Dual Channel PWM Controller with SCP / DTC Function General Description The FP545A is a dual channel PWM buck controller with short circuit protection (SCP) and adjustable maximum duty control (DTC) function. It includes one.5v precision voltage reference regulator, two error amplifiers, PWM control circuits, totem-pole output stages and under voltage lockout circuit (UVLO). It offers space and low cost in many applications such as the DC / DC converters and backlight inverters. Using FP545A, it is easy to complete a power conversion regulator design with few external components. The circuit diagram of the typical application example is as below. Features Wide Operating Voltage Range: 4~40V Feedback Reference Voltage:.5V Reference Voltage Precision: % Output Sink Current up to 00mA Oscillator Frequency: Max. 500KHz Low Quiescent Supply Current Variable Duty Control (DTC) UVLO Protection Function SCP Protection Function (Typ..3V) Package: SOP-6L / SSOP-6L Applications Dual Output Switch Regulator Backlight Inverter LCD Monitor /4
Function Block Diagram VCC RT CT DTC FB OUT EA+ / VREF Oscillator PWM COMP SCP Reference Voltage VREF Iscp R S UVLO R OUT EA+ EA- EA- FB PWM COMP DTC GND /4
Pin Descriptions SOP-6L CT Top View 6 V REF Name No. I / O Description CT I Connect a Capacitor for Oscillator Frequency Adjustment RT I Connect a Resistor for Oscillator Frequency Adjustment EA+ 3 I Output Error Amplifier Non-inverting Input SCP EA+ EA- RT EA+ EA- 3 4 5 4 3 EA- 4 I Output Error Amplifier Inverting Input FB 5 O Output Error Amplifier Output DTC 6 I Output Maximum Duty Control Voltage OUT 7 O Output Totem-pole Output FB DTC 5 6 FB DTC GND 8 P IC Ground V CC 9 P IC Power Supply OUT 0 O Output Totem-pole Output OUT 7 0 OUT DTC I Output Dead-Time Comparator GND 8 9 V CC FB O Output Error Amplifier Output EA- 3 I Output Error Amplifier Inverting Input EA+ 4 I Output Error Amplifier Non-inverting Input SCP 5 I Connect a Capacitor to Set Short Circuit Protection Timing V REF 6 O.5V Reference Voltage Output SSOP-6L CT RT EA+ EA- FB DTC OUT GND 3 4 5 6 7 8 Top View 6 5 4 3 0 9 V REF SCP EA+ EA- FB DTC OUT V CC Name No. I / O Description CT I Connect a Capacitor for Oscillator Frequency Adjustment RT I Connect a Resistor for Oscillator Frequency Adjustment EA+ 3 I Output Error Amplifier Non-inverting Input EA- 4 I Output Error Amplifier Inverting Input FB 5 O Output Error Amplifier Output DTC 6 I Output Maximum Duty Control Voltage OUT 7 O Output Totem-pole Output GND 8 P IC Ground V CC 9 P IC Power Supply OUT 0 O Output Totem-pole Output DTC I Output Dead-Time Comparator FB O Output Error Amplifier Output EA- 3 I Output Error Amplifier Inverting Input EA+ 4 I Output Error Amplifier Non-inverting Input SCP 5 I Connect a Capacitor to Set Short Circuit Protection Timing V REF 6 O.5V Reference Voltage Output 3/4
