AP61040

AP61040

Document overview

• Manufacturer or author: Diodes Incorporated
• PDF pages: 17

Technical content

Features

• VIN 2.15V to 5.5V
• Output Voltage Range: 0.6V to 5.5V ▪ Three Selectable Voltages between 0.6V, 2.5V, and 3.3V
• 400mA Continuous Output Current, Efficiency up to 95%
• 930nA Quiescent Current to Maximize Light-Load Efficiency
• 1.1MHz Switching Frequency
• Programmable Operation Mode through EN ▪ Pulse-Frequency Modulation ▪ Pulse-Width Modulation Regardless of Output Load
• Fully Protected for Overcurrent, Short Circuit, Overtemperature, and Undervoltage Lockout
• Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
• Halogen and Antimony Free. “Green” Device (Note 3)
• For automotive applications requiring specific change control (i.e. parts qualified to AEC-Q100/101/104/200, PPAP capable, and manufactured in IATF 16949 certified facilities), please contact us or your local Diodes representative. https://www.diodes.com/quality/product-definitions/ Pin Assignments SW VIN EN PGND VSEL1 FB A B C TOP VIEW 1 2 X1-WLB1208-6

Applications

• Wearables
• Fitness trackers
• Smart watches
• Health monitors
• Bluetooth low-energy devices
• Ultra-low power applications
• Energy harvesting 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.

© 2025 Copyright Diodes Incorporated. All Rights Reserved.

6 BALLS

VIN A2 Input supply for the logic control circuitries. PGND B2 Power Ground and analog ground that is used for control. FB C2 Feedback sensing terminal for the output voltage. Connect this pin to the resistive divider of the output. See Setting the Output Voltage section for more details. Figure 4. Functional Block Diagram

Document number: DS47332 Rev. 1 - 2 4 of 17 www.diodes.com July 2025 © 2025 Copyright Diodes Incorporated. All Rights Reserved. AP61040 Absolute Maximum Ratings (Note 4) (@TA = +25°C, unless otherwise specified.) Symbol Parameter Rating Unit VIN Supply Voltage -0.3 to +7.0 V VSW Switch Node Voltage -1.0 to VIN +0.3 (DC) V VSW Switch Node Voltage -2.5 to 8V (20ns) V All other pins - -0.3V to +7.0 V TJ Junction Temperature +150 °C TL Lead Temperature +260 °C ESD Susceptibility (Note 5) HBM Human Body Mode 3000 V CDM Charged Device Model 1000 V Notes: 4. Stresses greater than the 'Absolute Maximum Ratings' specified above may cause permanent damage to the device. These are stress ratings only; functional operation of the device at these or any other conditions exceeding those indicated in this specification is not im plied. Device reliability may be affected by exposure to absolute maximum rating conditions for extended periods of time. 5. Semiconductor devices are ESD sensitive and may be damaged by exposure to ESD events. Suitable ESD precauti ons should be taken when handling and transporting these devices. Thermal Resistance Symbol Parameter Package Rating, JEDEC (Note 6) AP61040 EVM (Note 7) Unit θJA Junction to Ambient WLB1208-6 100 60 °C/W θJC(TOP) Junction to Case (Top) WLB1208-6 49 35 °C/W θJB Junction to Board (bottom) WLB1208-6 15.7 12 °C/W ψJT Junction to Top Characterization Parameter WLB1208-6 4.6 1.2 °C/W ψJB Junction to Board Characterization Parameter WLB1208-6 15 12 °C/W θJC(BOT) Junction to Case (Bottom) WLB1208-6 - - °C/W Notes: 6. Device mounted on FR-4 substrate, JEDEC 4 layer 50mm x 50mm PCB board (2 oz copper), with minimum recommended pad layout. 7. Device mounted on Diodes evaluation board. See user guide for more detail. Recommended Operating Conditions (Note 8) (@TA = +25°C, unless otherwise specified.) Symbol Parameter Min Max Unit VIN Supply Voltage 2.15 5.5 V IOUT Output Current, 2.15V<VIN<2.5V, VOUT<1.8V - 300 mA Output Current, VIN>2.5V - 400 TJ Operating Junction Temperature -40 +125 °C Note: 8. The device function is not guaranteed outside of the recommended operating conditions.

