EP5368QI 600mA Synchronous Buck Regulator with Integrated Inductor RoHS Compliant; Halogen Free Description Features The EP5368QI is a synchronous buck converter with integrated Inductor, PWM controller, MOSFETS, and Compensation providing the smallest possible solution size. The EP5368QI requires only two small MLCC capacitors to make a complete solution. Integration of the inductor greatly simplifies design, contains noise, reduces part count, and reduces solution footprint. Low output ripple ensures compatibility with RF systems. * * * * * * * * * * * * * * * The EP5368QI operates at a switching frequency of 4 MHz, enabling this unprecedented level of integration and small external components. Type III voltage mode control is used to provide high noise immunity and wide control loop bandwidth. The device can source 600mA of current over the industrial temperature range and up to 700mA over the commercial temperature range. The small footprint makes this part ideal for space constrained applications. Output voltage is programmed via a 3-pin VID selector providing seven pre-programmed output voltages along with an option for external resistor divider. Integrated Inductor 3mm x 3mm x 1.1mm QFN package Only two low cost MLCC caps required 4 MHz switching frequency High efficiency, up to 94% Up to 700mA continuous output current Wide 2.4V to 5.5V input range VOUT Range 0.603V to VIN - 0.4V 100% duty cycle capable Less than 1 A standby current Low VOUT ripple for RF compatibility Short circuit and over current protection UVLO and thermal protection Stable over entire operating range RoHS compliant; MSL 3 260C reflow Application * * * * * Noise sensitive RF applications Area constrained applications Smart phones and PDAs Personal Media Players Advanced Mobile Processors, DSP, IO, Memory, Video, Multimedia Engines VSense ENABLE VIN Vin 4.7F 0603 VOUT Vout 22F 0805 EP5368QI VFB Voltage Select Figure 1: Features INTEGRATED INDUCTOR TECHNOLOGY VS0 V S1 VS2 GND Figure 2: Typical Application Schematic www.enpirion.com 03260 09/23/2010 Rev: F EP5368QI Ordering Information Pin Assignments (Top View) Temp Rating (C) Package -40 to +85 16-pin QFN T&R EP5368QI Evaluation Board Part Number EP5368QI EP5368QI-E Figure 3: Pin Out Diagram (Top View) Pin Description PIN NAME FUNCTION 1, 3, 9, 15, 16 NC NO CONNECT - These pins should not be electrically connected to each other or to any external signal, voltage, or ground. One or more of these pins may be connected internally. These pins must be soldered to the PCB. 2 PGND Power Ground Feed back pin for external divider option. When using the external divider option (VS0=VS1=VS2= high) connect this pin to the center of the external divider. Set the divider such that VFB = 0.6V. The "ground" side of the external divider should be connected to AGND. 4 VFB 5 VSENSE Sense pin for preset output voltages. Connect this to VOUT or as close to VOUT as possible to ensure the best regulation. 6 AGND Analog ground. This is the quiet ground for the internal control circuitry. 7, 8 VOUT 10, 11, 12 VS0, VS1, VS2 Output voltage select. VS2=pin10 VS1=pin11, VS0=pin12. Selects one of seven preset output voltages or choose external divider by connecting pins to logic high or low. Logic low is defined as VLOW 0.4V. Logic high is defined as VHIGH 1.4V. Any level between these two values is indeterminate. (Refer to section on output voltage select for more detail). 13 ENABLE Output enable: Enable = logic high, disable = logic low. Logic low is defined as VLOW 0.4V. Logic high is defined as VHIGH 1.4V. Any level between these two values is indeterminate. 