RICHTEK RT8064

®
RT8064
2A, 2MHz, Synchronous Step-Down Converter
General Description
Features
The RT8064 is a high efficiency synchronous, step-down
DC/DC converter. Its input voltage range is from 2.7V to
5.5V and provides an adjustable regulated output voltage
from 0.8V to 5V while delivering up to 2A of output current.
z
High Efficiency : Up to 95%
z
Adjustable Frequency : 200kHz to 2MHz
No Schottky Diode Required
0.8V Reference Allows Low Output Voltage
Low Dropout Operation : 100% Duty Cycle
Enable Function
External Soft-Start
Power Good Function
RoHS Compliant and Halogen Free
The internal synchronous low on-resistance power
switches increase efficiency and eliminate the need for
an external Schottky diode. The default switching
frequency is set at 2MHz, if the RT pin is left open. It can
also be varied from 200kHz to 2MHz by adding an external
resistor. Current mode operation with external
compensation allows the transient response to be
optimized over a wide range of loads and output capacitors.
z
z
z
z
z
z
z
Applications
z
z
Ordering Information
RT8064
Package Type
SP : SOP-8 (Exposed Pad-Option 2)
QW : WDFN-8L 3x3 (W-Type)
Lead Plating System
Z : ECO (Ecological Element with
Halogen Free and Pb free)
Note :
z
z
z
LCD TV and Monitor
Notebook Computers
Distributed Power Systems
IP Phones
Digital Cameras
Marking Information
RT8064ZSP
RT8064ZSP : Product Number
RT8064
ZSPYMDNN
YMDNN : Date Code
Richtek products are :
`
RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.
`
RT8064ZQW
Suitable for use in SnPb or Pb-free soldering processes.
28 : Product Code
28 YM
DNN
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
DS8064-07
November 2012
YMDNN : Date Code
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
1
RT8064
Pin Configurations
(TOP VIEW)
SS
2
EN
3
VIN
4
GND
8
PGOOD
7
FB
6
RT
9
5
COMP
SS
EN
VIN
LX
SOP-8 (Exposed Pad)
8
1
3
GND
COMP
6
4
9
5
2
7
PGOOD
FB
RT
LX
WDFN-8L 3x3
Typical Application Circuit
VIN
2.7V to 5.5V
4
R3
100k
RT8064
5
LX
VIN
L
VOUT
CIN
10µF
R1
8 PGOOD
PGOOD
ROSC
6 RT
FB
7
COMP 1
COUT
RCOMP
R2
CCOMP
GND
Chip Enable
3 EN
SS
9 (Exposed Pad)
2
CSS
10nF
Table 1. Recommended Components Selection for fSW = 1MHz
VOUT (V)
R1 (kΩ)
R2 (kΩ)
RCOMP (kΩ)
CCOMP (pF)
L (μH)
COUT (μF)
3.3
75
24
33
560
2
22
2.5
51
24
22
560
2
22
1.8
30
24
15
560
1.5
22
1.5
21
24
13
560
1.5
22
1.2
12
24
11
560
1.5
22
1
6
24
8.2
560
1.5
22
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
www.richtek.com
2
is a registered trademark of Richtek Technology Corporation.
DS8064-07
November 2012
RT8064
Functional Pin Description
Pin No.
Pin Name
Pin Function
SOP-8
(Exposed Pad)
WDFN-8L 3x3
1
1
COMP
2
2
SS
3
3
EN
4
4
VIN
5
5
LX
6
6
RT
7
7
FB
Feedback. Receives the feedback voltage from a resistive
divider connected across the output.
8
8
PGOOD
Power Good Indicator. This pin is an open drain logic output that
is pulled to ground when the output voltage is not within ±12.5%
of regulation point.
Error Amplifier Compensation Point. The current comparator
threshold increases with this control voltage. Connect external
compensation elements to this pin to stabilize the control loop.
Soft-Start Control Input. Connect a capacitor from SS to GND to
set the soft-start period. A 10nF capacitor sets the soft-start
period to 800μs (typ.).
