AP3434FNTR-G1 [DIODES]
Switching Controller,;
| 型号： | AP3434FNTR-G1 |
| 厂家： | 
DIODES INCORPORATED |
| 描述： | Switching Controller, 开关 |
| 文件： | 总15页 (文件大小：712K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
A Product Line of
PART OBSOLETE
Diodes Incorporated
NO ALTERNATE PART
AP3434
3A, 2MHZ HIGH PERFORMANCE SYNCHRONOUS BUCK CONVERTER
Description
Pin Assignments
The AP3434 is a current mode, PWM synchronous buck (step-down)
DC-DC converter, capable of driving a 3A load with high efficiency,
excellent line and load regulation.
(Top View)
Pin 1 Mark
Pin 1 Mark
The device integrates two N-channel power MOSFETs with low on-
resistance. Current mode control provides fast transient response and
cycle-by-cycle current limit.
16
15 14 13
12
1
1611 15
14
13
2
E P
1
10
3
4
9
SW
VIN
12
5
6
7
8
11 SW
2
VIN
GND
GND
The switching frequency of AP3434 can be programmable from
200kHz to 2MHz, which allows small-sized components, such as
capacitors and inductors. A standard series of inductors from several
different manufacturers are available. This feature greatly simplifies
the design of switch-mode power supplies.
E P
SW
10
3
4
9
SS
5
6
7
8
Under voltage lockout is internally set at 2.6V, but can be increased
by programming the threshold with a resistor network on the enable
pin. The output voltage startup ramp is controlled by the soft-start pin.
An open drain power good signal indicates the output is within 93% to
107% of its nominal voltage.
U-QFN3030-16
Features
The AP3434 is available in U-QFN3030-16 package.
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Input Voltage Range: 2.95V to 5.5V
0.8V Reference Voltage with ±3% Precision
Two 30mΩ (Typical) MOSFETs for High Efficiency at 3A Load
High Efficiency: Up to 94%
Applications
•
•
Low-voltage, High-density Power Systems
Point of Load Regulation for High Performance DSPs, FPGAs,
ASICs and Microprocessors
Output Current: 3A
Programmable Frequency: 200kHz to 2MHz
Current Mode Control
•
Broadband,
Networking
and
Optical
Communications
Synchronizes to External Clock
Infrastructure
Adjustable Soft-start
Soft Start-up into Pre-biased Output
UV and OV Power Good Output
Built-in Over Current Protection
Built-in Thermal Shutdown Function
Programmable UVLO Function
Built-in Over Voltage Protection
Thermally Enhanced 3mm×3mm 16-pin U-QFN3030-16
Totally Lead-free & Fully RoHS Compliant (Note1 & 2)
Halogen and Antimony Free. “Green” Device (Note 3)
Notes:
1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3) compliant.
2. See https://www.diodes.com/quality/lead-free/ for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green" and
Lead-free.
3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and
<1000ppm antimony compounds.
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© Diodes Incorporated
AP3434
Document number: DS37413 Rev. 3 - 4
A Product Line of
Diodes Incorporated
AP3434
Typical Applications Circuit
U1
L1 1.5µH
VOUT=1.8V
VIN=5V
16
1
10
11
12
13
SW
SW
VIN
VIN
VIN
R8 2.2Ω
(Optional)
C3
C2
R4
100kΩ
C6
0.1µF
2
C1
SW
R1
10µF 0.1µF
C10 2.2nF
(Optional)
14
15
BOOT
PGD
EN
6
AP3434
FB
R6 12.5kΩ
7
8
9
3
4
5
COMP
RT/CLK
SS
GND
GND
R7
10kΩ
C8
22µF
C9
22µF
R2
AGND
R3
7.5kΩ
R5
180kΩ
C7
0.01µF
C5
Optional
C4
2.7nF
Pin Description
Pin Number
Pin Name
Function
Supply input pin. A capacitor should be connected between the VIN and GND pin to keep the
DC input voltage constant
1,2,16
VIN
3,4
5
GND
AGND
FB
Power ground. This pin should be electrically connected to the power pad under the IC
Analog ground. This pin should be electrically connected to GND close to the device
