Data Sheet PRIMARY SIDE CONTROL IC FOR OFF-LINE BATTERY CHARGERS AP3706 General Description Features The AP3706 is a high performance AC/DC power supply controller for battery charger and adapter applications. The device uses Pulse Frequency Modulation (PFM) method to build discontinuous conduction mode (DCM) flyback power supplies. · · · · · The AP3706 provides constant voltage, constant current (CV/CC) regulation without requiring an optocoupler and secondary control circuitry. It also eliminates the need of loop compensation circuitry while maintaining stability. · · · · · The AP3706 achieves excellent regulation and high power efficiency, the no-load power consumption is less than 200mW at 265VAC input. Primary Side Control for Rectangular Constant Current and Constant Voltage Output Eliminates Opto-Coupler and Secondary CV/CC Control Circuitry Eliminates Control Loop Compensation Circuitry Flyback Topology in DCM Operation Random Frequency Modulation to Reduce System EMI Valley Turn on of External Power NPN Transistor Built-in Soft Start Open Circuit Protection Over Voltage Protection Short Circuit Protection Applications The AP3706 is available in SOIC-8 and DIP-8 packages. · · SOIC-8 Adapters/Chargers for Cell/Cordless Phones, PDAs, MP3 and Other Portable Apparatus Standby and Auxiliary Power Supplies DIP-8 Figure 1. Package Types of AP3706 Jul. 2008 Rev. 1.3 BCD Semiconductor Manufacturing Limited 1 Data Sheet PRIMARY SIDE CONTROL IC FOR OFF-LINE BATTERY CHARGERS AP3706 Pin Configuration M/P Package (SOIC-8/DIP-8) CS 1 8 COMP VCC 2 7 BIAS OUT 3 6 VDD GND 4 5 FB Figure 2. Pin Configurations of AP3706 (Top View) Pin Description Pin Number Pin Name Function 1 CS 2 VCC Supply voltage The primary current sense 3 OUT This pin drives the base of external power NPN switch 4 GND Ground 5 FB The voltage feedback from the auxiliary winding 6 VDD The 5V output of the internal voltage regulator 7 BIAS This pin sets the bias current inside AP3706 with an external resistor to GND 8 COMP This pin connects a bypass capacitor for CC function Jul. 2008 Rev. 1.3 BCD Semiconductor Manufacturing Limited 2 Data Sheet PRIMARY SIDE CONTROL IC FOR OFF-LINE BATTERY CHARGERS AP3706 Functional Block Diagram VCC 2 UVLO FB 6 pro OVP & OCkP 5 VDD Regulator & Bias 0.1V COMP Tonsec Detector UVLO Tons 7 pfm BIAS EA 4.0V Vea S&H Tons COMP CV_ctrl V+ R pfm_d V+ Q 3 pfm Driver OUT Vea S 1 t CS COMP 0.5V pfm LEB Delay 430ns pfm_d COMP VDD 0.46V I Tons 8 3.75V COMP COMP R Q CC_ctrl 4 GND S 0.75*I Figure 3. Functional Block Diagram of AP3706 Jul. 2008 Rev. 1.3 BCD Semiconductor Manufacturing Limited 3 Data Sheet PRIMARY SIDE CONTROL IC FOR OFF-LINE BATTERY CHARGERS AP3706 Ordering Information AP3706 Package - Circuit Type E1: Lead Free G1: Green Package M: SOIC-8 P: DIP-8 TR: Tape and Reel Blank: Tube Part Number Temperature Range SOIC-8 -40 to 85o C DIP-8 Lead Free Marking ID Green Lead Free Green Packing Type AP3706M-E1 AP3706M-G1 3706M-E1 3706M-G1 Tube AP3706MTR-E1 AP3706MTR-G1 3706M-E1 3706M-G1 Tape & Reel AP3706P-E1 AP3706P-G1 AP3706P-E1 AP3706P-G1 Tube BCD Semiconductor's Pb-free products, as designated with "E1" suffix in the part