Enable Control Input. Float or connect this pin to logic high for
enable. Connect to GND for disable.
Power Input Supply. Decouple this pin to GND with a capacitor.
Internal Power MOSFET Switches Output. Connect this pin to
the inductor.
Oscillator Resistor Input. Connect a resistor from this pin to
GND sets the switching frequency. If this pin is floating, the
frequency will be set at 2MHz internally.
Ground. The exposed pad must be soldered to a large PCB and
connected to GND for maximum power dissipation.
9 (Exposed Pad) 9 (Exposed Pad) GND
Function Block Diagram
RT
SD
VIN
ISEN
Slope
Com
OSC
COMP
0.8V
FB
OC
Limit
Output
Clamp
EA
10µA
Driver
LX
Hiccup
SS
Control
Logic
0.7V
EN
Enable
0.4V
P-G
NISEN
OTP
UV
GND
N-MOSFET ILIM
PGOOD
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
DS8064-07
November 2012
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
3
RT8064
Absolute Maximum Ratings
z
z
z
z
z
z
z
z
z
z
(Note 1)
Supply Input Voltage, VIN --------------------------------------------------------------------------------------- −0.3V to 6V
LX Pin Switch Voltage -------------------------------------------------------------------------------------------- −0.3V to (VIN + 0.3V)
<10ns ---------------------------------------------------------------------------------------------------------------- −5V to 8.5V
Other I/O Pin Voltages ------------------------------------------------------------------------------------------- −0.3V to (VIN + 0.3V)
LX Pin Switch Current -------------------------------------------------------------------------------------------- 5A
Power Dissipation, PD @ TA = 25°C
SOP-8 (Exposed Pad) ------------------------------------------------------------------------------------------- 1.333W
WDFN-8L 3x3 ------------------------------------------------------------------------------------------------------ 1.429W
Package Thermal Resistance (Note 2)
SOP-8 (Exposed Pad), θJA -------------------------------------------------------------------------------------- 75°C/W
SOP-8 (Exposed Pad), θJC ------------------------------------------------------------------------------------- 15°C/W
WDFN-8L 3x3, θJA ------------------------------------------------------------------------------------------------- 70°C/W
WDFN-8L 3x3, θJC ------------------------------------------------------------------------------------------------- 8.2°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 Model) -------------------------------------------------------------------------------------- 2kV
Recommended Operating Conditions
z
z
z
(Note 4)
Supply Input Voltage, VIN --------------------------------------------------------------------------------------- 2.7V to 5.5V
Junction Temperature Range ------------------------------------------------------------------------------------ −40°C to 125°C
Ambient Temperature Range ------------------------------------------------------------------------------------ −40°C to 85°C
Electrical Characteristics
(VIN = 3.3V, TA = 25°C, unless otherwise specified)
Parameter
Min
Typ
Max
Unit
0.784
0.8
0.816
V
Active , VFB = 0.78V, Not Switching
--
460
--
Shutdown
--
--
10
Output Voltage Line Regulation
VIN = 2.7V to 5.5V
--
0.1
--
%/V
Output Voltage Load Regulation
0A < ILOAD < 2A
--
0.25
--
%
Error Amplifier Trans-conductance gm
--
400
--
μA/V
Current Sense Trans-resistance
--
0.3
--
Ω
ROSC = 330kΩ
0.8
1
1.2
Switching
0.2
--
2
Feedback Reference Voltage
Symbol
VREF
DC Bias Current
Switching Frequency
EN Input Voltage
Test Conditions
Logic-High
VIH
1.6
--
--
Logic-Low
VIL
--
--
0.4
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
www.richtek.com
4
μA
MHz
V
is a registered trademark of Richtek Technology Corporation.
