Enpirion(R) Power Datasheet EN5367QI 6A PowerSoC Highly Integrated Synchronous Buck With Integrated Inductor Description Features The EN5367QI is a Power System on a Chip (PowerSoC) DC to DC converter with an integrated inductor, PWM controller, MOSFETs and compensation to provide the smallest solution size in a 5.5x10x3mm 54-pin QFN module. It offers high efficiency, excellent line and load regulation over temperature and up to the full 6A load range. The EN5367QI is specifically designed to meet the precise voltage and fast transient requirements of high-performance, low-power processor, DSP, FPGA, memory boards and system level applications in distributed power architecture. The EN5367QI also features switching frequency synchronization with an external clock, programmable soft-start as well as thermal shutdown, over-current and short circuit protection. The device's advanced circuit techniques, ultra high switching frequency, and proprietary integrated inductor technology deliver high-quality, ultra compact, non-isolated DC-DC conversion. The Altera Enpirion integrated inductor solution significantly helps to reduce noise. The complete power converter solution enhances productivity by offering greatly simplified board design, layout and manufacturing requirements. All Altera Enpirion products are RoHS compliant and lead-free manufacturing environment compatible. * * * * * * * * * * 0.1F High Efficiency (Up to 93%) Excellent Ripple and EMI Performance Up to 6A Continuous Operating Current Input Voltage Range (2.5V to 5.5V) Frequency Synchronization (External Clock) 3% VOUT Accuracy (Over Line/Load/Temperature) Optimized Total Solution Size (160mm2) Programmable Soft-Start Output Enable Pin and Power OK Thermal Shutdown, Over-Current, Short Circuit, and Under-Voltage Lockout Protection (UVLO) * RoHS Compliant, MSL Level 3, 260C Reflow Applications * Point of Load Regulation for Low-Power, ASICs Multi-Core and Communication Processors, DSPs, FPGAs and Distributed Power Architectures * Blade Servers, RAID Storage and LAN/SAN Adapter Cards, Wireless Base Stations, Industrial Automation, Test and Measurement, Embedded Computing, and Printers * Beat Frequency/Noise Sensitive Applications 0.1F Efficiency vs. Output Current 100 BTMP PG VDDB BGND PVIN 10 47F 1206 VOUT EN5367QI 80 47F 1206 RA CA AVIN 47nF 0805 ENABLE 0.1F VFB RCA SS PGND AGND SYNC 70 60 Actual Solution Size 160mm2 CONDITIONS VIN = 5.0V 50 40 30 VOUT = 3.3V 20 PGND 47nF 90 VOUT EFFICIENCY (%) VIN RB VOUT = 1.2V 10 0 0 Figure 1. Simplified Applications Circuit 1 2 3 4 OUTPUT CURRENT (A) 5 6 Figure 2. Highest Efficiency in Smallest Solution Size www.altera.com/enpirion 07013 October 11, 2013 Rev D EN5367QI Ordering Information Part Number Package Markings Temp Rating (C) Package Description EN5367QI EN5367QI -40 to +85 54-pin (5.5mm x 10mm x 3mm) QFN T&R EN5367QI QFN Evaluation Board EVB-EN5367QI Packing and Marking Information: www.altera.com/support/reliability/packing/rel-packing-and-marking.html NC 1 NC VFB SS NC 44 43 42 NC NC 45 ENABLE AGND 46 37 AVIN 47 POK NC 48 39 NC(SW) 49 38 NC(SW) 50 NC NC(SW) 51 40 NC(SW) 52 EAOUT NC 53 41 NC 54 Pin Assignments (Top View) 36 SYNC 2 35 BGND NC 3 34 VDDB NC 4 33 BTMP NC 5 32 PG NC 6 31 PVIN NC 7 30 PVIN NC 8 29 PVIN NC 9 28 PVIN KEEP OUT KEEP OUT 55 PGND 14 15 16 17 18 19 20 21 22 23 24 25 26 27 VOUT VOUT VOUT VOUT NC NC(SW) NC(SW) PGND PGND PGND PGND PGND PGND PGND 12 VOUT 13 11 VOUT VOUT 10 VOUT KEEP OUT Figure 3: Pin Out Diagram (Top View) NOTE A: NC pins are not to be electrically connected to each other or to any external signal, ground, or voltage. However, they must be soldered to the PCB. Failure to follow this guideline may result in part malfunction or damage. NOTE B: Shaded area highlights exposed metal below the package that is not to be mechanically or electrically connected to the PCB. Refer to Figure 9 for details. NOTE C: White `dot' on top left is pin 1 indicator on top of the device package. Pin Description PIN NAME 1-9, 18, 37, 40, 42, 45, 48, 53-54 NC 10-17 VOUT 19-20, 49-52 NC(SW) 21-27 PGND 28-31 PVIN 32 PG FUNCTION NO CONNECT - These pins may be internally connected. Do not connect them to each other or to any other electrical signal. Failure to follow this guideline may result in device damage. Regulated converter output. Connect these pins to the load and place output capacitor between these pins and PGND pins 21-24. NO CONNECT - These pins are internally connected to the common switching node of the internal MOSFETs. They are not to be electrically connected to any external signal, ground, or voltage. Failure to follow this guideline may result in damage to the device. Input/Output power ground. Connect these pins to the ground electrode of the input and output filter capacitors. See VOUT and PVIN pin descriptions for more details. Input power supply. Connect to input power supply. Decouple with input capacitor to PGND pins 25-27. High-side FET gate. This pin needs to be connected to BTMP using a 0.1F capacitor. 