Enpirion® Power Datasheet EN2390QI 9A PowerSoC Voltage Mode Synchronous Buck With Integrated Inductor Not Recommended for New Designs Description Features The EN2390QI is a Power System on a Chip (PowerSoC) DC-DC converter. It integrates MOSFET switches, small-signal control circuits, compensation and an integrated inductor in an advanced 11x10x3mm QFN module. It offers high efficiency, excellent line and load regulation over temperature. The EN2390QI operates over a wide input voltage range and is specifically designed to meet the precise voltage and fast transient requirements of highperformance products. The EN2390QI features frequency synchronization to an external clock, power OK output voltage monitor, programmable soft-start along with thermal and short circuit protection. The device’s advanced circuit design, ultra high switching frequency and proprietary integrated inductor technology delivers high-quality, ultra compact, nonisolated DC-DC conversion. • • • • Integrated Inductor, MOSFETS, Controller Total Solution Size Estimate: 235mm2 Wide Input Voltage Range: 4.5V – 14V 1% Initial Output Voltage Accuracy • Master/Slave Configuration for Parallel Operation o Up to 4 Devices with 29A capability Frequency Synchronization (External Clock) Output Enable Pin and Power OK Signal Programmable Soft-Start Time Under Voltage Lockout Protection (UVLO) Short Circuit Protection Thermal Shutdown Protection RoHS Compliant, MSL Level 3, 260oC Reflow • • • • • • • Applications The Altera Enpirion solution significantly helps in system design and productivity by offering greatly simplified board design, layout and manufacturing requirements. In addition, overall system level reliability is improved given the small number of components required with the Altera Enpirion solution. • • • • Space Constrained Applications Distributed Power Architectures Output Voltage Ripple Sensitive Applications Beat Frequency Sensitive Applications • Servers, Embedded Computing Systems, LAN/SAN Adapter Cards, RAID Storage Systems, Industrial Automation, Test and Measurement, and Telecommunications All Altera Enpirion products are RoHS compliant, halogen free and are compatible with lead-free manufacturing environments. 0.22µF PG VIN BTMP VDDB PVIN ON AVINO 1µF 47nF RA CA REA AVIN RCA VFB SS M/S CGND PGND PGND FQADJ AGND 90 80 2x 47µF 0805 EAIN ENABLE OFF 1µF VOUT BGND VOUT EN2390QI 4.75k 2x 22µF 1206 Efficiency vs. Output Current 100 RCLX RB EFFICIENCY (%) 47nF 70 60 50 VOUT = 3.3V 40 VOUT = 2.5V 30 VOUT = 1.8V 20 VOUT = 1.2V VOUT = 1.0V 10 CONDITIONS VIN = 12.0V AVIN = 3.3V Dual Supply 0 RFS 100k 0 1 2 3 4 5 6 OUTPUT CURRENT (A) 7 8 9 Figure 1. Simplified Applications Circuit (Footprint Optimized) Figure 2. Highest Efficiency in Smallest Solution Size 07515 June 2, 2015 Rev D EN2390QI Ordering Information Part Number EN2390QI EVB-EN2390QI Package Markings EN2390QI EN2390QI TAMBIENT Rating (°C) -40 to +85 Package Description 76-pin (11mm x 10mm x 3mm) QFN T&R QFN Evaluation Board Packing and Marking Information: www.altera.com/support/reliability/packing/rel-packing-and-marking.html FQADJ RCLX SS EAIN VFB 66 65 64 63 62 POK NC 67 57 CGND 68 ENABLE NC(SW) 69 AVIN NC(SW) 70 58 NC(SW) 71 AGND NC 72 59 NC 73 M/S NC 74 60 NC 75 61 NC 76 Pin Assignments (Top