Marking Information SOP-6L SSOP-6L FP545A - Halogen Free Lot Number Internal ID Per-Half Month Year Halogen Free: Halogen free product indicator Lot Number: Wafer lot number s last two digits For Example: 3386TB 86 Internal ID: Internal Identification Code Per-Half Month: Production period indicated in half month time unit For Example: January A (Front Half Month), B (Last Half Month) February C (Front Half Month), D (Last Half Month) Year: Production year s last digit 4/4
Ordering Information Part Number Operating Temperature Package MOQ Description FP545ADR-LF -0 C ~ +85 C SOP-6L 500EA Tape & Reel FP545ARR-LF -0 C ~ +85 C SSOP-6L 500EA Tape & Reel Absolute Maximum Ratings Parameter Symbol Conditions Min. Typ. Max. Unit Power Supply Voltage V CC 40 V Differential Input Voltage V ID 0 V Collector Output Voltage V O 40 V Collector Output Voltage I O 50 ma Maximum Junction Temperature T j +50 C Thermal Resistance Junction to Ambient Thermal Resistance Junction to Case Power Dissipation θ JA θ JC P D SOP-6L +90 C / W SSOP-6L +0 C / W SOP-6L +45 / W SSOP-6L +55 / W SOP-6L, T A = +5 650 mw SSOP-6L, T A = +5 450 mw Storage Temperature Range -65 +50 Lead Temperature (soldering, 0 sec) +60 Suggested IR Re-flow Soldering Curve 5/4
Recommended Operating Conditions Parameter Symbol Conditions Min. Typ. Max. Unit Supply Voltage 4 40 V Operating Temperature -0 +85 DC Electrical Characteristics (V CC = 6V, f=70khz, unless otherwise noted) Reference Section Parameter Symbol Test Conditions Min. Typ. Max. Unit Output Voltage (pin 6) V REF I O =ma.45.5.55 V Output Voltage Change with T A =-0 to +5-0. ± % Temperature T A =+5 to +85-0. ± % Input Voltage Regulation Output Voltage Regulation V REF / V REF V REF V CC =3.6V~40V.5 mv V REF / Io = 0.mA to ma 7.5 mv Short-circuit Output Current I SHORT V O =0 3 0 30 ma Under Voltage Lockout Section Upper Threshold Voltage (V CC ) V UPPER.8 V Lower Threshold Voltage (V CC ) V LOW.6 V I O (REF) = 0. ma, T A =5 Hysteresis (V CC ) V HYS 80 0 mv Reset Threshold Voltage (V CC ) V RESET.5.9 V Short-circuit Protection Control Section Input Threshold Voltage (SCP) V TH T A = 5..3.5 V Standby Voltage (SCP) V STANDBY No Pull-up 60 80 00 mv Latched Input Voltage (SCP) V LATCH No Pull-up 40 60 mv Input (Source) Current I SOURCE V I =0.7V, T A =5 -.5 - -.5 μa Comparator Threshold Voltage (Feedback) Oscillator Section V COMP (TH).0 V Frequency f C T =330pF, R T =0K 70 KH Z Standard Deviation of Frequency f C T =330pF, R T =0K 0 % Frequency Change with Voltage Frequency Change with Temperature Duty Control Section f / V V CC =3.6V to 40V % T A =-0 to 5-0.4 ± % f / T TA =5 to 85-0. ± % Input Bias current (DTC) I BIAS μa Latch Mode (Source) Current I (DTC) SOURCE T A =5-80 -00 μa Latched Input Voltage (DTC) V LATCH I O =40μA.3 V Input Threshold Voltage at f=0khz (DTC) V TH Zero Duty Cycle.05.5 V Maximum Duty Cycle..45 V 6/4
