External circuit topology
automatically determines whether CH2 is in step-up or
step-down mode. During step-up mode, the P-MOSFET
body can be controlled to disconnect the load if input
voltage is not higher than the VBAT .
CH3 : Step-down synchronous current mode DC/DC
conv erter wit h int ernal power MOSFETs and
compensation network.
CH4 : Step-down synchronous current mode DC/DC
conv erter wit h int ernal power MOSFETs and
compensation network.
CH5 : Step-up synchronous current mode DC/DC converter
with internal power MOSFET and compensation network.
The P-MOSFET body can be controlled to disconnect the
load.
CH6 : Asynchronous inverting current mode DC/DC
converter with internal power MOSFET and compensation
network.
System Reset : Accurate voltage detector for checking
CH2 output voltage status.
Voltage Detector : A general, low quiescent current voltage
detector for monitoring status of a node voltage such as
for RTC_LDO output or others.
CH1 : Synchronous Step-Up DC/DC Converter
CH1 is a synchronous step-up converter which can be
used for motor power. The converter operates at fixed
frequency and PWM current mode. The converter
integrates internal MOSFETs, compensation network and
synchronous rectifier for up to 95% efficiency.
The output voltage can be set by the following equation :
VOUT_CH1 = (1 + R1 / R2) x VFB1
where VFB1 is 0.8V typically.
CH2 : Synchronous Step-Up / Step-Down
Selectable DC/DC Converter
CH2 is a synchronous step-up / step-down auto-select
converter, typically for system I/O power. In either stepup or step-down, the converter operates in fixed frequency
PWM mode, Continuous Current Mode (CCM), and
Discontinuous Current Mode (DCM) with internal
MOSFETs, compensation network and synchronous
rectifiers for up to 95% efficiency.
Step-Up :
In step-up mode, CH2 also disconnects the load from its
input power node and discharges output node of CH2 when
it is turned off.
Step-Down :
CH7 : A WLED driver operating in either current source
mode or synchronous step-up mode with internal power
MOSFET and compensation network. Operation mode is
determined by LX7 initial voltage The P-MOSFET body in
step-up mode can be controlled to disconnect the load
disconnected.
CH1 to CH4 operate in PWM mode with 2MHz, while
CH5 to CH7 operate in PWM mode with 1MHz switching
frequency.
In step-down mode, the CH2 converter can be operated
at 100% maximum duty cycle to extend the input
operating voltage range. When the input voltage is close
to the output voltage, the converter enters low dropout
mode.
The output voltage can be set by the following equation :
VOUT_CH2 = (1 + R3 / R4) x VFB2
where VFB2 is 0.8V typically.
RTC_LDO : A 3.1V output LDO with low quiescent current
and high output voltage accuracy.
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18
DS9986A-00 May 2011
RT9986A
CH3 : Synchronous Step-Down DC/DC Converter
CH3 operates in fixed frequency PW M mode with
integrated internal MOSFETs and compensation network.
The CH3 step-down converter can be operated at 100%
maximum duty cycle to extend battery operating voltage
range. When the input voltage is close to the output
voltage, the converter enters low dropout mode with low
output ripple.
The output voltage can be set by the following equation :
to FB6, 1.2V equals to (VREF − VFB6) and 0.6V is VFB6
typical.
Reference Voltage
The RT9986A provides a precise 1.8V reference voltage,
VREF, with souring capability of 100µA. Connect a 0.1µF
ceramic capacitor from the VREF pin to GND. Reference
voltage is enabled by pulling EN6 to logic-high.
Furthermore, this reference voltage is internally pulled to
GND at shutdown.
VOUT_CH3 = (1 + R5 / R6) x VFB3
where VFB3 is 0.8V typically.
CH4 : Synchronous Step-Down DC/DC Converter
CH4 operates at fixed frequency PWM mode with
integrated internal MOSFETs and compensation network.
The CH4 step-down converter can be operated at 100%
maximum duty cycle to extend battery operating voltage
range. When the input voltage is close to the output
voltage, the converter enters low dropout mode with low
output ripple.