number, are RoHS compliant. Products with "G1" suffix are available in green packages. Absolute Maximum Ratings (Note 1) Parameter Value Unit Supply Voltage VCC -0.3 to 30 V Voltage at CS, BIAS, OUT, VDD, COMP to GND -0.3 to 7 V FB input (Pin 5) -40 to 10 V Internally limited A Power Dissipation at TA=25oC 0.657 W Operating Junction Temperature 150 oC Output Current at OUT Storage Temperature -65 to 150 o C Lead Temperature (Soldering, 10s) 300 oC Thermal Resistance Junction-to-Ambient 190 oC/W ESD (Machine Model) 200 V Note 1: Stresses greater than those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "Recommended Operating Conditions" is not implied. Exposure to "Absolute Maximum Ratings" for extended periods may affect device reliability. Jul. 2008 Rev. 1.3 BCD Semiconductor Manufacturing Limited 4 Data Sheet PRIMARY SIDE CONTROL IC FOR OFF-LINE BATTERY CHARGERS AP3706 Electrical Characteristics (VCC=15V, TA=25oC, unless otherwise specified.) Parameter Symbol Conditions Min Typ Max Unit 17 18.5 20 V 6.5 7.3 8.1 V 1.170 1.205 1.240 V 4.75 5.0 5.25 V VCC = VTH (ST)-0.5V, RBIAS=200kΩ, Before turn on 70 80 μA ICC(OPR) RBIAS=200kΩ 680 900 μA IOUT RBIAS=200kΩ UVLO SECTION VTH (ST) Start-up Threshold Minimal Operating Voltage VOPR(min) After turn on REFERENCE VOLTAGE SECTION BIAS Pin Voltage VBIAS VDD Pin Voltage VDD RBIAS=200kΩ, Before turn on STANDBY CURRENT SECTION IST Start-up Current Operating Current DRIVE OUTPUT SECTION OUT Maximum Current Sink Source 50 mA 25 30 VCS 490 510 530 mV VCS(PRE) 440 460 480 mV CURRENT SENSE SECTION Current Sense Threshold Pre-Current Sense Leading Edge Blanking 430 ns FEEDBACK INPUT SECTION Feedback Current Pin Input Leakage Feedback Threshold Enable Turn-on Voltage 10.0 12.5 15.0 μA VFB 3.90 4.00 4.10 V VFB(EN) -0.9 -0.7 -0.5 V VCOMP 3.42 3.60 3.78 V VFB(OVP) 7 8 9 V IFB VFB=4V COMP THRESHOLD VOLTAGE SECTION Turn-on Threshold Voltage PROTECTION SECTION Over Voltage Protection Jul. 2008 Rev. 1.3 BCD Semiconductor Manufacturing Limited 5 Data Sheet PRIMARY SIDE CONTROL IC FOR OFF-LINE BATTERY CHARGERS AP3706 Typical Performance Characteristics 100 19.5 90 19.0 Startup Current (μA) Start-up Voltage (V) 80 18.5 18.0 17.5 70 60 50 40 RBIAS=200kΩ 17.0 16.5 -40 -20 0 20 40 60 80 RBIAS=200kΩ 30 100 20 -40 120 -20 0 750 5.15 700 5.10 650 5.05 VDD (V) Operating Current (μA) 5.20 600 4.95 500 4.90 RBIAS=200kΩ 0 20 40 60 80 80 100 120 5.00 550 -20 60 Figure 5. Start-up Current vs. Ambient Temperature 800 400 -40 40 Ambient Temperature ( C) Figure 4. Start-up Voltage vs. Ambient Temperature 450 20 o o Ambient Temperature ( C) 100 4.85 4.80 -40 120 o -20 0 20 40 60 80 100 120 o Ambient Temperature ( C) Ambient Temperature ( C) Figure 7. VDD vs. Ambient Temperature Figure 6. Operating Current vs. Ambient Temperature Jul. 2008 Rev. 1.3 BCD Semiconductor Manufacturing Limited 6 Data Sheet PRIMARY SIDE CONTROL IC FOR OFF-LINE BATTERY CHARGERS AP3706 120 80 110 70 100 60 Out Source Current (mA) Start-up Current (μA) Typical Performance Characteristics (Continued) 90 80 70 60 50 40 100 o TA=25 C 150 50 40 30 20 10 200 250 300 350 0 100 400 Bias Resistor (kΩ) o TA=25 C 150 200 250 300 350 400 