AP2403 AKM | Alldatasheet
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[AP2403] MS1528-E-02 2014/01 - 1 - 1. Genaral Description The AP2403 is a Current-Mode Synchronous Step -Down DC -DC Convert er w ith excellent transient response. The output voltage is selectable from the range of 0.8V to 5.0V by an external resistor. The input supplies. Power MOSFETs are built in the AP2403; the maximum output current of the AP2403 is 2.5A. The switching frequency is selectable from 300 kHz to 4 MHz by the external re sistor. For the protections, the AP2403 has Over-Current protection, Low-Input Voltage protection , Thermal protection and Power-Good function. 2. Features 1. Input Voltage Range: Vin = 3.0V to 5.5V 2. Output Voltage Range: Vout = 0.8V to 5.0V (by the external resistor) 3. Maximum Output Load Current: Iout(max) = 2.5A http://akm.transim.com/ 4. Operation Temperature: Ta = -40C to 105C 5. Switching Frequency: 300kHz to 4MHz (Selectable by an external resistor and External Synchronous Mode is available by an external clock) 6. Internal Reference Voltage: 0.6V 1.5% 7. Maximum Duty: 100% 8. Low Input Voltage Protection 9. Power-Good Function 10. Over-Current Protection (Automatic recovery type) 11. Thermal Protection 12. Soft Start Function 13. Package: 16-pin HTSSOP Current-Mode PWM Step -Down DC -DC Converter AP2403
[AP2403] MS1528-E-02 2014/01 - 2 - 3. Table of Contents
- Block Diagram and Functions
Figure 1. Block Diagram
- Pin Configurations and Functions
Figure 2. Pin Layout
1 PWGD O
setting voltage, this pin becomes “H”.
2 FSYN I
by the resistor at the RT pin is available.
3 PWON I
4 RT O
5 SGND Signal Ground -
6 SS O
7 CC O
[AP2403] MS1528-E-02 2014/01 - 5 -
8 FB I
Input pin of Output Voltage Feedback Amplifier (Error Amp.) It c ontrols the output voltage so that the voltage at this pin becomes 0.6V. Connect t wo resistors for feedback between the output stage and the GND in series, and the FB pin must be connected to the middle point of these two resistors. HiZ (there is an external resistor between the GND)
9 VIN
Connect a capacitor of 4.7F or more between the VIN pin and the GND.
10 SW O
Internal Switching MOSFET Output It is connected to the middle point of the internal output N-channel MOSFET and the P-channel MOSFET. HiZ
11 SW O
Internal Switching MOSFET Output It is connected to the middle p oint of the internal output N-channel MOSFET and the P-channel MOSFET. HiZ
12 PGND
13 PGND
14 SW O
Internal Switching MOSFET Output It is connected to the middle point of the internal output N-channel MOSFET and the P-channel MOSFET. HiZ
15 SW O
Internal Switching MOSFET Output It is connected to the middle point of the internal output N-channel MOSFET and the P-channel MOSFET. HiZ
16 VIN
Connect a capacitor of 4.7F or more between the VIN pi n and the GND. Note 1. Pin state when the PWON pin = “L”
[AP2403] MS1528-E-02 2014/01 - 6 - 6. Absolute Maximum Ratings (GND=0V: Note 2) Parameters Symbol min max Unit VIN pin Vin 0.3 6.0 V SW pin VSW 0.3 Vin + 0.3 V All pins (Except SW pin, VIN pin) VIND 0.3 Vin V Junction Temperature (Note 4) Tj1 40 150 C Junction Temperature (Guaranteed Lifetime) Tj2 40 135 C Operating Ambient Temperature Ta 40 105 C Storage Ambient Temperature TSTG 40 150 C Power Dissipation (Ta=25 C) ( Note 3) Pd 2750 mW Note 2. All voltages with respect to the GND pin Note 3. Thermal Resistance of the package (Rth): 40C/W (JEDEC51, four layers PCB) Note 4. Continuous operation above Tj=135C may impair device reliability. WARNING: Operation at or beyond these limits may result in permanent damage to the device. Normal operation is not guaranteed at these extremes. 7. Recommended Operating Conditions (GND=0V) Parameter Symbol min typ max Unit VIN pin voltage Vin 3.0 5.5 V Output Current Iout 0 2.5 A Operating Ambient Temperature Top 40 105 C * AKM assumes no responsibility for the usage beyond the conditions in this datasheet.
