RT8561C - Richtek

RT8561C
High Voltage 8-CH LED Driver
General Description
Features
The RT8561C is a 40V 8-CH LED driver capable of
delivering 30mA to each channel with 10 LEDs (3.6V per
diode), for a total of 80 LEDs with one driver. The RT8561C
is a current mode boost converter that operates at 1MHz,
with a wide VIN range from 4.5V to 24V and an on chip
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High Voltage : VIN up to 24V, VOUT up to 40V
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Programmable Channel Current from 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 Detection of Unconnected and/or Broken
Channel
Programmable Over Voltage Protection
Disconnects LED in Shutdown
No Power Sequence Concern
VIN Under Voltage Lockout
Over Temperature Protection
Current Limiting Protection
Small 24-Lead WQFN Package
RoHS Compliant and Halogen Free
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current switch rated at 2.5A.
The PWM output voltage loop regulates the LED pins to
0.6V with an auto adjustment circuit allowing voltage
mismatches between LED strings. The RT8561C automati
cally detects and disconnects any unconnected and/or
broken strings during operation from the PWM loop to
prevent VOUT from over voltage.
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The 1.5% matched LED currents on all channels can be
simply programmed with a resistor or a current sink. A
very high contrast ratio true digital PWM dimming can be
achieved by driving the PWM pin with a PWM signal.
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Other protection features include programmable output
over voltage protection, LED current limit, PWM switch
current limit and thermal shutdown.
Applications
The RT8561C is available in a WQFN-24L 4x4 package.
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UMPC and Notebook Computer Backlight
GPS, Portable DVD Backlight
Desk Lights and Room Lighting
Ordering Information
Pin Configurations
LX
23
LX
24
GND
Lead Plating System
G : Green (Halogen Free and Pb Free)
GND
(TOP VIEW)
GND
Package Type
QW : WQFN-24L 4x4 (W-Type)
GND
RT8561C
22
21
20
19
Note :
LED1
1
18
VCC
Richtek products are :
LED2
2
17
CREG
LED3
3
16
LED8
LED4
4
15
LED7
LED5
5
14
LED6
OVP
6
13
EN
25
Marking Information
E4= : Product Code
E4=YM
DNN
YMDNN : Date Code
DS8561C-00 April 2011
VC
7
8
9
10
11
12
NC
Suitable for use in SnPb or Pb-free soldering processes.
ACTL
`
SS
ments of IPC/JEDEC J-STD-020.
GND
RISET
RoHS compliant and compatible with the current require-
NC
`
WQFN-24L 4x4
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1
RT8561C
Typical Application Circuit
VIN
4.5V to 24V
C5
10µF
C6
1µF
LED1
7 VC
R1
1.8k
LED2
LED7
LED8
17
CREG
9 SS
... :::
:
:
: 8 x 10 LED String
:
:
1
2
15
16
R2
OVP 6
RISET 10
VOUT
R3
C4
0.1µF
21, 22, 23, 24,
25 (Exposed Pad)
C7
:
:
:
:
...
11 ACTL
PWM Signal
R7
...
R6 1k
LX 19, 20
VCC
R5
1k 13
EN
5V
C2
3.9nF
:
:
:
:
RT8561C
18
C3
4.7µF
D1
C1
10µF
R4
10
C8
VOUT
40V MAX
L1
10µH
RISET
4.75k
ILED (mA) = 20 x 4.75
RISET (kΩ )
GND
Note :
Due to the limitation of maximum duty, 5V input can support typically to VOUT = 33V.
Figure 1. 1MHz, 20mA Full Scale Current PWM Dimming Control
Function Block Diagram
LX
OSC
VCC
-
4.2V
+
R
OVP
-
+
-
-
1.6V
+
EN
-
R
+
1.2V
CREG
LED1
S
+
LED2
Shutdown
+
-
5V
LDO
VOUT
Regulation
Unit
VC
.
.
.
LED7
+
5V
-
5µA
SS
LED8
+
ACTL
+
GND
-
-
RISET
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DS8561C-00 April 2011
RT8561C
Functional Pin Description
Pin No.
Pin Name
1, 2, 3, 4, 5
LED1, LED2,
LED3, LED4,
LED5
Channel 1 to Channel 5 LED current sink. Leave the pin unconnected if not
used.
6
OVP
Over Voltage Protection. PWM boost converter turns off when VOVP goes
higher than 1.2V.
7
VC
PWM boost converter loop compensation node.
8
NC
No Internal Connection.
9
SS
Soft Start Pin, a capacitor of at least 10nF is required for soft start.
10
RISET
A resistor or a current from DAC on this pin programs the full LED current.
11
ACTL
Analog/Digital dimming control. When using analog dimming,
ILED (mA) = 20 x 4.75 for VACTL ≥ 1.2V.