Feedback pin. Inverting node of the transconductance error amplifier
6
Compensation pin. This pin is the output of the transconductance error amplifier and the input
to the current comparator. Connect external compensation elements to this pin to stabilize the
control loop
7
COMP
8
RT/CLK
SS
Resistor timing or external clock input pin
Soft-start pin. An external capacitor connected to this pin sets the output voltage rise time. This
pin can also be used for tracking
9
10,11,12
13
SW
Internal power switch output pin. This pin is connected to the inductor and bootstrap capacitor
Bootstrap pin. A bootstrap capacitor is connected between the BOOT pin and SW pin. The
voltage across the bootstrap capacitor drives the internal high-side power MOSFET
BOOT
Power good indicator output. Asserts low if output voltage is low due to thermal shutdown,
over-current, over/under-voltage or EN shut down
14
15
PGD
EN
Enable pin, internal pull-up current source. Pull below 1.2V to disable. Float to enable. Can be
used to set the on/off threshold (adjust UVLO) with two additional resistors
Exposed Pad can be connected to GND, for best thermal performance thermal vias are
recommended under the package
EP
Exposed Thermal Pad
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© Diodes Incorporated
AP3434
Document number: DS37413 Rev. 3 - 4
A Product Line of
Diodes Incorporated
AP3434
Functional Block Diagram
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© Diodes Incorporated
AP3434
Document number: DS37413 Rev. 3 - 4
A Product Line of
Diodes Incorporated
AP3434
Absolute Maximum Ratings (Note 4)
Symbol
VIN
Parameter
Rating
Unit
V
VIN Pin Voltage
EN Pin Voltage
SW Pin Voltage
FB Pin Voltage
-0.3 to 6.5
-0.3 to 6.5
V
VEN
V
VSW
-0.3 to VIN+0.3
-0.3 to 6.5
-0.3 to 6.5
-0.3 to 6.5
-0.3 to 6.5
-0.3 to 6.5
70
V
VFB
COMP Pin Voltage
V
VCOMP
VPGD
VRT/CLK
VSS
PGD Pin Voltage
V
RT/CLK Pin Voltage
V
SS Pin Voltage
V
Thermal Resistance
ºC/W
ºC
ºC
ºC
V
θJA
Operating Junction Temperature
Storage Temperature
Lead Temperature (Soldering, 10sec)
ESD(Machine Model)
ESD(Human Body Model)
-40 to +125
-65 to +150
+260
TJ
TSTG
TLEAD
—
200
—
2000
V
Note 4: Stresses greater than 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 under “Recommended Operating Conditions” is not implied.
Exposure to “Absolute Maximum Ratings” for extended periods may affect device reliability.
Recommended Operating Conditions
Symbol
VIN
Parameter
Min
2.95
3
Max
5.5
—
Unit
V
Input Voltage
Maximum Output Current
A
IOUT(MAX)
TA
Operating Ambient Temperature
-40
+85
ºC
Electrical Characteristics (@VIN=2.95 to 5.5V, TA=+25ºC, unless otherwise specified. Specifications with boldface type apply
over full operating temperature range from -40 to +85ºC.)
Symbol
Parameters
Conditions
Min
Typ
Max
Unit
SUPPLY VOLTAGE (VIN PIN)
Input Voltage
—
2.95
—
5.5
V
VIN
IQ
V
FB=0.9V, VIN=5V,
TA=+25ºC, RT=400kΩ
EN=0V, TA=+25°C,
Quiescent Current
—
360
575
μA
V
Shutdown Supply Current
—
2
5
μA
ISHDN
2.95V≤VIN≤5.5V
ENABLE AND UVLO (EN PIN)
Rising
Falling
—
1.16
—
1.25
1.18
2.6
1.37
—
V
V
VEN_H
Enable Threshold
VEN_L
VUVLO
VHYS
Internal
Under
Voltage
Voltage
—
2.8
—
V
Lockout Threshold
Internal
Under
—
—
150
mV
Hysteresis
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© Diodes Incorporated
AP3434
Document number: DS37413 Rev. 3 - 4
A Product Line of
Diodes Incorporated
AP3434
Electrical Characteristics (Cont.) (@VIN=2.95 to 5.5V, TA=+25ºC, unless otherwise specified. Specifications with boldface type
apply over full operating temperature range from -40 to +85ºC.)
