AAT1109A

AAT1109A AAT | Alldatasheet

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Advanced Analog Technology, Inc. – 台灣類比科技股份有限公司 – – Advanced Analog Technology, Inc . – V 0 . 1 AAT1109A Preliminary and Provisional ONE-CHANNEL BOOST SWITCHING REGULATOR F e a t u r e s z Under-voltage lockout protection z Totem pole output z Output short circuit protection z Incorporates soft start function z Wide operating frequency： 10kHz to 1MHz z Shut down control z Low dissipation current : Typical 1.6mA in operation z Sop-8 & Tssop-8 package available Pin Configuration TOP VIEW FB OSC GND OUT -IN SCP Vcc CE (SOP-8 PACKAGE) (TSSOP-8 PACKAGE) General Description The AAT1109A is a one-channel switching regulator control IC incorporating a soft start function and a short circuit protection function. Each device consists of an on-chip voltage reference, error amplifier, pulse wi dth modulation controller, under-voltage protection, soft start and short circuit protection circuits. Switc hing frequencies up to 1MHz are set by an external resistor and capacitor. Soft-start time can be implemented by the SCP capacitor. Additionally, a chip enable feature is provided to power down reducing the supply current to 10uA. With a minimum number of external components, the AAT1109A offers a simple and cost effective solution.

Advanced Analog Technology, Inc. – 台灣類比科技股份有限公司 – – Advanced Analog Technology, Inc . – V 0 . 1 AAT1109A Pin Description Pin # Name I/O Description 1 -IN I Error amplifier inverting input pin

2 SCP I Soft start and SCP capacitor connection pin

3 Vcc Power supply

4 CE I Chip enable input pin（internal pull "H"）

5 OUT O Totem-type output pin

6 GND Ground

7 OSC O Capacitor and resistor connection pin for setting the oscillation frequency

8 FB O Error amplifier output pin

CHARACTERISTICS SYMBOL VALUE UNIT Supply voltage DDV 7 V Output current OI -120/+120 mA Operating free-air temperature range opeT -20 to 85 oC Storage temperature range stgT -65 to 150 oC Power dissipation Pd 500 mW Recommended Operating Conditions Symbol Min Max Unit Supply voltage, DDV DDV 2.6 6.5 V Error amplifier input voltage V I 0.5 1.6 V OSC capacitor TC 100 10000 pF OSC resistor TR 1.0 10 kΩ Oscillator frequency OSCf 10 1000 kHz Output current OI +30/-30 mA Operating free-air temperature opeT -20 85 oC

Advanced Analog Technology, Inc. – 台灣類比科技股份有限公司 – – Advanced Analog Technology, Inc . – V 0 . 1 AAT1109A Electrical Characteristics, DDV = 3.3V (Unless Otherwise Specified) (See Note 1) Oscillator Parameter Test Condition Min Typ Max Unit Oscillation frequency OSCf TC = 270pF, TR = 4.2k Ω 400 500 600 KHz Frequency variation with temperature f dT 5 % Frequency input stability dVf DDV = 2.6V to 6.5V 1 % Under-voltage Protection Parameter Test Condition Min Typ Max Unit Upper threshold voltage UPHV AT= 2 5 oC 2.12 2.47 2.85 V Lower threshold voltage UPLV AT= 2 5 oC 1.96 2.28 2.63 V Hysteresis ( UPHV – UPLV) HYSV AT= 2 5 oC 0.3 V Note1 : Typical values of all parameters are specified at AT =25 oC. Short Circuit Protection Control Parameter Test Condition Min Typ Max Unit Input threshold voltage 1rV 1.16 1.262 1.36 V Short-circuit detect threshold voltage 2rV 1.16 1.262 1.36 V Charging current SCPI Vscp=0v -1.0 -1.5 -2.15 µA Soft start Parameter Test Condition Min Typ Max Unit Charging current Ics Vscp=0v -1.0 -1.5 -2.15 µA Voltage at soft start completion Vts 1.16 1.262 1.36 V Shun Down Control Parameter Test Condition Min Typ Max Unit Shut down release voltage V sdh 0.5 V Shut down enable voltage V sdl 2.0 V