RISET (k Ω)
12
NC
No Internal Connection.
13
EN
Chip enable pin, when pulled low, chip is in shutdown mode.
LED6, LED7,
LED8
Channel 6 to Channel 8 LED current sink. Leave the pin unconnected if not
used.
17
CREG
4.7μF capacitor should be placed on this pin to stabilize the 5V output of the
internal regulator. This regulator is for chip internal use only.
18
VCC
Power supply of the chip. For good bypass, a low ESR capacitor is required.
LX
PWM boost converter switch node.
GND
Ground pin of the chip. The exposed pad must be soldered to a large PCB
and connected to GND for maximum power dissipation.
14, 15, 16
19, 20
21, 22, 23, 24,
25 (Exposed Pad)
DS8561C-00 April 2011
Pin Function
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RT8561C
Absolute Maximum Ratings
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(Note 1)
Supply Voltage, VCC ----------------------------------------------------------------------------------------------------LX Pin Voltage at Switching Off ---------------------------------------------------------------------------------------LED1 to LED8 Pin --------------------------------------------------------------------------------------------------------ACTL, EN ------------------------------------------------------------------------------------------------------------------OVP -------------------------------------------------------------------------------------------------------------------------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
24V
−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, VCC ---------------------------------------------------------------------------------------------- 4.5V to 24V
Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C
Ambient Temperature Range -------------------------------------------------------------------------------------------- −40°C to 85°C
Electrical Characteristics
(VCC = 17V, TA = 25°C, unless otherwise specified)
Parameter
Symbol
Supply Current
IVCC
VIN Under Voltage Lockout
Threshold
VUVLO
Shutdown Current
ISHDN
EN Threshold
Voltage
ACTL Threshold
Voltage
Test Conditions
Min
Typ
Max
Unit
VC ≤ 0.2V (Switching off)
--
3
5
mA
VIN Rising
--
4.2
4.5
Hysteresis
--
0.3
--
VEN = 0V
--
--
10
1.6
--
5
--
--
0.65
1.3
--
5
--
--
0.65
Logic-High VEN_H
Logic-Low
VEN_L
Logic-High VACTL_H
Logic-Low
EN Pin Input Current
VACTL_L
V
μA
V
V
IEN
VEN ≤ 5V
--
--
0.1
μA
ILED
2V > VLED > 0.6V, RISET = 4.75kΩ
19
20
21
mA
2V > VLED > 0.6V, RISET = 4.75kΩ
Calculating
(I (MAX) − I(MIN)) / IAverage x 100%
--
--
1.5
%
1.17
1.2
1.23
V
LED Current Programming
LED Current
LEDs Current Matching
RISET Pin Voltage
VRISET
3.6kΩ ≤ RISET ≤ 9.6kΩ, VACTL > 1.2V
Input Current of ACTL
IACTL
VACTL = 1.3V
--
1
2
μA
Un-connection
--
0.1
--
V
VLED Threshold
To be continued
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DS8561C-00 April 2011
RT8561C
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
0.8
1
1.2
MHz
--
100
--
ns
0.5
0.6
0.7
V
PWM Boost Converter
Switching Frequency
Minimum On Time
Regulated VLED
Highest Voltage LED String
Amplifier (gm) Output Current
2.4V > VC > 0.2V
--
±15
--
μA
VC Threshold
PWM Switch Off
0.1
0.2
--
V
--
0.3
0.5
Ω
I LIM
2.5
--
--
A
OVP Threshold
VOVP
1.1
1.2
1.3
V
OVP Input Current
I OVP
VOVP ≤ 3V
--
--
50
nA
Soft Start Current
I SS
VSS ≤ 2.5V
3
5
8
μA
--
150
--
°C
--
20
--
°C
LX RDS(ON)
LX Current Limit
OVP & Soft Start
Thermal Shutdown
Temperature
Thermal Shutdown Hysteresis
TSD
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.
