RT8297A/B
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Pin Configuration
(TOP VIEW)
WDFN-8L 2x2
1.5A, 17V, 340/800kHz Synchronous Step-Down Converter
Ordering Information
Note :
Richtek products are :
RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
General Description
The RT8297A/B is a high efficiency, monolithic
synchronous step-down DC-DC converter that can operate
at 340kHz/800kHz, while delivering up to 1.5A output
current from a 4V to 17V input supply. The RT8297A/B's
current mode architecture allows the transient response
to be optimized. Cycle-by-cycle current limit provides
protection against shorted outputs and soft-start eliminates
input current surge during start-up. Fault conditions also
include output under voltage protection, output over voltage
protection, and thermal shutdown. The low current (<5μA)
shutdown mode provides output disconnect, enabling easy
power management in battery-powered systems. The
RT8297A/B is available in a WDFN-8L 2x2 package.
Features
4V to 17V Input Voltage Range
1.5A Output Current
Internal N-MOSFET s
Current Mode Control
Fixed Frequency Operation : 340kHz/800kHz
Output Adjustable from 0.8V to 12V
Up to 95% Efficiency
Internal Compensation
Stable with Low ESR Ceramic Output Capacitors
Cycle-by-Cycle Over Current Protection
Input Under Voltage Lockout
Output Under Voltage Protection
Output Over Voltage Protection
Power Good Indicator
Thermal Shutdown Protection
RoHS Compliant and Halogen Free
Applications
Industrial and Commercial Low Power Systems
Computer Peripherals
LCD Monitors and TVs
Green Electronics/Appliances
Point of Load Regulation for High-Performance DSPs,
FPGAs, and ASICs
Marking Information SW
EN
VIN
GND
GND
PGOOD
FB
BOOT
7
6
5
1
2
3
4
8
GND
9
00 : Product Code
W : Date Code
RT8297AZQW
71 : Product Code
W : Date Code
RT8297BZQW
Package Type
QW : WDFN-8L 2x2 (W-Type)
RT8297A/B
Lead Plating System
Z : ECO (Ecological Element with
Halogen Free and Pb free)
A : 340kHz
B : 800kHz
00W
71W
RT8297A/B
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Typical Application Circuit
RT8297B
VIN
CIN
10µF
VIN
4V to 17V
PGOODPGOOD
EN FB
SW
BOOT
CBOOT
10nF 6.8µH
L
VOUT
3.3V
COUT
22µF x 2
47k
R1
15k
R2
Chip Enable
GND
1.5A
2
6
4
7, 8, 9 (Exposed Pad)
3
1
5
RT8297A
VIN
CIN
10µF
VIN
4V to 17V
PGOODPGOOD
EN FB
SW
BOOT
CBOOT
10nF 15µH
L
VOUT
3.3V
COUT
22µF x 2
110k
R1
36k
R2
Chip Enable
GND
1.5A
2
6
4
7, 8, 9 (Exposed Pad)
3
1
5
RT8297A
VOUT (V) L (H) R1 (k) R2 (k) COUT (F)
1.2 4.7 110 220 22 x 2
2.5 10 110 51 22 x 2
3.3 15 110 36 22 x 2
5 22 120 22 22 x 2
RT8297B
VOUT (V) L (H) R1 (k) R2 (k) COUT (F)
1.2 3.6 47 91 22 x 2
2.5 4.7 47 22 22 x 2
3.3 6.8 47 15 22 x 2
5 10 62 12 22 x 2
Table 1. Recommended Component Selection
RT8297A/B
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Functional Block Diagram
Pin No. Pin Na m e Pin Function
1 SW Switch node. Connect to external L-C filter.
2 VIN Input supply voltage. Must bypass with a suitably large ceramic
capacitor.
3 BOOT
Bootstrap for high side gate driver. Connect 0.01F or greater ceramic
capacitor from BOOT to SW pin.
4 EN
Chip enable. A logic-high enables the converter; a logic-low forces the
RT8297A/B into shutdown mode, reducing the supply current to less
than 5A. Attach this pin to VIN with a 100k pull up resistor for
automatic startup.
