Advanced Analog Technology, Inc. AAT1109A Preliminary and Provisional ONE-CHANNEL BOOST SWITCHING REGULATOR Features General Description z Under-voltage lockout protection z Totem pole output z Output short circuit protection z Incorporates soft start function z Wide operating frequency： 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 width modulation controller, under-voltage protection, soft start and short circuit protection circuits. Switching 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. 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 -IN 1 8 FB SCP 2 7 OSC Vcc 3 6 GND CE 4 5 OUT (SOP-8 PACKAGE) (TSSOP-8 PACKAGE) – – 台灣類比科技股份有限公司 – Advanced Analog Technology, Inc. – V 0.1 Advanced Analog Technology, Inc. AAT1109A Pin Description Pin # 1 2 3 4 5 6 7 8 Name -IN SCP Vcc CE OUT GND OSC FB I/O Description I Error amplifier inverting input pin I Soft start and SCP capacitor connection pin Power supply I Chip enable input pin（internal pull "H"） O Totem-type output pin Ground O Capacitor and resistor connection pin for setting the oscillation frequency O Error amplifier output pin Absolute Maximum Ratings CHARACTERISTICS Supply voltage SYMBOL VDD VALUE 7 UNIT V Output current IO -120/+120 mA Operating free-air temperature range Tope -20 to 85 o Storage temperature range Tstg -65 to 150 o Power dissipation Pd 500 C C mW Recommended Operating Conditions Supply voltage, VDD Error amplifier input voltage OSC capacitor OSC resistor Oscillator frequency Min 2.6 0.5 100 1.0 Max 6.5 1.6 10000 10 Unit V V pF kΩ 10 1000 kHz +30/-30 mA IO Output current Operating free-air temperature – Symbol VDD VI CT RT f OSC Tope -20 85 – 台灣類比科技股份有限公司 – Advanced Analog Technology, Inc. – o C V 0.1 Advanced Analog Technology, Inc. AAT1109A Electrical Characteristics, VDD = 3.3V (Unless Otherwise Specified) (See Note 1) Oscillator Parameter Test Condition Oscillation frequency f OSC Frequency variation with temperature Frequency input stability C T = 270pF, R T = 4.2kΩ Min Typ 400 500 f dT f dV Max Unit 600 KHz % 5 VDD = 2.6V to 6.5V % 1 Under-voltage Protection Parameter Test Condition o Min Typ Max Unit Upper threshold voltage VUPH TA = 25 C 2.12 2.47 2.85 V Lower threshold voltage VUPL TA = 25 oC 1.96 2.28 2.63 V Hysteresis ( VUPH – VUPL ) VHYS o TA = 25 C Note1 : Typical values of all parameters are specified at 0.3 V TA =25 C. o Short Circuit Protection Control Parameter Test Condition Min Typ Max Unit Input threshold voltage Vr1 1.16 1.262 1.36 V Short-circuit detect threshold voltage Charging current Vr 2 1.16 1.262 1.36 V -1.0 -1.5 -2.15 µA Min Typ Max Unit -1.0 -1.5 -2.15 µA 1.16 1.262 1.36 V Min Max Unit 0.5 V I SCP Vscp=0v Soft start Parameter Test Condition Charging current Voltage at soft start completion Ics Vscp=0v Vts Shun Down Control Parameter Test Condition Shut down release voltage Vsdh Shut down enable voltage Vsdl – 2.0 – 台灣類比科技股份有限公司 – Advanced Analog Technology, Inc. – Typ V V 0.1 Advanced Analog Technology, Inc. AAT1109A Electrical Characteristics, VDD = 3.3V (Unless Otherwise Specified) (See Note 1) Idle period adjustment section Parameter Test Conditions tDUTY Maximum duty cycle C T = 270pF, R T = 4.2kΩ VFB = 1.12v Min Typ Max Unit 75 85 93 % EA (Error Amplifier) Parameter Test Condition Input threshold voltage VT input stability VT