View) 56 S_OUT 2 55 S_IN NC 3 54 BGND NC 4 53 VDDB NC 5 52 BTMP NC 6 51 PG NC 7 50 AVINO NC 8 NC 9 NC 10 NC 11 NC NC 1 NC KEEP OUT KEEP OUT 15 PVIN 16 41 PVIN 17 40 PVIN 18 39 PVIN 33 34 35 36 PGND PGND PGND PGND KEEP OUT 38 32 NC(SW) PGND 31 NC(SW) 37 30 NC PGND 29 NC NC 28 NC VOUT NC VOUT NC 27 PVIN 42 26 43 VOUT 14 25 PVIN NC VOUT 44 24 13 VOUT NC 23 PVIN VOUT 45 22 12 VOUT PVIN 21 46 VOUT PVIN 20 47 VOUT PVIN 19 PVIN 48 NC 49 77 PGND 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. All pins including NC pins 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 16 for details. NOTE C: White ‘dot’ on top left is pin 1 indicator on top of the device package. www.altera.com/enpirion Page 2 07515 June 2, 2015 Rev D EN2390QI Pin Description I/O Legend: PIN P=Power G=Ground NAME I/O 1-19, 29, 30, 67, 72-76 NC NC 20-28 VOUT O 31, 32, 69-71 NC(SW) NC 33-38 PGND G 39-49 PVIN P 50 AVINO O 51 52 PG BTMP I/O I/O 53 VDDB O 54 BGND G 55 S_IN I 56 S_OUT O 57 POK O 58 ENABLE I 59 AVIN P 60 AGND G 61 M/S 62 VFB I/O 63 EAIN I 64 SS I/O 65 RCLX I/O 66 FQADJ I/O 68 CGND 77 PGND NC=No Connect I=Input O=Output I/O=Input/Output 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 33-35. 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 36-38. Internal 3.4V linear regulator output. Connect this pin to AVIN for applications where operation from a single input voltage (PVIN) is required. If AVINO is being used, place a 1µF, X5R, capacitor between AVINO and AGND as close as possible to AVINO. PMOS gate. Place a 47nF, X5R, capacitor between this pin and BTMP. Bottom plate ground. See pin 51 description. Internal regulated voltage used for the internal control circuitry. Place a 0.22µF, X5R, capacitor between this pin and BGND. Ground for VDDB. Do not connect BGND to any other ground. See pin 53 description. Digital synchronization input. This pin accepts either an input clock to phase lock the internal switching frequency or a S_OUT signal from another EN2390QI. Leave this pin floating if not used. Digital synchronization output. PWM signal is output on this pin. Leave this pin floating if not used. Power OK is an open drain transistor (pulled up to AVIN or similar voltage) used for power system state indication. POK is logic high when VOUT is within -10% to +20% of VOUT nominal. Leave this pin floating if not used. Output enable. Applying a logic high to this pin enables the output and initiates a softstart. Applying a logic low disables the output. ENABLE logic cannot be higher than AVIN (refer to Absolute Maximum Ratings). Do not leave floating. See Power Up/Down Sequencing section for details. 3.3V Input power supply for the controller. Place a 1µF, X5R, capacitor between AVIN and AGND Analog ground. This is the ground return for the controller. All AGND pins need to be connected to a quiet ground. A logic level low configures the device as Master and a logic level high configures the device as a Slave. Connect to ground in standalone mode. External feedback input. The feedback loop is closed through this pin. A voltage divider at VOUT is used to set the output voltage. The mid-point of the divider is connected to VFB. A phase lead network from this pin to VOUT is also required to stabilize the loop. Optional error amplifier