Symbol
Parameters
Conditions
Min
Typ
Max
Unit
VOLTAGE REFERENCE (FB PIN)
Voltage Reference
0.779
0.803
0.827
V
VREF
MOSFET
2.95V≤VIN≤5.5V
—
—
—
—
30
44
30
44
60
70
60
70
mΩ
mΩ
mΩ
mΩ
V
BOOT-SW=5V
High Side Switch On-
resistance
RON_H
VBOOT-SW=2.95V
VIN=5V
Low Side Switch On-
resistance
RON_L
VIN=2.95V
CURRENT LIMIT
Current Limit Threshold
—
4
—
—
A
ILIMIT
THERMAL SHUTDOWN
Thermal Shutdown
Hysteresis
—
—
—
—
+140
+20
—
—
TTSD
°C
°C
—
TIMING RESISTOR AND EXTERNAL CLOCK (RT/CLK PIN)
Switching Frequency Range
(RT Mode)
Switching Frequency Range
(CLK Mode)
—
—
—
—
200
—
2000
kHz
300
400
75
—
500
—
2000
600
—
kHz
kHz
ns
V
Switching Frequency
Minimum CLK Pulse Width
RT/CLK Voltage
fS
RT=400kΩ
—
—
—
—
0.5
1.6
0.6
—
RT=400kΩ
—
RT/CLK High Threshold
RT/CLK Low Threshold
—
—
—
2.2
—
V
—
0.4
V
BOOT (BOOT PIN)
BOOT Charge Resistor
BOOT-SW UVLO
—
—
16
—
—
Ω
RBOOT
VIN=5V
—
2.2
V
VIN=2.95V
SOFT START (SS PIN)
Charge Current
SS to Reference Crossover
—
—
2
—
—
µA
ISS
VSS=0.4V
98% Nominal
1.1
V
VSS
POWER GOOD (PGD PIN)
—
—
—
—
91
93
—
—
—
—
V
FB Falling (Fault)
VFB Rising (Good)
VFB Rising (Fault)
VFB Falling (Good)
Feedback Threshold
VFB_TH
%VREF
107
105
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© Diodes Incorporated
AP3434
Document number: DS37413 Rev. 3 - 4
A Product Line of
Diodes Incorporated
AP3434
Performance Characteristics
Supply Current vs. Input Voltage
Supply Current vs. Temperature
435
430
425
420
415
410
405
400
395
390
385
380
375
370
365
460
455
450
445
440
435
430
425
420
415
410
405
400
395
390
360
2.4 2.7 3.0 3.3 3.6 3.9 4.2 4.5 4.8 5.1 5.4 5.7
Input Voltage (V)
-50
-25
0
25
50
75
100
125
150
Temperature (oC)
UVLO Threshold vs. Temperature
EN Threshold vs. Temperature
2.60
2.55
2.50
2.45
2.40
2.35
2.30
2.25
1.28
1.27
1.26
1.25
1.24
1.23
1.22
1.21
1.20
1.19
1.18
1.17
1.16
1.15
1.14
V =5V
IN
Rising
Falling
2.20
Start Switching
Stop Switching
2.15
2.10
-50
-25
0
25
50
75
100
125
150
-50
-25
0
25
50
75
100
125
150
Temperature (oC)
Temperature (oC)
Efficiency vs. Output Current
Switching Frequency vs. Temperature
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
1020
1010
1000
990
980
970
960
950
940
930
920
VOUT=1.8V
V =3.3V
IN
RT=180k
V =5V
IN
-50
-25
0
25
50
75
100
125
150
0
300 600 900 1200 1500 1800 2100 2400 2700 3000 3300
Output Current (mA)
Temperature (oC)
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© Diodes Incorporated
AP3434
Document number: DS37413 Rev. 3 - 4
A Product Line of
Diodes Incorporated
AP3434
Performance Characteristics (Cont.)