Advanced Analog Technology, Inc. – 台灣類比科技股份有限公司 – – Advanced Analog Technology, Inc . – V 0 . 1 AAT1109A Electrical Characteristics, DDV = 3.3V (Unless Otherwise Specified) (See Note 1) Idle period adjustment section Parameter Test Conditions Min Typ Max Unit Maximum duty cycle tDUTY TC = 270pF, TR = 4.2k Ω VFB = 1.12v 75 85 93 % EA (Error Amplifier) Parameter Test Condition Min Typ Max Unit Input threshold voltage V T VFB = 0.7v 1.249 1.262 1.275 V VT input stability V TdV Vdd = 2.6 to 6.5v 2 8 mV VT variation with temperature V TdT AT= - 2 0 oC to 90 oC 1 % Input bias current IB 0.1 1 µA +OMV 1.4 1.7 Output voltage swing −OMV 0.05 0.2 V Output sink current +OMI FB=0.7V 3 20 mA Output source current −OMI FB=0.7V -45 -75 µA Open-loop voltage amplification VDA 70 85 dB Output section Parameter Test Condition Typ Max Unit High-level output voltage V OH I O=-30mA 1.9 2.3 V Low-level output voltage V OL I O=+30mA 0.8 1.2 V Rise time T rise C L=1000pF 100 nS Fall time T fall C L=1000pF 100 nS Operating Current Parameter Test Condition Min Typ Max Unit OFFDDI − Output ”OFF”state 1.3 mASupply current ONDDI − RT =4.2k 1.6 mA

Advanced Analog Technology, Inc. – 台灣類比科技股份有限公司 – – Advanced Analog Technology, Inc . – V 0 . 1 AAT1109A How to set the time constant for soft start and short circuit protection 1.Soft start At power on, the AAT1109A operates in soft start mode. The capacitor Cscp connected to SCP pin starts charging at a constant current. In the soft start mode, the voltage at SCP pin (VSCP) is input to the PWM comparator, so that the ON duty of the OUT pin is controlled by the VSCP. On completion of soft start operation, the voltage at the SCP pin stays low, the input from soft start circuit to the PWM comparator stay high, and enter the short circuit protection waiting state. Soft start time T s(sec) ~ 0.84 × CSCP (uF) 2.Short circuit protection If the switching regulator output suddenly drops due to loading effect , the error amplifier output is fixed at VOM+ and capacitor CSCP starts charging. When the voltage at the SCP pin reaches approximately 1.26V ,the output pin set low and SCP pin stays low. Once the protection circuit operates, the circuit can be recovered by setting the power supply. Short circuit detection time T scp(sec) ~ 0.84 × CSCP (uF)

Advanced Analog Technology, Inc. – 台灣類比科技股份有限公司 – – Advanced Analog Technology, Inc . – V 0 . 1 AAT1109A Function Block Diagram Soft start SCP VREF UVLO CE SCP VCC OUT UVC LATCH UVC Vref 1.26v -IN OSC PWM Comp. Err-Amp UVC OSC VDD SCP comp. GND FB Vref 1.26V Chip Enable VCC Vref 1.26V DTC 0.765V IREF CE CE CE CE CE

Advanced Analog Technology, Inc. – 台灣類比科技股份有限公司 – – Advanced Analog Technology, Inc . – V 0 . 1 AAT1109A Application Circuit 1 BOOST(step-up) CE -IN SCP FB VDD OSC OUT GND C4 R4 R3 C3 VDD VDD VOUT CE -IN AAT1109A Application Circuit 2 (with charge pump) CE -IN SCP FB VDD OSC OUT GND C4 R4 R3 C3 VDDC2 VDD VOUT CE -IN AAT1109A D3 D4 C8 C9 C10D6 VP 3*Vout≅ VN -Vout≅

Advanced Analog Technology, Inc. – 台灣類比科技股份有限公司 – – Advanced Analog Technology, Inc . – V 0 . 1 AAT1109A Boost （Step-up）Timing Chart 2.47V Lockout free OUTPU T SCP VDD 1.262V OSC FB ldle period setting volt age Reference input for short circuit Soft start setti ng voltage TscpTs out put short circui tsoft start output short circuit

Advanced Analog Technology, Inc. – 台灣類比科技股份有限公司 – – Advanced Analog Technology, Inc . – V 0 . 1 AAT1109A Package Dimension (Unit: Mil) 8 - p i n S O P θ DIMENSIONS IN MILLIMETERS DEMINSIONS IN INCHES SYMBOLS MIN NOM. MAX MIN NOM. MAX θ 0 --- 0 0 --- 0

Advanced Analog Technology, Inc. – 台灣類比科技股份有限公司 – – Advanced Analog Technology, Inc . – V 0 . 1 AAT1109A Package Dimension (Unit: Mil) 8-pin TSSOP Millimeters Inches Dimension Min Nom Max Min Nom Max D E θ L C A b e