5 FB Feedback input pin. For an adjustable output, connect an external
resistive voltage divider to this pin.
6 PGOOD
Power good indicator. The output of this pin is low if the output voltage is
12.5% less than the nominal voltage. Otherwise, it is an open drain.
7, 8, 9 (Exposed Pad) GND Ground. The exposed pad must be soldered to a large PCB and
connected to GND for maximum power dissipation.
Functional Pin Description
Internal
Regulator
+
-
Enable
Comparator
EN
2.5V
5k 3V
VIN
OSC
340kHz/800kHz
Foldback
Control
+
-
1pF
35pF 400k
+
-
Error Amp
0.8V
UV Comparator
+
-
+
-Current
Comparator
OV Comparator
0.4V UV
FB
R
SQ
Q
VA
+
-
0.7V
FB
BOOT
145m
SW
GND
PGOOD
Current Sense
Amplifier
Slope Comp
PGOOD
Comparator
VAVCC
140m
+
-
1V OV
RT8297A/B
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Parameter Symbol Test Conditions Min Typ Max Unit
Shutdown Supply Current ISHDN V
EN = 0V -- 1 5 A
Supply Current IOUT V
EN = 3V, VFB = 0.9V -- 0.6 1 mA
Feedback Reference Voltage VREF 4V VIN 17V 0.788 0.800 0.812 V
Feedback Current IFB V
FB = 0.8V -- 10 -- nA
High Side Switch On
Resistance RDS(ON)1 -- 145 -- m
Low Side Switch On
Resistance RDS(ON)2 -- 140 -- m
Upper Switch Current Limit Min. duty cycle, VBOOT VSW = 4.8V
maximum loading = 1.5A 2.45 3 4.65 A
Lower Switch Current Limit From drain to source -- 1 -- A
Oscillation Frequency fOSC1 For RT8297A 300 340 380 kHz
For RT8297B 700 800 900
Short-Circuit Oscillation
Frequency fOSC2 VFB = 0V, For RT8297A -- 95 -- kHz
VFB = 0V, For RT8297B -- 170 --
Maximum Duty Cycle DMAX VFB = 0.7V, For RT8297A -- 93 -- %
VFB = 0.7V, For RT8297B -- 84 -- %
(VIN = 12V, TA = 25°C, unless otherwise specified)
Electrical Characteristics
Recommended Operating Conditions (Note 4)
Supply Input Voltage, VIN ---------------------------------------------------------------------------------- 4V to 17V
Junction Temperature Range ------------------------------------------------------------------------------- −40°C to 125°C
Ambient Temperature Range ------------------------------------------------------------------------------- −40°C to 85°C
Absolute Maximum Ratings (Note 1)
Supply Voltage, VIN ----------------------------------------------------------------------------------------- −0.3V to 19V
SW --------------------------------------------------------------------------------------------------------------- −0.3V to (VIN + 0.3V)
BOOT to SW -------------------------------------------------------------------------------------------------- −0.3V to 6V
All Other Pins ------------------------------------------------------------------------------------------------- −0.3V to 6V
Power Dissipation, PD @ TA = 25°C
WDFN-8L 2x2 ------------------------------------------------------------------------------------------------- 0.833W
Package Thermal Resistance (Note 2)
WDFN-8L 2x2, θJA -------------------------------------------------------------------------------------------- 120°C/W
WDFN-8L 2x2, θJC -------------------------------------------------------------------------------------------- 8.2°C/W
Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------ 260°C
Junction Temperature ---------------------------------------------------------------------------------------- 150°C
Storage Temperature Range ------------------------------------------------------------------------------- −65°C to 150°C
ESD Susceptibility (Note 3)
HBM (Human Body Model) --------------------------------------------------------------------------------- 2kV
MM (Machine Model) ---------------------------------------------------------------------------------------- 200V
RT8297A/B
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Note 1. Stresses beyond those listed under “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.
