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AiT Semiconductor Inc. www.ait-ic.com A7116 DC-DC CONVERTER/ BUCK (STEP-DOWN) 1.5MHz, 700mA SYNCHRONOUS WITH LOW QUIESCENT CURRENT REV1.3 - JAN 2009 RELEASED, JAN 2020 UPDATED - - 1 - DESCRIPTION FEATURES The A7116 is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. The device is available in an adjustable version. Supply current with no load is 40 µA and drops to <1uA in shutdown. The 2.5V to 6.8V input voltage range makes the A7116 ideally suited for single Li-Ion, two to four AA battery -powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems. In power saving mode, 40µ A quiescent current is very suitable for DSP/MCU in standby operation; and in PWM mode, low output ripple voltage is good enough for noise sensitive applications. The two modes can be automatically switched according to the load current. Switching frequency is internally set at 1.5MHz, allowing the use of small surface mount inductors and capacitors. The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Low output voltages are easily supported with the 0.6V feedback reference voltage. The A7116 is available in a SOT -25 package. The A7116 is available in SOT-25 package.  High Efficiency: Up to 96%  1.5MHz Constant Switching Frequency  700mA Output Current at VIN=3.6V  Integrated Main switch and synchronous rectifier. No Schottky Diode Required  2.5V to 6.8V Input Voltage Range  Output Voltage as Low as 0.6V  100% Duty Cycle in Dropout  Quiescent Current: 40μA(input < 4.2V)  Slope Compensated Current Mode Control for Excellent Line and Load Transient Response  Short Circuit Protection  <1uA Shutdown Current  Available in SOT-25 package APPLICATION  Cellular and Smart Phones  Microprocessors and DSP Core Supplies  Wireless and DSL Modems  PDAs  MP3 / MP4 /PMP Player  Digital Still and Video Cameras  Portable Instruments TYPICAL APPLICATION CIRCUIT Basic Application Circuit with A7116 Adjustable version ORDER INFORMATION Package Type Part Number SOT-25 SPQ: 3,000pcs/Reel E5 A7116E5R-ADJZ A7116E5VR-ADJZ Note XX: Output Voltage ADJ=Adjustable Z: Pin Type A or B V: Halogen free Package R: Tape & Reel AiT provides all RoHS products

AiT Semiconductor Inc. www.ait-ic.com A7116 DC-DC CONVERTER/ BUCK (STEP-DOWN) 1.5MHz, 700mA SYNCHRONOUS WITH LOW QUIESCENT CURRENT REV1.3 - JAN 2009 RELEASED, JAN 2020 UPDATED - - 2 - PIN DESCRIPTION Top View Top View Pin # Symbol Function A B 1 3 RUN Regulator Enable control input. Drive RUN above 1.5V to turn on the part. Drive RUN below 0.6V to turn it off. In shutdown, all functions are disabled drawing <1μA supply current. Do not leave RUN floating. 2 2 GND Ground 3 5 SW Power Switch Output. It is the Switch note connection to Inductor. This pin connects to the drains of the internal P-CH and N-CH MOSFET switches. 4 1 VIN Supply Input Pin. Must be closely decoupled to GND, Pin 2, with a 2.2μF or greater ceramic capacitor. 5 4 VFB VFB (Adjustable): Feedback Input Pin. Connect FB to the center point of the external resistor divider. The feedback threshold voltage is 0.6V.