Parameter Symbol Test Conditions Min. Typ. Max. Unit Error Amplifier Section Input Offset Voltage V IO Vo (Feedback)=.5V -6 +6 mv Input Offset Current I IO Vo (Feedback)=.5V -00 +00 na Input Bias Current I BIAS Vo (Feedback)=.5V 60 500 na Common Mode Input Voltage V Range ICM V CC =3.6V to 40 V 0.3.6 V Open Loop Voltage Amplification A VO R F =00KΩ 70 80 db Unity Gain Bandwidth BW.5 MH Z Common Mode Rejection Ratio CMRR 60 80 db Positive Output Voltage Swing V POS Vref-0. V Negative Output Voltage Swing V NEG V Output (Sink) Current (Feedback) I SINK V ID = -0.V, V O =.5V 5.0 ma Output (Source) Current (Feedback) I SOURCE V ID =0.V, V O =.5V -90-40 μa Output Section Collector Off State Current I OFF V O =50V 0 μa Output Saturation Voltage V SAT I O =0mA 0.7 V Short Circuit Output Current I SC V O =6V 50 ma PWM Comparator Section Input Threshold Voltage at f=0khz (Feedback) Total Device V TH Zero Duty Cycle.05.5 V Maximum Duty Cycle..45 V Standby Supply Current I STANDBY Off State.3.8 ma Average Supply Current I AVE R T =0K.7.4 ma 7/4
Timing Waveform Oscillator Triangle Waveform Error Amplifier Output Dead-Time Input Voltage Short-Circuit Protection Comparator Input Voltage PWM Comparator Output Voltage.0 V.6 V.4 V.5 V H L Dead Time 00% Output Transistor Collector Waveform H L Protection Enable Terminal Waveform tpe.3 V 0 V Short-Circuit Protection Comparator Output Power Supply Voltage.8 V TYP Protection Enable Time, tpe = (0.658 * 0E6 * Cpe) in seconds H L 3.6 V 0 V Application Information FP545A Timing Diagram P POWER IN +Vin +Vin P OUTPUT # P3 +5.0V +3.3V + C3 00uF + C7 00uF C R4 K R9 0 Q C8 R5 K 9435 IC L +5.0V OUTPUT # C R3 330pF 0K 3 IC CT RT IN+ REF SCP IN+ REF 6 5 4 IN+ R 33K Q R 0 0uH D SCD4 R 0K % R3 3.3K % C9 R0 + C0 0uF/6V R 33K C4 4 5 IN- IN- FB IN- FB 3 C5 000pF R6 33K 000pF 6 7 DTC OUT DTC OUT 0 C7 R8 R7 C6 8 9 GND VCC FP545A DTC C R5 R7 R8 3 DTC DTC R0 0K 3 R4 C R K C4 R K R9 0K DTC OUT R6 33K R5 0 Q3 Q4 R6 0 9435 IC3 D SCD4 L3 0uH R4 0K % R7 K % C5 R3 +3.3V + C6 0uF/6V 8/4
Typical Operating Characteristics 9/4
.5 ERROR AMP MAXIMUM OUTPUT VOLTAGE SWING VS FREQUENCY Error Am p Maxim u m Outp ut Volta ge S win g - V.5.75.5.5 0.75 0.5 Vcc = 5 V TA = 5 o C 0.5 K 0K 00K M 0M f - Frequescy - Hz Figure 0/4
/4
STANDBY CURRENT VS FREE - AIR TEMPERATURE 5 Icc - Supply Current - ma 4.5 4 3.5 3.5 Average Supply Current Vcc = 6 V CT = 330pF R T = 0 KΩ Standby Current Vcc = 3.6 V, No Load.5 Standby Current Vcc = 40 V, No Load -5 0 5 50 75 00 o TA - Free-Air Temperature - C Figure 5 /4
Package Outline SOP-6L UNIT: mm Symbols Min. (mm) Max. (mm) A.346.75 A 0.0 0.54 A.44.65 D 9.804 0.007 E 3.80 3.987 H 5.79 6.97 L 0.406.70 θ 0 8 Note:. Package dimensions are in compliance with JEDEC outline: MS-0 AC.. Dimension D does not include molding flash, protrusions or gate burrs. 3. Dimension E does not include inter-lead flash or protrusions. 3/4
SSOP-6L (EP) UNIT: mm Symbols Min. (mm) Max. (mm) A.346.75 A 0.0 0.54 A.498 b 0.03 0.304 b 0.03 0.79 c 0.77 0.54 c 0.77 0.8 D 4.800 5.003 E 3.80 3.987 E 5.79 6.97 L 0.406.70 e 0.635 BASIC θ 0 8 Note:. Package dimensions are in compliance with JEDEC outline: MO-37 AB.. Dimension D does not include molding flash, protrusions or gate burrs. 3. Dimension E does not include inter-lead flash or protrusions. 4/4