AMS 2263 Excellent EMI performance is achieved with GENERAL DESCRIPTION frequency shuffling technique together with soft AMS2263 is a highly integrated current mode PWM switching control at the totem pole gate drive control IC optimized for high performance, low output. standby power and cost effective offline flyback Tone energy at below 20KHZ is minimized in the converter applications in sub 30W range. design and audio noise is eliminated during PWM switching frequency at normal operation is operation. AMS2263 is offered in SOT23-6, SOP-8 externally programmable and trimmed to tight and DIP-8 packages. range. At no load or light load condition, the IC operates in extended ‘burst mode’ to minimize FEATURES switching loss. Lower standby power and higher conversion efficiency is thus achieved. Efficiency and Minimum Standby Power Design. VDD low startup current and low operating current contribute to a reliable power on startup design with AMS2263. A large value resistor could Audio Noise Free Operation External Programmable standby power. internal slope compensation Internal Synchronized Slope Compensation Low VDD Startup Current and Low Operating improves Current (1.4mA) system large signal stability and reduces the possible sub-harmonic oscillation at high PWM Leading Edge Blanking on Current Sense Input duty cycle output. Leading-edge blanking on current sense(CS) input removes the signal glitch Good Protection Coverage With Auto Self-Recovery due to snubber circuit diode reverse recovery and thus greatly reduces the external component VDD Over Voltage Clamp and Under Voltage Lockout with Hysteresis (UVLO) count and system cost in the design. AMS2263 offers complete protection coverage with Gate Output Maximum Voltage Clamp (18V) Line Input Compensated Cycle-by-Cycle including Over-current Threshold Setting For Constant Cycle-by-Cycle current limiting (OCP), over load Output Power Limiting Over Universal Input protection (OLP), VDD over voltage clamp and Voltage Range. automatic self-recovery feature PWM Switching Frequency thus be used in the startup circuit to minimize the The Extended Burst Mode Control For Improved under voltage lockout (UVLO). The Gate-drive Overload Protection (OLP) output is clamped to maximum 18V to protect the power MOSFET. 1 Advanced Monolithic Systems http://www.ams-semitech.com AMS 2263 APPLICATIONS Offline AC/DC flyback converter for Battery Charger Power Adaptor Set-Top Box Power Supplies Open-frame SMPS BLOCK DIAGRAM TYPICAL APPLICATION Advanced Monolithic Systems 2 http://www.ams-semitech.com AMS 2263 GENERAL INFORMATION Pin Configuration Package Dissipation Rating The AMS2263 is offered in SOT23-6, DIP8 and SOP8 packages, shown as below. Package RθJA (°C/W) DIP8 90 SOP8 150 SOT23-6 200 Absolute Maximum Ratings Parameter Value VDD DC Supply Voltage 30 V VDD Zener Clamp VDD_Clamp+0.1V VoltageNote VDD DC Clamp Current 10 mA VFB Input Voltage -0.3 to 7V VSENSE Input Voltage to -0.3 to 7V Sense Pin VRI Input Voltage to RI Pin -0.3 to 7V Min/Max Operating -20 to 150 oC Junction Temperature TJ -55 to 160 oC Min/Max Storage Temperature Tstg Note: VDD_Clamp has a nominal value of 34V. Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, Ordering Information Part Number functional operation Description of the device at these or any other conditions beyond those indicated AMS2263MP SOT23-6,Pb-free under “recommended operating conditions” is not AMS2263AP DIP8, Pb-free implied. Exposure to absolute maximum-rated AMS2263CP SOP8, Pb-free conditions for extended periods may affect device reliability. 3 Advanced Monolithic Systems http://www.ams-semitech.com AMS 2263 TERMINAL ASSIGNMENTS Pin Name I/O Description GND P Ground FB I Feedback input pin. The PWM duty cycle is determined by voltage level into this pin and SENSE pin input. RI I Internal Oscillator frequency setting pin. A resistor connected between RI and GND sets the PWM frequency. SENSE I Current sense input pin. Connected to MOSFET current sensing resistor node. VDD P Chip DC power supply pin. GATE O Totem-pole gate drive output for the power MOSFET. RECOMMENDED OPERATING CONDITION Symbol Parameter Min Unit － Max VDD VDD Supply Voltage 10 to 30 V RI RI Resistor Value 100 Kohm TA Operating Ambient Temperature -20 to 85 o C ELECTRICAL CHARACTERISTICS (TA = 25OC if not otherwise noted) Symbol Parameter Test Conditions