AiT Semiconductor Inc. www.ait-ic.com A7116 DC-DC CONVERTER/ BUCK (STEP-DOWN) 1.5MHz, 700mA SYNCHRONOUS WITH LOW QUIESCENT CURRENT REV1.3 - JAN 2009 RELEASED, JAN 2020 UPDATED - - 3 - ABSOLUTE MAXIMUM RATINGS Input Supply Voltage -0.3V ~ +7V RUN, VFB Voltages 0.3V ~ VIN +0.3V SW Voltages -0.3V ~ VIN+0.3V P-Channel Switch Source Current (DC) 1000mA N-Channel Switch Sink Current (DC) 1000mA Peak SW Sink and Source Current 1.5A Package Thermal ResistanceNOTE1 θJA 220°C/W θJC 110°C/W Operating Temperature Range -40°C ~ +85°C Junction Temperature NOTE2 +125°C Storage Temperature Range -65°C ~ +150°C Lead Temperature (Soldering, 10s) +260°C ESD Susceptibility (HBM Mode) 3KV (CLASS2) Humidity 85% (CLASS1) Stresses above may cause permanent damage to the device. T hese are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the Electrical Characteristics is not implied. Exposure to absolute m aximum rating conditions for extended periods may affect device reliability. NOTE1: Thermal Resistance is specified with approximately 1 square of 1 Oz copper. NOTE2: TJ is calculated from the ambient temperature TA and power dissipation PD according to the following formula: TJ = TA + (PD)x(220°C/W)

AiT Semiconductor Inc. www.ait-ic.com A7116 DC-DC CONVERTER/ BUCK (STEP-DOWN) 1.5MHz, 700mA SYNCHRONOUS WITH LOW QUIESCENT CURRENT REV1.3 - JAN 2009 RELEASED, JAN 2020 UPDATED - - 4 - ELECTRICAL CHARACTERISTICSNOTE3 VIN=VRUN= 3.6V, TA = 25°C, unless otherwise noted. Parameter Conditions MIN TYP MAX unit Input Voltage Range 2.5 - 6.8 V Input DC Supply Current PWM Mode Power Saving Mode Shutdown Mode VFB=0.5V or VOUT=90% VFB=0.63V VFB=0V, VIN=4.2V 300 0.1 400 1.0 µA µA µA Regulated Feedback Voltage TA= +25°C 0.5880 0.6000 0.6120 V TA= 0°C ≤ TA ≤ 85°C 0.5865 0.6000 0.6135 V TA= -40°C ≤ TA ≤ 85°C 0.5820 0.6000 0.6180 V VFB Input Bias Current VFB = 0.65V - - ±30 nA Reference Voltage Line Regulation VIN = 2.5V to 5.5V - 0.4 0.80 % Output Voltage Line Regulation V IN= 2.5V to 5.5V - 0.4 0.80 % Output Voltage Load Regulation In Power Saving Mode - 0.5 - % Peak Inductor Current VIN=3V, VFB=0.5V or VOUT=90% Duty Cycle <35% 0.75 1.00 1.25 A Oscillator Frequency VFB=0.6V or VOUT=100% 1.2 1.5 1.8 MHz RDS(ON) of P-CH MOSFET ISW = 300mA - 0.40 0.50 Ω RDS(ON)of N-CH MOSFET ISW = -300mA - 0.35 0.45 Ω SW Leakage VRUN = 0V, VSW = 0V or 5V, VIN = 5V - ±0.01 ±1 µA RUN Threshold Low -40°C ≤ TA ≤ 85°C 0.6 V RUN Threshold High 1.5 - RUN Leakage Current - ±0.01 ±1 µA Thermal Shutdown - 165 - °C NOTE3: 100% production test at +25°C. Specifications over the temperature range are guaranteed by design and characterization.

AiT Semiconductor Inc. www.ait-ic.com A7116 DC-DC CONVERTER/ BUCK (STEP-DOWN) 1.5MHz, 700mA SYNCHRONOUS WITH LOW QUIESCENT CURRENT REV1.3 - JAN 2009 RELEASED, JAN 2020 UPDATED - - 5 - TYPICAL PERFORMANCE CHARACTERISTICS Test Figure 1 above unless otherwise specified 3. η vs. Io (VOUT=3.3V) 4. Load Transient Response VIN=3.6V,VOUT=1.8V,Io=0.1-0.7A 5. Output Ripple VIN=3.6V,VOUT=1.8V,Io=0.7A