2 07013 October 11, 2013 www.altera.com/enpirion Rev D EN5367QI PIN NAME 33 BTMP 34 VDDB 35 BGND 36 SYNC 38 ENABLE 39 POK 41 EAOUT 43 SS 44 VFB 46 AGND 47 AVIN 55 PGND FUNCTION Low side of the flying capacitor that drives the high-side FET gate. Connect to PG using a 0.1F capacitor. Regulated voltage used for internal control circuitry. Decouple with a 0.1F capacitor to BGND. Internal GND for VDDB. Connect to VDDB using a 0.1F capacitor. Do not tie to any grounds on the PCB. A clocked input to this pin will synchronize the internal switching frequency to the external signal. If the SYNC function is not to be used, this pin has to be grounded. Do not float this pin or tie it to a static high voltage. Input Enable. Applying a logic high enables the output and initiates a soft-start. Applying a logic low disables the output. Power OK is an open drain transistor used for power system state indication. POK is logic high when VOUT is within -10% of VOUT nominal. Optional Error Amplifier output. Allows for customization of the control loop. Soft-Start node. The soft-start capacitor is connected between this pin and AGND. The value of this capacitor determines the startup time. External Feedback Input. The feedback loop is closed through this pin. A voltage divider at VOUT is used to set the output voltage. The midpoint of the divider is connected to VFB. A phase lead capacitor from this pin to VOUT is also required to stabilize the loop. Analog Ground. This is the Ground return for the controller. Needs to be connected to the GND plane using a via right next to the pin. Input power supply for the controller. Needs to be decoupled to AGND with a 0.1F capacitor and connected to the input voltage at a quiet point through a 10 resistor. Not a perimeter pin. Device thermal pad to be connected to the system GND plane for heat sinking purposes through a matrix of vias. 3 07013 October 11, 2013 www.altera.com/enpirion Rev D EN5367QI 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 impair device life. Exposure to absolute maximum rated conditions for extended periods may affect device reliability. PARAMETER SYMBOL MIN MAX UNITS Voltages on : PVIN, AVIN, VOUT -0.3 6.5 V Voltages on: ENABLE, POK, SYNC -0.3 VIN+0.3 V Voltages on: VFB, SS -0.3 2.75 V -65 150 C 150 C Reflow Temp, 10 Sec, MSL3 JEDEC J-STD-020A 260 C ESD Rating (based on Human Body Model) 2000 V ESD Rating (based on CDM) 500 V Storage Temperature Range TSTG Maximum Operating Junction Temperature TJ-ABS Max Recommended Operating Conditions PARAMETER SYMBOL MIN MAX UNITS VIN 2.5 5.5 V Output Voltage Range (Note 1) VOUT 0.60 VIN - VDO V Output Current IOUT 6 A Input Voltage Range Operating Ambient Temperature TA -40 +85 C Operating Junction Temperature TJ -40 +125 C Thermal Characteristics SYMBOL TYP UNITS Thermal Resistance: Junction to Ambient (0 LFM) (Note 2) PARAMETER JA 22 C/W Thermal Resistance: Junction to Case (0 LFM) JC 2 C/W Thermal Shutdown TSD 150 C Thermal Shutdown Hysteresis TSDH 20 C Note 1: VDO (Dropout Voltage) is defined as (ILOAD x Dropout Resistance). Please refer to Electrical Characteristics Table. Note 2: Based on 2oz. external copper layers and proper thermal design in line with EIJ/JEDEC JESD51-7 standard for high thermal conductivity boards. 4 07013 October 11, 2013 www.altera.com/enpirion Rev D EN5367QI Electrical Characteristics NOTE: VIN=5.5V, Minimum and Maximum values are over operating ambient temperature range unless otherwise noted. Typical values are at TA = 25C. PARAMETER SYMBOL Operating Input Voltage VIN TEST CONDITIONS MIN TYP 2.5 MAX UNITS 5.5 V Under Voltage LockVUVLOR out - VIN Rising Voltage above which UVLO is not asserted 2.25 V Under Voltage LockVUVLOF out - VIN Falling Voltage below which UVLO is asserted 2.05 V Shut-Down Supply Current IS ENABLE=0V 100 A Feedback Pin Voltage VFB Feedback Pin Voltage VFB Feedback pin Input Leakage Current (Note 3) IFB VFB pin input leakage current VOUT Rise Time (Note 