Parameter Symbol Test Conditions Min Typ Max Unit
Minimum On-Time tON -- 100 125 ns
Input Under Voltage Lockout
Threshold VUVLO -- 3.5 -- V
Input Under Voltage Lockout
Threshold Hysteresis VUVLO -- 200 -- mV
EN Threshold
Voltage
Logic-High VIH 2.7 -- -- V
Logic-Low VIL -- -- 0.4
EN Pull Low Current VEN = 2V, VFB = 1V -- 1 -- A
Soft-Start Period tSS -- 1 -- ms
Thermal Shutdown TSD -- 150 -- C
Thermal Shutdown
Hysteresis TSD -- 15 -- C
Power Good Threshold
Rising -- 0.7 -- V
Power Good Threshold
Hysteresis -- 130 -- mV
Power Good Pull Down
Resistance -- 12 --
Output OVP Trip Threshold -- 125 -- %VREF
Output OVP Prop Delay -- 10 -- s
Output UVP Trip Threshold -- 50 -- %VREF
Output UVP Prop Delay -- 2 -- s
RT8297A/B
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Typical Operating Characteristics
Output Voltage vs . Output Current
4.90
4.94
4.98
5.02
5.06
5.10
0.0 0.3 0.6 0.9 1.2 1.5
Output Current (A)
Output Voltage (V)
RT8297A, VIN = 12V, VOUT = 5V
Output Voltage vs. Output Current
3.20
3.24
3.28
3.32
3.36
3.40
0.0 0.3 0.5 0.8 1.0 1.3 1.5
Output Current (A)
Output Voltage (V)
RT8297B, VIN = 12V, VOUT = 3.3V
Reference Voltage vs. Temperature
0.60
0.65
0.70
0.75
0.80
0.85
0.90
0.95
1.00
-50 -25 0 25 50 75 100 125
Temperature (°C)
Reference Voltage (V)
RT8297A, VIN = 12V, IOUT = 0A
Reference Voltage vs. Temperature
0.60
0.65
0.70
0.75
0.80
0.85
0.90
0.95
1.00
-50 -25 0 25 50 75 100 125
Temperature (°C)
Reference Voltage (V)
RT8297B, VIN = 12V, IOUT = 0A
Efficiency vs. Output Current
0
10
20
30
40
50
60
70
80
90
100
0.01 0.10 1.00 10.00
Output Current (A)
Efficiency (%)
RT8297A, VIN = 12V
VOUT = 5V
VOUT = 3.3V
VOUT = 1.2V
Efficiency vs. Output Current
0
10
20
30
40
50
60
70
80
90
100
0.01 0.10 1.00 10.00
Output Current (A)
Efficiency (%)
RT8297B, VIN = 12V
VOUT = 5V
VOUT = 3.3V
VOUT = 1.2V
RT8297A/B
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Quiescent Current vs. Input Voltage
600
650
700
750
800
850
900
950
1000
4 6 8 1012141618
Input Voltage (V)
Quiescent Current (μA
)
RT8297B, VEN = 3.3V, VFB = 0.85V
Quiesc ent Current vs. Input Voltage
600
650
700
750
800
850
900
4 6 8 1012141618
Input Voltage (V)
Quiescent Current (μA
)
RT8297A, VEN = 3.3V, VFB = 0.85V
Frequency vs. Te m pe rature
700
725
750
775
800
825
850
875
900
-50 -25 0 25 50 75 100 125
Temperature (°C)
Frequency (kHz) 1
RT8297B, VOUT = 3.3V, IOUT = 0.3A
Frequency vs. Tempe rature
250
275
300
325
350
375
400
-50 -25 0 25 50 75 100 125
Temperature (°C)
Frequency (kHz) 1
RT8297A, VOUT = 3.3V, IOUT = 0.3A
Frequency vs. Input Voltage
780
790
800
810
820
830
840
850
860
4 6 8 1012141618
Input Voltage (V)
Frequency (kHz) 1
RT8297B, VOUT = 3.3V, IOUT = 0.3A
Frequency vs. Input Voltage
310
315
320
325
330
335
340
345
350
355
4 6 8 1012141618
Input Voltage (V)
Frequency (kHz) 1
RT8297A, VOUT = 3.3V, IOUT = 0.3A