Min Typ Max 3 20 Unit Supply Voltage (VDD) I_VDD_Startup VDD Start up VDD =12.5V, RI=100K Current Measure Leakage uA current into VDD I_VDD_Ops Operation Current 1.4 VDD=16V, mA RI=100Kohm, VFB=3V UVLO(ON) VDD Under Voltage Lockout Enter 7.5 8.5 9.5 V UVLO(OFF) VDD Under Voltage Lockout Exit 13.5 14.5 15.5 V (Recovery) VDD_Clamp VDD Zener Clamp Voltage IVDD = 5 mA 34 V ΔVFB /ΔVcs 2.0 V/V 4.8 V 1 mA Feedback Input Section(FB Pin) AVCS PWM Input Gain VFB_Open VFB Open Loop Voltage IFB_Short FB pin short circuit current Short FB pin to GND and measure current 4 Advanced Monolithic Systems http://www.ams-semitech.com AMS 2263 VTH_0D VTH_PL Zero Duty Cycle FB Threshold VDD = 16V, Voltage RI=100Kohm Power Limiting 0.75 V FB Threshold 3.7 V TD_PL Power limiting Debounce Time 47 mSec ZFB_IN Input Impedance 6 Kohm DC_MAX Maximum Duty Cycle 75 % 330 ns 40 Kohm 120 nSec Voltage VDD=18V,RI=100Kohm, FB=3V, CS=0 Current Sense Input(Sense Pin) T_blanking Leading edge blanking time RI = 100 Kohm ZSENSE_IN Input Impedance TD_OC OCP Control Delay GATE with 1nF to GND VTH_OC Over Current Threshold Voltage at FB=3.3V, RI=100 Kohm 0.70 0.75 0.80 V 60 65 70 KHZ zero Duty Cycle Oscillator FOSC Normal Oscillation Frequency RI = 100 Kohm ∆f_Temp Frequency Temperature Stability VDD = 16V, 5 % 5 % o RI=100Kohm, TA -20 C to 85 oC ∆f_VDD Frequency Voltage Stability VDD = 12-25V, RI=100Kohm RI_range Operating RI Range V_RI_open RI open load voltage Fosc_BM Burst Mode Base Frequency 50 VDD = 16V, 100 150 Kohm 2 V 22 KHZ RI = 100Kohm Gate Drive Output VOL Output Low Level VDD = 16V, Io = -20 mA VOH Output High Level VDD = 16V, Io = 20 mA V_Clamp Output Clamp Voltage Level T_r Output Rising Time T_f Output Falling Time 0.8 10 V V 18 V VDD = 16V, CL = 1nf 200 nSec VDD = 16V, CL = 1nf 70 nSec Frequency Shuffling ∆f_OSC Frequency Modulation range RI=100K -3 3 % /Base frequency f_shuffling Shuffling Frequency RI=100K 5 Advanced Monolithic Systems http://www.ams-semitech.com 64 HZ AMS 2263 CHARACTERIZATION PLOTS VDD = 16V, RI = 100 Kohm, TA = 25oC condition applies if not otherwise noted. 6 Advanced Monolithic Systems http://www.ams-semitech.com AMS 2263 OPERATION DESCRIPTION The AMS2263 is a highly integrated PWM loss on the snubber circuit. The magnitude of controller flyback power loss is in proportion to the number of converter applications in sub 30W power range. switching events within a fixed period of time. The extended burst mode control greatly reduces Reducing switching events leads to the reduction the standby power consumption and helps the on the power loss and thus conserves the energy. design easily meet the international power AMS2263 conservation requirements. according to the loading condition. At from no • IC optimized for offline self adjusts the switching mode load to light/medium load condition, the FB input Startup Current and Start up Control Startup current of AMS2263 is designed to be very drops below burst mode threshold level. low so that VDD could be charged up above enters Burst Mode control. The Gate drive output UVLO threshold level and device starts up quickly. switches only when VDD voltage drops below a A large value startup resistor can therefore be preset level and FB input is active to output an on used to minimize the power loss yet provides state. Otherwise the gate drive remains at off reliable startup in application. For AC/DC state tominimize the switching loss and reduces adaptor with universal input range design, a 2 MΩ, the standby power consumption to the greatest 1/8 W startup resistor could be used together with extend. a VDD capacitor to provide a fast startup and low the audio noise at any loading conditions. • power dissipation solution. • Device The frequency control also eliminates Oscillator Operation A resistor connected between RI and GND sets Operating Current The Operating current of AMS2263 is low at 1.4mA. the constant current source to charge/discharge Good efficiency is achieved with AMS2263 low the internal cap and thus the PWM oscillator operating current together with extended burst frequency is determined. mode control features. between RI and switching frequency follows the • below equation within the specified RI in Kohm Frequency shuffling for EMI improvement The frequency Shuffling/jittering is range at nominal loading operational condition. (switching frequency