3) tRISE Measured from when VIN > VUVLOR & ENABLE pin voltage crosses its logic high threshold to when VOUT reaches its final value. CSS = 47 nF Soft Start Capacitor Range CSS_RANGE Output Drop Out Voltage Resistance (Note 3) VDO RDO Continuous Output Current IOUT_Max_Cont Over Current Trip Level IOCP VIN = 5V, VOUT = 1.2V Disable Threshold VDISABLE ENABLE pin logic low. 0.0 0.6 V ENABLE Threshold VENABLE ENABLE pin logic high 2.5V VIN 5.5V 1.8 VIN V ENABLE Lockout Time TENLOCKOUT ENABLE pin Input Current IENABLE Switching Frequency (Free Running) Feedback node voltage at: VIN = 5V, ILOAD = 0, TA = 25C Feedback node voltage at: 2.5V VIN 5.5V 0A ILOAD 6A 0.735 0.75 0.765 V 0.7275 0.75 0.7725 V 5 nA 4.70 ms 68 nF 600 100 mV m 6 A -5 2.82 3.76 10 VINMIN - VOUT at Full load Input to Output Resistance 300 50 0 9 A 2.4 ms ENABLE pin has ~180k pull down 30 A FSW Free Running frequency of oscillator 4 MHz External SYNC Clock Frequency Lock Range FPLL_LOCK Range of SYNC clock frequency SYNC Pin Threshold - Lo VSYNC_LO SYNC Clock Logic Level SYNC Pin Threshold - Hi VSYNC_HI SYNC Clock Logic Level (Note 4) 5 07013 October 11, 2013 3.2 1.8 4.2 MHz 0.8 V 2.5 V www.altera.com/enpirion Rev D EN5367QI PARAMETER SYMBOL POK Threshold POKT Output voltage as a fraction of expected output voltage POK Output low Voltage VPOKL With 1mA current sink into POK 0.4 V POK Output Hi Voltage VPOKH 2.5V VIN 5.5V VIN V POK pin VOH leakage current (Note 3) IPOK POK high 1 A SYNC Pin Current TEST CONDITIONS SYNC Pin is <2.5V MIN TYP MAX 90 <100 UNITS % nA Note 3: Parameter not production tested but is guaranteed by design. Note 4: For proper operation of the SYNC circuit, the high-level amplitude of the SYNC signal should not be above 2.5V. 6 07013 October 11, 2013 www.altera.com/enpirion Rev D EN5367QI Typical Performance Curves Efficiency vs. Output Current 100 90 90 80 80 EFFICIENCY (%) EFFICIENCY (%) Efficiency vs. Output Current 100 70 60 VOUT = 2.5V 50 VOUT = 1.8V 40 30 VOUT = 1.2V 20 VOUT = 1.0V 10 CONDITIONS VIN = 3.3V 70 60 VOUT = 3.3V 50 VOUT = 2.5V 40 30 VOUT = 1.8V 20 VOUT = 1.2V 10 VOUT = 1.0V 0 0 0 1 2 3 4 OUTPUT CURRENT (A) 5 0 6 1.215 VOUT = 1.0V OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 2 3 4 OUTPUT CURRENT (A) 5 6 1.220 1.015 1.010 1.005 1.000 0.995 0.990 CONDITIONS VIN = 3.3V 0.985 VOUT = 1.2V 1.210 1.205 1.200 1.195 1.190 CONDITIONS VIN = 3.3V 1.185 1.180 0.980 0 1 2 3 4 OUTPUT CURRENT (A) 5 0 6 Output Voltage vs. Output Current 1 2 3 4 OUTPUT CURRENT (A) 5 6 Output Voltage vs. Output Current 1.820 2.520 1.815 2.515 VOUT = 1.8V OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1 Output Voltage vs. Output Current Output Voltage vs. Output Current 1.020 1.810 1.805 1.800 1.795 1.790 CONDITIONS VIN = 3.3V 1.785 VOUT = 2.5V 2.510 2.505 2.500 2.495 2.490 CONDITIONS VIN = 3.3V 2.485 1.780 2.480 0 1 2 3 4 OUTPUT CURRENT (A) 5 6 0 7 07013 CONDITIONS VIN = 5.0V October 11, 2013 1 2 3 4 OUTPUT CURRENT (A) 5 6 www.altera.com/enpirion Rev D EN5367QI Typical Performance Curves (Continued) Output Voltage vs. Output Current Output Voltage vs. Output Current 1.820 1.015 1.815 VOUT = 1.0V OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1.020 1.010 1.005 1.000 0.995 0.990 CONDITIONS VIN = 5.0V 0.985 1.805 1.800 1.795 1.790 1.780 0 1 2 3 4 OUTPUT CURRENT (A) 5 6 0 2 3 4 OUTPUT CURRENT (A) 5 6 3.320 2.515 3.315 VOUT = 2.5V OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1 Output Voltage vs. Output Current Output Voltage vs. Output Current 2.520 2.510 2.505 2.500 2.495 2.490 CONDITIONS VIN = 5.0V 2.485 VOUT = 3.3V 3.310 3.305 3.300 3.295 3.290 CONDITIONS VIN = 5.0V 3.285 3.280 2.480 0 1 2 3 4 OUTPUT CURRENT (A) 5 6 0 1 2 3 4 OUTPUT CURRENT (A) 5 6 Output Voltage vs. Input Voltage Output Voltage vs. Input Voltage 1.020 1.820 LOAD = 0A 1.015 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) CONDITIONS VIN = 5.0V 1.785 0.980 LOAD = 2A 1.010 LOAD = 4A LOAD = 6A 1.005 1.000 0.995 0.990 CONDITIONS TA = 25 C VOUT_NOM = 1.0V 0.985 LOAD = 0A 1.815 LOAD = 2A 1.810 LOAD = 4A LOAD = 6A 1.805 1.800 1.795 1.790 CONDITIONS TA = 25 C VOUT_NOM = 1.8V 1.785 1.780 0.980 2.5 3 3.5 4 4.5 INPUT VOLTAGE (V) 5 2.5 5.5 8 07013 VOUT = 1.8V 1.810 October 11, 2013 3 3.5 4 4.5 INPUT VOLTAGE (V) 5 5.5 www.altera.com/enpirion Rev D EN5367QI Typical Performance Curves (Continued) Output Voltage vs. Temperature Output Voltage vs. Temperature 1.820 LOAD = 0.1A 1.815 LOAD = 2A 1.810 LOAD = 4A 1.805 LOAD = 6A CONDITIONS VIN = 3.3V VOUT_NOM = 1.8V OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1.820 LOAD = 8A 1.800 1.795 1.790 1.785 LOAD = 0.1A 1.815 LOAD = 2A 1.810 LOAD = 4A 1.805 LOAD = 6A LOAD = 8A 1.800 1.795 1.790 1.785 1.780 1.780 -40 -15 10 35 60 AMBIENT TEMPERATURE ( C) -40 85 Output Voltage vs. Temperature LOAD = 0.1A 1.815 LOAD = 2A 1.810 LOAD = 4A 1.805 LOAD = 6A CONDITIONS VIN = 5.0V VOUT_NOM = 1.8V OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 85 1.820 LOAD = 8A 1.800 1.795 1.790 LOAD = 0.1A 1.815 LOAD = 2A 1.810 LOAD = 4A 1.805 LOAD = 6A CONDITIONS VIN = 5.5V VOUT_NOM = 1.8V LOAD = 8A 1.800 1.795 1.790 1.785 1.785 1.780 1.780 -40 10 35 60 -15 AMBIENT TEMPERATURE ( C) 85 -40 Output Current De-rating 5.500 5.000 4.500 4.000 3.500 3.000 VOUT = 1.8V 2.500 VOUT = 2.5V -15 10 35 60 AMBIENT TEMPERATURE ( C) 85 Output Current De-rating 6.000 MAXIMUM OUTPUT CURRENT (A) MAXIMUM OUTPUT CURRENT (A) -15 10 35 60 AMBIENT TEMPERATURE ( C) Output Voltage vs. Temperature 1.820 CONDITIONS VIN = 3.3V TJMAX = 125 C JA = 22 C/W 5.5x10x3mm QFN No Air Flow 2.000 6.000 5.500 5.000 4.500 4.000 3.500 VOUT = 1.0V 3.000 VOUT = 1.8V VOUT = 2.5V 2.500 VOUT = 3.3V CONDITIONS VIN = 5.0V TJMAX = 125 C JA = 22 C/W 5.5x10x3mm QFN No Air Flow 2.000 55 60 65 70 75 80 AMBIENT TEMPERATURE ( C) 85 55 9 07013 CONDITIONS VIN = 4.3V VOUT_NOM = 1.8V October 11, 2013 60 65 70 75 80 AMBIENT TEMPERATURE ( C) 85 www.altera.com/enpirion Rev D EN5367QI Typical Performance Characteristics Output Ripple at 20MHz Bandwidth Output Ripple at 20MHz Bandwidth VOUT (AC Coupled) VOUT (AC Coupled) CONDITIONS VIN = 3.3V VOUT = 2.5V NO LOAD CIN = 47F (1206) COUT = 47F(1206) + 10F(0805) CONDITIONS VIN = 3.3V VOUT = 2.5V LOAD = 6A CIN = 47F (1206) COUT = 47F(1206) + 10F(0805) Output Ripple at 20MHz Bandwidth Output Ripple at 20MHz Bandwidth VOUT (AC Coupled) VOUT (AC Coupled) CONDITIONS VIN = 5V VOUT = 1V NO LOAD CIN = 47F (1206) COUT = 47F(1206) + 10F(0805) CONDITIONS VIN = 5V VOUT = 1V LOAD = 6A CIN = 47F (1206) COUT = 47F(1206) + 10F(0805) Enable Power Up/Down Enable Power Up/Down ENABLE ENABLE VOUT VOUT POK POK No Load CONDITIONS VIN = 5.5V, VOUT = 3.3V CIN = 47F(1206) + 47nF(0805) COUT = 47F(1206), Css = 47nF Load = 6A CONDITIONS VIN = 5.5V, VOUT = 3.3V CIN = 47F(1206) + 47nF(0805) COUT = 47F(1206), Css = 47nF 10 07013 October 11, 2013 www.altera.com/enpirion Rev D EN5367QI Typical Performance Characteristics (Continued) Load Transient from 0.01 to 6A Load Transient from 0.01 to 6A VOUT (AC Coupled) LOAD VOUT (AC Coupled) CONDITIONS VIN = 5.5V, VOUT = 1.0V CIN = 47F(1206) + 47nF (0805) COUT = 47F (1206) LOAD 11 07013 October 11, 2013 CONDITIONS VIN = 5.5V, VOUT = 3.3V CIN = 47F(1206) + 47nF (0805) COUT = 47F (1206) www.altera.com/enpirion Rev D EN5367QI Functional Block Diagram PG BTMP PVIN UVLO Thermal Limit P-Drive Current Limit NC(SW) VOUT Mode Logic N-Drive (-) PWM Comp (+) SYNC PGND Compensation Network PLL/Sawtooth Generator Regulated Voltage (-) Error Amp (+) ENABLE SS BGND VDDB VFB Power Good Logic POK AVIN Soft Start Voltage Reference Regulated Voltage AGND EAOUT Figure 4: Functional Block Diagram 12 07013 October 11, 2013 www.altera.com/enpirion Rev D EN5367QI Functional Description signal has to be low for at least the ENABLE Lockout Time (2.4ms) in order for the device to respond to a falling edge on this pin. Note that the device should not be enabled into a pre-biased output. Synchronous Buck Converter The EN5367QI is a synchronous, programmable power supply with integrated power MOSFET switches and integrated inductor. The nominal input voltage range is 2.5V to 5.5V. The output voltage is programmed using an external resistor divider network. The control loop is voltage-mode with a type III compensation network. Much of the compensation circuitry is internal to the device. However, a phase lead capacitor is required along with the output voltage feedback resistor divider to complete the type III compensation network. The device uses a low-noise PWM topology. Up to 6A of continuous output current can be drawn from this converter. The 4 MHz switching frequency allows the use of small size input / output capacitors, and realizes a wide loop bandwidth within a small foot print. Pre-Bias Operation The EN5367QI is not designed to be turned on into a pre-biased output voltage. Be sure the output capacitors are not charged or the output of the EN5367QI is not pre-biased when the EN5367QI is first enabled. Frequency Synchronization The power supply has the following protection features: * Over-Current