Bias Resistor (kΩ) Figure 9. OUT Source Current vs. Bias Resistor Figure 8. Start-up Current vs. Bias Resistor Jul. 2008 Rev. 1.3 BCD Semiconductor Manufacturing Limited 7 Data Sheet PRIMARY SIDE CONTROL IC FOR OFF-LINE BATTERY CHARGERS AP3706 Operation Description Bridge VIN Vg + VS LM NP C1 IS + CO IO VAUX Q1 NAUX OUT AP3706 NS VO D1 IP FB GND CS RCS Figure 10. Simplified Flyback Converter Controlled by AP3706 The energy stored in the magnetizing inductance LM each cycle is therefore: Figure 10 illustrates a simplified flyback converter controlled by AP3706. 1 Eg = × LM ⋅ Ipk 2 2 Constant Primary Peak Current The primary current ip(t) is sensed by a current sense resistor RCS as shown in Figure 10. So the power transferring from the input to the output is given by: The current rises up linearly at a rate of: dip (t ) vg (t ) = dt LM 1 P = × LM × Ipk2 × f SW 2 ................(1) ................(4) Where the fsw is the switching frequency. When the peak current Ipk is constant, the output power depends on the switching frequency fsw. See equation 2 Constant Voltage Operation The AP3706 captures the auxiliary winding feedback voltage at FB pin and operates in constant-voltage (CV) mode to regulate the output voltage. Assuming the secondary winding is master, the auxiliary winding is slave during the D1 on-time. The auxiliary voltage is given by: Ip 0A Figure 11. Primary Current Waveform As illustrated in Figure 11, when the current ip(t) rises up to Ipk, the switch Q1 turns off. The constant peak current is given by: Vcs Ipk = Rcs ................(3) V AUX = ................(2) Jul. 2008 Rev. 1.3 N AUX × (Vo + Vd ) NS ................(5) BCD Semiconductor Manufacturing Limited 8 Data Sheet PRIMARY SIDE CONTROL IC FOR OFF-LINE BATTERY CHARGERS AP3706 Operation Description (Continued) The relationship between the output constant-current and secondary peak current Ipks is given by: Where the Vd is the diode forward drop voltage. See equation 5 1 Tons ................(7) Iout = × Ipks× 2 Tons + Toffs At the instant of D1 turn-on, the primary current transfers to the secondary at an amplitude of: 0V 2/3 Tons Ipks = Tons NP × Ipk NS ................(8) Figure 12. Auxiliary Voltage Waveform Thus the output constant-current is given by: The output voltage is different from the secondary voltage in a diode forward drop voltage. The diode drop voltage depends on the current. If the secondary voltage is always detected at a constant secondary current, the difference between the output voltage and the secondary voltage will be a fixed Vd. The voltage detection point is at two-thirds of the D1 on-time. The CV loop control function of AP3706 then generates a D1 off-time to regulate the output voltage. 1 N Tons 2 N Iout = × P × Ipk × = × P × Ipk 2 NS Tons + Toffs 7 N S ................