Start Up from VIN (VIN=5V, VOUT=1.8V, IOUT=3A)
Disable IC (VIN=5V, VOUT=1.8V, IOUT=3A)
VEN
2V/div
VIN
2V/div
VOUT
VOUT
1V/div
VSS
2V/div
1V/div
VSS
2V/div
IL
IL
2A/div
2A/div
Time 3.2ms/div
Time 20µs/div
Load Transient Response (VIN=5V, VOUT=1.8V, IOUT=0 to 3A)
Synchronizing to External Clock (fCLOCK=2MHz)
VOUT(AC)
200mV/div
VCLOCK
2V/div
VSW
2V/div
IOUT
2A/div
Time 200µs/div
Time 500ns/div
Short Circuit Protection (VIN=5V, VOUT=1.8V, IOUT=3A)
Short Circuit Recovery (VIN=5V, VOUT=1.8V, IOUT=3A)
VOUT
1V/div
VOUT
1V/div
VSS
2V/div
VSS
2V/div
VCOMP
VCOMP
0.5V/div
IL
IL
2A/div
2A/div
Time 3.2ms/div
Time 3.2ms/div
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© Diodes Incorporated
AP3434
Document number: DS37413 Rev. 3 - 4
A Product Line of
Diodes Incorporated
AP3434
Application Note
Theory of Operation
The AP3434 consists of a reference voltage module, slope compensation circuit, error amplifier, PWM comparator, current limit circuit, two N-
channel MOSFETs etc. (Refer to the Functional Block Diagram on page 3 for detailed information)
Soft-start
The AP3434 integrates an internal soft start circuit to minimize inrush currents or provide power supply sequencing during power up. A capacitor
connected between SS pin and ground implements the soft-start time. The AP3434 has an internal pull-up current source of 2μA, which charges
the external slow start capacitor. Equation 1 calculates the required slow start capacitor, ISS is the internal slow start charging current of 2μA, and
VREF is the internal voltage reference of 0.803V.
tSS (ms)× ISS (µA)
………………….(1)
CSS (nF) =
VREF (V )
During normal operation, if the VIN goes below the UVLO, or the EN pin is pulled below 1.2V, or a thermal shutdown occurs, the AP3434 will stop
switching and the SS pin will be discharged to 40mV before reinitiating a powering up sequence.
Enable and Adjusting UVLO
The AP3434 are disabled when the VIN falls below 2.6V. If an application requires a higher under-voltage lockout (UVLO), use the EN pin as
shown in Figure 1 to adjust the input voltage UVLO by using two external resistors. The EN pin has an internal pull-up current source that provides
the default condition of the AP3434 operating when the EN pin floats. Once the EN pin voltage exceeds 1.25V, an additional 2.55μA of hysteresis
is added. When the EN pin is pulled below 1.18V, the 2.55μA hysteresis is removed. This additional current facilitates input voltage hysteresis.
For AP3434, the divider resistor R1 and R2 on the EN pin can be calculated according to equation 2 and 3.
0.944×VSTART −VSTOP
…………………...(2)
R1=
2.59×10−6
1.18× R1
………………(3)
R2 =
VSTOP −1.18+ R1×3.2×10−6
AP3434
VIN
0.6μA
2.55μA
R1
R2
EN
Figure 1. Adjustable Under Voltage Lock Out
Adjusting Output Voltage
The output voltage is set with a resistor divider from the FB pin. It is recommended to use divider resistors with 1% tolerance or better. Start with a
10kΩ R2 resistor and use the equation 4 to calculate R1. To improve efficiency at very light loads consider using larger value resistors. If the
values are too high, the regulator is more susceptible to noise and voltage errors from the FB input current are noticeable.
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© Diodes Incorporated
AP3434
Document number: DS37413 Rev. 3 - 4
A Product Line of
Diodes Incorporated
AP3434
Application Note (Cont.)
Resistor R1 can be calculated according to equation 4.
VOUT
AP3434
R1
FB
SS
0.803V
R2
V
OUT
……………………….. (4)
R1= R2×
−1
0.803
Figure 2. Voltage Divider Circuit
Synchronize Using the RT/CLK Pin
The RT/CLK pin of AP3434 is used to synchronize the converter with an external system clock referring to Figure 3. To implement the
synchronization feature in a system, connect a square wave to the RT/CLK pin with an on-time of at least 75ns. When the clock is detected on the
RT/CLK pin, a mode change occurs and the pin becomes a synchronization input. The internal amplifier is disabled. If clocking edges stop, the
internal amplifier is re-enabled and the mode returns to the frequency set by the resistor. The low level of the square wave must be lower than
0.6V and the high level higher than 1.6V typically. The synchronization frequency range is from 300kHz to 2000kHz. The rising edge of the SW is
synchronized to the falling edge of RT/CLK pin. Figure 4 shows a typical synchronizing waveform, the clock frequency is 2MHz.