DS8561C-00 April 2011
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RT8561C
Typical Operating Characteristics
Efficiency vs. Input Voltage
LED Current vs. Input Voltage
100
22.0
90
21.2
LED Current (mA)
80
Efficiency (%)
21.6
80LEDs
70
60
50
40
30
20.8
20.4
LED1
LED2
LED3
LED4
LED5
LED6
LED7
LED8
20.0
19.6
19.2
20
18.8
10
18.4
18.0
0
4
6
8
10
12
14
16
18
20
22
4
24
6
8
10
14
16
18
20
22
24
Input Voltage (V)
Input Voltage (V)
VRISET vs. Temperature
LED Current vs. Temperature
24
1.24
23
1.22
22
1.20
21
VRISET (V)
LED Current (mA)
12
20
19
1.18
1.16
1.14
18
1.12
17
VIN = 12V
VIN = 12V
1.10
16
-50
-25
0
25
50
75
100
-50
125
-25
0
25
50
75
100
125
Temperature (°C)
Temperature (°C)
LED Current vs. PWM Duty Cycle
VRISET vs. Input Voltage
25
1.25
1.24
20
LED Current (mA)
1.23
VRISET (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
Input Voltage (V)
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18
20
22
24
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 (%)
DS8561C-00 April 2011
RT8561C
Shutdown Current vs. Temperature
Shutdown Current vs. Input Voltage
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Shutdown Current (μA)1
Shutdown Current (μA)1
10
8
6
4
2
4
6
8
10
12
14
16
18
20
22
4
3
2
1
VIN = 12V, VEN = 0V
VEN = 0V
0
5
0
-50
24
-25
0
50
75
100
125
Temperature (°C)
Input voltage (V)
Switch Off Current vs. Input Voltage
SS Current vs. Temperature
4.0
8.0
3.8
7.6
3.6
7.2
3.4
6.8
SS Current (μA)
Switch Off Current (mA)
25
3.2
3.0
2.8
2.6
6.4
6.0
5.6
5.2
4.8
2.4
2.2
4.4
VCOMP = 0V
VIN = 12V, CSS = 0.1μF
4.0
2.0
4
6
8
10
12
14
16
18
20
22
-50
24
-25
0
25
50
75
100
125
Temperature (°C)
Input Voltage (V)
OVP Voltage vs. Temperature
SS Current vs. Input Voltage
6.0
1.30
1.28
1.26
OVP Voltage (V)
SS Current (μA)
5.8
5.6
5.4
5.2
1.24
1.22
1.20
1.18
1.16
1.14
CSS = 0.1μF
5.0
1.12
VIN = 12V
1.10
4
6
8
10
12
14
16
18
Input Voltage (V)
DS8561C-00 April 2011
20
22
24
-50
-25
0
25
50
75
100
125
Temperature (°C)
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RT8561C
OVP Voltage (V)
OVP Voltage vs. Input Voltage
Line Transient Response
1.4
14V
1.2
12V
1.0
10V
0.8
IOUT
(100mA/Div)
0.6
0.4
0.2
VIN
VIN = 10.8V to 13.2V
0.0
4
6
8
10
12
14
16
18
20
22
24
Time (50ms/Div)
Input Voltage (V)
Power On from EN
EN
(2V/Div)
VOUT
(20V/Div)
LX
(20V/Div)
I IN
(100mADiv)
VIN = 12V
Time (10ms/Div)
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DS8561C-00 April 2011
RT8561C
Applications Information
The RT8561C 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 current
limit protection features.
Input UVLO
The input operating voltage range of the RT8561C is 4.5V
to 24V. An input capacitor at the VCC pin can reduce
ripple voltage. It is recommended to use a ceramic 10μF
or larger capacitor as the input capacitor. This IC provides
an Under Voltage Lockout (UVLO) function to enhance
the stability during startup.
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 RT8561C features digital dimming control scheme.
A very high contrast ratio true digital PWM dimming can
be achieved by driving the ACTL pin with a PWM signal at
the recommended PWM frequency range from 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. Refer to Table 1 and Figure 2.
Soft-Start
The RT8561C employs a soft-start feature to limit the inrush
current. The soft-start circuit prevents excessive inrush
current and input voltage droop. The soft-start time is
determined by the capacitor, C4, which is connected to
the SS pin with 5μA constant current. The value of capacitor
C4 is user defined to satisfy the designer's requirement.
LED Connection
The RT8561C provides an 8-CH LED driver with each
channel capable of supporting up to 10 LEDs. The 8 LED
strings are connected from VOUT to pins 1, 2, 3, 4, 5, 14,
15, and 16 respectively. If one of the LED channels is not
in use, the LED pin should be tied to ground directly.
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.
LED Current vs. PWM Duty Cycle
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Setting and Regulation of LED Current
The LED current can be calculated by the following
equation :
ILED (mA) = 20 x 4.75
RISET (kΩ)
where, RISET is the resistor between the RISET pin and
GND.
This setting is the reference for the LED current at LED1
to LED8 and represents the sensed LED current for each
string. The DC/DC converter regulates the LED current
according to the setting.
DS8561C-00 April 2011
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 2. LED Current vs. PWM Dimming Duty Cycle
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RT8561C
Over Voltage Protection
The RT8561C equips an Over Voltage Protection (OVP)
function. When the voltage at the OVP pin reaches a
threshold of approximately 1.2V, the MOSFET driver
output (LX) will be turned “OFF”. The MOSFET driver
output (LX) will be turned “ON” again once the voltage at
OVP drops below the threshold voltage 1.2V.
