RT8562B

RT8562B
High Voltage 8-CH LED Driver
General Description
Features
The RT8562B is a 40V 8-CH LED driver capable of
delivering 30mA to each channel with 10 LEDs (3.6V per
diode), total of 80 LEDs with one driver. The RT8562B is
a current mode boost converter opearated at 1MHz, wide
VIN range covers from 4.5V to 24V and the on-chip current
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High Voltage : VIN up to 24V, VOUT up to 40V, Driving
up to 80 x 3.6V LEDs (10 each channel)
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switch is rated at 2.5A.
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Channel Current Programmabe 10mA to 30mA and
Matched to 1.5%
Current Mode PWM 1MHz Boost Converter
Easy and High Accuracy Digital Dimming by PWM
Signal
Programmable Soft-Start
Automatic Detecting Unconnected and/or Broken
Channel
Programmable Over Voltage Protection
Disconnects LED in Shutdown
VIN Under Voltage Lockout
Over Temperature Protection
Current Limiting Protection
Small 24-Lead WQFN Package
RoHS Compliant and Halogen Free
The PWM output voltage loop regulates the LED pins to
0.6V with an auto-adjustment circuit allowing voltage
mismatches between LED strings. The RT8562B automatically detects and disconnects any unconnected and/or
broken strings during operation from PWM loop to prevent
VOUT from over voltage.
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The 1.5% matched LED currents on all channels are simply
programmed with a resistor or a current sink. A very high
contrast ratio true digital PWM dimming can be achieved
by driving PWM pin with a PWM signal.
Other protecting features include programmable output
over voltage protection, LED curren limit, PWM switch
current limit and thermal shutdown.
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Applications
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UMPC and Notebook Computer Backlight
GPS, Portable DVD Backlight
Desk Lights and Room Lighting
The RT8562B is packaged with a tiny footprint package of
WQFN-24L 4x4 packages.
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Ordering Information
Pin Configurations
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RT8562B
VIN
COMP
NC
LX2
LX1
Lead Plating System
G : Green (Halogen Free and Pb Free)
VDC
(TOP VIEW)
Package Type
QW : WQFN-24L 4x4 (W-Type)
24
23
22
21
20
19
Note :
EN
1
18
PGND2
Richtek products are :
NC
2
17
PGND1
SS
3
16
OVP
15
CH1
14
CH2
13
CH3
5
PWM
6
25
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
DS8562B-06
June 2011
CH8
7
8
9
10
11
12
CH4
Suitable for use in SnPb or Pb-free soldering processes.
4
CH5
`
NC
GND
ISET
ments of IPC/JEDEC J-STD-020.
GND
CH6
RoHS compliant and compatible with the current require-
CH7
`
WQFN-24L 4x4
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1
RT8562B
Typical Application Circuit
VIN
4.5V to 24V
C5
10µF
1 EN
LX2 20
15
CH1
14
CH2
C6
1µF
CH7
R6
1k
6 PWM
22 COMP
PWM Signal
R1
1.8k
24
C3
4.7µF
CH8
R7
C7
8
... ::
GND
:
: 10 LED String
:
:
:
:
7
R2
OVP 16
ISET 11
VOUT
R3
VDC
3 SS
:
:
:
:
...
VIN
LX1 19
R8
100k
C2
3.9nF
:
:
:
:
RT8562B
23
R5
1k
D1
C1
10µF
R4
10
5V
VOUT
40V MAX
L
10µH
RISET
4.75k
5, 25 (Exposed Pad)
C4
0.1µF
ILED (mA) =
20 x 4.75
RISET (kΩ)
Note :
1. Due to the limitaion of maximum duty 5V input can support typically to VOUT = 33V.
2. Due to the limitaion of maximum duty 4V input can support typically to VOUT = 26V.
Figure 1. 1MHz, 20mA Full Scale Current PWM Dimming Control
Function Block Diagram
LX1, LX2
OSC
VIN
2.8V
CH1
S
+
R
OVP
1.6V
+
+
-
-
1.2V
-
R
+
EN
VDC
+
CH2
Shutdown
+
-
5V
LDO
VOUT
Regulation
Unit
COMP
.