The output voltage can be set by the following equation:
VOUT_CH4 = (1 + R7 / R8) x VFB4
where VFB4 is 0.8V typically.
CH5 : Synchronous Step-Up DC/DC Converter
CH5 is a high voltage synchronous step-up converter for
CCD positive power. The converter operates at fixed
frequency PWM mode, CCM, DCM, and PSM (pulse skip
mode) with integrated internal MOSFETs, compensation
network and load disconnect function.
The output voltage can be set by the following equation:
VOUT_CH5 = (1 + R9 / R10) x VFB5
where VFB5 is 1.25V typically.
CH6 : INV DC/DC Converter
This converter integrates an internal P-MOSFET with
internal compensation and needs an external Schottky
diode to provide CCD negative power supply.
The output voltage can be set by the following equation :
VOUT_CH6 = −(R11 / R12) x (1.2V) + 0.6V
where R11 and R12 are the feedback resistors connected
DS9986A-00 May 2011
CH7 : WLED Driver
CH7 is a WLED driver that can operate in either current
source mode or synchronous step-up mode, as determined
by LX7's initial voltage level.
Table 1. CH7 WLED setting
CH7 Operating Mode
Current Source
LX7
< 0.25V
Synchronous Step-Up
> 1V
When CH7 works in current source mode, it sinks an
accurate LED current modulated by EN7 high duty such
that it is easily dimmed from 0mA to 30mA. If CH7 works
in synchronous step-up mode, it integrates synchronous
step-up mode with an internal MOSFET and internal
compensation to output a voltage up to 15V. The LED
current is set via an external resistor and controlled via
the PWM duty on the EN7 pin. Regardless of the mode,
holding EN7 low for more than 32ms will turn off CH7.
In addition, CH7 will be turned on until the CH2 soft-start
is finished.
CH7 WLED Current Dimming Control
If CH7 is in synchronous step-up mode, the WLED current
is set by an external resistor. If CH7 is in current source
mode, the sink current into the FB7 pin is 30mA typically
when EN7 is high. Regardless of the mode, dimming is
always controlled by the duty of pulse-width modulated
signal on the EN7 pin. The PWM dimming duty must be
over 10%.
The average current through WLED can be set by the
following equations :
ILED (mA) = [250mV / R (W)] x Duty (%) (for step-up mode)
or ILED (mA) = 30mA x Duty (%) (for current source mode)
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19
RT9986A
R is the current sense resistor from FB7 to GND and Duty
is the duty of the PWM dimming signal into EN7 pin.
Dimming frequency range is from 1kHz to 100kHz but
2kHz to 20kHz should be avoided to prevent distraction
from audio noise.
VDDM Bootstrap
To support bootstrap function, the RT9986A includes a
power selection circuit which selects between BAT and
PVDD1 to create the internal node voltage VDDI and VDDM.
VDDM is the power of all the RT9986A control circuits
and must be connected to an external decoupling capacitor
by way of the VDDM pin. The VDDI is the power input of
the RTC LDO. The output PVDD1 of CH1 can bootstrap
VDDM and VDDI. The RT9986A includes UVLO circuits
to monitor VDDM and BAT voltage status.
RTC LDO
The RT9986A provides a 3.1V output LDO for real time
clock. The LDO features low quiescent current (5µA) and
high output voltage accuracy. This LDO is always on, even
when the system is shut down. For better stability, is it
recommended to connect a 0.1µF to the RTCPWR pin.
The RTC LDO includes pass transistor body diode control
to avoid the RTCPWR node from back-charging into the
input node VDDI.
System Reset
The RT9986A also provides a system voltage detector to
monitor system power status via FB2. If FB2 level is lower
than 90% setting, the open drain output pin SYSR will
pull down. When FB2 level is higher than 95% setting,
the SYSR pin will go high after 10ms.
Voltage Detector
The RT9986A provides a voltage detector to detect the
voltage status at the VCHK pin. The input power of the
voltage detector is RTCPWR and the detector is always
on. 55ms after VCHK voltage > 1.616V, the open drain
output /RST will be pulled high. If VCHK < 1.6V, the /RST
pin will be pulled down to GND immediately.