Protection * Thermal Shutdown with Hysteresis. * Under-voltage Lockout The switching frequency of the DC/DC converter can be phase-locked to an external clock source to move unwanted beat frequencies out of band. To avail this feature, the clock source should be connected to the SYNC pin. An activity detector recognizes the presence of an external clock signal and automatically phase-locks the internal oscillator to this external clock. Phase-lock will occur as long as the input clock frequency is in the lock range specified in the Electrical Characteristics Table. If the SYNC function is not to be used, this pin has to be grounded. Do not float this pin or tie it to a static high voltage. Additional Features: Spread Spectrum Mode * * * The external clock frequency may be swept within the SYNC frequency lock range at repetition rates of up to 10 kHz in order to reduce EMI frequency components. Protection Features: Frequency Synchronization (External Clock) Programmable Soft-start Output Enable and Power OK Power Up-Down Sequencing Soft-Start Operation During power-up, ENABLE should not be asserted before PVIN, and PVIN should not be asserted before AVIN. Tying all three pins together meets these requirements. ENABLE can also be tied to AVIN and come up with it, while PVIN can be safely ramped up and down. Alternatively, PVIN can be brought high after AVIN is asserted, and the device can be turned on and off by toggling the ENABLE pin. During Soft-start, the output voltage is ramped up gradually upon start-up. The output rise time is controlled by the choice of soft-start capacitor, which is placed between the SS pin (30) and the AGND pin (32). Rise Time [ms]: T R (Css [nF]* 0.08) 25% where rise time is in ms, and CSS is in nF. During start-up of the converter, the reference voltage to the error amplifier is linearly increased to its final level by an internal current source of approximately 10uA. Typical soft-start rise time is ~3.75ms with a soft-start capacitor of 47nF. The rise time is measured from when VIN > VUVLOR and ENABLE pin voltage crosses its logic high threshold, to when VOUT reaches its programmed value. Enable Operation The ENABLE pin provides a means to enable normal operation or to shut down the device. A logic high will enable the converter into normal operation. When the ENABLE pin is asserted (high) the device will undergo a normal soft start. A logic low will disable the converter. A logic low will power down the device in a controlled manner and the device is subsequently shut down. The ENABLE 13 07013 October 11, 2013 www.altera.com/enpirion Rev D EN5367QI POK Operation approximately 150C. After a thermal shutdown event, when the junction temperature drops by approx 20C, the converter will re-start with a normal soft-start. The POK signal is an open drain signal (requires a pull up resistor to VIN or similar voltage) from the converter indicating the output voltage is within the specified range. The POK signal will be logic high (VIN ) when the output voltage is above 90% of programmed VOUT. If the output voltage goes below this threshold, the POK signal will be a logic low. Input Under-Voltage Lock-Out Internal circuits ensure that the converter will not start switching until the input voltage is above the specified minimum voltage. Hysteresis, input deglitch and output leading edge blanking ensure high noise immunity and prevent false UVLO triggers. Over-Current Protection The current limit function is achieved by sensing the current flowing through the Power PFET. When the sensed current exceeds the over current trip point, both power FETs are turned off for the remainder of the switching cycle. If the over-current condition is removed, the over-current protection circuit will enable normal PWM operation. If the over-current condition persists, the soft start capacitor will gradually discharge causing the output voltage to fall. When the OCP fault is removed, the output voltage will ramp back up to the desired voltage. This circuit is designed to provide high noise immunity. Compensation The EN5367QI uses a type 3 compensation network. As noted earlier, a piece of the compensation network is the phase lead capacitor CA in Figure 1. This network is optimized for use with about 50F of output capacitance and will provide wide loop bandwidth and excellent transient performance for most applications. Voltage mode operation provides high noise immunity at light load. In some applications