DS8064-07
November 2012
RT8064
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
Switch On-Resistance, High
RDS(ON)_P ILX = 0.5A
--
180
250
mΩ
Switch On-Resistance, Low
RDS(ON)_N ILX = 0.5A
--
120
160
mΩ
Peak Current Limit
ILIM
2.4
3.5
--
A
VIN Rising
--
2.4
--
VIN Falling
--
2.2
--
Under Voltage Lockout
Threshold
V
VIN − 0.7 VIN − 0.4
RT Shutdown Threshold
VRT
VRT Rising
--
Soft-Start Period
tSS
CSS = 10nF
--
800
--
μs
--
87.5
--
%VOUT
PGOOD Trip Threshold
V
Note 1. Stresses beyond those listed “Absolute Maximum Ratings” may cause permanent damage to the device. These are
stress ratings only, and 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 may
affect device reliability.
Note 2. θJA is measured at TA = 25°C on a high effective thermal conductivity four-layer test board per JEDEC 51-7. θJC is
measured at 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.
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
DS8064-07
November 2012
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
5
RT8064
Typical Operating Characteristics
Efficiency vs. Output Current
100
90
90
80
80
70
70
Efficiency (%)
Efficiency (%)
Efficiency vs. Output Current
100
60
50
40
30
20
60
50
40
30
20
10
10
VIN = 5V, VOUT = 1.1V, IOUT = 0A to 2A
0
VIN = 5V, VOUT = 3.3V, IOUT = 0A to 2A
0
0
0.5
1
1.5
2
0
0.5
Output Current (A)
2
Output Voltage vs. Output Current
1.130
3.340
1.120
3.330
Output Voltage (V)
Output Voltage (V)
1.5
Output Current (A)
Output Voltage vs. Output Current
1.110
1.100
1.090
3.320
3.310
3.300
3.290
1.080
VIN = 5V, VOUT = 1.1V, IOUT = 0A to 2A
VIN = 5V, VOUT = 3.3V, IOUT = 0A to 2A
3.280
1.070
0
0.5
1
1.5
0
2
0.5
Output Current (A)
1
1.5
2
Output Current (A)
Switching Frequency vs. Temperature
Reference Voltage vs. Temperature
1.04
0.84
1.03
0.83
1.02
Reference Voltage (V)
Switching Frequency (MHz)1
1
1.01
1.00
0.99
0.98
0.97
0.96
0.82
0.81
0.80
0.79
0.78
0.77
0.95
VIN = 5V, VOUT = 1.1V, IOUT = 0.6A, RRT = 330kΩ
0.94
VIN = 5V, VOUT = 1.1V
0.76
-50
-25
0
25
50
75
100
Temperature (°C)
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
www.richtek.com
6
125
-50
-25
0
25
50
75
100
125
Temperature (°C)
is a registered trademark of Richtek Technology Corporation.
DS8064-07
November 2012
RT8064
Enable Voltage vs. Temperature
1.6
2.7
1.5
2.6
1.4
2.5
Enable Voltage (V)
VIN UVLO (V)
VIN UVLO vs. Temperature
2.8
Rising
2.4
2.3
2.2
Falling
2.1
1.3
Rising
1.2
1.1
1.0
2.0
0.8
1.9
0.7
1.8
Falling
0.9
0.6
-50
-25
0
25
50
75
100
125
0
25
50
75
100
Load Transient Response
Load Transient Response
125
VOUT
(100mV/Div)
VIN = 5V, VOUT = 1.1V, IOUT = 1A to 2A,
RCOMP = 10kΩ, CCOMP = 560pF
IOUT
(1A/Div)
VIN = 5V, VOUT = 3.3V, IOUT = 1A to 2A,
RCOMP = 33kΩ, CCOMP = 560pF
Time (100μs/Div)
Time (100μs/Div)
Switching
Switching
VLX
(5V/Div)
VLX
(5V/Div)
VOUT
(10mV/Div)
VOUT
(10mV/Div)
VIN = 5V, VOUT = 1.1V, IOUT = 2A
Time (500ns/Div)
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
DS8064-07
-25
Temperature (°C)
VOUT
(100mV/Div)
IOUT
(1A/Div)
-50
Temperature (°C)
November 2012
VIN = 5V, VOUT = 3.3V, IOUT = 2A
Time (500ns/Div)
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
7
RT8064
Power On from VIN
Power Off from VIN
VIN
(5V/Div)
VIN
(5V/Div)
VOUT
(1V/Div)
VPGOOD
(10V/Div)
VOUT
(1V/Div)
VPGOOD
(10V/Div)
IOUT
(2A/Div)
IOUT
(2A/Div)
VIN = 5V, VOUT = 1.1V, IOUT = 2A, EN = High
VIN = 5V, VOUT = 1.1V, IOUT = 2A, EN = High
Time (2.5ms/Div)
Time (5ms/Div)
Power On from EN
Power Off from EN
VEN
(5V/Div)
VOUT
(2V/Div)
VEN
(5V/Div)
VOUT
(2V/Div)
VPGOOD
(5V/Div)
IOUT
(5A/Div)
VPGOOD
(5V/Div)
IOUT
(5A/Div)
VIN = 5V, VOUT = 1.1V, IOUT = 2A
Time (500μs/Div)
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
www.richtek.com
8
VIN = 5V, VOUT = 1.1V, IOUT = 2A
Time (250μs/Div)
is a registered trademark of Richtek Technology Corporation.
