R7521GN

® R7521 PWM Controller for Half-Bridge Converters General Description Features The R7521 is a with PWM controller with supervisor function inside. The controller can be applied on half-bridge converter or push-pull converter, which needs two interleaved gate drivers with 180 degree phase shift. Four multiple outputs can be monitored by R7521 and there is a "Power Good" signal to acknowledge the following system. The controller also has remote control pin and fully protection of each output, such as output over voltage, under voltage and over power protection. The DET pin is applied to detect AC line condition. R7521 incorporates over power protection. R7521 also contains FC pin to control Fan's speed by PT voltage variation. The integrated control circuit of R7521 provides complete functions and saves the Fan control external circuit of ATX power. z Two PWM Driver Outputs for Push-Pull and HalfBridge Converters z Built-In Supervisor Saves Cost and Components Voltage Mode PWM Controller Output Over Voltage and Under Voltage Protections of Each Output Remote ON/OFF Power Good Indicator with Adaptive Time Sequence Input Under Voltage Detector and Warning Over Power Protection Adjustable Soft-Start For ATX Power Application Fun Speed Control z z z z z z z z z Simplified Application Circuit + +12V + -12V V12 DET FAN1 - +5V + FC INV SS + V33 +5VSB - + RT R7521 COMP +12V FAN2 V5 +12V + +12V -12V GND OPP PSON PT VDD C1 PG C2 Transfer to Primary Driver TL431 +5V Copyright © 2012 Richtek Technology Corporation. All rights reserved. R7521-00 December 2012 Downloaded from Arrow.com. is a registered trademark of Richtek Technology Corporation. www.richtek.com 1 R7521 Ordering Information Pin Configurations R7521 Package Type N: DIP-16 S: SOP-16 Lead Plating System G : Green (Halogen Free and Pb Free) Note : Richtek products are : ` (TOP VIEW) RT FC V12 V33 V5 PT DET VDD SS INV COMP PSON PG GND C1 C2 16 RoHS compliant and compatible with the current require- 2 15 3 14 4 13 5 12 6 11 7 10 8 9 SOP-16 ments of IPC/JEDEC J-STD-020. ` Suitable for use in SnPb or Pb-free soldering processes. RT 16 SS FC 2 15 INV Marking Information V12 3 14 COMP R7521GS V33 4 13 PSON V5 5 12 PG PT 6 11 GND DET 7 10 C1 VDD 8 9 C2 R7521GS : Product Number R7521 GSYMDNN YMDNN : Date Code R7521GN RichPower R7521 GNYMDNN R7521GN : Product Number Copyright © 2012 Richtek Technology Corporation. All rights reserved. www.richtek.com 2 Downloaded from Arrow.com. DIP-16 YMDNN : Date Code is a registered trademark of Richtek Technology Corporation. R7521-00 December 2012 R7521 Functional Pin Description Pin No. Pin Name Pin Function SOP-16 DIP-16 1 1 RT 2 2 FC Reference Current Setting. Connected to an external resistor to set the internal reference current. Fan Control I/O. 3 3 V12 12V Output Sense Pin. 4 4 V33 3.3V Output Sense Pin. 5 5 V5 5V Output Sense Pin. 6 6 PT Over Power Sense Pin. 7 7 DET VAC Input Detector Input. 8 8 VDD Bias of Controller. Source from 5V standby power. 9 9 C2 PWM Driver Output 2. 10 10 C1 PWM Driver Output 1. 11 11 GND Ground. 12 12 PG Power Good Signal Output (open collector type.). 13 13 PSON Remote On/Off Control with 24ms De_bounce Time. 14 14 COMP Error Amplifier Output. 15 15 INV Negative Input of error amplifier. 