AP3419

AP3419
1.0MHZ, 2A STEP-DOWN DC-DC BUCK CONVERTER
Description
Pin Assignments
NEW PRODUCT
The AP3419 is a 2A step-down DC-DC converter. At heavy load, the
constant frequency PWM control performs excellent stability and
transient response. No external compensation components are
required.
(Top View)
Pin 1 Mark
The AP3419 supports a range of input voltages from 2.7V to 5.5V,
allowing the use of a single Li+/Li- polymer cell, multiple
Alkaline/NiMH cell, and other standard power sources. The output
voltage is adjustable from 0.6V to the input voltage. The AP3419
employs internal power switch and synchronous rectifier to minimize
external part count and realize high efficiency. During shutdown, the
input is disconnected from the output and the shutdown current is less
than 1μA. Other key features include over-temperature and short
circuit protection, and under-voltage lockout to prevent deep battery
discharge.
EN
1
6
FB
GND
2
5
NC
LX
3
4
VIN
TSOT26
Applications
The AP3419 delivers 2A maximum output current while consuming
only 90μA of no-load quiescent current. Ultra-low RDS(ON) integrated
MOSFETs and 100% duty cycle operation make the AP3419 an ideal
choice for high output voltage, high current applications which require
a low dropout threshold.
The AP3419 is available in TSOT26 package.