modifications to the compensation may be required. For more information, contact Altera Power Applications support. Thermal Overload Protection Thermal shutdown circuit will disable device operation when the Junction temperature exceeds 14 07013 October 11, 2013 www.altera.com/enpirion Rev D EN5367QI Application Information The EN5367QI output voltage is programmed using a simple resistor divider network. Figure 1 shows the resistor divider configuration. Recommended Input Capacitors Description VOUT CA RA MFG 47nF, 50V or 25V, 10% X7R, 0805 (1 capacitor needed right next to device input pins) 47F, 10V, 20% X5R, 1206 (1 capacitor needed in parallel with 47nF above) 22F, 10V, 20% X5R, 1206 (2 capacitors needed in parallel with 47nF above) RCA VFB P/N Murata GRM21BR71H473KA01L Taiyo Yuden TMK212B7473KD-T Murata GRM31CR61A476ME15L Taiyo Yuden LMK316BJ476ML-T Murata GRM31CR61A226ME19L Taiyo Yuden LMK316BJ226ML-T Table 1. Recommended Input Capacitors RB Output Capacitor Selection The EN5367QI has been nominally optimized for use with a 47F/1206 output capacitor. For better output ripple performance, use an additional 10F/0805 capacitor. Low ESR ceramic capacitors are required with X5R or X7R rated dielectric formulation. Y5V or equivalent dielectric formulations must not be used as these lose too much capacitance with frequency, temperature and bias voltage. Refer to Table 2 for recommendations. Figure 1: VOUT Resistor Divider & Compensation Capacitor The feedback and compensation network values depend on the input voltage and output voltage. Calculate the external feedback and compensation network values with the equations below. RA [k] = 30 x VIN [V] *Round RA up to closest standard value Output ripple voltage is determined by the aggregate output capacitor impedance. Output impedance, denoted as Z, is comprised of effective series resistance, ESR, and effective series inductance, ESL: CA [pF] = 2975 / RA [k] *Round CA down to closest standard value RB[k] = (VFB x RA) / (VOUT - VFB) [V] VFB = 0.75V nominal *Use closest suitable value for RB [k] Z = ESR + ESL RCA = VIN x (1.95 - 0.46 x VOUT) k Placing output capacitors in parallel reduces the impedance and will hence result in lower ripple voltage. Input Capacitor Selection 1 Z Total The EN5367QI requires a 47F/1206 and a 47nF/0805 input capacitor. Low-cost, low-ESR ceramic capacitors should be used as input capacitors for this converter. The dielectric must be X5R or X7R rated. Y5V or equivalent dielectric formulations must not be used as these lose too much capacitance with frequency, temperature and bias voltage. 1 1 1 + + ... + Z1 Z 2 Zn Typical Ripple Voltages Output Capacitor Configuration The first capacitor next to the PVIN and PGND pins must be a 47nF, 0805, X7R capacitor. Behind this first capacitor there can be either a single 47F capacitor or 2x22F capacitors. Refer to Table 1 for recommendations. Typical Output Ripple (mVp-p) (as measured on EN5367QI Evaluation Board)* 1 x 47F 47F + 10F 17 9 * Note: 20 MHz BW limit 15 07013 = October 11, 2013 www.altera.com/enpirion Rev D EN5367QI Power-Up Sequencing Recommended Output Capacitors Description 47F, 6.3V, 20% X5R, 1206 (1 capacitor needed) 10F, 10V, 10% X5R, 1206 (Optional 1 capacitor in parallel with 47F above) MFG During power-up, ENABLE should not be asserted before PVIN, and PVIN should not be asserted before AVIN. Tying all three pins together meets these requirements. P/N Murata GRM31CR60J476ME19L Taiyo Yuden JMK316BJ476ML-T Murata GRM31CR71A106KA01L Taiyo Yuden LMK316BJ226ML-T Technical Suport Contact Altera Power Applications regarding the use of this (www.altera.com/mysupport). Table 2. Recommended Output Capacitors 16 07013 October 11, 2013 support product www.altera.com/enpirion Rev D EN5367QI Thermal Considerations PIN = POUT / Thermal considerations are important power supply design facts that cannot be avoided in the real world. Whenever there are power losses in a system, the heat that is generated by the power dissipation needs to be accounted for. PIN 19.8W / 0.88 22.5W The power dissipation (PD ) is the power loss in the system and can be calculated by subtracting the output power from the input power. The Altera Enpirion EN5367QI DC-DC converter is packaged in a 5.5x10x3mm 54-pin QFN package. The QFN package is constructed with copper lead frames that have exposed thermal pads. The exposed thermal pad on the package should be soldered directly on to a copper ground pad on the printed circuit board (PCB) to act as a heat sink. The recommended maximum junction temperature for continuous operation is 125C. Continuous operation above 125C may reduce long-term reliability. The device has a thermal overload protection circuit designed to turn off the device at an approximate junction temperature value of 150C. The following example and calculations illustrate the thermal performance of the EN5367QI. PD = PIN - POUT 22.5W - 19.8W 2.7W With the power dissipation known, the temperature rise in the device may be estimated based on the theta JA value (JA). The JA parameter estimates how much the temperature will rise in the device for every watt of power dissipation. The EN5367QI has a JA value of 22 C/W without airflow. Determine the change in temperature (T) based on PD and JA. T = PD x JA T 2.7W x 22C/W = 59.4C 60C VIN = 5V The junction temperature (T J ) of the device is approximately the ambient temperature (T A) plus the change in temperature. We assume the initial ambient temperature to be 25C. VOUT = 3.3V T J = T A + T IOUT = 6A T J 25C + 60C 85C First calculate the output power. The maximum operating junction temperature (T JMAX) of the device is 125C, so the device can operate at a higher ambient temperature. The maximum ambient temperature (T AMAX) allowed can be calculated. Example: POUT = 3.3V x 6A = 19.8W Next, determine the input power based on the efficiency () shown in Figure 6. T AMAX = T JMAX - PD x JA Efficiency vs. Output Current 125C - 60C 65C The maximum ambient temperature the device can reach is 65C given the input and output conditions. Note that the efficiency will be slightly lower at higher temperatures and this calculation is an estimate. 100 90 88% EFFICIENCY (%) 80 70 60 50 40 30 20 VOUT = 3.3V 10 CONDITIONS VIN = 5.0V 0 0 1 2 3 4 OUTPUT CURRENT (A) 5 6 Figure 6: Efficiency vs. Output Current For VIN = 5V, VOUT = 3.3V at 6A, 88% = POUT / PIN = 88% = 0.88 17 07013 October 11, 2013 www.altera.com/enpirion Rev D EN5367QI Engineering Schematic Figure 7: Engineering Schematic with Engineering Notes 18 07013 October 11, 2013 www.altera.com/enpirion Rev D EN5367QI Layout Recommendation Recommendation 4: The thermal pad underneath the component must be connected to the system ground plane through as many vias as possible. The drill diameter of the vias should be 0.33mm, and the vias must have at least 1 oz. copper plating on the inside wall, making the finished hole size around 0.20-0.26mm. Do not use thermal reliefs or spokes to connect the vias to the ground plane. This connection provides the path for heat dissipation from the converter. Recommendation 5: Multiple small vias (the same size as the thermal vias discussed in recommendation 4) should be used to connect ground terminal of the input capacitor and output capacitors to the system ground plane. It is preferred to put these vias along the edge of the GND copper closest to the +V copper. These vias connect the input/output filter capacitors to the GND plane, and help reduce parasitic inductances in the input and output current loops. Recommendation 6: AVIN is the power supply for the small-signal control circuits. It should be connected to the input voltage at a quiet point. In Figure 8 this connection is made at the input capacitor. Recommendation 7: The layer 1 metal under the device must not be more than shown in Figure 8. Refer to the section regarding Exposed Metal on Bottom of Package. As with any switch-mode DC/DC converter, try not to run sensitive signal or control lines underneath the converter package on other layers. Recommendation 8: The VOUT sense point should be just after the last output filter capacitor. Keep the sense trace short in order to avoid noise coupling into the node. Recommendation 9: Keep RA, CA, RB, and RCA close to the VFB pin (Refer to Figure 8). The VFB pin is a high-impedance, sensitive node. Keep the trace to this pin as short as possible. Whenever possible, connect RB directly to the AGND pin instead of going through the GND plane. Recommendation 10: Follow all the layout recommendations as close as possible to optimize performance. Altera Enpirion provides schematic and layout reviews for all customer designs. Please contact local Sales Representatives for references to Altera Power Applications support. Figure 8: Top Layout with Critical Components Only (Top View). See Figure 7 for corresponding schematic. This layout only shows the critical components and top layer traces for minimum footprint in