16 16 SS Soft-Start. SS is as the non-inverting input of error amplifier. Function Block Diagram V33 V5 V12 PG RT FC UVS Fan Control PG Logic UVP OFF 254ms Delay VBIAS PT OVP UVAC S/H DET 1.9V VDD Enable Logic - + VDD VDD 3.2V - C1 Driver 8µA 1.4V + PSON D Q clk QN P C 6ms Delay + PT VDD POR - 24ms De_bounce 2ms Delay S 2.5V + + - Q C2 R QN + - Reset OSC SS INV Copyright © 2012 Richtek Technology Corporation. All rights reserved. R7521-00 December 2012 Downloaded from Arrow.com. GND DMAX COMP is a registered trademark of Richtek Technology Corporation. www.richtek.com 3 R7521 Operation The R7521 is a PWM controller with supervisor functions. The PWM signal C1 and C2 drive primary-side switching power transistor by transformer, and the supervisor monitors each output. The R7521 provides fruitful protection functions that protect system from damage. Each output is protected by OVP, UVP, and OPP. The functions description as follow : Output Over-Voltage Protection The R7521 has an output Over-Voltage Protection (OVP) function, which monitors the 3.3V, 5V and 12V output voltages, to prevent power system and loads from damages during one or more output OV condition(s). The OVP starts monitoring the voltages on V33, V5 and V12 at the end of the PSONB de-bounce time. When an Over-Voltage (OV) condition appears at one of the monitored pins for more than the 0.6ms (typical) deglitch time, the PG voltage goes low to indicate one of the output voltages is out of regulation. Meanwhile the R7521 disables PWM output and protects the power supply system. The OVP condition is latched until PSON is toggled from low to high or VDD restarts. Output Under-Voltage Protection The R7521 provides under voltage protection for the 3.3V, 5V and 12V outputs. The UVP continuously monitors the voltage on V33, V5 and V12. When an Under Voltage (UV) protection condition appears at either one of the monitored pins for more than 2ms (typical) deglitch time, the PG voltage goes low to indicate one of the output voltages is out of regulation. Meanwhile, the R7521 disables the PWM output and protects the power supply system. The UVP condition is latched until PSON is toggled from low to high or VDD restarts. Copyright © 2012 Richtek Technology Corporation. All rights reserved. www.richtek.com 4 Downloaded from Arrow.com. Output Over-Power Protection The R7521 has an output over-power protection (OPP) function, which monitors total output power. The PT pin of R7521 senses primary-side switching current by current transformer (CT). When over power or output short condition appears, the OPP exceeds the trigger voltage (1.9V) for 6ms (typical), the R7521 disables PWM output and protects the power supply system. In addition, the PT can monitor −12V output voltage, and the OPP condition is latched until PSON is toggled from low to high or VDD restarts. PG Outputs In general, the PG voltage pulled high by an external resistor connected to the 5V output, indicates the status of the outputs. The PG keeps at low state when VDD voltage < UVLO threshold, PSON = H, PGI voltage < 1.2V or one of the faults, including UVP, OVP and OPP, occurs. PSON De-bounce The R7521 provides a remote ON/OFF control input pin (PSON) for PC power supply applications. A built-in 24ms (typical) de-bounce circuit performs rising and falling edge noise de-bounce functions to identify valid PSON input signals. The PSON also has a TTL logic-compliant input voltage threshold and a hysteresis design against input noise. Soft-Start The SS offers an internal 8μA (typical) constant current. Connect a capacitor between the SS and GND pins to set the soft-start time. Therefore, the soft-start time is tSS = 8μ x CSS. During soft-start period, the UVP and OPP protection is disabled to prevent wrong UVP, OPP protection. is a registered trademark of Richtek Technology Corporation. R7521-00 December 2012 R7521 Absolute Maximum Ratings z z z z z z z z (Note 1) Supply Input Voltage, VDD --------------------------------------------------------------------------------------------IDD ---------------------------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C SOP-16 --------------------------------------------------------------------------------------------------------------------DIP-16 ----------------------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2) SOP-16, θJA --------------------------------------------------------------------------------------------------------------DIP-16, θJA ----------------------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) -----------------------------------------------------------------------------Junction Temperature ---------------------------------------------------------------------------------------------------Storage Temperature Range ------------------------------------------------------------------------------------------ESD Susceptibility (Note 3) HBM (Human Body Model) --------------------------------------------------------------------------------------------MM (Machine Model) ---------------------------------------------------------------------------------------------------- Recommended Operating Conditions z z z z 5V 30mA 0.92W 1.68W 108.6°C/W 59.6°C/W 260°C 150°C −65°C to 150°C 2kV 200V (Note 4) Supply Input Voltage, VDD --------------------------------------------------------------------------------------------- 4V to 6V Frequency ------------------------------------------------------------------------------------------------------------------ 60kHz Junction Temperature Range ------------------------------------------------------------------------------------------- −40°C to 125°C Ambient Temperature Range ------------------------------------------------------------------------------------------- −40°C to 85°C Electrical Characteristics (VDD = 5V, RT = 62kΩ, TA = 25°C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit POR Section DC Supply Voltage VDD 4 -- 6 V On Threshold Voltage VTH_ON -- 3.65 -- V Off Threshold Voltage VTH_OFF -- 3.4 -- V Operating Supply Current IDD_OP VDD = 5V, VCOMP = 2.5V -- -- 10 mA Normal PWM Frequency fOSC RT = 62kΩ 55 60 65 kHz Maximum Duty Cycle DCYMAX Both for C1 and C2 -- 46 -- % Frequency Variation Versus VDD Deviation fDV VDD = 5V -- -- 2 % Frequency Variation Versus Temperature Deviation fDT TA = −20°C to 85°C -- -- 5 % Ramp of Oscillator VP -- 2 -- V Zero Duty Offset VOFFSET -- 0.5 -- V RT Reference Voltage VREF_RT 0.98 1 1.02 V Oscillator Section fOSC = 35kHz to 70kHz Copyright © 2012 Richtek Technology Corporation. All rights reserved. R7521-00 December 2012 Downloaded from Arrow.com. is a registered trademark of Richtek Technology Corporation. www.richtek.com 5 R7521 Parameter Symbol Test Conditions Min Typ Max Unit Protection Section OVP of 3.3V Output VOVP_V33 3.9 4.1 4.3 V OVP of 5V Output VOVP_V5 5.8 6.1 6.5 V OVP of 12V Output VOVP_V12 -- 2.5 -- V UVP of 3.3V Output VUVP_V33 2 2.6 2.8 V UVP of 5V Output VUVP_V5 3 3.6 3.9 V UVP of 12V Output VUVP_V12 -- 1.25 -- V UVS of 3.3V Output VUVS_V33 2.5 2.8 3 V UVS of 5V Output VUVS_V5 4 4.3 4.5 V UVS of 12V Output VUVS_V12 -- 1.75 -- V Time Delay of OVP T OVP 0.37 0.6 1.35 ms Time Delay of UVP T UVP 1.2 2 4.2 ms Time Delay of UVS T UVS 0.9 1.4 2.2 ms Over Power Protection VPT 1.7 1.9 2.1 V PT Delay -- 6 -- ms PT Cycle Limit 2.9 3.2 3.5 V (Note 5) (Note 5) (Note 5) Power Good Section Power Good Time Delay TPG -- 254 -- ms DET Voltage Sense for PG VDET 0.45 0.5 0.55 V PG Output Saturation Level VOL IPG = 5mA -- -- 5 V PG Leakage Current ILK VPG = 5V -- -- 1 µA Error Amplifier Section Reference Voltage VREF2 2.45 2.5 2.55 V Open Loop Gain AVOL 50 60 -- dB Unit Gain Bandwidth BW 0.3 1 -- MHz Power Supply Rejection Ratio PSRR 50 -- -- dB PSON Threshold Voltage VTH 1 1.4 2 V PSON Sourcing Current IPSON -- -- 0.5 mA PSON De_bounce Time T DEB ON -- 24 -- OFF -- 8 -- Delay Time Between PSON = 1 and PG = 0 TPSOFF (m.o + D-FF) 1.5 2 4 ms 6.7 8 9.3 µA Remote On/Off Section ms Soft-Start Section SS Charging Current ISS Copyright © 2012 Richtek Technology Corporation. All rights reserved. www.richtek.com 6 Downloaded from Arrow.com. is a registered trademark of Richtek