.
.
CH7
5V
+
-
5uA
SS
CH8
PWM
+
+
-
-
ISET
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2
DS8562B-06
June 2011
RT8562B
Functional Pin Description
Pin No.
Pin Name
Pin Function
1
EN
Chip enable pin, when pulled low, chip is in shutdown mode. There
should be a pull low 100kΩ resistor connected to GND when the control
signal is floating.
2, 4, 21
NC
No Internal Connection.
3
SS
Soft-Start pin, a capacitor of at least 10nF is required for soft start.
5,
25 (Exposed Pad)
GND
Ground pin of the chip. The exposed pad must be soldered to a large
PCB and connected to GND for maximum power dissipation.
6
PWM
Digital Dimming Control.
11
ISET
A resistor or a current from DAC on this pin programs the full LED current.
Channel 5 to Channel 8 LED Current Sink. Leave the pin unconnected if
not used.
Channel 1 to Channel 4 LED Current Sink. Leave the pin unconnected if
not used.
Over Voltage Protection. PWM boost converter turns off when VOVP goes
higher than 1.2V.
10, 9, 8, 7
CH5 to CH8
15, 14, 13, 12
CH1 to CH4
16
OVP
17, 18
PGND1, PGND2 Power Ground (LX1/LX2 power return).
19, 20
LX1, LX2
PWM boost converter switch node.
22
COMP
PWM boost converter loop compensation node.
23
VIN
Power supply of the chip. For good bypass, a low ESR capacitor is
required.
24
VDC
Put 1μF capacitor on this pin to stabilize the 5V output of the internal
regulator. This regulator is for chip internal use only.
DS8562B-06
June 2011
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3
RT8562B
Absolute Maximum Ratings
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(Note 1)
Supply Voltage, VIN -----------------------------------------------------------------------------------------------------LX1, LX2 Pin Voltage at Switching Off -------------------------------------------------------------------------------CH1 to CH8 Pin -----------------------------------------------------------------------------------------------------------PWM, EN, OVP Pin Voltage ------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C
WQFN-24L 4x4 -----------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2)
WQFN-24L 4x4, θJA ------------------------------------------------------------------------------------------------------WQFN-24L 4x4, θJC -----------------------------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 3)
HBM (Human Body Mode) ---------------------------------------------------------------------------------------------MM (Machine Mode) ------------------------------------------------------------------------------------------------------
Recommended Operating Conditions
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28V
50V
50V
−0.3V to 5.5V
1.923W
52°C/W
7°C/W
150°C
260°C
−65°C to 150°C
2kV
200V
(Note 4)
Supply Input Voltage, VIN ----------------------------------------------------------------------------------------------- 4.5V to 24V
Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C
Ambient Temperature Range -------------------------------------------------------------------------------------------- −40°C to 85°C
Electrical Characteristics
(VIN = 17V, TA = 25°C, unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
COMP ≤ 0.2V (Switching off)
--
3
5
mA
VIN Rising
--
2.8
3.5
Hysteresis
--
0.4
--
Supply Current
IVIN
VIN Under Voltage
Lockout Threshold
VUVLO
Shutdown Current
ISHDN
VEN ≤ 0.7V
--
--
10
μA
EN Pin Input Current
IEN
VEN ≤ 5V
--
--
0.1
μA
1.6