AP3434
VRT/CLK
2V/div
RT/CLK
VSW
2V/div
Clock
Source
RT
Time 400ns/div
Figure 4. Synchronizing Waveform
Figure 3. Synchronizing to a System Clock
Constant Switching Frequency and Timing Resistor
The switching frequency of the AP3434 is adjustable over a wide range from 200kHz to 2000kHz by placing a resistor with maximum value of
1000kΩ and minimum of 85kΩ, respectively, on the RT/CLK pin. An internal amplifier holds this pin at a fixed voltage when connecting an external
resistor to ground to set the switching frequency. The VRT/CLK is typically 0.5V. To determine the timing resistance for a given switching frequency,
use the equation 5.
311890
……………………….(5)
RT (kΩ) =
fSW (kHz)1.0793
133870
RT (kΩ)0.9393
………………………..(6)
f
SW (kHz) =
To reduce the solution size one should typically set the switching frequency as high as possible, but tradeoffs of the efficiency, maximum input
voltage and minimum controllable on time should be considered.
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AP3434
Document number: DS37413 Rev. 3 - 4
A Product Line of
Diodes Incorporated
AP3434
Application Note (Cont.)
Over Current Protection
The AP3434 implements a cycle-by-cycle current limit. The high side switch current is detected during each cycle. During SCP conditions, VOUT is
pulled down and VCOMP is driven to high, increasing the switch current. When the increased high side switch current is continuously detected to
trigger the current limit of high side switch 6 times, the high side and low side switches are turned off for about 2.5ms. Then both switches start
switching and they will not be turned off until the next 6 OCPs are triggered. The IC works with a hiccup mode during SCP conditions.
Power Good
The PGD pin output is an open drain MOSFET. The output is pulled low when the FB voltage enters the fault condition by falling below 91% or
rising above 107% of the nominal internal reference voltage. There is a 2% hysteresis on the threshold voltage, so when the FB voltage rises to
the good condition above 93% or falls below 105% of the internal voltage reference the PGD output MOSFET is turned off. It is recommended to
use a pull-up resistor between the values of 1kΩ and 100kΩ to a voltage source that is 5V or less. The PGD is in a valid state once the VIN input
voltage is greater than 1.2V.
Thermal Shutdown
The AP3434 implement an internal thermal shutdown to protect itself if the junction temperature exceeds +140°C. Switching is stopped when the
junction temperature exceeds the thermal trip threshold. Once the die temperature decreases below +120°C, the device reinitiates the soft start
operation. The thermal shutdown hysteresis is +20°C.
Component Selection
Typical application circuit of AP3434 is shown in Figure 5. For the major component selection please refer to the following section.
U1
L1 1.5µH
VOUT=1.8V
VIN=5V
16
1
10
11
12
13
SW
SW
VIN
VIN
VIN
R8 2.2Ω
(Optional)
C3
C2
R4
100kΩ
C6
0.1µF
C1
Optional
2
SW
R1
10µF 0.1µF
C10 2.2nF
(Optional)
14
15
BOOT
PGD
EN
6
AP3434
FB
R6 12.5kΩ
7
8
9
3
4
5
COMP
RT/CLK
SS
GND
GND
R7
10kΩ
C8
22µF
C9
22µF
R2
AGND
R3
7.5kΩ
R5
180kΩ
C7
0.01µF
C5
Optional
C4
2.7nF
Figure 5. Typical Application of AP3434
Input Capacitor
The AP3434 requires a high quality ceramic, type X5R or X7R, input decoupling capacitor of at least 4.7μF effective capacitance and in some
applications a bulk capacitor. The effective capacitance includes any DC bias effects. To ensure a stable operation, the input capacitor should be
placed as close to the VIN pin as possible, and its value varies according to different load and different characteristic of input impedance.
There are two important parameters of the input capacitor: the voltage rating and RMS current rating. The voltage rating of the input capacitor
should be at least 1.25 times larger than the maximum input voltage. The capacitor must also have a RMS current rating greater than the
maximum input current ripple of the AP3434. The RMS current of input capacitor can be expressed as:
VOUT
VIN
VOUT
VIN
………..(7)
ICIN_RMS = IOUT(MAX)
×
× 1−
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© Diodes Incorporated
AP3434
Document number: DS37413 Rev. 3 - 4
A Product Line of
Diodes Incorporated
AP3434
Application Note (Cont.)