Technology Corporation. R7521-00 December 2012 R7521 Parameter Symbol Test Conditions Min Typ Max Unit Fan Control Section Sourcing Current of FC IFC 6 -- -- mA Voltage Range of FC VFC 0.2 -- 4 V PWM Output Section Rising Time TR VDD = 5V, C L = 1.8nF -- 20 55 ns Falling Time TF VDD = 5V, C L = 1.8nF -- 15 50 ns RDS_ON of Top and Bottom Leg R DS_ON VDD = 5V -- -- 4.4 Ω Note 1. Stresses beyond those listed “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 in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may affect device reliability. Note 2. θJA is measured at TA = 25°C on a high effective thermal conductivity four-layer test board per JEDEC 51-7. Note 3. Devices are ESD sensitive. Handling precaution is recommended. Note 4. The device is not guaranteed to function outside its operating conditions. Note 5. The V12 pin must to use divider resistor. Propose setting the ratio is 1/6. Copyright © 2012 Richtek Technology Corporation. All rights reserved. R7521-00 December 2012 Downloaded from Arrow.com. is a registered trademark of Richtek Technology Corporation. www.richtek.com 7 R7521 Typical Application Circuit HV DET + 150 2W 470µF/16V + 510 1/4W 470µF/16V 27 3W 104/50V 4.7 1/4W +5V + 6Ts T1 ERL-35-14PIN 1N4148 470µF/16V 15 1/4W SBL3045P 3Ts 2907 104/50V 4.7 1/4W 1Ts PR1004 +12V -12V 1K 103/50V 91K 10 2W + 100 2K 2K 1N4148 30 222/50V 8550 1N4148 TL431 1.5k 1% 1N4148 T2 EEL-16 (N=1:4) + 4.7 SBL3045P 100 1N4148 MP1320 2200µF/10V 2907 1N4148 1N4148 50Ts 2200µF/10V 10N40 C1 +3.3V T4 3.3 1N4148 10R 1N4148 1N4148 3Ts 4.7k 2.2µF C2 104/ 4.7 50V 1/4W 50Ts -12V 470µF/10V 10N40 14Ts + 3.3 PR1004 470µF/10V 7N241 102/1kV 47/5W 10R 820k 1/4W NTC 103/50V 7N241 + 820k 1/4W 7Ts 225J/250V V40100P +12V + > 1N4148 7Ts SWITCH + N 4.7nF 275V 4.7nF 275V 820µF/220V VAC LF1 EE-25 560k 1/4W 0.33µF/275V > 250V/7A 820µF/220V 14Ts L PT 100K HV Copyright © 2012 Richtek Technology Corporation. All rights reserved. Downloaded from Arrow.com. +3.3V +5V PT 101/50V V33 V5 PT PSON 103/50V 3.6k 47k 104/50V 47k PSON PG PG GND DET C1 C1 VDD C2 C2 +5V 5C6 is a registered trademark of Richtek Technology Corporation. R7521-00 December 2012 153/50V INV COMP 5VSB_F 33 222/50V 68k SS 22.1k 10k 22.1k 333/50V RT V12 51k 5C1 10k 50k - FC +12V 2.7k 2.49k 1% 2N2222 1K 33 62k 104/ 50V 4.7k TL431 +3.3V +5V +12V - 1k DET 1k FAN1 FAN2 + 2.51k 1% T3 EEL-19 PC817C www.richtek.com 8 +12V + R7521 + 560 1000µF/10V 10R 103/50V 1N4007 R7912 + RT 10µF/50V GND1 COMP GND2 100k DRAIN1 DRAIN2 CS 1.6 VDD + +5VSB 1000µF/10V 750k 1N4007 750k 103/50V +5VSB_F 150k 102k/1kV R7521 Typical Operating Characteristics Frequency vs. Temperature FB & FBS vs. Temperature 80 2.5 FB FBS Frequency (Hz). Voltage (V) 2.49 2.48 2.47 60 40 20 2.46 0 2.45 -30 -15 0 15 30 45 60 75 90 105 120 Temperature (°C) Copyright © 2012 Richtek Technology Corporation. All rights reserved. R7521-00 December 2012 Downloaded from Arrow.com. -30 -15 0 15 30 45 60 75 90 105 120 Temperature (°C) is a registered trademark of Richtek Technology Corporation. www.richtek.com 9 R7521 Application Information Fan Control In order to effectively utilize the fan to disperse heat and reduce acoustic noise, the R7521 provides FC pin to control Fan's speed. Figure 1 shows the relationship between FC voltage and load in ATX 300W power supply application. Beside, the R7521 has fine over power protection. As Figure 3, total power limit is constant, and won't follow Vin variation. Set the ratio of OPP resistive divider to decide the total limit. Total Power Limit vs. VIN 160% FC vs. Load 150% Total Power (%) 1.6 1.4 FC Voltage 1.2 1 0.8 0.6 140% 130% 120% 110% The Total Power Limit is constant. 