AAT1102 AAT | Alldatasheet
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Advanced Analog Technology, Inc. – Advanced Analog Technology, Inc. – Page 1 of 18 V4.0 AAT1102 Product information presented is current as of publication date. Details are subject to change without notice ADVANCED PWM DC-DC CONVERTER WITH INTERNAL SWITCH AND SOFT-START
FEATURES
1.6A, 0.23Ω, Internal Switch High Efficiency: 90% Adjustable Output: DD V to 12.5V Adjustable Frequency: 640kHz or 1.3MHz Wide Input Range: +2.6V to +5.5V Low Shutdown Current: A 1.0 µ Programmable Soft-Start Small 8-Pin MSOP Package PIN CONFIGURATION GENERAL DESCRIPTION The AAT1102 is a step-up DC-DC converter with a 1.6A, Ω internal switch. Equipped with an external compensation pin, this device offers user flexibility in determining loop dynamic and adjusting operating frequency. AAT1102 also allows the use of small, low equivalent resistance (ESR) ceramic output capacitor, and it’s capable of converting a standard input of 3.3V to multiple outputs of 8V, V , and 23V. Furthermore, filtering and loop performance are facilitated and enhanced by a high switching frequency of either 640 kHz or1.3MHz. The AAT1102’s versatility comes with a power-smart design. A soft-start programmed with an external capacitor that sets the input current ramp rate, reduces the current consumption to A 1.0 µ in shutdown mode. When operating, a mere 2.6V input yields an impressive output voltage as high as 12.5V. High switching frequency and economical design allow AAT1102 to be less than 1.1mm high. Its compact 8-pin MSOP package and superior performance make it an ideal part for biasing TFT displays. AAT1102 SS FREQ V DD SW EO IN GND SHDN 8-Pin MSOP TOP VIEW
Advanced Analog Technology, Inc. – Advanced Analog Technology, Inc. – Page 2 of 18 V4.0 AAT1102 PIN DESCRIPTIONS PIN NAME FUNCTION EO Compensation Pin for Error Amplifier IN Feedback Pin with a Typical Reference Voltage of 1.24V, OUT V = IN(1+ R2 R1 ) SHDN Shutdown Control Pin. The Device Will Turn Off When SHDN is Low GND Ground SW Switch Pin DD V Power Supply Pin FREQ Frequency Select Pin. Switch Oscillator Frequency to 640kHz When FREQ is Low, and 1.3MHz When FREQ is High SS Soft-Start Control Pin. No Soft-Start When the Pin is Left Open ABSOLUTE MAXIMUM RATINGS PARAMETER SYMBOL VALUE UNIT SW to GND 3.0 to +18 V IN, SHDN, DD V , FREQ to GND 3.0 to +6 V SS, EO to GND 3.0 V to ( DD V + 0.3V) V RMS SW Pin Current SW I 1.2 A Continuous Power Dissipation C T = 8-Pin MSOP (De-Rate mW 1.4 / above +70 dP 330 mW Operation Temperature Range C T to +85 Storage Temperature Range storage T to +125 Lead Temperature (Soldering for 10 seconds) L T +300 Note: 1. Absolute Maximum Ratings are threshold limit values that must not be exceeded. 2. Operation above these absolute maximum ratings may cause degradation or permanent damage to the device. 3. These are stress ratings only and do not necessarily imply functional operation below these limits.