DS8064-07
November 2012
RT8064
Application Information
The basic IC application circuit is shown in Typical
Application Circuit. External component selection is
determined by the maximum load current and begins with
the selection of the inductor value and operating frequency
followed by CIN and COUT.
Main Control Loop
During normal operation, the internal upper power switch
(P-MOSFET) is turned on at the beginning of each clock
cycle. Current in the inductor increases until the peak
inductor current reaches the value defined by the output
voltage (VCOMP) of the error amplifier. The error amplifier
adjusts its output voltage by comparing the feedback signal
from a resistive voltage divider on the FB pin with an internal
0.8V reference. When the load current increases, it causes
a reduction in the feedback voltage relative to the reference.
The error amplifier increases its output voltage until the
average inductor current matches the new load current.
When the upper power MOSFET shuts off, the lower
synchronous power switch (N-MOSFET) turns on until
the beginning of the next clock cycle.
Output Voltage Setting
The output voltage is set by an external resistive voltage
divider according to the following equation :
VOUT = VREF × ⎛⎜ 1 + R1 ⎞⎟
R2 ⎠
⎝
where VREF equals to 0.8V typical.
The resistive voltage divider allows the FB pin to sense a
fraction of the output voltage as shown in Figure 1.
VOUT
R1
FB
RT8064
R2
Soft-Start
The IC contains an external soft-start clamp that gradually
raises the output voltage. The soft-start timing is
programmed by the external capacitor between SS pin
and GND. The chip provides an internal 10μA charge current
for the external capacitor. If 10nF capacitor is used to set
the soft-start, the period will be 800μs (typ.).
Power Good Output
The power good output is an open-drain output and requires
a pull up resistor. When the output voltage is 12.5% above
or 12.5% below its set voltage, PGOOD will be pulled
low. It is held low until the output voltage returns to within
the allowed tolerances once more. During soft-start,
PGOOD is actively held low and is only allowed to transition
high when soft-start is over and the output voltage reaches
87.5% of its set voltage.
Operating Frequency
Selection of the operating frequency is a tradeoff between
efficiency and component size. Higher frequency operation
allows the use of smaller inductor and capacitor values.
Lower frequency operation improves efficiency by reducing
internal gate charge and switching losses but requires
larger inductance and/or capacitance to maintain low output
ripple voltage.
The operating frequency of the IC is determined by an
external resistor, ROSC, that is connected between the RT
pin and ground. The value of the resistor sets the ramp
current that is used to charge and discharge an internal
timing capacitor within the oscillator. The practical switching
frequency ranges from 200kHz to 2MHz. However, when
the RT pin is floating, the internal frequency is set at 2MHz.
Determine the RT resistor value by examining the curve
below. Please notice the minimum on time is about 90ns.