14 VIN Regulated Output Voltage Input voltage pin. Supplies power to the IC. Enpirion 2010 all rights reserved, E&OE 03260 2 09/23/2010 www.enpirion.com Rev: F EP5368QI Absolute Maximum Ratings CAUTION: Absolute Maximum ratings are stress ratings only. Functional operation beyond the recommended operating conditions is not implied. Stress beyond the absolute maximum ratings may cause permanent damage to the device. Exposure to absolute maximum rated conditions for extended periods may affect device reliability. PARAMETER SYMBOL MIN MAX UNITS VIN -0.3 7.0 V Voltages on: ENABLE, VSENSE, VS0 - VS2 -0.3 VIN +0.3 V Voltage on: VFB -0.3 2.7 V -65 150 C Reflow Temp, 10 Sec, MSL3 JEDEC J-STD-020C 260 C ESD Rating (based on Human Body Mode) 2000 V Input Supply Voltage Storage Temperature Range TSTG Recommended Operating Conditions PARAMETER SYMBOL MIN MAX UNITS Input Supply Voltage VIN 2.4 5.5 V Operating Ambient Temperature TA - 40 85 C Operating Junction Temperature TJ - 40 125 C SYMBOL TYP UNITS JA 85 C/W TJ-TP 150 C 15 C Thermal Characteristics PARAMETER Thermal Resistance: Junction to Ambient (0 LFM) Thermal Overload Trip Point Thermal Overload Trip Point Hysteresis Enpirion 2010 all rights reserved, E&OE 03260 3 09/23/2010 www.enpirion.com Rev: F EP5368QI Electrical Characteristics NOTE: TA = -40C to +85C unless otherwise noted. Typical values are at TA = 25C, V IN = 3.6V CIN = 4.7F 0603 MLCC, COUT = 22F 0805 MLCC PARAMETER SYMBOL Operating Input Voltage Range VIN Under Voltage Lock-out - VIN Rising VUVLO_R Under Voltage Lock-out - VIN Falling VUVLO_F Drop Out Resistance RDO Input to Output Resistance in 100% duty cycle operation. Output Voltage Range VOUT External Feedback Mode VID Mode Dynamic Voltage Slew Rate (VID Change) VSLEW VOUT Initial Accuracy (VID Preset Mode) VOUT_INITIAL TA = 25C, VIN = 3.6V; ILOAD = 100mA ; 0.8V VOUT 3.3V VOUT_ALL -40C TA +85C 2.4V VIN 5.5V; 0.8V VOUT 3.3V 0A ILOAD 700A VFB_INITIAL TA = 25C, VIN = 3.6V; ILOAD = 100mA ; 0.8V VOUT 3.3V 0.591 Feedback Pin Voltage Accuracy over line, load, and temperature variations VFB_ALL -40C TA +85C 2.4V VIN 5.5V; 0.8V VOUT 3.3V 0A ILOAD 700A 0.585 Feedback Pin Input Current IFB Continuous Output Current IOUT VIN = 5V, 0.603V <VOUT < 3.3V, TA = -40C to +85C 600 mA Continuous Output Current IOUT VIN = 5V, 0.603V <VOUT < 3.3V, TA = -10C to +85C (Application Circuit Figure 6) 700 mA Shut-Down Current ISD Enable = Low PFET OCP Threshold IILM 2.4V VIN 5.5V, 0.6V VIN 3.3V 1.4 VS0-VS2, Enable Voltage Threshold VTH Pin = Low 0.0 0.4 Pin = High 1.4 VIN VS0-VS2 Pin Input Current IVSX 1 nA Operating Frequency FOSC 4 MHz VOUT Accuracy (VID Preset Mode) over line, load and temperature variation Feedback Pin Voltage Initial Accuracy TEST CONDITIONS MIN TYP MAX UNITS 5.5 V 2.2 2.3 V 2.1 2.2 V 400 500 m 2.4 0.603 0.8 0.975 VIN-VDO 3.3 1.5 V 2.025 V/mS -2 +2 % -3 +3 % .603 0.615 V .603 0.621 V 100 nA 0.75 A 2 A Soft Start Operation Soft-Start Slew Rate VSS VID programming mode 0.975 1.5 2.025 V/mS VOUT Rise Time TSS VFB programming mode 0.784 1.2 1.628 mS Enpirion 2010 all rights reserved, E&OE 03260 4 09/23/2010 www.enpirion.com Rev: F EP5368QI 100 100 95 95 90 90 85 85 Efficiency (%) Efficiency (%) Typical Performance Characteristics 80 75 70 80 75 70 65 65 60 60 55 55 50 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 50 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 Load Current (A) Load Current (A) Efficiency Versus Load; VIN = 3.3V, VOUT (from top to bottom) 2.5V, 1.8V, 1.5V, 1.2V. Efficiency Versus Load; VIN = 3.7V, VOUT (from top to bottom) 2.5V, 1.8V, 1.5V, 1.2V. 100 95 90 Efficiency (%) 85 80 75 70 65 60 55 50 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 Load Current (A) Efficiency Versus Load; VIN = 5V, VOUT (from top to bottom) 3.3V, 2.5V, 1.8V, 1.5V, 1.2V. Transient, VIN = 3.6V, VOUT = 1.2V, Load = 0-500mA Startup, VIN = 3.6V, VOUT = 1.5V, Load = 500mA Shutdown, VIN = 3.6V, VOUT = 1.5V, Load = 500mA Enpirion 2010 all rights reserved, E&OE 03260 5 09/23/2010 www.enpirion.com Rev: F EP5368QI Voltage Ripple, VIN = 3.3V, VOUT = 1.8V, Load = 0mA COUT = 1x 22 F, 0805, 2.0mV/Div. Voltage Ripple, VIN = 3.3V, VOUT = 1.8V, Load = 600mA F, 0805, 2.0mV/Div. COUT = 1x 22 Voltage Ripple, VIN = 3.3V, VOUT = 1.8V, Load = 0mA F, 0805, 2.0mV/Div. COUT = 2x 10 Voltage Ripple, VIN = 3.3V, VOUT = 1.8V, Load = 600mA COUT = 2x 10 F, 0805, 2.0mV/Div. Enpirion 2010 all rights reserved, E&OE 03260 6 09/23/2010 www.enpirion.com Rev: F EP5368QI Functional Block Diagram VIN UVLO Thermal Limit Current Limit ENABLE NC(SW) Soft Start P-Drive (-) Logic VOUT PWM Comp (+) N-Drive GND VSENSE Sawtooth Generator Compensation Network (-) Switch Error Amp VFB (+) DAC Voltage Select VREF Package Boundry VS0 VS1 VS2 Figure 4: Functional Block Diagram Enpirion 2010 all rights reserved, E&OE 03260 7 09/23/2010 www.enpirion.com Rev: F EP5368QI Detailed Description Functional Overview The EP5368QI is a complete DCDC converter solution requiring only two low cost MLCC capacitors. MOSFET switches, PWM controller, Gate-drive, compensation, and inductor are integrated into the tiny 3mm x 3mm x 1.1mm package to provide the smallest footprint possible while maintaining high efficiency, low ripple, and high performance. The converter uses voltage mode control to provide the simplest implementation and high noise immunity. The device operates at a 4MHz switching frequency. The high switching frequency allows for a wide control loop bandwidth providing excellent transient performance. The high switching frequency further enables the use of very small components making possible this unprecedented level of integration. Enpirion's proprietary power MOSFET technology provides very low switching loss at frequencies of 4 MHz and higher, allowing for the use of very small internal components, and high performance. Integration of the magnetics virtually eliminates the design/layout issues normally associated with switch-mode DCDC converters. All of this enables much easier and faster incorporation into various applications to meet demanding EMI requirements. Output voltage is chosen from seven preset values via a three pin VID voltage select scheme. An external divider option enables the selection of any voltage in VIN to 0.603V range. This reduces the number of components that must be qualified and reduces inventory burden. The VID pins can be toggled on the fly to implement glitch free dynamic voltage scaling. Protection features include under-voltage lockout (UVLO), over-current protection (OCP), short circuit protection, and thermal overload protection. Integrated Inductor product family featuring integrated inductors. The EP5368QI utilizes a proprietary low loss integrated inductor. The use of an internal inductor localizes the noises associated with the output loop currents. The inherent shielding and compact construction of the integrated inductor reduces the radiated noise that couples into the traces of the circuit board. Further, the package layout is optimized to reduce the electrical path length for the AC ripple currents that are a major source of radiated emissions from DCDC converters. The integrated inductor significantly reduces parasitic effects that can harm loop stability, and makes layout very simple. Stable Over Wide Range of Operating Conditions The EP5368QI utilizes an internal type III compensation network and is designed to provide a high degree of stability over a wide range of operating conditions. The device operates over the entire input and output voltage range with no external modifications required. The very high switching frequency allows for a very wide control loop bandwidth. Soft Start Internal soft start circuits limit in-rush current when the device starts up from a power down condition or when the "ENABLE" pin is asserted "high". Digital control circuitry limits the VOUT ramp rate to levels that are safe for the Power MOSFETS and the integrated inductor. The EP5368QI has two soft start operating modes. When VOUT is programmed using a preset voltage in VID mode, the device has a constant slew rate. When the EP5368QI is configured in external resistor divider mode, the