Advanced Analog Technology, Inc. – Advanced Analog Technology, Inc. – Page 3 of 18 V4.0 AAT1102
ELECTRICAL CHARACTERISTICS
V SHDN = , FREQ = GND, unless otherwise specified. Typical values are at C T C o PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Input Supply Voltage Range DD V 2.6 5.5 V DD V Under Voltage Lockout UVLO When DD V is rising, typical hysteresis is 40mV; SW remains off below this level 2.25 2.38 2.52 V IN V = 1.3V, not switching 0.21 0.35 Quiescent Current DD I IN V = 1.0V, switching 1.2 5.0 mA Shutdown Current SC I SHDN = GND 0.1 10.0 A µ ERROR AMPLIFIER PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Feedback Voltage IN V Level to produce VEO = 1.24V 1.222 1.240 1.258 V DD V Input Bias Current IN I VIN= 1.24V nA Feedback-Voltage Line Regulation Level to produce VEO = 1.24V, 2.6V < DD V < 5.5V 0.05 0.15 %/V Transconductance m g A µ 105 240 A µ Voltage Gain V A 1,500 V/V OSCILLATOR PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS FREQ = GND 540 640 740 Frequency OSC f FREQ = DD V 1,100 1,320 1,600 kHz FREQ = GND Maximum Duty Cycle MAX D FREQ = DD V
Advanced Analog Technology, Inc. – Advanced Analog Technology, Inc. – Page 4 of 18 V4.0 AAT1102 , FREQ = GND, unless otherwise specified. Typical values are at C TC o N-CHANNEL SWITCH PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Current Limit LIM I DD V = 1V, Duty Cycle = 65% 1.2 1.6 2.3 A On-Resistance ON R SW I = 1.2A 0.23 0.50 Ω Leakage Current SWOFF I SW V = 12V 0.01 20.00 A µ SOFT-START PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Reset Switch Resistance 300 Ω Charge Current SS V = 1.2V 1.5 4.0 7.0 A µ CONTROL INPUTS PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Input Low Voltage IL V SHDN, FREQ; DD V = 2.6V to 5.5V 0.3˙ DD V V Input High Voltage IH V SHDN, FREQ; DD V = 2.6V to 5.5V 0.7˙ DD V V Hysteresis SHDN, FREQ 0.1˙ DD V V FREQ Pull-Down Current FREQ I 1.8 5.0 9.0 A µ SHDN Input Current SHDN I 0.001 1.000 A µ
Advanced Analog Technology, Inc. – Advanced Analog Technology, Inc. – Page 5 of 18 V4.0 AAT1102 Typical Operating Characteristics LOAD CURRENT(mA) STEP-UP REGULATOR OUTPUT VOLTAGE vs.LOAD CURRENT(VMAIN=8.3V) INPUT VOLTAGE(V) INDUCTOR CURRENT(mA) MAXIMUM INDUCTOR CURRENT(VMAIN=8.3V) vs. INPUT VOLTAGE
Advanced Analog Technology, Inc. – Advanced Analog Technology, Inc. – Page 6 of 18 V4.0 AAT1102 Fig. 1 TYPICAL APPLICATION CIRCUIT OFF ON/ TO 2.6V VDD
Advanced Analog Technology, Inc. – Advanced Analog Technology, Inc. – Page 7 of 18 V4.0 AAT1102 Fig. 2 BLOCK DIAGRAM Σ
Advanced Analog Technology, Inc. – Advanced Analog Technology, Inc. – Page 8 of 18 V4.0 AAT1102 Fig. 3 AAT1102 IN A SEPIC CONFIGURATION TO 2.6V VDD
Advanced Analog Technology, Inc. – Advanced Analog Technology, Inc. – Page 9 of 18 V4.0 AAT1102 Fig. 4 MULTIPLE-OUTPUT TFT LCD POWER SUPPLY