modulation) implemented AMS2263. The oscillation frequency is modulated The relationship in with a random source so that the tone energy is • spread out. The spread spectrum minimizes the Blanking conduction band EMI and therefore reduces Cycle-by-Cycle current limiting is offered in system design challenge. AMS2263 current mode PWM control. The switch • Current Sensing and Leading Edge current is detected by a sense resistor into the Extended Burst Mode Operation At zero load or light load condition, majority of the sense pin. An internal leading edge blanking power dissipation in a switching mode power circuit chops off the sense voltage spike at initial supply is from switching loss on the MOSFET MOSFET on state due to Snubber diode reverse transistor, the core loss of the transformer and the recovery so that the external RC filtering on 7 Advanced Monolithic Systems http://www.ams-semitech.com AMS 2263 sense input is no longer required. The current is added for MOSFET gate protection at higher limit comparator is disabled and thus cannot turn than expected VDD input. off the external MOSFET during the blanking • period. PWM duty cycle is determined by the Good power supply system reliability is achieved current sense input voltage and the FB input with voltage. Cycle-by-Cycle current limiting (OCP), Over Load •Internal Synchronized Slope Compensation Protection Controls its rich protection Protection (OLP) and over features including voltage clamp, Under Built-in slope compensation circuit adds voltage Voltage Lockout on VDD (UVLO). ramp onto the current sense input voltage for The OCP threshold tracks PWM Duty cycles and PWM generation. This greatly improves the close is line voltage compensated to achieve constant loop output power limit over the universal input voltage stability at CCM and prevents the sub-harmonic oscillation and thus reduces the range with recommended reference design. output ripple voltage. At overload condition when FB input voltage • exceeds power limit threshold value for more than Gate Drive AMS2263 Gate is connected to an external TD_PL, control circuit reacts to shut down the MOSFET gate for power switch control. Too weak output power MOSFET. Device restarts when the VDD voltage drops below UVLO limit. gate drive strength results in higher conduction and switch loss of MOSFET while too VDD is supplied by transformer auxiliary winding strong gate drive output compromises the EMI. output. It is clamped when VDD is higher than A good tradeoff is achieved through the built-in threshold value. The power MOSFET is shut totem pole gate design with right output strength down when VDD drops below UVLO limit and and dead time control. The low idle loss and good device enters power on start-up sequence EMI system design is easier to achieve with this thereafter. dedicated control scheme. An internal 18V clamp 8 Advanced Monolithic Systems http://www.ams-semitech.com AMS 2263 PACKAGE MECHANICAL DATA SOT-23-6 PACKAGE OUTLINE DIMENSIONS Symbol Dimensions In Millimeters Dimensions In 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 0.400 0.012 0.016 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 e1 0.950TYP 1.800 L 0.037TYP 2.000 0.700REF 0.071 0.079 0.028REF L1 0.300 0.600 0.012 0.024 θ 00 80 00 80 9 Advanced Monolithic Systems http://www.ams-semitech.com AMS 2263 SOP8 PACKAGE OUTLINE DIMENSIONS 10 Advanced Monolithic Systems http://www.ams-semitech.com AMS 2263 DIP8 PACKAGE OUTLINE DIMENSIONS 11 Advanced Monolithic Systems http://www.ams-semitech.com AMS 2263 Disclaimer: • AMS reserves the right to make changes to the information herein for the improvement of the design and performance without further notice! Customers should obtain the latest relevant information before placing orders and should verify that such information is complete and current. • All semiconductor products malfunction or fail with some probability under special conditions. When using AMS products in system design or complete machine manufacturing, it is the responsibility of the buyer to comply with the safety standards strictly and take essential measures to avoid situations in which a malfunction or failure of such AMS products could cause loss of body injury or damage to property. • AMS will supply the best possible product for customers! 12 Advanced Monolithic Systems http://www.ams-semitech.com