device has a constant VOUT ramp time. Output voltage slew rate and ramp time is given in the Electrical Characteristics Table. Excess bulk capacitance on the output of the device can cause an over-current condition at startup. Enpirion has introduced the world's first Enpirion 2010 all rights reserved, E&OE 03260 8 09/23/2010 www.enpirion.com Rev: F EP5368QI When operating in VID mode, the maximum total capacitance on the output, including the output filter capacitor and bulk and decoupling capacitance, at the load, is given as: COUT_TOTAL_MAX = COUT_Filter + COUT_BULK = 700uF When the EP5368QI output voltage is programmed using and external resistor divider the maximum total capacitance on the output is given as: -3 COUT_TOTAL_MAX = 1.251x10 /VOUT Farads The above number and formula assume a no load condition at startup. Over Current/Short Circuit Protection The current limit function is achieved by sensing the current flowing through a sense PMOSFET which is compared to a reference current. When this level is exceeded the PFET is turned off and the N-FET is turned on, pulling VOUT low. This condition is maintained for a period of 1mS and then a normal soft start is initiated. If the over current condition still persists, this cycle will repeat in a "hiccup" mode. Under Voltage Lockout During initial power up an under voltage lockout circuit will hold-off the switching circuitry until the input voltage reaches a sufficient level to insure proper operation. If the voltage drops below the UVLO threshold, the lockout circuitry will again disable the switching. Hysteresis is included to prevent chattering between states. Enable The ENABLE pin provides a means to shut down the converter or enable normal operation. A logic low will disable the converter and cause it to shut down. A logic high will enable the converter into normal operation. In shutdown mode, the device quiescent current will be less than 1 uA. NOTE: This pin must not be left floating. Thermal Shutdown When excessive power is dissipated in the chip, the junction temperature rises. Once the junction temperature exceeds the thermal shutdown temperature the thermal shutdown circuit turns off the converter output voltage thus allowing the device to cool. When the junction temperature decreases by 15C, the device will go through the normal startup process. Application Information Output Voltage Select To provide the highest degree of flexibility in choosing output voltage, the EP5368QI uses a 3 pin VID, or Voltage ID, output voltage select arrangement. This allows the designer to choose one of seven preset voltages, or to use an external voltage divider. Internally, the output of the VID multiplexer sets the value for the voltage reference DAC, which in turn is connected to the non-inverting input of the error amplifier. This allows the use of a single feedback divider with constant loop gain and optimum compensation, independent of the output voltage selected. Enpirion 2010 all rights reserved, E&OE 03260 Table 1 shows the various VS0-VS2 pin logic states and the associated output voltage levels. A logic "1" indicates a connection to VIN or to a "high" logic voltage level. A logic "0" indicates a connection to ground or to a "low" logic voltage level. These pins can be either hardwired to VIN or GND or alternatively can be driven by standard logic levels. Logic low is defined as VLOW 0.4V. Logic high is defined as VHIGH 1.4V. Any level between these two values is indeterminate. These pins must not be left floating. 