AiT Semiconductor Inc. www.ait-ic.com A7116 DC-DC CONVERTER/ BUCK (STEP-DOWN) 1.5MHz, 700mA SYNCHRONOUS WITH LOW QUIESCENT CURRENT REV1.3 - JAN 2009 RELEASED, JAN 2020 UPDATED - - 6 - BLOCK DIAGRAM

AiT Semiconductor Inc. www.ait-ic.com A7116 DC-DC CONVERTER/ BUCK (STEP-DOWN) 1.5MHz, 700mA SYNCHRONOUS WITH LOW QUIESCENT CURRENT REV1.3 - JAN 2009 RELEASED, JAN 2020 UPDATED - - 7 - DETAILED INFORMATION Operation A7116 is a monolithic switching mode Step- Down DC-DC converter. It utilizes internal MOSFETs to achieve high efficiency and can generate very low output voltage by using internal reference at 0.6V. It operates at a fixed switchi ng frequency, and uses the slope compensated current mode architecture. This Step-Down DC-DC Converter supplies 700mA output current at VOUT = 1.8V with input voltage range from 2.5V to 6.8V. Current Mode PWM Control Slope compensated current mode PWM control provides stable switching and cycle-by-cycle current limit for excellent load and line responses and protection of the internal main switch (P -Ch MOSFET) and synchronous rectifier (N-CH MOSFET). During normal operation, the internal P-Ch MOSFET is turned on for a certain time to ramp the inductor current at each rising edge of the internal oscillator, and switched off when the peak inductor current is above the error voltage. The current comparator, ICOMP, limits the peak inductor current. When the main switch is off, the synchronous rectifier will be turned on immediately and stay on until either the inductor current starts to reverse, as indicated by the current reversal comparator, I ZERO, or the beginning of the next clock cycle. The OVDET comparator controls output transient overshoots by turning the main switch off and keeping it off until the fault is no longer present. Power Saving Mode Operation At very light loads, the A7116 automatically enters Power Saving Mode. In power saving mode at light load, a control circuit puts most of the circuit into sleep in order to reduce quiescent current and improve efficiency at light load. When the output voltage drops to certain threshold, the control circuit turns back on the oscillator and the PWM control loop, boosting output backup. When an upper threshold is reached, the control circuit again puts most of circuit into sleep, reducing quiescent current. During Power Saving Mode operation, the converter positions the output voltage slightly higher than the nominal output voltage during PWM operation, allowing additional headroom for voltage drop during a load transient from light to heavy load. While the power saving mode improves light load efficiency, however, with the turning on and off, the noise or ripple voltage is larger than that in the PWM Mode.

AiT Semiconductor Inc. www.ait-ic.com A7116 DC-DC CONVERTER/ BUCK (STEP-DOWN) 1.5MHz, 700mA SYNCHRONOUS WITH LOW QUIESCENT CURRENT REV1.3 - JAN 2009 RELEASED, JAN 2020 UPDATED - - 8 - Dropout Operation When the input voltage decreases toward the value of the output voltage, the A7116 allows the main switch to remain on for more than one switching cycle and increases the duty cycle (NOTE4) until it reaches 100 %. The output voltage then is the input voltage minus the voltage drop across the main switch and the inductor. At low input supply voltage, the RDS(ON) of the P-Channel MOSFET increases, and the efficiency of the converter decreases. Caution must be exercised to ensure the heat dissipated not to exceed the maximum junction temperature of the IC. NOTE4: The duty cycle D of a step-down converter is defined as: x100%V V100%x f x T D IN OUT OSCON ≈= Where TON is the main switch on time and fOSC is the oscillator frequency (1.5MHz). Maximum Load Current The A7116 will operate with input supply voltage as low as 2.5V, however, the maximum load current decreases at lower input due to large IR drop on the main switch and synchronous rectifier. The slope compensation signal reduces the peak inductor current as a function of the duty cycle to prevent sub-harmonic oscillations at duty cycles greater than 50%. Conversely the current limit increases as the duty cycle decreases. Layout Guidance When laying out the PCB board, the following suggestions should be taken to ensure proper operation of the A7116. These items are also illustrated graphically in Figure 1 & Figure 2. 1. The power traces, including the GND trace, the SW trace and the V IN trace should be kept short, direct and wide. 2. The VFB pin should be connected directly to the feedback resistor. The resistive divider R1/R2 must be connected between the (+) plate of COUT and ground. 3. Connect the (+) plate of C1 to the VIN pin as closely as possible. This capacitor provides the AC current to internal power MOSFET. 4. Keep the switching node, SW, away from the sensitive VFB node. 5. Keep the (-) plates of C1 and C3 as close as possible.