--
5.5
--
--
1
1.3
--
5
--
--
0.65
2V > VCHx > 0.6V, R ISET = 4.75kΩ, V PWM > 1.2V
19
20
21
mA
2V > V CHx > 0.6V, RISET = 4.75kΩ, VPWM >
1.2V, Calculating
(I(MAX) − I(MIN)) / IAverage x 100%
--
--
1.5
%
EN Voltage Logic-High VEN_H
Input
Logic-Low VEN_L
PWM
Logic-High VPWM_H
Voltage
Logic-Low VPWM_L
Input
V
V
V
LED Current Programming
LED Current
ICHx
LEDs Current Matching
ISET Pin Voltage
VISET
3.6kΩ ≤ RISET ≤ 9.6kΩ, VPWM > 1.2V
1.17
1.2
1.23
V
Input Current of PWM
IPWM
VIN = 12V, V EN = 3.3V, V PWM = 5.5V
--
1
--
μA
Threshold of PWM
VPWM
LED Current Off
--
--
0.65
V
Un-connection
--
0.1
--
V
VCHx Threshold
To be continued
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4
DS8562B-06
June 2011
RT8562B
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
0.8
1
1.2
MHz
--
100
--
ns
0.5
0.6
0.7
V
--
±15
--
μA
0.1
0.2
--
V
--
0.3
0.5
Ω
2.5
--
--
A
--
88
--
%
1.1
1.2
1.3
V
PWM Boost Converter
Switching Frequency
Minimum On Time
Regulated VCHx
Highest Voltage LED String
Amplifier (gm) Output Current
2.4V > COMP > 0.2V
COMP Threshold
PWM Switch Off
LX1, LX2 RDS(ON)
LX1, LX2 Current Limit
ILIM
SW Maximum Duty
OVP & Soft Start
OVP Threshold
VOVP
OVP Input Current
IOVP
VOVP ≤ 3V
--
--
50
nA
Soft Start Current
ISS
VSS ≤ 2.5V
3
5
8
μA
Thermal Shutdown Temperature
T SD
--
150
--
°C
--
20
--
°C
Thermal Shutdown Hysteresis
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 the natural convection at TA = 25°C on a high-effective four layers thermal conductivity test board of
JEDEC 51-7 thermal measurement standard. The case point of θJC is on the expose pad for the WQFN package.
Note 3. Devices are ESD sensitive. Handling precaution is recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
DS8562B-06
June 2011
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5
RT8562B
Typical Operating Characteristics
LED Current vs. Input Voltage
Efficiency vs. Input Voltage
100
24
23
90
80LEDs
22
LED Current (mA)
Efficiency(%)
80
70
60
50
40
30
21
20
19
CH1
CH2
CH3
CH4
CH5
CH6
CH7
CH8
18
17
16
15
20
14
10
13
0
12
4
6
8
10
12
14
16
18
20
22
24
4
Input Voltage(V)
6
8
12
14
16
18
20
22
24
Input Voltage (V)
LED Current vs. Temperature
VISET vs. Temperature
24
1.24
23
1.22
22
1.20
21
VISET (V)
LED Current (mA)
10
20
19
1.18
1.16
1.14
18
1.12
17
VIN = 12V
VIN = 12V
1.10
16
-40 -25 -10
5
20
35 50
65
80
-40
95 110 125
-15
10
35
60
85
110
135
Temperature (°C)
Temperature (°C)
LED Current vs. PWM Duty Cycle
VISET vs. Input Voltage
25
1.25
1.24
20
LED Current (mA)
1.23
V ISET (V)
1.22
1.21
1.20
1.19
1.18
15
PWM = 200Hz
PWM = 1kHz
PWM = 10kHz
PWM = 30kHz
10
5
1.17
1.16
VPWM = 0V to 3V, VIN = 12V
0
1.15
4
6
8
10
12
14
16
18
Input Voltage (V)
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6
20
22
24
0
0
0.1
10
0.2
1
20 0.3
30 0.4
40 0.5
50 0.6
60 0.7
70 0.8
80 0.9
90 100
Duty Cycle (%)
DS8562B-06
June 2011
RT8562B
Shutdown Current vs. Input Voltage
Shutdown Current vs. Temperature
6
8
Shutdown Current (uA)
Shutdown Current (uA)
10
6
4
2
VEN = 0V
0
4
6
8
10
12
14
16
18
20
22
5
4
3
2
1
VIN = 12V, VEN = 0V
0
24
-40 -25 -10
5
Input Voltage (V)
35
50
65
80
95 110 125
Temperature (°C)
S S C u rre n t v s . T e m p e ra tu re
Switch Off Current vs. Input Volatge
4.0
8 .0
3.8
7 .6
3.6
7 .2
3.4
6 .8
SS Current (uA)
Switch Off Current (mA)
20
3.2
3.0
2.8
2.6
6 .4
6 .0
5 .6
5 .2
4 .8
2.4
4 .4
2.2
COMP = 0V
2.0
4
6
8
10
12
14
16
18
20
22
VIN = 12V, CSS = 0.1μF
4 .0
-4 0
24
-1 5
10