GND
Figure 1. Setting the Output Voltage
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
DS8064-07
November 2012
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
9
RT8064
Switching Frequency (MHz)1
2.4
and the power is supplied by a wall adapter through long
wires, a load step at the output can induce ringing at the
input. At best, this ringing can couple to the output and
be mistaken as loop instability. At worst, a sudden inrush
of current through the long wires can potentially cause a
voltage spike at VIN large enough to damage the part.
2.0
1.6
1.2
0.8
Slope Compensation and Peak Inductor Current
0.4
0.0
0
300
600
900
1200
1500
1800
2100
RRT (kΩ)
Figure 2. Switching Frequency vs. RT Resistor
Inductor Selection
For a given input and output voltage, the inductor value
and operating frequency determine the ripple current. The
ripple current, ΔIL, increases with higher VIN and decreases
with higher inductance.
V
V
ΔIL = ⎛⎜ OUT ⎞⎟ × ⎛⎜ 1− OUT ⎞⎟
f
x
L
VIN ⎠
⎝
⎠ ⎝
Having a lower ripple current reduces not only the ESR
losses in the output capacitors but also the output voltage
ripple. Highest efficiency operation is achieved by reducing
ripple current at low frequency, but attaining this goal
requires a large inductor.
For the ripple current selection, the value of ΔIL = 0.4 (IMAX)
is a reasonable starting point. The largest ripple current
occurs at the highest VIN. To guarantee that the ripple
current stays below a specified maximum value, the
inductor value needs to be chosen according to the following
equation :
⎡ VOUT
⎤ ⎡
VOUT ⎤
L= ⎢
⎥ × ⎢1 − VIN(MAX) ⎥
f
x
I
Δ
L(MAX)
⎣
⎦ ⎣
⎦
Slope compensation provides stability in constant
frequency architectures by preventing sub-harmonic
oscillations at duty cycles greater than 50%. It is
accomplished internally by adding a compensating ramp
to the inductor current signal. Normally, the peak inductor
current is reduced when slope compensation is added.
For the IC, however, separated inductor current signal is
used to monitor over current condition, so the maximum
output current stays relatively constant regardless of the
duty cycle.
Hiccup Mode Under Voltage Protection
A Hiccup Mode Under Voltage Protection (UVP) function
is provided for the IC. When the FB voltage drops below
half of the feedback reference voltage, VFB, the UVP
function is triggered to auto soft-start the power stage
until this event is cleared. The Hiccup Mode UVP reduces
the input current in short circuit conditions, but will not be
triggered during soft-start process.
Under Voltage Lockout Threshold
The RT8064 includes an input under voltage lockout
protection (UVLO) function. If the input voltage exceeds
the UVLO rising threshold voltage, the converter will reset
and prepare the PWM for operation. However, if the input
voltage falls below the UVLO falling threshold voltage during
normal operation, the device will stop switching. The UVLO
rising and falling threshold voltage has a hysteresis to
prevent noise caused reset.
Using Ceramic Input and Output Capacitors
Higher values, lower cost ceramic capacitors are now
becoming available in smaller case sizes. Their high ripple
current, high voltage rating and low ESR make them ideal
for switching regulator applications. However, care must
be taken when these capacitors are used at the input and
output. When a ceramic capacitor is used at the input
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
www.richtek.com
10
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
is a registered trademark of Richtek Technology Corporation.
DS8064-07
November 2012
RT8064
maximum power dissipation can be calculated by the
following formula :
PD(MAX) = (TJ(MAX) − TA) / θJA
Layout Considerations
Follow the PCB layout guidelines for optimal performance
of the IC.
where TJ(MAX) is the maximum junction temperature, TA is
the ambient temperature, and θJA is the junction to ambient
thermal resistance.
`
Connect the terminal of the input capacitor (s), CIN, as
close to the VIN pin as possible. This capacitor provides
the AC current into the internal power MOSFETs.
For recommended operating condition specifications, the
maximum junction temperature is 125°C. The junction to
ambient thermal resistance, θJA, is layout dependent. For
SOP-8 (Exposed Pad) packages, the thermal resistance,
θJA, is 75°C/W on a standard JEDEC 51-7 four-layer
thermal test board. For WDFN-8L 3x3 packages, the
thermal resistance, θJA, is 70°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
formulas :
`
LX node experiences high frequency voltage swings so
should be kept within a small area.