9 09/23/2010 www.enpirion.com Rev: F EP5368QI Dynamically Adjustable Output Table 1 VID Voltage Select Settings VS2 0 0 0 0 1 1 1 VS1 0 0 1 1 0 0 1 VS0 0 1 0 1 0 1 0 1 1 1 VOUT 3.3V 2.5V 1.8V 1.5V 1.25V 1.2V 0.8V User Selectable As described above, the external voltage divider option is chosen by connecting the VS0, VS1, and VS2 pins to VIN or logic "high". The EP5368QI uses a separate feedback pin, VFB, when using the external divider. VSENSE must be connected to VOUT as indicated in Figure 5. VSense ENABLE Vin 4.7uF 0603 VOUT Vout Ra EP5368QI VS2 22F 0805 VFB VS0 VS1 Rb GND Figure 5: External Divider Application Circuit The output voltage is selected by the following formula: VOUT = 0.603V (1 + Ra Rb ) Ra must be chosen as 200k to maintain loop gain. Then Rb is given as: Rb = 1.206 x10 5 VOUT - 0.603 VOUT can programmed over the range of 0.603V to VIN-0.4V. Enpirion 2010 all rights reserved, E&OE 03260 Dynamic transitioning between internal VID settings and the external divider is not allowed. Input and Output Capacitors External Voltage Divider VIN The EP5368QI is designed to allow for dynamic switching between the predefined VID voltage levels The inter-voltage slew rate is optimized to prevent excess undershoot or overshoot as the output voltage levels transition. The slew rate is identical to the softstart slew rate and is provided in the electrical characteristics table. The input capacitance requirement is 4.7uF 0603 MLCC. The input capacitor must be a X5R/X7R MLCC. Y5V or equivalent dielectric formulations lose capacitance with frequency, bias, and with temperature, and are not suitable for switch-mode DC-DC converter input filter applications. The output capacitance requirement is approximately 20uF. Enpirion recommends a single 22uF 0805 MLCC. Ripple performance can be improved by using 2 x 10uF 0805 MLC capacitors. As described in the Soft Start section, there is a limitation on the maximum bulk capacitance that can be placed on the output of this device. Please refer to that section for more details. The output capacitor must be a X5R/X7R or equivalent MLCC. Y5V or equivalent dielectric formulations lose capacitance with frequency, bias, and temperature and are not suitable for switch-mode DC-DC converter output filter applications. Please consult Enpirion Applications Support for other capacitor case size combinations. Operation at 700mA Output Current Operation at 700mA is supported by using the application circuit shown in Figure 6. The modification in the compensation is to ensure stability over the entire set of input and output voltage conditions. 10 09/23/2010 www.enpirion.com Rev: F EP5368QI VIN Vin 4.7uF 0603 VOUT Vout Ra EP5368QI Ca 22F 0805 2) Ca = 15pF 0402 MLCC capacitor. 3) Then Rb is given as: Rb = VFB VS0 VS1 VS2 1) Ra = 249k VSense ENABLE Rb GND 1.501x10 5 VOUT - 0.603 VOUT can be programmed over the range of 0.603V to VIN-0.4V. 4) Do not connect the sense line. Figure 6: Applications Circuit for Operation at 700mA For 700mA operation, use component values: NOTE: Stability cannot be assured if these guidelines are not followed. the following Recommended PCB Footprint Figure 7: EP5368QI Package PCB Footprint Enpirion 2010 all rights reserved, E&OE 03260 11 09/23/2010 www.enpirion.com Rev: F EP5368QI Package Dimensions Figure 8: EP5368QI Package Dimensions NOTE: for details on product marking, please refer to the product marking guide which can be found on the Enpirion Website WWW.ENPIRION.COM Contact Information Enpirion, Inc. Perryville III 53 Frontage Road Suite 210 Hampton, NJ 08827 Phone: +1 908-894-6000 Fax: +1 908-894-6090 Enpirion reserves the right to make changes in circuit design and/or specifications at any time without notice. Information furnished by Enpirion is believed to be accurate and reliable. Enpirion assumes no responsibility for its use or for infringement of patents or other third party rights, which may result from its use. Enpirion products are not authorized for use in nuclear control systems, as critical components in life support systems or equipment used in hazardous environment without the express written authority from Enpirion. Enpirion 2010 all rights reserved, E&OE 03260 12 09/23/2010 www.enpirion.com Rev: F Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Altera: EP5368QI-E EVB-EP5368QI