Table 1. Typical Surface Mount Inductors

AiT Semiconductor Inc. www.ait-ic.com A7116 DC-DC CONVERTER/ BUCK (STEP-DOWN) 1.5MHz, 700mA SYNCHRONOUS WITH LOW QUIESCENT CURRENT REV1.3 - JAN 2009 RELEASED, JAN 2020 UPDATED - - 11 - Input Capacitor Selection The input capacitor reduces the surge current drawn from the input and switching noise from the device. The i nput capacitor impedance at the switching frequency shall be less than input source impedance to prevent high frequency switching current passing to the input. A low ESR input capacitor sized for maximum RMS current must be used. Ceramic capacitors with X5R or X7R dielectrics are highly recommended because of their low ESR and small temperature coefficients. A 4.7µF ceramic capacitor for most applications is sufficient. Output Capacitor Selection The output capacitor is required to keep the output voltage ripple small and to ensure regulation loop stability. The output capacitor must have low impedance at the switching frequency. Ceramic capacitors with X5R or X7R dielectrics are recommended due to their low ESR and high ripple current. The output rip ple V OUT is determined by:  +−≤ C3x f x 8 1ESR x L x f x V )V(Vx VΔV OSCOSCIN OUTIN OUT OUT

AiT Semiconductor Inc. www.ait-ic.com A7116 DC-DC CONVERTER/ BUCK (STEP-DOWN) 1.5MHz, 700mA SYNCHRONOUS WITH LOW QUIESCENT CURRENT REV1.3 - JAN 2009 RELEASED, JAN 2020 UPDATED - - 12 -

PACKAGE INFORMATION

Dimension in SOT-25 (Unit: mm) Symbol Millimeters Inches Min Max Min Max A 1.050 1.250 0.041 0.049 A1 0.000 0.100 0.000 0.004 A2 1.050 1.150 0.041 0.045 b 0.300 0.500 0.012 0.020 c 0.100 0.200 0.004 0.008 D 2.820 3.020 0.111 0.119 E 1.500 1.700 0.059 0.067 E1 2.650 2.950 0.104 0.116 e 0.950(BSC) 0.037(BSC) e1 1.800 2.000 0.071 0.079 L 0.300 0.600 0.012 0.024 θ 0° 8° 0° 8°

AiT Semiconductor Inc. www.ait-ic.com A7116 DC-DC CONVERTER/ BUCK (STEP-DOWN) 1.5MHz, 700mA SYNCHRONOUS WITH LOW QUIESCENT CURRENT REV1.3 - JAN 2009 RELEASED, JAN 2020 UPDATED - - 13 - IMPORTANT NOTICE AiT Semiconductor Inc. (AiT) reserves the right to make changes to any its product, specifications, to discontinue any integrated circuit product or service without notice, and advises its customers to obtain the latest version of relevant information to verify, before plac ing orders, that the information being relied on is current. AiT Semiconductor Inc. ‘s integrated circuit products are not designed, intended, authorized, or warranted to be suitable for use in life support applications, devices or systems or other criti cal applications. Use of AiT products in such applications is understood to be fully at the risk of the customer. As used herein may involve potential risks of death, perso nal injury, or server property, or environmental damage. In order to minimize risks associated with the customer's applications, the customer should provide adequate design and operating safeguards. AiT Semiconductor Inc . assumes to no liability to customer product design or application support. AiT warrants the performance of its products of the specifications applicable at the time of sale.