5V or 3.3V Point of Load Conversion

Telecom/Networking Equipment

Set Top Boxes

Storage Equipment

Video Cards

DDR Power Supply
Features

Output Current: Up to 2A

Output Voltage: 0.6V to VIN

Input Voltage: 2.7V to 5.5V

Peak Efficiency Up to 95%

90μA (Typ) No Load Quiescent Current

Shutdown Current: <1μA

100% Duty Cycle Operation

1MHz Switching Frequency

Internal Soft Start

No External Compensation Required

Current Limit Protection

Thermal Shutdown

TSOT26 package

Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 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) compliant.
2. See http://www.diodes.com/quality/lead_free.html 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.
AP3419
Document number: DS36543 Rev. 3 - 2
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AP3419
Typical Applications Circuit
VIN=2.7V to 5.5V
VIN
NEW PRODUCT
GND
AP3419
CIN
22mF
VOUT=1.8V
LX
C1
22pF
R1
300k
COUT
22mFx2
FB
EN
ON OFF
L1 2.2mH
R2
150k
Pin Descriptions
Pin Number
Pin Name
Function
1
EN
Enable control input. Force this pin voltage above 1.5V enables the chip, and
below 0.4V shuts down the device
2
GND
3
LX
The drains of the internal main and synchronous power MOSFETs
4
VIN
Bias supply. Chip main power supply pin
5
NC
No connected
6
FB
Feedback voltage to internal error amplifier. The threshold voltage is 0.6V
AP3419
Document number: DS36543 Rev. 3 - 2
Ground pin
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AP3419
Functional Block Diagram
4
NEW PRODUCT
____
OSC
FREQ
SHIFT
S
Q
R
_
Q
_
VIN
1
EN
EA
PWM
+ COMP
_
6
FB
VIN
+
IAMP
SWITCHING
LOGIC AND
BLOCKING
CIRCUIT
_
+
SLOPE COMP
+
1M OSC
3
ANTISHOOT
THRU
LX
0.6V REF
2
SHUTDOWN
GND
Absolute Maximum Ratings (Note 4)
Symbol
Parameter
Rating
Unit
-0.3 to 6
V
VIN
Input Voltage
VEN
EN Pin Voltage
-0.3 to VIN+0.3
V
VLX
LX Pin Voltage
-0.3 to VIN+0.3
V
VFB
Feedback Pin Voltage
-0.3 to VIN+0.3
V
θJA
Thermal Resistance (Junction to Ambient)
220
°C/W
TJ
Operating Junction Temperature
+150
°C
-65 to +150
°C
TSTG
Storage Temperature
TLEAD
Lead Temperature (Soldering, 5 sec)
+300
°C
VMM
ESD (Machine Model)
200
V
VHBM
ESD (Human Body Model)
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.
AP3419
Document number: DS36543 Rev. 3 - 2
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AP3419
Recommended Operating Conditions
NEW PRODUCT
Symbol
Parameter
Min
Max
Unit
VIN
Input Voltage Range
2.7
5.5
V
TA
Operating Ambient Temperature
-40
+85
°C
TJ
Junction Temperature Range
-40
+125
°C
Electrical Characteristics (@VIN = 5V, VOUT = 1.8V, L = 2.2µH, COUT = 22µFx2, TA = +25°C, unless otherwise specified.)
Symbol
Parameters
Conditions
Min
Typ
Max
Unit
Input Voltage Range
–
2.7
–
5.5
V
Output Voltage Range
–
0.6
–
VIN
V
VFB
Regulated Feedback Voltage
–
0.588
0.6
0.612
V
IFB
FB Leakage Current
VFB = 1V
–
–
0.2
μA
IQ
Quiescent Current
VFB = 0.65V
–
90
–
μA
ISD
Shutdown Current
VEN = 0V
–
–
1
μA
ILIM
Peak Inductor Current
–
3
–
–
A
fOSC
Oscillator Frequency
–
–
1
–
MHz
Drain to Source On-state
Resistance
ILX = 100mA, high side
–
110
–
ILX = 100mA, low side
–
80
–
VENH
EN High Threshold
–
1.5
–
–
V
VENL
EN Low Threshold
–
–
–
0.4
V
EN Leakage Current
VIN = VEN = 5V
-1.0
–
1.0
μA
VUVLO
Input UVLO Threshold
–
–
2.4
2.7
V
VHYS
UVLO Hysteresis
–
–
0.2
–
V
TOTP
Over Temperature Protection
–
–
+160
–
°C
TOTH
OTP Hysteresis
–
–
+30
–
°C
VIOVP
VIN Over Voltage Protection
—
—
6.25
—
V
VIHSY
IOVP Hysteresis
—
—
0.25
—
V
Soft-start Time
–
–
1.8
–
ms
VIN
VOUT
RDS(ON)
IEN
tSS
AP3419
Document number: DS36543 Rev. 3 - 2
mΩ
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AP3419
Performance Characteristics (@TA = +25°C, VIN = 5V, VOUT = 1.8V, unless otherwise specified.)
Efficiency vs. Load Current
Feedback Reference Voltage vs. Temperature
0.620
90
0.615
Feedbaxk Reference Voltage (V)
100
80
Efficiency (%)
60
50
40
30
VIN=5V, VOUT=1.0V
VIN=5V, VOUT=1.8V
VIN=5V, VOUT=3.3V
20
10
1
10
100
0.610
0.605
0.600
0.595
0.590
0.585
0.580
-60
0
1000
-40
-20
0
20
40
60
80
100
120
140
o
Temperature ( C)
IOUT (mA)
PFET Drain-Source On-State Resistance vs. Temperature
NFET Drain-Source On-State Resistance vs. Temperature
120
200
190
110
170
NFET RDS(ON) (m)
PFET RDS(ON) (m)
180
160
150
140
130
100
90
80
70
120
60
110
100
-60
-40
-20
0
20
40
60
80
100
120
50
-60
140
-40
-20
0
40
60
80
100
120
140
o
Temperture ( C)
Inductor Current Limit vs. Temperature
Oscillation Frequency vs. Temperature
1.20
4.4
1.15
4.2
1.10
Oscilliator Frequecny (MHz)
4.6
4.0
3.8
3.6
3.4
3.2
3.0
2.8
2.6
-60
20
Temperture ( C)
o
Inductor Current Limit (A)