35
60
85
110
135
T e m p e rature (°C)
Input Volatge (V)
OVP Voltage vs. Temperature
SS Current vs. Input Volatge
1.30
6.0
1.28
1.26
OVP Voltage (V)
SS Current (uA)
5.8
5.6
5.4
1.24
1.22
1.20
1.18
1.16
1.14
5.2
1.12
CSS = 0.1μF
5.0
4
6
8
10
12
14
16
18
Input Volatge (V)
DS8562B-06
June 2011
20
22
24
VIN = 12V
1.10
-40
-15
10
35
60
85
110
135
Temperature (°C)
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7
RT8562B
Line Transient Response
OVP Voltage vs. Input Volatge
1.4
VIN = 10.8V to 13.2V
OVP Voltage (V)
1.2
1.0
0.8
VIN
(5V/Div)
0.6
0.4
IOUT
(100mA/Div)
0.2
0.0
4
6
8
10
12
14
16
18
20
Time (50ms/Div)
22
Input Volatge (V)
Power On from EN
OVP
VEN
(2V/Div)
VIN
(10V/Div)
VOUT
(20V/Div)
VOUT
(50V/Div)
I IN
(500mADiv)
VIN = 12V, CSS = 0.1μF
Time (10ms/Div)
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LX1, LX2
(50V/Div)
VIN = 12V, All LED Pin Open
Time (2.5ms/Div)
DS8562B-06
June 2011
RT8562B
Applications Information
The RT8562B is a current mode boost converter operating
at 1MHz to power up to 80 white LEDs with a
programmable current for uniform intensity. The part
integrates current sources, soft-start, and easy analog
and digital dimming control. The protection block provides
the circuitry for over-temperature, over-voltage and currentlimit protection features.
LED connection
Input UVLO
The LED current can be calculated by the following
equation :
ILED (mA) = 20 x 4.75
RISET (kΩ)
The input operating voltage range of the RT8562B is 4.5V
to 24V. An input capacitor at the VIN pin can reduce ripple
voltage. It is recommended to use a ceramic 10μF or larger
capacitance as the input capacitor. This IC provides an
under voltage lockout (UVLO) function to enhance the
stability when startup.
Power Sequence
Please refer to the below Figure 2. The recommended
power-on sequence is that the PWM/VIN ready before
EN ready. If not, the soft-start function will be disabled.
As to power off sequence, the EN must be pulled low
before PWM/VIN turning low.
Power On
sequence
Power Off
sequence
Abnormal Power On
sequence
VIN
UVLO
PWM
EN
EN must be turned
on late than VIN
and PWM signal
Soft-Start
VOUT
EN must be turned
off early than VIN
and PWM signal
No Soft-Start
If PWM turns
on late
Figure 2. Power On Sequence Control by EN
Soft-Start
The RT8562B employs a soft-start feature to limit the inrush
current. The soft-start circuit prevents the excessive inrush
current and input voltage droop. The soft-start time is
determined by capacitor CSS connected to SS pin with
5μA constant current to charge CSS. The value of capacitor
CSS is user-defined to satisfy the designer's requirement.
The RT8562B equips 8-CH LED drivers and each channel
supports up to 10 LEDs. The 8 LED strings are connected
from VOUT to pin 7, 8, 9, 10, 12, 13, 14, and 15
respectively. If one of the LED channel is not used, the
LED pin should be opened directly.
Setting and Regulation of LED current
Where, the RISET is the resister between ISET pin and
GND.
This setting is the reference for the LED current at CH1 to
CH8 and represents the sensed LED current for each string.
The DC/DC converter regulates the LED current according
to the setting.
If VIN is close to VOUT and smaller than VOUT, the control
loop may turn on the power switch with minimum on time
and then skip cycles to maintain LED current regulation.
Brightness Control
The RT8562B features the digital dimming control scheme.