0.4 100% 180Vac 0.2 230Vac The FC Initial Voltage is 0.543V 0 25% 50% 75% 100% 265Vac VIN Figure 3. Over Power Limit and VIN Relation Curve Load Figure 1. FC Voltage Variation VAC Detecting Protection Over Power Protection DET is connected to secondary winding through a resistive divider for VAC input detecting. When VAC fails, the voltage When ATX power is over power or in output short condition, the R7521 will shut down the controller. As shown in Figure 2, if the over power condition appears, PT voltage exceeds the trigger voltage (1.9V) and exists for 6ms (typical), the PWM output will be latched. of DET is lower than 0.5V, and PG signal will be pulled low to indicate VAC power-down. Set the ratio of resistive divider to decide the DET weight. The bypass capacitor is used to filter the switching noise. + + +12V R1 DET + R2 DET - C 0.5V R7521 Figure 4. VAC Detecting Circuit Figure 2. Over Power Protection Copyright © 2012 Richtek Technology Corporation. All rights reserved. www.richtek.com 10 Downloaded from Arrow.com. is a registered trademark of Richtek Technology Corporation. R7521-00 December 2012 R7521 Thermal Considerations PD(MAX) = (TJ(MAX) − TA) / θJA where TJ(MAX) is the maximum junction temperature, TA is the ambient temperature, and θJA is the junction to ambient thermal resistance. For recommended operating condition specifications, the maximum junction temperature is 125°C. The junction to ambient thermal resistance, θJA, is layout dependent. For SOP-16 package, the thermal resistance, θJA, is 108.6°C/ 2.0 Maximum Power Dissipation (W)1 For continuous operation, do not exceed absolute maximum junction temperature. The maximum power dissipation depends on the thermal resistance of the IC package, PCB layout, rate of surrounding airflow, and difference between junction and ambient temperature. The maximum power dissipation can be calculated by the following formula : Four-Layer PCB 1.6 DIP-16 1.2 0.8 SOP-16 0.4 0.0 0 25 50 75 100 125 Ambient Temperature (°C) Figure 5. Derating Curve of Maximum Power Dissipation W on a standard JEDEC 51-7 four-layer thermal test board. For DIP-16 package, the thermal resistance, θJA, is 59.6°C/ W on a standard JEDEC 51-7 four-layer thermal test board. The maximum power dissipation at TA = 25°C can be calculated by the following formula : PD(MAX) = (125°C − 25°C) / (108.6°C/W) = 0.92W for SOP-16 package PD(MAX) = (125°C − 25°C) / (59.6°C/W) = 1.68W for DIP-16 package The maximum power dissipation depends on the operating ambient temperature for fixed T J(MAX) and thermal resistance, θJA. The derating curve in Figure 5 allows the designer to see the effect of rising ambient temperature on the maximum power dissipation. Copyright © 2012 Richtek Technology Corporation. All rights reserved. R7521-00 December 2012 Downloaded from Arrow.com. is a registered trademark of Richtek Technology Corporation. www.richtek.com 11 R7521 Outline Dimension H A M B J F C I D Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 9.804 10.008 0.386 0.394 B 3.810 3.988 0.150 0.157 C 1.346 1.753 0.053 0.069 D 0.330 0.508 0.013 0.020 F 1.194 1.346 0.047 0.053 H 0.178 0.254 0.007 0.010 I 0.102 0.254 0.004 0.010 J 5.791 6.198 0.228 0.244 M 0.406 1.270 0.016 0.050 16–Lead SOP Plastic Package Copyright © 2012 Richtek Technology Corporation. All rights reserved. www.richtek.com 12 Downloaded from Arrow.com. is a registered trademark of Richtek Technology Corporation. R7521-00 December 2012 R7521 Dimensions In Millimeters Symbol Dimensions In Inches Min Max Min Max A 3.700 4.320 0.146 0.170 A1 0.381 0.710 0.015 0.028 A2 3.200 3.600 0.126 0.142 b 0.360 0.560 0.014 0.022 b1 1.143 1.778 0.045 0.070 D 18.800 19.300 0.740 0.760 E 6.200 6.600 0.244 0.260 E1 7.620 8.255 0.300 0.325 e L 2.540 3.000 0.100 3.600 0.118 0.142 16-Lead DIP Plastic Package Richtek Technology Corporation 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries. R7521-00 December 2012 Downloaded from Arrow.com. www.richtek.com 13