Output Capacitor
The output capacitor is the most critical component of a switching regulator. It is used for filtering output and keeping the loop stable. The typical
value is 44μF.
The primary parameters for output capacitor are the voltage rating and the equivalent series resistance (ESR). A low ESR capacitor is preferred to
keep the output voltage ripple low. The output ripple is calculated as the following:
1
……………..(8)
∆VOUT ≈ ∆IL ×(RESR
+
)
8× f ×COUT
Where f is the switching frequency, COUT is the output capacitance and △IL is the ripple current in the inductor.
Inductor
The inductor is used to supply smooth current to output when it is driven by a switching voltage. The higher the inductance, the lower the peak-to-
peak ripple current, as the higher inductance usually means the larger inductor size, so some trade-offs should be made when select an inductor.
The AP3434 is a synchronous buck converter. It always works on continuous current mode (CCM), and the inductor value can be selected as the
following:
VIN −VOUT
f ×VIN × IOUT ×k
…………………. ….(9)
L =VOUT ×(
)
Where VOUT is the output voltage, VIN is the input voltage, IOUT is the output current, k is the coefficient of ripple current, and its typical value is 20%
to 40%. Another important parameter for the inductor is the current rating. Exceeding an inductor's maximum current rating may cause the
inductor to saturate and overheat. If inductor value has been selected, the peak inductor current can be calculated as the following:
VIN −VOUT
2× f ×VIN × L
…………..(10)
IPEAK = IOUT +VOUT ×(
)
It should be ensured that the current rating of the selected inductor is 1.5 times of the IPEAK
.
Slow Start Capacitor
The slow start capacitor determines the output voltage soft start time during power up.
The slow start capacitor value can be calculated using equation 11.
tSS (ms)× ISS (µA) ……………………… (11)
CSS (nF) =
VREF (V )
In AP3434, ISS is 2μA and VREF is 0.803V.
Bootstrap Capacitor
A 0.1μF ceramic capacitor must be connected between the BOOT pin and the SW pin for normal operation. It is recommended to use a ceramic
capacitor with X5R or better grade dielectric.
Feedback Resistors
It is recommended to use divider resistors with 1% tolerance or better. Start with a 10kΩ for the R7 resistor and use the equation 12 to calculate
R6.
V
…………………………………(12)
OUT
R6 = R7×
−1
0.803
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AP3434
Document number: DS37413 Rev. 3 - 4
A Product Line of
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AP3434
Application Note (Cont.)
Compensation
The output capacitor and the load resistance largely determine where the error amplifier poles and zeros need to be placed for optimum transient
response and loop stability. The corner frequency of the pole and zero generated by output capacitor are:
1
………………………..(13)
fP1
=
=
2π × RLOAD ×COUT
1
………………………. .. (14)
fZ1
2π × RESR ×COUT
Where RLOAD is the load resistance, COUT is the output capacitance and RESR is the capacitor ESR.
The error amplifier provides most of the loop gain. After selecting the output capacitor, the control loop is compensated by tailoring the frequency
response of the error amplifier. The low frequency pole of the error amplifier is the dominant pole and is determined primarily by CCOMP and the
output resistance of the error amplifier as shown by:
1
…………………..(15)
fP2
=
2π × ROUT _ EA ×CCOMP
Resistor RCOMP adds a zero to the frequency response to control gain in the mid frequency range. This zero frequency is:
1
……………………..(16)
fZ 2
=
2π × RCOMP ×CCOMP
Where RCOMP and CCOMP are compensation resistor and capacitor connected to COMP pin, ROUT_EA is the output impedance of the error amplifier.
A 7.5kΩ resistor and 2.7nF capacitor are used in typical application.
Layout Consideration
PCB layout is very important to the performance of AP3434. The loop which switching current flows through should be kept as short as possible.
The external components (especially CIN) should be placed as close to the IC as possible.
The feedback trace should be routed far away from the inductor and noisy power traces, and it needs to be routed as direct as possible. Locate
the feedback divider resistor network near the feedback pin with short leads.