A very high contrast ratio true digital PWM dimming can
be achieved by driving PWM pin with a PWM signal and
the recommended PWM frequency is 100Hz to 10kHz.
Dimming frequency can be sufficiently adjusted from
100Hz to 30kHz. However, LED current cannot be 100%
proportional to duty cycle especially for high frequency
and low duty ratio because of physical limitation caused
by inductor rising time. Please refer to Table 1 and Figure 3.
Table 1.
Dimming Frequency (Hz)
100 < fPWM ≤ 200
200 < fPWM ≤ 500
500 < fPWM ≤ 1k
1k < fPWM ≤ 2k
2k < fPWM ≤ 5k
5k < fPWM ≤ 10k
10k < f PWM ≤ 20k
Duty (Min.)
0.16%
0.40%
0.80%
1.60%
4.00%
8.00%
16.00%
Duty (Max.)
100%
100%
100%
100%
100%
100%
100%
Note : The minimum duty in Table 1 is based on the application
circuit and does not consider the deviation of current linearity.
DS8562B-06
June 2011
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9
RT8562B
LED Current vs. PWM Duty Cycle
25
LED Current (mA)
20
15
PWM = 200Hz
PWM = 1kHz
PWM = 10kHz
PWM = 30kHz
10
5
VPWM = 0V to 3V, VIN = 12V
0
0
0
0.1
10
0.2
20
0.3
1
30 0.4
40 0.5
50 0.6
60 0.7
70 0.8
80 0.9
90 100
Duty Cycle (%)
Figure 3. LED Current vs. PWM Dimming Duty Cycle
Over Temperature Protection
The RT8562B has over temperature protection (OTP)
function to prevent the excessive power dissipation from
overheating. The OTP will shut down switching operation
while the junction temperature exceeds 150°C. Main
converter starts switching when junction temperature
cooling down approximately 20°C.
Inductor Selection
The value of the output inductor (L), where the transition
from discontinuous to continuous mode occurs is
approximated by the following equation :
L=
(VOUT − VIN ) × VIN2
2 × IOUT × f × VOUT 2
Where,
Over Voltage Protection
The RT8562B equips over voltage protection (OVP)
function. When the voltage at the OVP pin reaches a
threshold of approximately 1.2V, the MOSFET driver
output (LX1, LX2) will be turned “OFF”. The MOSFET
driver output (LX1, LX2) will be turned “ON” again once
the voltage at OVP drops below the threshold voltage 1.2V.
So, the output voltage can be clamped at a certain voltage
level and it can be calculated by the following equation :
VOUT, OVP = VOVP × ⎛⎜ 1+ R2 ⎞⎟
⎝ R3 ⎠
Where
R2 and R3 are the voltage divider connected to OVP pin.
VOVP is typically 1.2V.
If at least one string is in normal operation, the controller
will automatically ignore the open strings and continue to
regulate the current for the string(s) in normal operation.
VOUT = maximum output voltage.
VIN = minimum input voltage.
f = operating frequency.
IOUT = sum of current from all LED strings.
η is the efficiency of the power converter.
The boost converter operates in discontinuous mode over
the entire input voltage range when the L1 inductor value
is less than this value L. With an inductance greater than
L, the converter operates in continuous mode at the
minimum input voltage and may be discontinuous at higher
voltages.
The inductor must be selected with a saturation current
rating greater than the peak current provided by the
following equation :
IPEAK = VOUT × IOUT + VIN × T ⎛⎜ VOUT − VIN ⎞⎟
η × VIN
2 × L ⎝ VOUT
⎠
Current Limit Protection
The RT8562B can limit the peak current to achieve over
current protection. RT8562B senses the inductor current
through LX1, LX2 pins in the switch-on period. The duty
cycle depends on the current sense signal summing with
the internal slope compensation compared to the COMP
signal. The internal N-MOSFET will be turned off when
the current signal is larger than the COMP signal. In the
off period, the inductor current will descend. The internal
MOSFET is turned on by the oscillator in the next begining
cycle.