NEW PRODUCT
70
1.05
1.00
0.95
0.90
0.85
0.80
0.75
-40
-20
0
20
40
60
80
100
120
140
o
Document number: DS36543 Rev. 3 - 2
-40
-20
0
20
40
60
80
100
120
140
o
Temperature ( C)
AP3419
0.70
-60
Temperature ( C)
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AP3419
Performance Characteristics (Cont. @TA = +25°C, VIN = 5V, VOUT = 1.8V, unless otherwise specified.)
Enable Turn on Characteristic (IOUT=2A)
Enable Turn off Characteristic (IOUT=2A)
VEN
(2V/div)
NEW PRODUCT
VEN
(2V/div)
VOUT
(1V/div)
VOUT
(1V/div)
IL
(2A/div)
IL
(2A/div)
VSW
(5V/div)
VSW
(5V/div)
Time (5ms/div)
Time (5ms/div)
Short Current Protection (IOUT=2A)
VOUT
(1V/div)
SCP Recovery (IOUT=2A)
VOUT
(1V/div)
IL
(2A/div)
IL
(2A/div)
VSW
(5V/div)
VSW
(5V/div)
Time (50ms/div)
Time (50ms/div)
Load Transient (IOUT=0.1A to 2A)
Load Transient (IOUT=1A to 2A)
VOUT_AC
(100mV/div)
VOUT_AC
(100mV/div)
IOUT
(1A/div)
IOUT
(1A/div)
Time (100µs/div)
AP3419
Document number: DS36543 Rev. 3 - 2
Time (100µs/div)
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AP3419
Application Information
Typical application circuit is shown in the application circuit and for the circuit parameters setting please refers to the following descriptions.
Under Voltage Lockout (UVLO) Circuit
When the VIN drops lower than the UVLO detector threshold, the UVLO circuit starts to operate, V REF stops, and high-side switch and low-side
switch built-in switch transistors turn “OFF”. As a result, V OUT drops according to the COUT capacitance value and the load. When the VIN is rising
higher than UVLO released voltage, the IC will restart the operation.
NEW PRODUCT
Short Circuit Protection and Recovery
When the AP3419 output node is shorted to GND that VFB drops under 0.3V, AP3419 will enter hiccup mode to protect itself. If short circuit is
removed, and VFB rises over 0.3V, the AP3419 recovers to normal operation again. If the AP3419 reaches OCP threshold while short circuit, the
AP3419 will enter cycle by cycle current limit mode until the current under OCP threshold.
Over Temperature Protection
The internal thermal temperature protection circuitry is provided to protect the integrated circuit in the event that the maximum junction
temperature is exceeded. When the junction temperature exceeds +160°C, it shuts down the internal control circuit and switching power MOSFET.
The AP3419 will restart automatically under the control of soft start circuit when the junction temperature decreases to +130°C.
Input Over Voltage Protection
When input voltage of AP3419 is near 6.25V, the IC will enter Input-Over-Voltage-Protection. It would be shut down and there will be no output
voltage in this state. As the input voltage goes down below 6V, it will leave input OVP and recover the output voltage.
Ordering Information
AP3419 XX XX - XX
Package
Packing
RoHS/Green
KT : TSOT26
TR: Tape & Reel
G1 : Green
Product Name
Package
Temperature Range
TSOT26
-40 to +85°C
Part Number
AP3419KTTR-G1
Marking ID
L8J
Packing
3000/Tape & Reel
Marking Information
(Top View)
First Line: Logo and Marking ID
AP3419
Document number: DS36543 Rev. 3 - 2
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AP3419
Package Outline Dimensions
Please see AP02002 at http://www.diodes.com/datasheets/ap02002.pdf for the latest version.
(1)
Package Type: TSOT26
TSOT26
Dim Min Max Typ
A
1.00


A1 0.01 0.10

A2 0.84 0.90

D
2.90


E
2.80


E1
1.60


b
0.30 0.45

c
0.12 0.20

e
0.95


e1
1.90


L
0.30 0.50
L2
0.25


θ
0°
8°
4°
θ1
4°
12° 
All Dimensions in mm
D
NEW PRODUCT
e1
E
E1
L2
c
4x1
e
L

6x b
A
A2
A1
Suggested Pad Layout
Please see AP02001 at http://www.diodes.com/datasheets/ap02001.pdf for the latest version.
(1)
Package Type: TSOT26
C
C
Dimensions Value (in mm)
C
0.950
X
0.700
Y
1.000
Y1
3.199
Y1
Y (6x)
X (6x)
AP3419
Document number: DS36543 Rev. 3 - 2
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AP3419
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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).
NEW PRODUCT
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written approval of the Chief Executive Officer of Diodes Incorporated. As used herein:
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representatives against any damages arising out of the use of Diodes Incorporated products in such safety-critical, life support devices or systems.
Copyright © 2015, Diodes Incorporated
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AP3419
Document number: DS36543 Rev. 3 - 2
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