`
Keep all sensitive small signal nodes away from the LX
node to prevent stray capacitive noise pick up.
`
Connect the FB pin directly to the feedback resistors.
The resistive voltage divider must be connected between
VOUT and GND.
Place the feedback
resistors as close to
the IC as possible
Place the compensation
components as close to
the IC as possible
PD(MAX) = (125°C − 25°C) / (75°C/W) = 1.333W for
SOP-8 (Exposed Pad) package
GND
R2
CCOMP
PD(MAX) = (125°C − 25°C) / (70°C/W) = 1.429W for
WDFN-8L 3x3 package
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
Four-Layer PCB
RCOMP
SS
EN
CSS
VIN
GND
8
2
7
GND
3
6
9
4
5
CIN
PGOOD
R1
FB
RT
L1
VOUT
VIN
VOUT
GND
ROSC
LX should be connected
to inductor by wide and
short trace, and keep
sensitive components
away from this trace
LX
COUT
Place the input and output capacitors
as close to the IC as possible
Place the feedback
resistors as close to
the IC as possible
Place the compensation
components as close to
the IC as possible
GND
WDFN-8L 3x3
R2
CCOMP
RCOMP
SOP-8 (Exposed Pad)
CSS
GND
CIN
VIN
COMP
SS
EN
1
VIN
4
2
3
8
GND
Maximum Power Dissipation (W)1
The maximum power dissipation depends on the operating
ambient temperature for fixed T J(MAX) and thermal
resistance, θJA. The derating curves in Figure 3 allow the
designer to see the effect of rising ambient temperature
on the maximum power dissipation.
COMP
9
7
6
5
PGOOD
FB
RT
LX
L1
COUT
VOUT
R1
VOUT
GND
ROSC
LX should be connected
to inductor by wide and
short trace, and keep
sensitive components
away from this trace
Place the input and output capacitors
as close to the IC as possible
0
25
50
75
100
125
Ambient Temperature (°C)
Figure 4. PCB Layout Guide
Figure 3. Derating Curve of Maximum Power Dissipation
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
DS8064-07
November 2012
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
11
RT8064
Outline Dimension
H
A
M
EXPOSED THERMAL PAD
(Bottom of Package)
Y
J
X
B
F
C
I
D
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
4.801
5.004
0.189
0.197
B
3.810
4.000
0.150
0.157
C
1.346
1.753
0.053
0.069
D
0.330
0.510
0.013
0.020
F
1.194
1.346
0.047
0.053
H
0.170
0.254
0.007
0.010
I
0.000
0.152
0.000
0.006
J
5.791
6.200
0.228
0.244
M
0.406
1.270
0.016
0.050
X
2.000
2.300
0.079
0.091
Y
2.000
2.300
0.079
0.091
X
2.100
2.500
0.083
0.098
Y
3.000
3.500
0.118
0.138
Option 1
Option 2
8-Lead SOP (Exposed Pad) Plastic Package
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
www.richtek.com
12
is a registered trademark of Richtek Technology Corporation.
DS8064-07
November 2012
RT8064
D2
D
L
E
E2
1
e
SEE DETAIL A
b
2
1
2
1
A
A1
A3
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
0.200
0.300
0.008
0.012
D
2.950
3.050
0.116
0.120
D2
2.100
2.350
0.083
0.093
E
2.950
3.050
0.116
0.120
E2
1.350
1.600
0.053
0.063
e
L
0.650
0.425
0.026
0.525
0.017
0.021
W-Type 8L DFN 3x3 Package
Richtek Technology Corporation
5F, No. 20, Taiyuen Street, Chupei City
Hsinchu, Taiwan, R.O.C.
Tel: (8863)5526789
Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should
obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot
assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be
accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third
parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries.
DS8064-07
November 2012
www.richtek.com
13