RT8297A/B
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Quiesce nt Current vs. Tempe rature
0.60
0.65
0.70
0.75
0.80
0.85
0.90
-50 -25 0 25 50 75 100 125
Temperature (°C)
Quiescent Current (mA
)
RT8297A, VIN = 12V, VEN = 3.3V, VFB = 0.85V
Quiescent Current v s. Temperature
0.60
0.65
0.70
0.75
0.80
0.85
0.90
-50 -25 0 25 50 75 100 125
Temperature (°C)
Quiescent Current (mA
)
RT8297B, VIN = 12V, VEN = 3.3V, VFB = 0.85V
Current Limit vs. Input Voltage
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
4 6 8 1012141618
Input Voltage (V)
Current Limit (A)
VOUT = 1.2V
VOUT = 3.3V
RT8297A
Current Limit vs. Te mperature
2.5
2.8
3.1
3.4
3.7
4.0
-50 -25 0 25 50 75 100 125
Temperature (°C)
Current Limit (A)
VIN = 12V, VOUT = 1.2V
RT8297B
Current Limit vs . Tem perature
1.5
1.8
2.1
2.4
2.7
3.0
3.3
3.6
3.9
-50 -25 0 25 50 75 100 125
Temperature (°C)
Current Limit (A) 1
RT8297A
VIN = 12V, VOUT = 1.2V
Current Lim it vs. Input Voltage
2.0
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
4.0
4681012141618
Input Voltage (V)
Current Limit (A)
VOUT = 1.2V
VOUT = 3.3V
RT8297B
RT8297A/B
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VIN = 12V, VOUT = 3.3V, IOUT = 0.1A to 1.5A
Load Transient Response
Time (1ms/Div)
IOUT
(1A/Div)
VOUT
(50mV/Div)
RT8297B
VIN = 12V, VOUT = 3.3V, IOUT = 1.5A
Switching
Time (500ns/Div)
IL
(1A/Div)
VSW
(10V/Div)
VOUT
(5mV/Div)
RT8297B
VIN = 12V, VOUT = 3.3V, IOUT = 0.1A to 1.5A
Load Transient Response
Time (1ms/Div)
IOUT
(1A/Div)
VOUT
(100mV/Div)
RT8297A
VIN = 12V, VOUT = 3.3V, IOUT = 1.5A
Switching
Time (5μs/Div)
IL
(1A/Div)
VSW
(10V/Div)
VOUT
(5mV/Div)
RT8297A
VIN = 12V, VOUT = 3.3V, IOUT = 1.5A
Power On from EN
Time (500μs/Div)
IOUT
(2A/Div)
VEN
(5V/Div)
VOUT
(2V/Div)
RT8297A
PGOOD
(5V/Div)
RT8297B, VIN = 12V, VOUT = 3.3V, IOUT = 1.5A
Power On from EN
Time (500μs/Div)
IOUT
(2A/Div)
VEN
(5V/Div)
VOUT
(2V/Div)
PGOOD
(5V/Div)
RT8297A/B
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RT8297B, VIN = 12V, VOUT = 3.3V, IOUT = 1.5A
Power Off from EN
Time (100μs/Div)
IOUT
(2A/Div)
VEN
(5V/Div)
VOUT
(2V/Div)
PGOOD
(5V/Div)
VIN = 12V, VOUT = 3.3V, IOUT = 1.5A
Power Off from EN
Time (100μs/Div)
VEN
(5V/Div)
VOUT
(2V/Div)
RT8297A
PGOOD
(5V/Div)
IOUT
(2A/Div)
RT8297A/B
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Application Information
The RT8297A/B is a synchronous high voltage buck
converter that can support the input voltage range from
4V to 17V and the output current can be up to 1.5A.
Output Voltage Setting
The resistive divider allows the FB pin to sense the output
voltage as shown in Figure 1.
Figure 1. Output Voltage Setting
RT8297A/B
GND
FB
R1
R2
VOUT
The output voltage is set by an external resistive divider
according to the following equation :
OUT REF
R1
V = V 1
R2
Where VREF is the feedback reference voltage (0.8V typ.).