Document number: DS47332 Rev. 1 - 2 5 of 17 www.diodes.com July 2025 © 2025 Copyright Diodes Incorporated. All Rights Reserved. AP61040 Electrical Characteristics (At TJ = +25°C, VIN = 3.6V, VEN = 3.6V unless otherwise specified. Min/Max limits apply across the recommended operating junction temperature range, -40°C to +125°C, and input voltage range, 2.15V to 5.5V, unless otherwise specified.) Symbol Parameter Test Conditions Min Typ Max Unit ISHDN Shutdown Supply Current VEN = 0V, VIN=5.5V - 34 470 nA IQ Supply Current (Quiescent) VEN = VIN, VSEL1=Open, VFB = 1.0V - 930 1500 nA PFM, VEN = VIN - 1000 1600 nA PWM, VSEL1=Open, VFB = 1.0V - 93 - µA POR/UVLO VIN Power On Reset Voltage Threshold, Rising Edge - - 2.07 2.15 V Vin, Undervoltage Lockout Threshold, Falling Edge - - 1.90 2.00 V Hysteresis - - 170 - mV RDS(ON)1 High-Side Switch On-Resistance from VIN to SW - - 321 440 mΩ RDS(ON)2 Low-Side Switch On-Resistance from SW to PGND - - 150 210 mΩ RDischarge VOUT Soft Discharge On-Resistance - - 50 - Ω Leakage Current SW HS Q1 Leakage Current SW= 0V, VIN=5.5V, EN=0V - - 1 µA ILIMIT Positive HS Current Limit, Q1 - 600 800 - mA ILIMIT_VALLEY LS Current Limit, Q2 Current from Source to Drain - - 470 - mA INLIMIT Negative LS Current Limit, Q2 Current from Drain to Source - - 400 - mA FSW Oscillator Frequency - - 1.1 - MHz VFB Feedback Voltage VSEL1 = OPEN 0.588 0.6 0.612 V VSEL1 = GND 2.450 2.500 2.550 V VSEL1 = VIN 3.235 3.300 3.365 V VEN EN Logic High - 1.4 - - V EN Logic Low - - 0.4 V VVSEL1 VSEL1 Logic High - 1.4 - - V VSEL1 Logic OPEN - 0.5 - 0.9 V VSEL1 Logic Low - - - 0.4 V TSS Soft-Start Period - - 0.8 - ms TSD Thermal Shutdown (Note 9) - - 150 - °C Thermal Hysteresis (Note 9) - - 25 - °C Note: 9. Compliance to the datasheet limits is assured by one or more methods: production test, characterization, and/or design.

© 2025 Copyright Diodes Incorporated. All Rights Reserved. Figure 11. IQ vs. Temperature Figure 12. fsw vs. Load

Document number: DS47332 Rev. 1 - 2 13 of 17 www.diodes.com July 2025 © 2025 Copyright Diodes Incorporated. All Rights Reserved. AP61040

Application Information

Alternatively, the output voltage can be programmed via VSEL1. Table 2 shows the voltage selection settings. Connect FB directly to the output. The maximum transition time of VSEL1 and VSEL2 must be less than 100µs to avoid an undefined voltage state. Table 2 VSEL1 Selection Overcurrent Protection The AP61040 detects the current limit on the high side, Q1, to protect the device against overload or short-circuit conditions. The peak current in the switch is monitored cycle-by-cycle with a comparator delay of approximately 100ns to guard against noise glitches. If the high-side Q1 current limit is reached, the high-side Q1 is turned off and the low-side Q2 is turned on until the switch current decreases below the OC threshold. The frequency is reduced to protect the device from damage. The Q1 peak current limit remains active during this state. After 17 consecutive cycles in this OCP event, the regulator enters hiccup mode where all power FETs are turned off and will wait for 15ms before attempting to restart. Reverse Current Protection During fixed frequency operation, a reverse-current comparator on switch Q2 monitors the current entering VOUT. When this current exceeds 400mA (typical), switch Q2 will be turned off for the remainder of the switching cycle. This feature protects the buck converter from excessive reverse current if the buck output is held above the regulation voltage by an external source. Undervoltage Lockout The undervoltage lockout (UVLO) feature prevents abnormal operation if the supply voltage is too low to guarantee proper operation. When the VIN voltage falls below the UVLO threshold, the regulator is disabled. Thermal Shutdown A built-in thermal protection feature protects the AP61040 if the die temperature reaches +150°C (typical). At this die temperature, the regulator is completely shut down. The die temperature continues to be monitored in this thermal -shutdown mode. When the die temperature falls to +1 25°C (typical), the device will resume normal operation. When exiting thermal shutdown, the AP61040 will execute its soft-start sequence. Output Active Discharge The buck provides an internal 50Ω resistor for output active discharge function. The internal resistor discharges the energy stored in the output capacitor to PGND whenever the regulator is disabled. When the regulator remains enabled, the internal resistor is disconnected from the output. Inductor Selection An inductor with a high-frequency core material (e.g., ferrite core) should be used to minimize core losses and provide good efficiency. The inductor must be able to handle the peak switching currents without saturating. A 2.2µH inductor with a ≥600mA saturation current rating is recommended. Select an inductor with a low DCR to provide good efficiency. In applications where radiated noise must be minimized, a toroidal or shielded inductor can be used. VIN and VOUT Capacitor Selection The input and output capacitors should be a ceramic X5R type with low ESL and ESR. The recommended input capacitor value is 10µF, as this would provide adequate RMS current to minimize the input voltage ripple. A minimum of 10µF is required to maintain full functionality of the part. The recommended output capacitor is 10µF, 10V, X5R. Note that the effective value of a ceramic capacitor derates with DC voltage bias across it. This decreasing may be up to 70% of the rated capacitance. Refer to the capacitor datasheet to ensure the combined effective output capacitance is at least 30µF for proper operation over the entire recommended load current range. Low output capacitance may lead to a large output voltage drop during load transients or unstable operation. VFB (V) VSEL1 L1 (µH) 0.6 OPEN 2.2 2.5 0 2.2 3.3 1 2.2