variation with temperature Input bias current Output voltage swing VT VTdV VTdT VFB = 0.7v Vdd = 2.6 to 6.5v TA = -20 oC to 90 oC Min Typ Max Unit 1.249 1.262 1.275 V 2 8 mV 1 % IB 1.4 VOM + VOM − 0.1 1.7 1 0.05 0.2 µA V Output sink current I OM + FB=0.7V 3 20 mA Output source current I OM − FB=0.7V -45 -75 µA Open-loop voltage amplification A VD 70 85 dB Output section Parameter Test Condition High-level output voltage Low-level output voltage Rise time Fall time VOH VOL Trise Tfall IO=-30mA IO=+30mA CL=1000pF CL=1000pF Typ 1.9 2.3 0.8 100 100 Max Unit 1.2 V V nS nS Operating Current Parameter Supply current – Test Condition Min I DD−OFF Output ”OFF”state Typ 1.3 I DD−ON RT =4.2k 1.6 – 台灣類比科技股份有限公司 – Advanced Analog Technology, Inc. – Max Unit mA mA V 0.1 Advanced Analog Technology, Inc. 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 Ts(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 Tscp(sec) ~ 0.84 × CSCP (uF) – – 台灣類比科技股份有限公司 – Advanced Analog Technology, Inc. – V 0.1 Advanced Analog Technology, Inc. AAT1109A Function Block Diagram VDD CE C h ip E n a b le GND IR E F V ref 1 .2 6 V SCP com p. LATCH SCP CE S o ft sta rt SCP O SC O SC UVC UVC CE UVLO PW M C om p. V re f 1 .2 6 v VCC FB VREF CE CE D TC 0 .7 6 5 V VCC V ref 1 .2 6 V E rr-A m p OUT -IN UVC – CE – 台灣類比科技股份有限公司 – Advanced Analog Technology, Inc. – V 0.1 Advanced Analog Technology, Inc. AAT1109A Application Circuit 1 BOOST(step-up) VDD CE L1 CE 4 1 -IN SCP 2 8 FB VDD 3 7 OSC D1 C4 VOUT R4 VDD C1 C2 R1 -IN R3 OUT Q1 R2 5 6 C3 GND AAT1109A Application Circuit 2 (with charge pump) VDD CE L1 CE 4 1 -IN SCP 2 8 FB VDD 3 7 OSC C4 D1 VOUT C1 VDD C2 R1 -IN R3 Q1 R2 VP ≅ 3*Vout VN ≅ -Vout D6 D2 C6 D3 C7 – OUT C5 D4 R4 C8 D5 5 6 C3 GND AAT1109A C10 C9 D7 – 台灣類比科技股份有限公司 – Advanced Analog Technology, Inc. – V 0.1 Advanced Analog Technology, Inc. AAT1109A Boost （Step-up）Timing Chart 1.262V FB Reference input for short circuit ldle period setting voltage Soft start setting voltage OSC OUTPU T SCP soft start output short circuit output short circuit Ts Tscp 2.47V Lockout free VDD – – 台灣類比科技股份有限公司 – Advanced Analog Technology, Inc. – V 0.1 Advanced Analog Technology, Inc. AAT1109A Package Dimension (Unit: Mil) 8-pin SOP θ DIMENSIONS IN MILLIMETERS – DEMINSIONS IN INCHES SYMBOLS MIN NOM. MAX MIN NOM. MAX A 1.47 1.60 1.73 0.058 0.063 0.068 A1 0.10 --- 0.22 0.004 --- 0.008 A2 --- 1.45 --- --- 0.057 --- b 0.33 0.41 0.51 0.013 0.016 0.020 C 0.19 0.20 0.25 0.0075 0.008 0.0098 D 4.80 4.85 4.95 0.189 0.191 0.195 E 5.80 6.00 6.20 0.228 0.236 0.244 E1 3.80 3.90 4.00 0.150 0.154 0.157 e --- 1.27 --- --- 0.050 --- L 0.38 0.71 1.27 0.015 0.028 0.050 y --- --- 0.076 --- --- 0.00. θ 0 --- 0 0 --- 0 – 台灣類比科技股份有限公司 – Advanced Analog Technology, Inc. – V 0.1 Advanced Analog Technology, Inc. AAT1109A Package Dimension (Unit: Mil) 8-pin TSSOP θ E E1 D L C Millimeters A1 A Dimension b – e Inches Min Nom Max Min Nom Max A 1.00 1.10 1.20 0.039 0.043 0.047 A1 0.025 0.10 0.175 0.002 0.004 0.006 b ------ 0.22 ------ ------- 0.008 ------- C ------ 0.127 ------- ------- 0.005 ------- D 2.90 3.00 3.10 0.114 0.118 0.122 E 6.20 6.40 6.60 0.244 0.252 0.260 E1 4.30 4.40 4.50 0.169 0.173 0.177 e --- 0.65 --- --- 0.026 --- L 0.45 0.60 0.75 0.020 0.024 0.028 θ 0° 3° 8° 0° 3° 8° – 台灣類比科技股份有限公司 – Advanced Analog Technology, Inc. – V 0.1