[AP2403] MS1528-E-02 2014/01 - 7 - 8. Electrical Characteristics (VIN=5.0V, Tj=40C to 135C, unless otherwise specified) Parameter Symbol min typ max Unit Conditions Operating Input Voltage Range Vin 3.0 - 5.5 V Feedback REF Voltage VFBref 591 600 609 mV Tj=25°C Operation Current Consumption (No Switching) ISUPPLY 0.48 0.8 1.12 mA Tj=25°C Stand-by Current Istandby - - 10 A Tj=25°C Load Regulation (Note 5) VLOAD - 1 - % 0A to 2A, Ta=-40°C to 105°C Output Pch MOSFET RDS(ON) Rpmos - 65 100 mΩ Tj=25°C Output Nch MOSFET RDS(ON) Rnmos - 65 100 mΩ Tj=25°C Over-Current Detection Ioclpeak 3.15 4.5 - A Tj=25°C Oscillator Frequency Fosc 300 - 4000 kHz RT=702kΩ to 47kΩ FSYN Input Frequency Range Fext300 240 - 360 kHz RT=702kΩ (at 300kHz) Fext2000 1600 - 2400 kHz RT=100kΩ (at 2MHz) Oscillator Accuracy Facu 20 0 20 % RT=100kΩ (at 2MHz), Tj=25°C Maximum ON Duty (Note 5) MAXDuty - - 100 % UVLO Detection Voltage Vuvlo 2.30 2.50 2.85 V UVLO Release Voltage Vuvlorel 2.35 2.70 2.90 V UVLO Hysteresis Vuvhys 0.05 0.20 0.50 V Output Over Voltage Detection Vovp +26 +30 +34 % against VFBref Charge Current (to Capacitor of Soft Start) Iss+ 18.0 20.0 22.0 A Css=0V → 1.0V (at rise) Tj=25°C Discharge Current (to Capacitor of Soft Start) Iss- 0.70 1.0 1.30 A Css=1.0V→0.40V (at fall) Tj=25°C (in hiccup operation) Thermal Protection Detection (Note 6) Tsd 135 155 185 C Thermal Protection Hysteresis (Note 6) Tsdhys 5 15 25 C High side Power Good Detection Vpgonh +16 +20 +24 % by contrast with VFBref High side Power Good Release Vpgoffh +21 +25 +29 % by contrast with VFBref Low side Power Good Detection Vpgonl 16 20 24 % by contrast with VFBref Low side Power Good Release Vpgoffl 21 25 29 % by contrast with VFBref Power Good Hysteresis Vpghys 3 5 7 % Power-OFF Threshold Vponl - - 0.4 V Power-ON Threshold Vponh 1.5 - - V Power-ON Hysteresis Vponhys 50 100 150 mV Gm (Error amplifier) Gm 360 500 730 A/V Tj=25°C Threshold voltage (of FSYN pin) VEih 0.7*VIN - - V Tj=25°C VEil - - 0.3*VIN V Tj=25°C Output voltage (of PWGD pin) VPoh VIN0.4 - - V Ipoh=100A VPol - - 0.4 V Ipol=100A Note 5. A reference value with the recommended circuit Note 6. Design assurance values
[AP2403] MS1528-E-02 2014/01 - 8 - 9. Functional Descriptions 1. Shutdown The AP2403 is in shutdown condition when a Low signal is input to the PWON pin even if power supply was input to the VIN pin. When a High signal is input to the PWON pin, the AP2403 is powered up in soft-start mode. 2. Soft Start Mode: This function prevent s an overshoot of the output voltage when the AP2403 is powered up . It controls the output voltage slowly. During the soft-start period a capacitor connected to the SS pin is charged from 0V to 1.0V by a 20A constant current. In soft start, an output voltage rising is controlled by changing the over-voltage limitation value linearly in accor dance with the SS pin voltage. When this function starts, the over-current limitation value is fixed in 50% (2.25A typ.). It changes linearly during the period which the SS pin voltage increases to 1.0V from 0.5V. When a soft start operation is completed, the AP2403 shifts to a PWM control. 3. Constant Voltage Operation: The AP2403 operates by Current-mode PWM controls. It determines the target value of inductance current by amplifying the voltage difference between the FB pin and 0.6V which is feedback reference voltage. The internal P-channel MOSFET is powered on u ntil the inductance current meets the target value. When the inductance current reaches the target value , the built-in P-channel MOSFET becomes OFF and the built-in N-channel MOSFET becomes ON. Then the AP2403 operates in synchronous rectification mode. 4. Prevention of Incorrect Operation in Low Voltage (UVLO: Under Voltage Lock Out): When the V5 pin voltage becomes less than 2.5V by a main power supply voltage decrease, all circuit blocks in the AP2403 are stopped and the AP2403 becomes UVLO state. The UVLO state has hysteresis, and the AP2403 keeps UVLO state until the main power supply voltage rises again and exceeds 2.5V. When the UVLO state is released, the AP2403 restarts by a soft start operation. 