Document
Description
The AP3441 and AP3441L are 3A step-down DC-DC converters. At heavy load, the constant-frequency PWM control performs excellent stability and transient response. No external compensation components are required.
AP3441/L
1MHZ, 3A STEP-DOWN DC-DC BUCK CONVERTER
Pin Assignments
(Top View) Pin 1 Mark
The AP3441/L 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 AP3441/L 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.
The AP3441/L delivers 3A maximum output current while consuming only 55μA of no-load quiescent current. Ultra-low RDS(ON) integrated MOSFETs and 100% duty cycle operation make the AP3441/L an ideal choice for high output voltage, high current applications which require a low dropout threshold. Pulse skip mode to maintain high efficiency at light-load conditions.
FB 1 PG 2 VIN 3 PGND 4
8 SGND 7 EN 6 LX 5 NC
U-DFN2020-8 (Type E)
The AP3441/L is available in U-DFN2020-8 (Type E) package.
Features
Input Voltage: 2.7V to 5.5V Output Voltage: 0.6V to VIN 0.6V Reference Voltage with ±1.5% Precision 55µA (Typical) No Load Quiescent Current Shutdown Current: <1µA 100% Duty Cycle Operation 1MHz Switching Frequency No External Compensation Required Short Circuit Protection
441L: Latch Off Protection AP3441: Hiccup Mode Protection Over Voltage Protection AP3441L: Latch Off Protection AP3441: Non Latch Off Protection Thermal Shutdown U-DFN2020-8 (Type E) Package Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. “Green” Device (Note 3)
Applications
Post DC-DC Voltage Regulation Set Top Boxes Notebook Computer PAD
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.
AP3441/L
Document number: DS39754 Rev. 3 - 2
1 of 13 www.diodes.com
September 2019
© Diodes Incorporated
Typical Applications Circuit
AP3441/L
VIN=2.7V to 5.5V VIN
CIN 22mF OFF ON
EN
L1 2.2mH LX
C1 22pF
FB
PG
PGND
SGND
AP3441/L
VOUT=1.8V
R1 200kΩ
COUT 22mFx2
R2 100kΩ
Pin Descriptions
Pin Number 1 2 3 4 5 6 7 8
EP
Pin Name FB PG VIN
PGND NC LX EN
SGND
Exposed Pad
Function
Feedback voltage to internal error amplifier, the threshold voltage is 0.6V. Power good indicator, open drain output. PG is pulled up to VIN when the output voltage is within 20% of the regulation level, otherwise it is low. Bias supply. Chip main power supply pin
Power ground pin
No connection
The drains of the internal main and synchronous power MOSFET. Enable control input. Force this pin voltage above 1.5V enables the chip, and below 0.4V shuts down the device. Signal ground pin Exposed metal pad on the underside of the package without any electrical connection to internal circuit. It is recommended to connect this pad to the PC board ground plane in order to improve heat dissipation.
AP3441/L
Document number: DS39754 Rev. 3 - 2
2 of 13 www.diodes.com
September 2019
© Diodes Incorporated
Functional Block Diagram
EN 7
Slope Compensation
Shutdown Comparator
PG 2
Bias Generator
Soft Start
Oscillator
OCP Comparator
UVLO
Current Sensing
PWM Comparator
Control Logic
Buffer & Dead Time
Control Logic
1 FB
Bandgap Reference
Error Amplifier
SCP OVP
AP3441L only
Latch Off Circuit
Reverse Inductor Current Comparator
VIN OVP Comparator
AP3441/L
VIN 3
6 LX
4 PGND
8 SGND
Functional Block Diagram of AP3441/L
AP3441/L
Document number: DS39754 Rev. 3 - 2
3 of 13 www.diodes.com
September 2019
© Diodes Incorporated
AP3441/L
Absolute Maximum Ratings (Note 4)
Symbol
Parameter
Rating
Unit
VIN
Input Voltage
VEN
EN Pin Voltage
VFB
FB Pin Voltage
VLX
LX Pin Voltage
VLX
LX Pin Voltage
VFB
Feedback Pin Voltage
PD
Power Dissipation (On PCB, TA = +25°C)
-0.3 to 6
V
-0.3 to VIN+0.3
V
-0.3 to VIN+0.3
V
-0.3 to VIN+0.3
V
-3 to VIN +3 for <20ns
V
-0.3 to VIN+0.3
V
1.4
W
θJA
Thermal Resistance (Junction to Ambient)
70
°C/W
θJC
Thermal Resistance (Junction to Case, Simulation)
8.2
°C/W
Note:
TJ
Operating Junction Temperature
+150
°C
TSTG
Storage Temperature
-55 to +150
°C
VHBM
ESD (H.