Thus, the output voltage can be clamped at a certain
voltage level as shown in the following equation :
VOUT, OVP = VOVP × ⎛⎜ 1+ R2 ⎞⎟
⎝ R3 ⎠
Hence, even when VIN is ready, the control circuit will
still wait for the arrival of PWM and EN before the LEDs
can react :
VIN
VOUT
EN
ACTL
Figure 3. EN/ACTL Prior to VIN
where
R2 and R3 are the resistors in a voltage divider connected
to the 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.
UVLO
VIN
UVLO
VOUT
EN
ACTL
Current Limit Protection
The RT8561C can limit the peak current to achieve over
current protection. The RT8561C senses the inductor
current through the LX pin during the switch on period.
The duty cycle depends on the current sense signal
summed up with the internal slope compensation and
compared to the VC 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 beginning cycle.
Figure 4. VIN Tums Off Prior to EN/ACTL
VIN
VOUT
EN
ACTL
Figure 5. EN Prior to ACTL Signal
Over Temperature Protection
The RT8561C has an Over Temperature Protection (OTP)
function to prevent excessive power dissipation from
overheating the device. The OTP will shut down switching
operation when the junction temperature exceeds 150°C.
The main converter will start switching again once the
junction temperature cools down approximately by 20°C.
VIN
VOUT
EN
Power Sequence
The RT8561C can apply these power on/off sequences
among VLED, EN and ACTL as shown in the charts below.
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ACTL
Figure 6. EN Prior to ACTL Signal
DS8561C-00 April 2011
RT8561C
Diode Selection
VIN
VOUT
EN
ACTL
Figure 7. ACTL Prior to EN Signal
Schottky diode is a good choice for an asynchronous boost
converter due to its small forward voltage. However, when
selecting a Schottky diode, important parameters such
as power dissipation, reverse voltage rating and pulsating
peak current should all be taken into consideration.
Choose a suitable diode with reverse voltage rating greater
than the maximum output voltage.
Capacitor Selection
VIN_POK
LED_ON
ACTL
EN
Figure 8
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,
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
⎠
DS8561C-00 April 2011
The input capacitor reduces current spikes from the input
supply and minimizes noise injection into 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 based
on the output voltage ripple requirements. The minimum
value of the output capacitor COUT is approximately given
by the following equation :
(VOUT − VIN ) × IOUT
COUT =
η × VRIPPLE × VOUT × f
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) = (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
RT8561C, 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 :
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RT8561C
PD(MAX) = (125°C − 25°C) / (52°C/W) = 1.923W for
WQFN-24L 4x4 package
17
LED3
3
LED4
4
LED5
5
OVP
6
8
9
10
11
12
ACTL
NC
25
R1
C2
0.00
GND
50
75
100
125
LX
18
GND
GND
C6
2
0.40
Ambient Temperature (°C)
19
1
C8
25
20
LED2
1.20
0
21
LED1
7
0.80
GND
GND
22
LX
GND
23
RISET
1.60
24
VIN
L
SS
2.00
C1
NC
Four-Layer PCB
GND
D
VC
Maximum Power Dissipation (W)1
2.40
VOUT
C5
GND
The maximum power dissipation depends on the operating
ambient temperature for fixed T J(MAX) and thermal
resistance, θJA. For the RT8561C package, the derating
curve in Figure 9 allows the designer to see the effect of
rising ambient temperature on the maximum power
dissipation.
Place these components
as close as possible.
R4
VCC
16
Locate the C6 as
CREG close to VCC pin as
LED8 possible.
15
LED7
14
LED6
13
EN
Locate the compensation
components to VC pin as
close as possible.
Figure 10. PCB Layout Guide
Figure 9. Derating Curve for RT8561C Package
Layout Guideline
PCB layout is very important for designing power switching
converter circuits. Some recommended layout guides that
should be strictly be followed are shown as follows :
`
The power components L1, D1, CVIN1, 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 these trace during operation.
`
Place L1 and D1 connected to LX pin as close as possible.
The trace should be short and wide as possible.
`
Recommend place CVIN2 close to VCC pin.
`
Pin7 is the compensation point to adjust system
stability. Place the compensation components to pin7
as close as possible, no matter the compensation is
RC or capacitance.
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DS8561C-00 April 2011
RT8561C
Outline Dimension
D2
D
SEE DETAIL A
L
1
E
E2
e
b
1
2
DETAIL A
Pin #1 ID and Tie Bar Mark Options
A
A3
A1
Symbol
1
2
Note : The configuration of the Pin #1 identifier is optional,
but must be located within the zone indicated.
Dimensions In Millimeters
Min
Dimensions In Inches
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.
DS8561C-00 April 2011
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