Advanced Analog Technology, Inc. – Advanced Analog Technology, Inc. – Page 10 of 18 V4.0 AAT1102 Inductor selection s IN IN peak L Lf D V I I , where D is duty cycle And D I I o IN = 1 o IN V V D = 1 The inductor current rating must be greater than L(peak) I Loop Compensation Design Fig.1. Closed-current loop for boost with PCM Fig.2. Block diagram of boost converter with PCM Power Stage Transfer Functions The duty to output voltage transfer function p T is: n n z esr p o p w s w s w s w s T d v s T ξ Where c L c O p r R D r V T c esr Cr w And L r D R w L z c L L n r R LC r R D w L c L c L c L R D r r R LC L D r R r R r C ξ F DS L R D Dr r r 1( − Lr is the inductor equivalent series resistance, cr is capacitor ESR, L R is the converter load resistance, C is output filter capacitor, DS r is the transistor on-resistance, and F R is the diode forward resistance. The duty to inductor current transfer function pi T is: n n zi pi l pi w s w s w s T d i s T ξ Where ) , c L c L O pi r R L r R V T c L zi r R C w
Advanced Analog Technology, Inc. – Advanced Analog Technology, Inc. – Page 11 of 18 V4.0 AAT1102 Current Sampling Transfer Function Error voltage to duty transfer function m F is: sh zi cs pi n n s ei m w s w s s R T w s w s f v d s F ξ Where α α π s sh w w a a M M M M α s s f w Therefore, m F depends on duty to inductor current transfer function pi T , and sf is the clock switching frequency; cs R is the current-sense amplifier transresistance. For the boost converter M = IN V / L and M = ( O V - IN V )/ L For AAT1102 , cs R = 0.275 V/A, a M is slope compensation, a M =0.8106. The closed-current loop transfer function icl T is: s sh zi n n pi cs s icl f s w s w s w s w s T R f s T ξ The Voltage-Loop Gain With Current Loop Closed The control to output voltage transfer function d T is: s T s T s v s v s T p icl c o d The voltage-loop gain with current loop closed is: s T s T s L d c vi β pi cs p s c c m T R T f s w s R g β s h s zi z z f sw s w s w s w s Where Vo VFB β The compensator transfer function s w s R g v v s T c c m fb c c , where c c c C R w Fig.3. Voltage loop compensator Compensator design guide: 1. Crossover frequency s ci f f 2. Gain margin>10dB 3. Phase margin>40 4. The s Lvi at crossover frequency, Therefore, the compensator resistance, c R is determined by:
Advanced Analog Technology, Inc. – Advanced Analog Technology, Inc. – Page 12 of 18 V4.0 AAT1102 ) D r R D r R kg CR f V V R L c L m cs ci FB o c FB V is equal to reference voltage, REF V REF V =1.24V, k is the correct factor, and ( − k 5. The output filter capacitor is chosen so C . L R pole cancels c R . c C zero c L c c r R C C R , and c L c c r R R C C Example: IN V =5V, O V =9.6V, O I =250mA, sf =600 kHz, FB V =1.25V, uH L 8.6 uS gm 105 275 cs R V/A, Ω 1.0 Lr Ω DS r Ω m r C , k =7 Ω 4.1 F R cif kHz, c C =1.3nF, c R = 27k , C =4.7uF Fig.4. CH1: PWM waveform, CH2, p p v − for Vo Fig.5. Bode diagram using Matlab simulation
Advanced Analog Technology, Inc. – Advanced Analog Technology, Inc. – Page 13 of 18 V4.0 AAT1102 PACKAGE DIMENSION MSOP-8
Advanced Analog Technology, Inc. – Advanced Analog Technology, Inc. – Page 14 of 18 V4.0 AAT1102 PACKAGE DIMENSION (CONT.) MSOP-8
Advanced Analog Technology, Inc. – Advanced Analog Technology, Inc. – Page 15 of 18 V4.0 AAT1102 TAPE AND REEL PACKING METHOD: 2,500PCS/REEL, 1 REEL/BOX
Advanced Analog Technology, Inc. – Advanced Analog Technology, Inc. – Page 16 of 18 V4.0 AAT1102 TAPE AND REEL (CONT.) PACKING METHOD: 2,500PCS/REEL, 1 REEL/BOX
Advanced Analog Technology, Inc. – Advanced Analog Technology, Inc. – Page 17 of 18 V4.0 AAT1102 PART MARKING MSOP8 TOP MARKING 1102 MAAC MSOP8 BACK MARKING YYWW
Advanced Analog Technology, Inc. – Advanced Analog Technology, Inc. – Page 18 of 18 V4.0 AAT1102