External Bootstrap Diode
Connect a 10nF low ESR ceramic capacitor between the
BOOT pin and SW pin. This capacitor provides the gate
driver voltage for the high side MOSFET. It is recommended
to add an external bootstrap diode between an external
5V and the BOOT pin for efficiency improvement when
input voltage is lower than 5.5V or duty ratio is higher
than 65%. The bootstrap diode can be a low cost one
such as 1N4148 or BAT54. The external 5V can be a 5V
fixed input from system or a 5V output of the RT8297A/B.
Note that the external boot voltage must be lower than
5.5V
Figure 2. External Bootstrap Diode
RT8297A/B
SW
BOOT
5V
10nF
OUT OUT
L
IN
VV
I = 1
fL V
Having a lower ripple current reduces not only the ESR
losses in the output capacitors but also the output voltage
ripple. High frequency with small ripple current can achieve
highest efficiency operation. However, it requires a large
inductor to achieve this goal. For the ripple current
selection, the value of ΔIL = 0.2(IMAX) will be a reasonable
starting point. The largest ripple current occurs at the
highest VIN. To guarantee that the ripple current stays
below the specified maximum, the inductor value should
be chosen according to the following equation :
OUT OUT
L(MAX) IN(MAX)
VV
L = 1
fI V
Over Voltage Protection (OVP)
The RT8297A/B provides Over Voltage Protection function
when output voltage over 125%. The internal MOS will be
turned off. The control will return to normal operation if
over voltage condition is removed.
Under Voltage Protection (UVP)
For the RT8297A/B, it provides Hiccup Mode Under
Voltage Protection (UVP). When the FB voltage drops
below 50% of the feedback reference voltage, the UVP
function will be triggered and the RT8297A/B will shut down
for a period of time and then recover automatically. The
Hiccup Mode UVP can reduce input current in short-circuit
conditions.
Inductor Selection
The inductor value and operating frequency determine the
ripple current according to a specific input and output
voltage. The ripple current ΔIL increases with higher VIN
and decreases with higher inductance.
Thermal Shutdown
Thermal shutdown is implemented to prevent the chip from
operating at excessively high temperatures. When the
junction temperature is higher than 150°C, the whole chip
is shutdown. The chip is automatically re-enable when
the junction temperature cools down by approximately
15 degrees.
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CIN and COUT Selection
The input capacitance, CIN, is needed to filter the
trapezoidal current at the source of the high side MOSFET.
To prevent large ripple current, a low ESR input capacitor
sized for the maximum RMS current should be used. The
RMS current is given by :
OUT IN
RMS OUT(MAX) IN OUT
VV
I = I 1
VV
This formula has a maximum at VIN = 2VOUT, where IRMS =
IOUT/2. This simple worst-case condition is commonly used
for design because even significant deviations do not offer
much relief. Choose a capacitor rated at a higher
temperature than required. Several capacitors may also
be paralleled to meet size or height requirements in the
design. For the input capacitor, a 10μF low ESR ceramic
capacitor is recommended. For the recommended
capacitor, please refer to table 3 for more detail. The
selection of COUT is determined by the required ESR to
minimize voltage ripple. Moreover, the amount of bulk
capacitance is also a key for COUT selection to ensure
that the control loop is stable. Loop stability can be
checked by viewing the load transient response as
described in a later section. The output ripple, ΔVOUT , is
determined by :
OUT L OUT
1
VIESR
8fC
The output ripple will be highest at the maximum input
voltage since ΔIL increases with input voltage. Multiple
capacitors placed in parallel may be needed to meet the
ESR and RMS current handling requirement. Dry tantalum,
special polymer, aluminum electrolytic and ceramic
capacitors are all available in surface mount packages.
Special polymer capacitors offer very low ESR value.
However, it provides lower capacitance density than other
types. Although Tantalum capacitors have the highest
capacitance density, it is important to only use types that
pass the surge test for use in switching power supplies.
Aluminum electrolytic capacitors have significantly higher
ESR. However, it can be used in cost-sensitive applications
for ripple current rating and long term reliability
considerations. Ceramic capacitors have excellent low
ESR characteristics but can have a high voltage coefficient
and audible piezoelectric effects. The high Q of ceramic
capacitors with trace inductance can also lead to significant
ringing.
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 input and
output. When a ceramic capacitor is used at the input
and the power is supplied by a wall adapter through long
wires, a load step at the output can induce ringing at the
input, VIN. 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.