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Diode Selection
Schottky diode is a good choice for an asynchronous
Boost converter due to the small forward voltage. However,
for power dissipation, reverse voltage rating and pulsating
peak current are the important parameters of Schottky
diode consideration. Choose a suitable diode whose
reverse voltage rating is greater than the maximum output
voltage.
DS8562B-06
June 2011
RT8562B
Capacitor Selection
Four-Layer PCB
Maximum Power Dissipation (W)
The input capacitor reduces current spikes from the input
supply and minimizes noise injection to the converter. For
most applications, a 10μF ceramic capacitor is sufficient.
A value higher or lower may be used depending on the
noise level from the input supply and the input current to
the converter.
It is recommended to choose a ceramic capacitor bases
on the output voltage ripple requirements. The minimum
value of the output capacitor COUT is approximately given
by the following equation :
COUT =
(VOUT − VIN ) × IOUT
η × VRIPPLE × VOUT × f
2.0
1.6
1.2
0.8
0.4
0.0
0
25
50
75
100
125
Ambient Temperature (°C)
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 dissipaton can be calculated by the
following formula :
PD(MAX) =
Figure 4. Derating Curve for RT8562B Package
Layout Guideline
PCB layout is very important to design power switching
converter circuits. The following layout guide lines should
be strictly followed for best performance of the RT8562B.
`
The power components L, D1, C1, COUT1 and COUT2 must
be placed as close as possible to reduce the ac current
loop. The PCB trace between power components must
be short and wide as possible due to large current flow
through these trace during operation.
`
Place L and D1 connected to LX pin as close as possible.
The trace should be short and wide as possible.
`
It is recommend to place C6 close to VIN pin.
`
Pin22 is the compensation point to adjust system
stability. Place the compensation components to pin22
as close as possible.
TJ(MAX) − TA
θJA
Where TJ(MAX) is the maximum junction temperature, TA is
the ambient temperature, and θJA is the junction to ambient
thermal resistance.
For recommended operating condition specifications of
RT8562B, the maximum junction temperature is 125°C
and TA is the ambient temperature. The junction to ambient
thermal resistance, θJA is layout dependent. For WQFN24L 4x4 packages, the thermal resistance, θJA is 52°C/W
on a standard JEDEC 51-7 four-layer thermal test board.
The maximum power dissipaton at TA = 25°C can be
calculated by the following formula :
P D(MAX) = 125°C − 25°C = 1.923W
52°C/W
for WQFN-24 4x4 package
The maximum power dissipation depends on the operating
ambient temperature for fixed T J(MAX) and thermal
resistance,θJA. For RT8562B package, the derating curbe
in Figure 4 allows the designer to see the effect of rising
ambient temperature on the maximum power dissipation.
DS8562B-06
June 2011
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11
RT8562B
VIN
Locate the compensation
components to COMP
pin as close as possible.
R4
C1
GND
R1
C6
COMP
LX2
LX1
23
D1
NC
VIN
24
COUT2
L
CVC2
VDC
Locate the CVIN2 as
close to VIN pin as
possible.
Place power components
as close as possible.
C2
22
21
20
19
COUT1
VOUT
EN
1
18
PGND2
NC
2
17
PGND1
16
OVP
15
CH1
14
CH2
13
CH3
PWM
6
25
CH8
7
8
9
10
11
12
CH4
5
ISET
GND
GND
CH5
4
CH6
NC
CH7
SS
3
Figure 5
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12
DS8562B-06
June 2011
RT8562B
Outline Dimension
D2
D
SEE DETAIL A
L
1
E
E2
e
b
1
1
2
2
DETAIL A
Pin #1 ID and Tie Bar Mark Options
A
A3
A1
Note : The configuration of the Pin #1 identifier is optional,
but must be located within the zone indicated.
Dimensions In Millimeters
Dimensions In Inches
Symbol
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
0.180
0.300
0.007
0.012
D
3.950
4.050
0.156
0.159
D2
2.300
2.750
0.091
0.108
E
3.950
4.050
0.156
0.159
E2
2.300
2.750
0.091
0.108
e
L
0.500
0.350
0.020
0.450
0.014
0.018
W-Type 24L 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.
DS8562B-06
June 2011
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13