5. Output Over-Voltage Protection (OVP): When the output voltage becomes +30% or more of the setting value, the built -in P-channel MOSFET and the built-in N -channel MOSFET become OFF state and the AP2403 enters protection mode. This state is maintained until the built-in P-channel MOSFET is turned on by the FB amplifier. The AP2403 is in normal operation when recovering from the output over-voltage protection. It does not shift to soft-start mode. 6. Hiccup type Output Over-Current Limitation (OCL): This function reduces the output voltage and the output current by Hiccup operation in an over-current condition. When the over -current conditio n is detected, the built -in P -channel MOSFET and the built -in N-channel MOSFET become OFF and the SS pin voltage which is 1.0V discharged from 1.0V to 0.4V by a continuous current of 1.0uA. The AP2403 stops its operation without shifting to a soft start operation in this discharging period of the SS pin. When the SS pin voltage decreases to 0.4V, the AP2403 enters a soft start operation after the SS pin voltage is discharged further to the GND level by the internal switch. The AP2403 repeats this sequence until the over current condition is removed.
[AP2403] MS1528-E-02 2014/01 - 9 - 7. Thermal Protection (TSD: Thermal Shutdown) The chip temperature is monitored, and t he built -in P -channel MOSFET and the built-in N -channel MOSFET are stop ped when the chip temperature becomes about 150 C. T he thermal protection function discharges electrical charge of the SS pin at this time, therefore a recovery sequence from the thermal protection is always in a soft start operation . This function has a hysteresis, and the AP2403 is restarted by soft start when the chip temperature decreases 15C from the thermal shutdown threshold. 8. Oscillation Frequency Setting: The oscillation frequency is determined by a resistor which is connected between the RT pin and the GND. Refer to the equation of this resistor value for frequency setting in the page of the application information. 9. External Synchronization External synchronization is available by i nputting a clock to the FSYN pin . The external synchronization frequency is determined by a resistor which is connected between the RT pin and the GND, and the AP2403 accepts a frequency within 20% of this setting value. 10. Power Good The AP2403 has a power-good function which indicates output voltage condition. The PWGD pin becomes High level (VIN level), when the output voltage reaches a level that is within 25% of the setting value. The PWGD pin is always in Low level, during a power-off condition and a soft start operation.
Figure 3. Start Up Timing
Figure 4. Over Current Protection Timing
Figure 5. External Synchronous Timing 33% Fixed It changes in 67% of the rest. the RT pin for an external synchronization. clock, the AP2403 operates according to the internal clock. clock, the AP2403 operates according to an external clock.
[AP2403] MS1528-E-02 2014/01 - 13 - 10. Application Information 1. Inductance: An external inductor must be selected so that the maximum ripple current will be 30% of the rated current. The main power voltage (Vin) is the maximum value of input voltage range. The external inductor value is determined by following equation. 2. Phase Compensation: Resistors and a capacitor for phase compensation are connected between the CC pin and the Vref/SS pin. Recommended values of these are shown below but they are not fixed. These values can be changed according to the VIN and VOUT frequency settings to optimize the phase compensation. (values shown below is in the case of “11. Recommended External Circuits”) R4＝220[kΩ], R5 ＝4.7[kΩ], C5=2200[pF] 3. Soft Start Time: Soft-start time is determined by the C4 capacitor which is connected between the SS pin and the GND. The relation of the capacitance and the soft-start time is calculated by the following equation. Tss = C4／20×10-6 [s] 4. Suspended Time in Hiccup Operation: The suspended time in Hiccup operation is determined by the C4 capacitor which is connected between the SS pin and the GND. The relation of the capacitance and the suspended time is calculated by the following equation. 5. Output Voltage: The output voltage is determined by the feedback resistors, and those two resistors are placed in series between the output capacitor and the GND. Those resistor value of R2 (the output capacitor to FB pin) and R1 (FB pin to GND) are calculated by the following equation. Please note that the operation may become unstable by an influence of the switching noise when the current which flows in the resistor becomes too small. 6. Oscillation Frequency: The oscillation frequency is determined by the R3 resistor which is connected between the RT pin and the GND. The relation of the resistor value and the oscillation frequency is calculated by the following equation. ]H[FrequencyVin0.6 Vout-VinVoutL ）（ ]s[ 101 C40.6T 6-HIC ＝ ]V[R1 R210.6Vout ＝ ][102.352.1 )1033-y1/Frequenc0.6R3 12- Ω （＝
Figure 6. HTSSOP-16 DERATING CURVE operated within the power dissipation.