singlesupply mode with ENABLE tied to AVIN. Alternate circuit configurations & other low-power pins need to be connected and routed according to customer application. Please see the Gerber files at www.altera.com/enpirion for details on all layers. Recommendation 1: Input and output filter capacitors should be placed on the same side of the PCB, and as close to the EN5367QI package as possible. They should be connected to the device with very short and wide traces. Do not use thermal reliefs or spokes when connecting the capacitor pads to the respective nodes. The +V and GND traces between the capacitors and the EN5367QI should be as close to each other as possible so that the gap between the two nodes is minimized, even under the capacitors. Recommendation 2: The PGND connections for the input and output capacitors on layer 1 need to have a slit between them in order to provide some separation between input and output current loops. Recommendation 3: The system ground plane should be the first layer immediately below the surface layer. This ground plane should be continuous and un-interrupted below the converter and the input/output capacitors. 19 07013 October 11, 2013 www.altera.com/enpirion Rev D EN5367QI Design Considerations for Lead-Frame Based Modules Exposed Metal on Bottom of Package Lead-frames offer many advantages in thermal performance, in reduced electrical lead resistance, and in overall foot print. However, they do require some special considerations. In the assembly process lead frame construction requires that, for mechanical support, some of the lead-frame cantilevers be exposed at the point where wire-bond or internal passives are attached. This results in several small pads being exposed on the bottom of the package, as shown in Figure 9. Only the thermal pad and the perimeter pads are to be mechanically or electrically connected to the PC board. The PCB top layer under the EN5367QI should be clear of any metal (copper pours, traces, or vias) except for the thermal pad. The "shaded-out" area in Figure 9 represents the area that should be clear of any metal on the top layer of the PCB. Any layer 1 metal under the shaded-out area runs the risk of undesirable shorted connections even if it is covered by soldermask. The solder stencil aperture should be smaller than the PCB ground pad. This will prevent excess solder from causing bridging between adjacent pins or other exposed metal under the package. Please consult EN5367QI QFN Package Soldering Guidelines for more details and recommendations. Figure 9: Lead-Frame exposed metal (Bottom View) Shaded area highlights exposed metal that is not to be mechanically or electrically connected to the PCB. 20 07013 October 11, 2013 www.altera.com/enpirion Rev D EN5367QI Recommended PCB Footprint Figure 10: EN5367QI PCB Footprint (Top View) The solder stencil aperture for the thermal pad is shown in blue and is based on Enpirion power product manufacturing specifications. 21 07013 October 11, 2013 www.altera.com/enpirion Rev D EN5367QI Package and Mechanical Figure 11: EN5367QI Package Dimensions (Bottom View) Packing and Marking Information: www.altera.com/support/reliability/packing/rel-packing-and-marking.html 22 07013 October 11, 2013 www.altera.com/enpirion Rev D EN5367QI Contact Information Altera Corporation 101 Innovation Drive San Jose, CA 95134 Phone: 408-544-7000 www.altera.com (c) 2013 Altera Corporation--Confidential. All rights reserved. ALTERA, ARRIA, CYCLONE, ENPIRION, HARDCOPY, MAX, MEGACORE, NIOS, QUARTUS and STRATIX words and logos are trademarks of Altera Corporation and registered in the U.S. Patent and Trademark Office and in other countries. All other words and logos identified as trademarks or service marks are the property of their respective holders as described at www.altera.com/common/legal.html. Altera warrants performance of its semiconductor products to current specifications in accordance with Altera's standard warranty, but reserves the right to make changes to any products and services at any time without notice. Altera assumes no responsibility or liability arising out of the application or use of any information, product, or service described herein except as expressly agreed to in writing by Altera. Altera customers are advised to obtain the latest version of device specifications before relying on any published information and before placing orders for products or services. 23 07013 October 11, 2013 www.altera.com/enpirion Rev D