Power On/Off Sequence for CH1 to CH4
EN1234 will turn on/off CH1 to CH4 in preset sequence.
When EN1234 goes high, CH1 will turn on first. 3.5ms
after CH1 is turned on, CH3 will turn on. 3.5ms after CH3
is turned on, CH4 will turn on. 3.5ms after CH4 is turned
on, CH2 will turn on.
CH1 to CH4 Power-Off Sequence is :
When EN1234 goes low, CH2 will turn off first and internally
discharge output.
When FB2 < 0.1V, CH4 will turn off and also internally
discharge output via the LX4 pin. When FB4 < 0.1V, CH3
will turn off and internally discharge output via the LX3
pin. Likewise, when FB3 < 0.1V, CH1 will turn off and
discharge output. After FB1 < 0.1V, CH1 to 4 shutdown
sequence will be completed.
Thermal Considerations
For continuous operation, do not exceed absolute
maximum junction temperature. The maximum power
dissipation depends on the thermal resistance of the IC
package, PCB layout, rate of surrounding airflow, and
difference between junction and ambient temperature. The
maximum power dissipation can be calculated by the
following formula :
PD(MAX) = (TJ(MAX) − TA) / θJA
where TJ(MAX) is the maximum junction temperature, TA is
the ambient temperature, and θJAis the junction to ambient
thermal resistance.
For recommended operating condition specifications of
the RT9986A, the maximum junction temperature is 125°C
and TA is the ambient temperature. The junction to ambient
thermal resistance, θJA, is layout dependent. For WQFN32L 4x4 packages, the thermal resistance, θJA, is 27.8°C/
W on a standard JEDEC 51-7 four-layer thermal test board.
The maximum power dissipation at TA = 25°C can be
calculated by the following formula :
PD(MAX) = (125°C − 25°C) / (27.8°C/W) = 3.59W for
WQFN-32L 4x4 package
The maximum power dissipation depends on the operating
ambient temperature for fixed T J(MAX) and thermal
resistance,θJA. For the RT9986A package, the derating
curve in Figure 1 allows the designer to see the effect of
rising ambient temperature on the maximum power
dissipation.
CH1 to CH4 Power On Sequence is:
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20
DS9986A-00 May 2011
RT9986A
Maximum Power Dissipation (W)
4.0
Layout Consideration
Four-Layers PCB
3.6
For the best performance of the RT9986A, the following
PCB layout guidelines must be strictly followed.
3.2
2.8
2.4
}
Place the input and output capacitors as close as
possible to the input and output pins respectively for
good filtering.
}
Keep the main power traces as wide and short as
possible.
}
The switching node area connected to LX and inductor
should be minimized for lower EMI.
}
Place the feedback components as close as possible
to the FB pin and keep these components away from
the noisy devices.
}
Connect the GND and Exposed Pad to a strong ground
plane for maximum thermal dissipation and noise
protection.
2.0
1.6
1.2
0.8
0.4
0.0
0
25
50
75
100
125
Ambient Temperature (°C)
Figure 1. Derating Curves for RT9986A Packages
Place the feedback components as close as possible to
the FB pin and keep away from noisy devices.
C3
VOUT_CH1
GND
C21
R2
BAT
LX6
PVDD2
LX2
EN1234
GND
L2
L6
PVDD1
C4
C5
GND
R3
R4
C22
Connect the
Exposed Pad to
a ground plane.
GND
L1
LX1
LX6
R1
VBAT
VOUT_CH2
EN56
GND
VBAT
C6
C2
32
31
30
29
28
27
26
25
C16
C18
R11
C15
R12
VOUT_CH6
24
FB2
VREF
2
23
SYSR
FB6
3
22
RTCPWR
VOUT6
4
21
VDDM
FB7
5
20
LX5
PVDD7
6
19
PVDD5
LX7
7
18
FB5
EN7
8
17
RST
GND
L5
C1
C14
D2
C10
R7
R8
C9
10
11
12
13
14
15
16
PVDD3
LX3
L4
VOUT_CH4
9
FB3
GND
VNEG
C19
VCHK
C20
FB4
L7
33
PVDD4
D4 D3
R13
1
LX4
D1
GND
VBAT
FB1
C12
R10
GND
VOUT_CH3
C8
GND
Input/Output capacitors must be placed as
close as possible to the Input/Output pins.
