AP3842N8

AP3842/3/4/5 High Performance Current Mode PWM Controller Features • • • • • • • • • • • General Description The AP3842/3/4/5 family of control ICs provides the necessary features to implement off-line or DC to DC fixed frequency current mode control schemes with a minimal external parts count. Internally implemented circuits include under voltage lockout featuring start-up current less than 0.5 mA, a precision reference trimmed for accuracy at the error amp input, logic to insure latched operation, a PWM comparator which also provides current limit control, and a totem pole output stage designed to source or sink high peak current. The output stage, suitable for driving N-Channel MOSFETs, is low in the off-state. Differences between members of this family are the under-voltage lockout thresholds and maximum duty cycle ranges. The AP3842 and AP3844 have UVLO thresholds of 16V(on) and 10V(off), ideally suited for off-line applications. The corresponding thresholds for the AP3843 and AP3845 are 8.5V and 7.6V. The AP3842 and AP3843 can operate to duty cycles approaching 100%. A range of the zero to < 50% is obtained by the AP3844 and AP3845 by the addition of an internal toggle flip flop which blanks the output off every other clock cycle. Optimized for Off-Line and DC to DC Converters Low Start-Up Current (≦0.5mA) Automatic Feed Forward Compensation Pulse-by-Pulse Current Limiting Enhanced Load Response Characteristics Under-Voltage Lockout (UVLO) with Hysteresis Double Pulse Suppression High Current Totem Pole Output Internally Trimmed Bandgap Reference Current Mode Operation to 500KHZ Low Ro Error Amplifier Pin Connections PDIP-8L, SOP-8L Top View COMP. VFB ISENSE RT/CT 1 2 3 4 8 7 6 5 VREF VI OUTPUT GROUND Ordering Information AP 384X X X X Part No. 2:3842 3:3843 4:3844 5:3845 Package S8:SOP-8L N8:PDIP-8L Lead Free Packing Blank: Tube Blank : Normal L : Lead Free Package A : Taping This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of this product. No rights under any patent accompany the sale of the product. Rev.1.0 Oct.11, 2004 1/8 AP3842/3/4/5 High Performance Current Mode PWM Controller Block Diagram ( toggle flip flop used only in AP3844 and AP3845 ) Vi 7 36V GROUND 5 16V UVLO S/R 8 INTERNAL BIAS 5V REF VREF 5V 50mA 2.50V VREF GOOD LOGIC T 2R R S R 1V CURRENT SENSE COMPARATOR PWM LATCH 6 RT/CT 4 OUTPUT OSC. ERROR AMP. 2 VFB COMP CURRENT SENSE 1 3 AP384X Absolute Maximum Ratings Symbol Vi Vi Io Eo Ptot Ptot Tstg TL Parameter Supply Voltage (low impedance source) Supply Voltage (li < 30mA) Output Current Output Energy (capacitive load) Analog Inputs (pins2,3) Error Amplifier Output Sink Current Power Dissipation at Tamb ≦500C (PDIP8) Power Dissipation at Tamb ≦250C (SOP8) Storage Temperature Range Lead Temperature (soldering 10s) Value 36 Self Limiting ±0.7 5 -0.3 to 5.5 10 1.25 800 -65 to 150 260 Unit V A µJ V mA W mW o C o C *Notes: 1. All voltages are with respect to pin 5, all currents are positive into the specified terminal. Electrical Characteristics (Unless otherwise stated, these specifications apply for 0≦Tamb≦70 C for AP384X ; Vi = 15V(note 5); RT = 10KΩ;CT = 3.3nF) o Symbol Parameter Test Conditions AP384X