Since the SW connection is the switching node, the output inductor should be located very close to the SW pins, and the area of the PCB
conductor is minimized to prevent excessive capacitive coupling.
The boot capacitor must also be located close to the device. The sensitive analog ground connections for the feedback voltage divider,
compensation components, slow start capacitor and frequency set resistor should be connected to a separate analog ground trace.
The RT/CLK pin is sensitive to noise so the RT resistor should be located as close as possible to the IC and routed with minimal lengths of trace.
Figure 6. Top View of PCB Layout
Figure 7. Bottom View of PCB Layout
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© Diodes Incorporated
AP3434
Document number: DS37413 Rev. 3 - 4
A Product Line of
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AP3434
Ordering Information
AP3434 XX XX – XX
Product Name
Package
FN : U-QFN3030-16
Packing
RoHS/Green
G1 : Green
TR : Tape & Reel
Diodes IC’s Pb-free products with "G1" suffix in the part number, are RoHS compliant and green.
Package
Temperature Range
Part Number
Marking ID
Packing
5000/Tape & Reel
U-QFN3030-16
-40 to +85ºC
AP3434FNTR-G1
B1J
Marking Information
(Top View)
: AAC Logo
B1J: Marking ID (Per Datasheet)
YWW: Year and Work Week of Mold Operation
M: Assembly Site Code
XX: The 7th & 8th Digits of Batch No.
· Pin 1 Mark
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Document number: DS37413 Rev. 3 - 4
A Product Line of
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AP3434
Package Outline Dimensions
(1) Package Type: U-QFN3030-16
A3
A1
U-QFN3030-16
Type B
A
Dim
A
Min Max Typ
0.55 0.65 0.60
Side View
A1
A3
b
0
0.05 0.02
0.15
−
−
0.18 0.28 0.23
D
e
D
2.95 3.05 3.00
D2
E
E2
e
1.40 1.60 1.50
2.95 3.05 3.00
1.40 1.60 1.50
(Pin #1 ID)
0.50
−
−
0.450
L
0.35 0.45 0.40
200
0.
R
0.625
Z
−
−
E
E2
All Dimensions in mm
D2
L (16x)
Z (8x)
b (16x)
Bottom View
Suggested Pad Layout
(1) Package Type: U-QFN3030-16
C
G
G1
Value
Dimensions
(in mm)
C
G
G1
X
X1
Y
Y1
0.500
0.150
0.150
0.350
1.800
0.600
1.800
Y1
X1
Y (16x)
X (16x)
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© Diodes Incorporated
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Document number: DS37413 Rev. 3 - 4
A Product Line of
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AP3434
IMPORTANT NOTICE
DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
(AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION).
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without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the
application or use of this document or any product described herein; neither does Diodes Incorporated convey any license under its patent or
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all risks of such use and will agree to hold Diodes Incorporated and all the companies whose products are represented on Diodes Incorporated
website, harmless against all damages.
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Should Customers purchase or use Diodes Incorporated products for any unintended or unauthorized application, Customers shall indemnify and
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indirectly, any claim of personal injury or death associated with such unintended or unauthorized application.
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This document is written in English but may be translated into multiple languages for reference. Only the English version of this document is the
final and determinative format released by Diodes Incorporated.
LIFE SUPPORT
Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express
written approval of the Chief Executive Officer of Diodes Incorporated. As used herein:
A. Life support devices or systems are devices or systems which:
1. are intended to implant into the body, or
2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the
labeling can be reasonably expected to result in significant injury to the user.
B. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the
failure of the life support device or to affect its safety or effectiveness.
Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices or systems, and
acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any
use of Diodes Incorporated products in such safety-critical, life support devices or systems, notwithstanding any devices- or systems-related
information or support that may be provided by Diodes Incorporated. Further, Customers must fully indemnify Diodes Incorporated and its
representatives against any damages arising out of the use of Diodes Incorporated products in such safety-critical, life support devices or systems.
Copyright © 2017, Diodes Incorporated
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© Diodes Incorporated
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Document number: DS37413 Rev. 3 - 4
相关型号：
AP3435MPTR-G1
Switching Regulator, Current-mode, 4.5A, 1000kHz Switching Freq-Max, PDSO8, SOP-8
DIODES
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