R9
L3
C7
VBAT
C13
VOUT_CH5
R5
R6
LX should be connected to Inductor by wide and short
trace, keep sensitive components away from this trace
Figure 2. PCB Layout Guide
DS9986A-00 May 2011
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21
RT9986A
Protection
type
BAT
Table 2. Protection Items
Threshold (typical)
Refer to Electrical
Protection methods
spec
IC
Shutdown
Delay time
CH2
Step-Up
VDDM power reset
or all enable pins
set to low
VDDM power reset
or all enable pins
set to low
VDDM power
reset or all enable
pins set to low
VDDM power reset
or all enable pins
set to low
VDDM power reset
or all enable pins
set to low
UVLO
BAT < 1.3V
IC Shutdown.
No-delay
OVP
VDDM > 6V
Automatic reset at VDDM <
5.75V
100ms
UVLO
VDDM < 2.4V
IC Shutdown.
No-delay
Current
Limit
N-MOSFET
Current > 3A
N-MOSFET off, P-MOSFET off.
Automatic reset at next clock
100ms
cycle.
PVDD1
OVP
PVDD1 > 6V
N-MOSFET off, P-MOSFET off. No-delay
PVDD1
UVP
PVDD1 < (BAT − 0.8V)
or PVDD1 < 1.28V after N-MOSFET off, P-MOSFET off. 100ms
soft-start end.
VDDM power reset
or all enable pins
set to low
FB1 UVP
FB1 < 0.4V after
soft-start end.
VDDM power reset
or all enable pins
set to low
VDDM power reset
or all enable pins
set to low
VDDM power reset
or all enable pins
set to low
VDDM
CH1
Step-Up
Reset method
N-MOSFET off, P-MOSFET off. No-delay
FB1 Over
FB1 < 0.7V
Load (OL)
IC Shutdown when OL occur
each cycle until 100ms.
Current
Limit
N-MOSFET Current >
3A
N-MOSFET off, P-MOSFET off.
Automatic reset at next clock
100ms
cycle.
PVDD2
OVP
PVDD2 > 6V
N-MOSFET off, P-MOSFET off. No-delay
PVDD2
UVP
PVDD2 < (BAT − 0.8V)
or PVDD2 < 1.28V after N-MOSFET off, P-MOSFET off. 100ms
soft-start end.
FB2 UVP
FB2 < 0.4V after
soft-start end.
N-MOSFET off, P-MOSFET off. No-delay
FB2 Over
Load
FB2 < 0.7V
IC Shutdown when OL occur
each cycle until 100ms.
Current
Limit
P-MOSFET
Current > 1.6A
N-MOSFET off, P-MOSFET off.
Automatic reset at next clock
100ms
cycle.
FB2 < 0.4V after
soft-start end.
N-MOSFET off, P-MOSFET off. No-delay
FB2 < 0.7V
IC Shutdown when OL occur
each cycle until 100ms.
CH2
FB2 UVP
Step-Down
FB2 Over
Load
100ms
100ms
100ms
VDDM power reset
or all enable pins
set to low
VDDM power reset
or all enable pins
set to low
VDDM power reset
or all enable pins
set to low
VDDM power reset
or all enable pins
set to low
VDDM power reset
or all enable pins
set to low
VDDM power reset
or all enable pins
set to low
VDDM power reset
or all enable pins
set to low
To be continued
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22
DS9986A-00 May 2011
RT9986A
Protection
type
100ms
FB3 < 0.4V after
soft-start end.
N-MOSFET off, P-MOSFET off.
No-delay
FB3 Over
Load
FB3 < 0.7V
IC Shutdown when OL occur
each cycle until 100ms.
100ms
Current
Limit
P-MOSFET
Current > 1.6A
N-MOSFET off, P-MOSFET off.
Automatic reset at next clock
cycle.
100ms
FB4 < 0.4V after
soft-start end.
N-MOSFET off, P-MOSFET off.