Min. Typ. Max. Unit REFERENCE SECTION VREF Output Voltage ∆VREF Line Regulation ∆VREF Load Regulation ∆VREF/∆T Temperature Stability Total Output Variation eN ISC Tj = 250C I0=1mA 4.90 5.00 5.10 V 12V≦Vi≦25V 2 20 mV 1mA≦Io≦20mA 3 25 mV (Notes 2) 0.2 0.4 mV/0C Line, Load, Temperature (Notes 2) 4.82 5.18 V 10Hz≦f≦10KHz Tj=250C (Notes 50 µV Output Noise Voltage 2) 0 Long Term Stability Tamb=125 C, 1000Hrs (Notes 2) 5 25 mV Output Short Circuit current -85 -120 mA Anachip Corp. www.anachip.com.tw 2/8 Rev.1.0 Oct.11, 2004 AP3842/3/4/5 High Performance Current Mode PWM Controller Electrical Characteristics(Continued) (Unless otherwise stated, these specifications apply for 0≦Tamb≦70 C for AP384X ; Vi = 15V(note 5); RT = 10KΩ;CT = 3.3nF) o Symbol Parameter Test Conditions Tj=250C (Notes 6, 7) 12V≦Vi≦25V TMIN≦Tamb≦TMAX (Notes 2) VPIN4 Peak to Peak 0 Tj=25 C VPIN4=2V VPIN1=2.5V VFB=5V 0V≦V0≦4V Tj=25oC 12V≦Vi≦25V VPIN2=2.7V VPIN1=1.1V VPIN2=2.3V VPIN1=5V VPIN2=2.3V; RL=15KΩ to ground VPIN2=2.7V; RL=15KΩ to pin 8 (Notes3&Notes4) VPIN1=5V (Notes3) 12≦Vi≦25V (Notes3) AP384X Min. Typ. Max. 49 52 0.2 0.5 1.6 8.3 55 1 Unit KHz % % V mA V µA dB MHz dB mA mA V V V/V V dB µA ns V V V V ns ns V V V V V % % % mA mA V OSCILLATOR SECTION fs Oscillator Frequency Voltage Stability Temperature Stability V4 Amplitude Discharge Current ERROR AMP SECTION V2 Feedback Input Voltage Ib Input Bias Current AVOL B Unity Gain Bandwidth Supply Voltage Rejection SVRR Ratio IO Output Sink Current IO Output Source Current VOUT High VOUT Low CURRENT SENSE SECTION Gv Gain V3 Maximum Input Signal Supply Voltage Rejection SVRR Ratio Ib Input Bias Current Delay to Output OUTPUT SECTION VOL VOH Output Low Level Output High Level 7.8 8.8 2.42 2.50 2.58 -0.1 -2 65 90 0.7 1 60 2 -0.5 5 70 6 -0.8 7 0.8 3 1 70 -2 150 -10 300 0.4 2.2 1.1 3.15 1.1 2.85 0.9 Tr Rise Time Tf Fall Time VOLS UVLO Saturation UNDER-VOLTAGE LOCKOUT SECTION Start Threshold Min Operating Voltage After Turn-on PWM SECTION Maximum Duty Cycle Minimum Duty Cycle TOTAL STANDBY CURRENT Ist Ii Viz Start-up Current Operating Supply Current Zener Voltage ISINK= 20mA ISINK= 200mA ISOURCE= 20mA ISOURCE= 200mA Tj=250C CL=1nF (Notes2) Tj=250C CL=1nF (Notes2) Vcc = 6V ; Isink = 1mA 3842/4 3843/5 3842/4 3843/5 3842/3 3844/5 13 12 0.1 1.6 13.5 13.5 50 50 0.1 16 8.4 10 7.6 96 48 150 150 1.1 17.5 9 11.5 8.2 14.5 7.8 8.5 7.0 94 47 50 0 0.5 17 Vi=14V,3842/4 ; Vi=6.5V 3843/5 VPIN2=VPIN3=0V Ii=25mA 0.3 30 12 36 Anachip Corp. www.anachip.com.tw 3/8 Rev.1.0 Oct.11, 2004 AP3842/3/4/5 High Performance Current Mode PWM Controller Notes：2.These parameters, although guaranteed, are not 100% tested in production. 3.Parameter measured at trip point of latch with VPIN2=0. 4.Gain defined as: ∆VPIN1 ; 0≦VPIN3≦0.8V A= ∆VPIN3 5.Adjust Vi above the start threshold before setting at 15V. 6.Output frequency equals oscillator frequency for the AP3842 and AP3843. 7.Output frequency is one and half oscillator frequency for the AP3844 and AP3845. Figure 1 : Error Amp Configuration. 2.5V 0.8 mA Zf Zf 2 COMP 1 VFB Error amp can source or sink up to 0.5mA Figure 2 : Under Voltage Lockout. ON/OFF COMMAND TO REST OF IC I CC V i 7 AP3842 AP3843 AP3844 AP3845 V