(9) Leading Edge Blanking When the power switch is turned on, a turn-on spike will occur on the sense-resistor. To avoid falsetermination of the switching pulse, a 430ns leadingedge blanking is built in. During this blanking period, the current sense comparator is disabled and the gate driver can not be switched off. Constant Current Operation The AP3706 is designed to work in constant-current (CC) mode. Figure 13 shows the secondary current waveforms. See equation 8 Is CCM Protection The AP3706 is designed to operate in discontinuous conduction mode (DCM) in both CV and CC modes. To avoid operating in continuous conduction mode (CCM), the AP3706 detects the falling edge of the FB input voltage on each cycle. If a 0.1V falling edge of FB is not detected, the AP3706 will stop switching. Iout 0A Tons Toffs Figure 13. Secondary Current Waveform OVP & OCkP The AP3706 includes output over-voltage protection (OVP) and open circuit protection (OCkP) circuitry as shown in Figure 14. If the voltage at FB pin exceeds 8V, 100% above the normal detection voltage, or the -0.7V falling edge of the FB input can not be monitored, the AP3706 will immediately shut off and enters hiccup mode. The AP3706 sends out a fault detection pulse every 8ms in hiccup mode until the fault has been removed. In CC operation, the CC loop control function of AP3706 will keep a fixed proportion between D1 ontime Tons and D1 off-time Toffs by discharging or charging the capacitance connected in COMP pin. The fixed proportion is Tons 4 = Toffs 3 ................(6) Jul. 2008 Rev. 1.3 BCD Semiconductor Manufacturing Limited 9 Data Sheet PRIMARY SIDE CONTROL IC FOR OFF-LINE BATTERY CHARGERS AP3706 Operation Description (Continued) FB COMP pro 8V R Q S COMP -0.7V Timer_8ms UVLO Figure 14. OVP and OCkP Function Block Typical Application Bridge T1 D2 5V/1A VO+ + J1 AC 85-264V C1 R1 + C2 R6 Z1 C6 D1 + VOR2 Q1 VCC CS OUT R9 AP3706 R3 BIAS C5 FB GND COMP VDD R7 R4 R5 C3 C4 R10 R11 R8 Figure 15. 5V/1A Output for Battery Charger of Mobile Phone Jul. 2008 Rev. 1.3 BCD Semiconductor Manufacturing Limited 10 Data Sheet PRIMARY SIDE CONTROL IC FOR OFF-LINE BATTERY CHARGERS AP3706 Mechanical Dimensions SOIC-8 4.700(0.185) 5.100(0.201) 7° Unit: mm(inch) 0.320(0.013) 1.350(0.053) 1.750(0.069) 8° 8° 7° 0.675(0.027) 0.725(0.029) D 5.800(0.228) 1.270(0.050) 6.200(0.244) TYP D 20:1 φ 0.800(0.031) 0.300(0.012) R0.150(0.006) 0.100(0.004) 0.200(0.008) 0° 8° 1.000(0.039) 3.800(0.150) 4.000(0.157) 0.330(0.013) 0.190(0.007) 0.250(0.010) 1° 5° 0.510(0.020) 0.900(0.035) R0.150(0.006) 0.450(0.017) 0.800(0.031) Jul. 2008 Rev. 1.3 BCD Semiconductor Manufacturing Limited 11 Data Sheet PRIMARY SIDE CONTROL IC FOR OFF-LINE BATTERY CHARGERS AP3706 Mechanical Dimensions (Continued) DIP-8 Unit: mm(inch) 0.700(0.028) 7.620(0.300)TYP 1.524(0.060) TYP 6° 5° 6° 3.200(0.126) 3.600(0.142) 3.710(0.146) 4.310(0.170) 4° 4° 0.510(0.020)MIN 3.000(0.118) 3.600(0.142) 0.204(0.008) 0.360(0.014) 8.200(0.323) 9.400(0.370) 0.254(0.010)TYP 2.540(0.100) TYP 0.360(0.014) 0.560(0.022) 0.130(0.005)MIN 6.200(0.244) 6.600(0.260) R0.750(0.030) Φ3.000(0.118) Depth 0.100(0.004) 0.200(0.008) 9.000(0.354) 9.400(0.370) Jul. 2008 Rev. 1.3 BCD Semiconductor Manufacturing Limited 12 BCD Semiconductor Manufacturing Limited http://www.bcdsemi.com IMPORTANT NOTICE BCD Semiconductor Manufacturing Limited reserves the right to make changes without further notice to any products or specifications herein. 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