No-delay
FB4 Over
Load
FB4 < 0.7V
IC Shutdown when OL occur
each cycle until 100ms.
100ms
Current
Limit
N-MOSFET
Current > 1.2A
N-MOSFET off, P-MOSFET off.
Automatic reset at next clock
cycle.
100ms
PVDD5
OVP
PVDD5 > 21V
N-MOSFET off, P-MOSFET off.
No-delay
FB5 UVP
FB5 < 0.6V after
soft-start end.
N-MOSFET off, P-MOSFET off.
No-delay
FB5 Over
Load
FB5 < 1.1V
IC Shutdown when OL occur
each cycle until 100ms.
100ms
Current
Limit
P-MOSFET
Current > 1.5A
P-MOSFET off. Automatic reset
at next clock cycle.
100ms
VOUT6
OVP
VOUT6 < −13V
P-MOSFET off.
No-delay
FB6 UVP
FB6 >1.2V
P-MOSFET off.
No-delay
FB6 Over
Load
FB6 > 0.74V
IC Shutdown when OL occur
each cycle until 100ms.
100ms
Current
Limit
N-MOSFET
Current > 0.8A
N-MOSFET off, P-MOSFET off.
Automatic reset at next clock
cycle.
100ms
PVDD7
OVP
PVDD7 > 15V
Shutdown CH7
Not
applicable
Thermal
Shutdown
Temperature >
160°C
All channels stop switching
No-delay
CH4
FB4 UVP
Step-Down
CH7
WLED
Thermal
IC
Shutdown
Delay time
N-MOSFET off, P-MOSFET off.
Automatic reset at next clock
cycle.
CH3
FB3 UVP
Step-Down
CH6
Inverter
Protection methods
P-MOSFET
Current > 1.6A
Current
Limit
CH5
Step-Up
Threshold (typical)
Refer to Electrical
spec
DS9986A-00 May 2011
Reset method
VDDM power
reset or all enable
pins set to low
VDDM power
reset or all enable
pins set to low
VDDM power
reset or all enable
pins set to low
VDDM power
reset or all enable
pins set to low
VDDM power
reset or all enable
pins set to low
VDDM power
reset or all enable
pins set to low
VDDM power
reset or all enable
pins set to low
VDDM power
reset or all enable
pins set to low
VDDM power
reset or all enable
pins set to low
VDDM power
reset or all enable
pins set to low
VDDM power
reset or all enable
pins set to low
VDDM power
reset or all enable
pins set to low
VDDM power
reset or all enable
pins set to low
VDDM power
reset or all enable
pins set to low
VDDM power
reset or all enable
pins set to low
VDDM power
reset or all enable
pins set to low
VDDM power
reset or all enable
pins set to low
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23
RT9986A
Outline Dimension
1
1
2
2
DETAIL A
Pin #1 ID and Tie Bar Mark Options
Note : The configuration of the Pin #1 identifier is optional,
but must be located within the zone indicated.
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
0.700
0.800
0.028
0.031
A1
0.000
0.050
0.000
0.002
A3
0.175
0.250
0.007
0.010
b
0.150
0.250
0.006
0.010
D
3.900
4.100
0.154
0.161
D2
2.650
2.750
0.104
0.108
E
3.900
4.100
0.154
0.161
E2
2.650
2.750
0.104
0.108
e
L
0.400
0.300
0.016
0.400
0.012
0.016
W-Type 32L QFN 4x4 Package
Richtek Technology Corporation
Richtek Technology Corporation
Headquarter
Taipei Office (Marketing)
5F, No. 20, Taiyuen Street, Chupei City
5F, No. 95, Minchiuan Road, Hsintien City
Hsinchu, Taiwan, R.O.C.
Taipei County, Taiwan, R.O.C.
Tel: (8863)5526789 Fax: (8863)5526611
Tel: (8862)86672399 Fax: (8862)86672377
Email: [email protected]
Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek reserves the right to make any change in circuit
design, specification or other related things if necessary without notice at any time. No third party intellectual property infringement of the applications should be
guaranteed by users when integrating Richtek products into any application. No legal responsibility for any said applications is assumed by Richtek.
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24
DS9986A-00 May 2011