- Recommended External Circuits
Figure 7. Standard Recommended Circuit Example
Figure 8. Recommended Layout Pattern
[AP2403] MS1528-E-02 2014/01 - 17 - 13. Package ■ Outline Dimensions HTSSOP 16 -pin (Unit: mm)
[AP2403] MS1528-E-02 2014/01 - 18 - ■ Marking 1) Pin #1 indication 2) Date Code : XXXXXX (6 digits: Date Code) 3) Marketing Code : AP2403
[AP2403] MS1528-E-02 2014/01 - 19 - 14. Revision History Date (Y/M/D) Revision Page Contents 13/04/23 00 First edition 13/07/02 01 4, 9, 12, The correction of the description of I/O in Pin Configuration and Functions The correction of the type error in TIMING CHART AT OVER CURRENT PROTECTION (the shifting of the equations of T3 and T4) Deletion of the diode of D1 in Figure 7 Deletion of the symbol of D1 in Figure 8 14/01/24 02 14 Addition of “Power Dissipation”
[AP2403] MS1528-E-02 2014/01 - 20 - IMPORTANT NOTICE 0. Asahi Kasei Microdevices Corporation (“AKM”) reserves the right to make changes to the information contained in this document without notice. When you consider any use or application of AKM product stipulated in this document ( “Product”), please make inquiries the sales office of AKM or authorized distributors as to current status of the Products. 1. All information included in this document are provided only to illustrate the operation and application examples of AKM Products . AKM neither makes warranties or representations with respect to the accuracy or completeness of the information contained in this document nor grants any license to any intellectual property rights or any other rights of AKM or any third party with respect to the information in this document. You are fully responsible for use of such information contained in this document in your product design or applications . AKM ASSUMES NO LIABILITY FOR ANY LOSSES INCURRED BY YOU OR THIRD PARTIES ARISING FROM THE USE OF SUCH INFORMATION IN YOUR PRODUCT DESIGN OR APPLICATIONS. 2. The Product is neither intended nor warranted for use in equipment or systems that require extraordinarily high levels of quality and/or reliability and/or a malfunction or failure of which may cause loss of human life, bodily injury, serious property damage or serious public impact , including but not limited to, equipment used in nuclear facilities, equipment used in the aerospace industry, medical equipment, equipment used for automobiles, trains, ships and other transportation, traffic signaling equipment, equipment us ed to control combustions or explosions, safety devices, elevators and escalators, devices related to electric power, and equipment used in finance-related fields. Do not use Product for the above use unless specifically agreed by AKM in writing. 3. Though AKM works continually to improve the Product’s quality and reliability, you are responsible for complying with safety standards and for providing adequate designs and safeguards for your hardware, software and systems which minimize risk and avoid situati ons in which a malfunction or failure of the Product could cause loss of human life, bodily injury or damage to property, including data loss or corruption. 4. Do not use or otherwise make available the Product or related technology or any information contained in this document for any military purposes, including without limitation, for the design, development, use, stockpiling or manufacturing of nuclear, chemical, or biological weapons or missile technology products (mass destruction weapons). When exporting the Products or related technology or any information contained in this document, you should comply with the applicable export control laws and regulations and follow the procedures required by such laws and regulations. The P roducts and related technology may not be used for or incorporated into any products or systems whose manufacture, use, or sale is prohibited under any applicable domestic or foreign laws or regulations. 5. Please contact AKM sales representative for details as to environmental ma tters such as the RoHS compatibility of the Product. Please use the Product in compliance with all applicable laws and regulations that regulate the inclusion or use of controlled substances, including without limitation, the EU RoHS Directive. AKM assumes no liability for damages or losses occurring as a result of noncompliance with applicable laws and regulations. 6. Resale of the Product with provisions different from the statement and/or technical features set forth in this document shall immediately vo id any warranty granted by AKM for the Product and shall not create or extend in any manner whatsoever, any liability of AKM. 7. This document may not be reproduced or duplicated, in any form, in whole or in part, without prior written consent of AKM.