Document number: DS47332 Rev. 1 - 2 14 of 17 www.diodes.com July 2025 © 2025 Copyright Diodes Incorporated. All Rights Reserved. AP61040 The AP61040 works at a 400mA load current. A 2oz copper in both the top and bottom layer is recommended. Correct PCB layout is critical for proper operation of the AP61040. The following are some general guidelines for the recommended layout: 1. The input and output capacitors should be positioned directly across VIN-PGND and as close to the IC as possible to ensure noise-free operation. 2. The ground connections of the input and output capacitors should be kept as short as possible. The objective is to minimize the current loop between the ground pads of the input and output capacitors and the PGND pins of the IC. Use via, if required, to take advantage of a PCB ground layer underneath the regulator. 3. Fill the second layer with PGND. The single point connects the GND to the second layer’s PGND. 4. Minimize the trace lengths on the feedback loop to avoid switching noise pick-up. Via should be avoided on the feedback loop to minimize the effect of board parasitic, particularly during load transients. 5. The SW trace should be short. 6. See figure 35 below for more details on the recommended layout. SW EN PVIN VIN PGND SW1 1 2 A B C VSEL1 FB SW VOUT PGND Figure 35. Recommended Layout Design

Document number: DS47332 Rev. 1 - 2 15 of 17 www.diodes.com July 2025 © 2025 Copyright Diodes Incorporated. All Rights Reserved. AP61040

Ordering Information

X1-WLB1208-6 7 : Tape & Reel Orderable Part Number Package Package Code Packing Quantity Carrier Part Number Suffix AP61040CP6-7 X1-WLB1208-6 CP6 3,000 Tape and Reel -7 Marking Information X1-WLB1208-6 XX : Identification Code (Top View) X : Internal Code YWX X X Y : Year : 0~9 W : Week : A~Z : 1~26 week; a~ z : 27~52 week; z represents 52 and 53 week Orderable Part Number Package Identification Code AP61040CP6-7 X1-WLB1208-6 KB

Document number: DS47332 Rev. 1 - 2 16 of 17 www.diodes.com July 2025 © 2025 Copyright Diodes Incorporated. All Rights Reserved. AP61040 Package Outline Dimensions Please see http://www.diodes.com/package-outlines.html for the latest version. X1-WLB1208-6 X1-WLB1208-6 Dim Min Max Typ A 0.400 0.500 0.450 A1 0.155 0.195 0.175 A2 0.225 0.275 0.250 A3 0.020 0.030 0.025 b 0.200 0.260 0.230 D 1.160 1.220 1.190 D1 0.770 0.830 0.800 E 0.760 0.820 0.790 E1 0.370 0.430 0.400 e 0.400 BSC SD 0.000 BSC SE 0.200 BSC All Dimensions in mm Suggested Pad Layout Please see http://www.diodes.com/package-outlines.html for the latest version. X1-WLB1208-6 Dimensions Value (in mm) C 0.400 C1 0.800 D 0.250 Mechanical Data

• Moisture Sensitivity: Level 1 per J-STD-020
• Terminals: Finish – Matte Tin Plated Leads, Solderable per MIL-STD-202, Method 208
• Weight: 0.7 mg (Approximate) E D SE e AA2 A1 Ø b ( 6 X ) A 1 C O R N E R B Y M A R K IN G S e a tin g P la n e SD 1 2 A B C C ØD

Document number: DS47332 Rev. 1 - 2 17 of 17 www.diodes.com July 2025 © 2025 Copyright Diodes Incorporated. All Rights Reserved. AP61040 IMPORTANT NOTICE 1. DIODES INCORPORATED (Diodes) AND ITS SUBSIDIARIES MAKE NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO ANY INFORMATION CONTAINED IN THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICUL AR PURPOSE OR NON -INFRINGEMENT OF THIRD PARTY INTELLECTUAL PROPERTY RIGHTS (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). 2. The Information contained herein is for informational purpose only and is provided only to illustrate the operation of Diodes ’ products described herein and application examples. Diodes does not assume any liability arising out of the application or use of this document or any product described herein. This document is intended for skilled and technically trained engineering customers and users who design with Diodes’ products. Diodes’ products may be used to facilitate safety-related applications; however, in all instances customers and users are responsible for (a) selecting the appropriate Diodes products for their applications, (b) evaluating the suitability of Diodes’ products for their intended applications, (c) ensuring their applications, which inco rporate Diodes’ products, comply the applicable legal and regulatory requirements as well as safety and functional - safety related standards, and (d) ensuring they design with appropriate safeguards (including testing, validation, quality co ntrol techniques , redundancy, malfunction prevention, and appropriate treatment for aging degradation) to minimize the risks associated with their applications. 3. Diodes assumes no liability for any application-related information, support, assistance or feedback that may be provided by Diodes from time to time. 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