Checking Tran sient Re spon se
The regulator loop response can be checked by looking
at the load transient response. Switching regulators take
several cycles to respond to a step in load current. When
a load step occurs, VOUT immediately shifts by an amount
equal to ΔILOAD (ESR) also begins to charge or discharge
COUT generating a feedback error signal for the regulator
to return VOUT to its steady-state value. During this
recovery time, VOUT can be monitored for overshoot or
ringing that would indicate a stability problem.
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 :
Table 2. Suggested Inductors for Typical
Application Circuit
Component
Supplier Series Dimensions
(mm)
TDK VLF10045 10 x 9.7 x 4.5
TDK SLF12565 12.5 x 12.5 x 6.5
TAIYO
YUD EN NR8040 8 x 8 x 4
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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, the
maximum junction temperature is 125°C. The junction to
ambient thermal resistance, θJA, is layout dependent. For
WDFN-8L 2x2 package, the thermal resistance, θJA, is
120°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) / (120°C/W) = 0.833W for
WDFN-8L 2x2 package
The maximum power dissipation depends on the operating
ambient temperature for fixed TJ(MAX) and thermal
resistance, θJA. The derating curve in Figure 3 allows the
designer to see the effect of rising ambient temperature
on the maximum power dissipation.
Figure 3. Derating Curve of Maximum Power Dissipation
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0 25 50 75 100 125
Ambient Temperature (°C)
Maximum Power Dissipation (W)
Four-Layer PCB
Layout Consideration
Follow the PCB layout guidelines for optimal performance
of the RT8297A/B
Keep the traces of the main current paths as short and
wide as possible.
Put the input capacitor as close as possible to the device
pins (VIN and GND).
SW node is with high frequency voltage swing and
should be kept at small area. Keep sensitive
components away from the SW node to prevent stray
capacitive noise pickup.
Place the feedback components to the FB pin as close
as possible.
The GND and Exposed Pad should be connected to a
strong ground plane for heat sinking and noise protection.
Figure 4. PCB Layout Guide
VOUT
SW
SW
EN
VIN
GND
GND
PGOOD
FB
BOOT
7
6
5
1
2
3
4
8
GND
9
VOUT
COUT
CIN
L
CBOOT
R2
R1
GND
Input capacitor must
be placed as close
to the IC as possible.
SW should be connected to
inductor by wide and short trace.
Keep sensitive components
away from this trace.
The resistor divider must be
connected as close to the
device as possible.
RT8297A/B
14
DS8297A/B-07 June 2018www.richtek.com
©
Copyright 2018 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation.
Table 3. Suggested Capacitors for CIN and COUT
Location Component Supplier Part No. Capacitance (F) Case Siz e
CIN MURATA GRM31CR61E106K 10 1206
CIN TDK C3225X5R1E106K 10 1206
CIN T AIYO YUDEN TMK316BJ106ML 10 1206
COUT MURATA GRM32ER61E226M 22 1210
COUT MURATA GRM21BR60J226M 22 0805
COUT TDK C3225X5R0J226M 22 1210
COUT TAIYO YUDEN EMK325BJ226MM 22 1210
RT8297A/B
15
DS8297A/B-07 June 2018 www.richtek.com
Richtek Technology Corporation
14F, No. 8, Tai Yuen 1st Street, Chupei City
Hsinchu, Taiwan, R.O.C.
Tel: (8863)5526789
Richtek products are sold by description only. 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.
Dim ensions In Millimeters Dimen sion s 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 0.200 0.300 0.008 0.012
D 1.950 2.050 0.077 0.081
D2 1.000 1.250 0.039 0.049
E 1.950 2.050 0.077 0.081
E2 0.400 0.650 0.016 0.026
e 0.500 0.020
L 0.300 0.400
0.012 0.016
Outline Dimension
W-Type 8L DFN 2x2 Package
11
2
2
Note : The configuration of the Pin #1 identifier is optional,
but must be located within the zone indicated.
DETAIL A
Pin #1 ID and Tie Bar Mark Options
D
1
E
A3
A
A1
D2
E2
L
b
e
SEE DETAIL A