input. Allows for customization of the control loop for performance optimization. Leave this pin floating if not used. Soft-start node. The soft-start capacitor is connected between this pin and AGND. The value of this capacitor determines the startup time. See Soft-Start Operation in the Functional Description section for details. Short circuit protection. Connect a 100k resistor from RCLX to ground. Adding a resistor (RFS) to this pin will adjust the switching frequency of the EN2390QI. See Table 1 for suggested resistor values on RFS for various PVIN/VOUT combinations to maximize efficiency. Do not leave this pin floating. Test pin. For Enpirion Internal Use Only. Connect to GND plane at all times. Not a perimeter pin. Device thermal pad to be connected to the system GND plane for heat-sinking purposes. www.altera.com/enpirion Page 3 07515 June 2, 2015 Rev D EN2390QI 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. MIN MAX UNITS Pin Voltages – PVIN, VOUT, PG PARAMETER SYMBOL -0.5 15 V Pin Voltages – ENABLE, S_IN, M/S, POK -0.5 AVIN + 0.3 V Pin Voltages – AVINO, AVIN, ENABLE, S_IN, S_OUT, M/S -0.5 6.0 V Pin Voltages – VFB, SS, EAIN, RCLX, FQADJ, VDDB, BTMP -0.5 2.75 V Dual Supply PVIN Rising and Falling Slew Rate (Note 1) 0.3 25 V/ms Single Supply PVIN Rising and Falling Slew Rate (Note 1) 0.3 6 V/ms 14 A 150 °C 150 °C 260 °C 2000 V Maximum Continuous Output Current IOUT_CONT_MAX Storage Temperature Range TSTG Maximum Operating Junction Temperature -65 TJ-ABS Max Reflow Temp, 10 Sec, MSL3 JEDEC J-STD-020A ESD Rating (based on Human Body Model) Recommended Operating Conditions SYMBOL MIN MAX UNITS Input Voltage Range PARAMETER PVIN 4.5 14 V AVIN: Controller Supply Voltage AVIN 2.5 5.5 V Output Voltage Range (Note 2) VOUT 0.75 3.3 V Output Current IOUT 0 9 A 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 3) PARAMETER θJA 15 °C/W Thermal Resistance: Junction to Case (0 LFM) θJC 1.5 °C/W Thermal Shutdown TSD 160 °C Thermal Shutdown Hysteresis TSDH 35 °C Note 1: PVIN rising and falling slew rates cannot be outside of specification. For accurate power up sequencing, use a fast ENABLE logic (>3V/100µs) after both AVIN and PVIN are high. Note 2: Dropout: Maximum VOUT ≤ VIN - 2.5V Note 3: Based on 2oz. external copper layers and proper thermal design in line with EIJ/JEDEC JESD51-7 standard for high thermal conductivity boards. www.altera.com/enpirion Page 4 07515 June 2, 2015 Rev D EN2390QI Electrical Characteristics NOTE: VIN=12V, Minimum and Maximum values are over operating ambient temperature range unless otherwise noted. Typical values are at TA = 25°C. PARAMETER SYMBOL Operating Input Voltage PVIN Controller Input Voltage AVIN TEST CONDITIONS MIN TYP MAX UNITS 4.5 14.0 V 2.5 5.5 V AVIN Under Voltage Lock-out rising AVINUVLOR Voltage above which UVLO is not asserted 2.3 V AVIN Under Voltage Lock-out falling AVINOVLOF Voltage below which UVLO is asserted 2.1 V IAVIN 11 mA AVINO 3.4 V AVIN pin Input Current Internal Linear Regulator Output Voltage IPVINS PVIN=12V, AVIN=3.4V, ENABLE=0V 300 µA IAVINS PVIN=12V, AVIN=3.4V, ENABLE=0V 50 µA Feedback Pin Voltage VFB Feedback Pin Voltage VFB Feedback pin Input Leakage Current IFB Feedback node voltage at: VIN = 12V, ILOAD = 0, TA = 25°C Only Feedback node voltage at: 4.5V ≤ VIN ≤ 14V 0A ≤ ILOAD ≤ 9A, TA = -40 to 85°C VFB pin input leakage current (Note 4) Shut-Down Supply Current VOUT Rise Time tRISE CSS = 47nF (Note 4, Note 5, Note 6) 0.594 0.60 0.606 V 0.588 0.60 0.612 V 5 nA -5 1.96 2.8 3.64 ms 10 47 68 nF 0 9 A Soft Start Capacitor Range CSS_RANGE Continuous Output Current IOUT_MAX_CONT Subject to thermal derating ENABLE Logic High VENABLE_HIGH 4.5V ≤ VIN ≤ 14V; 1.25 AVIN V ENABLE Logic Low VENABLE_LOW 4.5V ≤ VIN ≤ 14V; 0 0.95 V ENABLE Lockout Time TENLOCKOUT ENABLE pin Input Current IENABLE 8 AVIN = 5.5V ENABLE = 1.8V; ENABLE = 3.3V; ENABLE = 5.5V; 5 11 23 RFS =3.01kΩ 1.0 Switching Frequency FSW External SYNC Clock Frequency Lock Range FPLL_LOCK Range of SYNC clock frequency (See Table 1) S_IN Threshold – Low VS_IN_LO S_IN Clock Logic Low Level (Note 3) S_IN Threshold – High VS_IN_HI S_IN Clock Logic High Level (Note 3) S_OUT Threshold – Low VS_OUT_LO S_OUT Clock Logic Low Level (Note 3) S_OUT Threshold – VS_OUT_HI S_OUT Clock Logic High Level 0.8 1.8 1.8 ms 8 18 32 µA MHz 1.8 MHz 0.8 V 2.5 V 0.8 V 2.5 V www.altera.com/enpirion Page 5 07515 June 2, 2015 Rev D EN2390QI PARAMETER SYMBOL High POK Lower Threshold TEST CONDITIONS POKLT Percentage of Nominal Output Voltage for POK to be Low POK Output low Voltage VPOKL With 4mA Current Sink into POK POK Output Hi Voltage VPOKH PVIN Range: 4.5V ≤ VIN ≤ 14V POK pin VOH leakage current IPOKL TYP MAX VT-LOW Tie Pin to GND M/S Pin Logic High VT-HIGH Pull up to AVIN Through an External Resistor REXT IM/S 90 POK High (Note 3) M/S Pin Logic Low M/S Pin Input Current MIN UNITS (Note 3) REXT = 15kΩ; AVIN = 3.4V; AVIN = 5.5V; 1.8 % 0.4 V AVIN V 1 µA 0.8 V V 65 175 µA Note 4: Parameter not production tested but is guaranteed by design. Note 5: Rise time calculation begins when AVIN > VUVLO and ENABLE = HIGH. Note 6: VOUT Rise Time Accuracy does not include soft-start capacitor tolerance. www.altera.com/enpirion Page 6 07515 June 2, 2015 Rev D EN2390QI Typical Performance Curves Efficiency vs. Output Current 100 90 90 80 80 EFFICIENCY (%) EFFICIENCY (%) Efficiency vs. Output Current 100 70 60 50 VOUT = 3.3V 40 VOUT = 2.5V 30 VOUT = 1.8V 20 VOUT = 1.2V 10 VOUT = 1.0V CONDITIONS VIN = 12.0V Single Supply 70 60 50 VOUT = 3.3V 40 VOUT = 2.5V 30 VOUT = 1.8V 20 VOUT = 1.2V 0 0 0 1 5 2 3 4 6 OUTPUT CURRENT (A) 7 8 9 0 MAXIMUM OUTPUT CURRENT (A) MAXIMUM OUTPUT CURRENT (A) 9 8 7 6 4 3 CONDITIONS VIN = 12V TJMAX = 125°C θJA = 15°C/W 11x10x3mm QFN No Air Flow VOUT = 1.0V VOUT = 1.2V VOUT = 1.8V VOUT = 2.5V VOUT = 3.3V 2 8 7 3 9 8 7 6 5 4 3 VOUT = 1.0V CONDITIONS VIN = 12V TJMAX = 125°C θJA = 12.5°C/W 11x10x3mm QFN Air Flow (200fpm) VOUT = 1.2V VOUT = 1.8V VOUT = 2.5V VOUT = 3.3V 2 25 30 35 40 45 50 55 60 65 70 75 80 85 AMBIENT TEMPERATURE (°C) MAXIMUM OUTPUT CURRENT (A) MAXIMUM OUTPUT CURRENT (A) 9 4 8 Output Current De-rating with Heat Sink 10 5 7 9 Output Current De-rating with Air Flow (400fpm) CONDITIONS VIN = 12V TJMAX = 125°C θJA = 11°C/W 11x10x3mm QFN Air Flow (400fpm) 2 3 4 5 6 OUTPUT CURRENT (A) 10 25 30 35 40 45 50 55 60 65 70 75 80 85 AMBIENT TEMPERATURE (°C) 6 1 Output Current De-rating with Air Flow (200fpm) Output Current De-rating 10 5 VOUT = 1.0V 10 CONDITIONS VIN = 12.0V AVIN = 3.3V Dual Supply VOUT = 1.0V VOUT = 1.2V VOUT = 1.8V VOUT = 2.5V VOUT = 3.3V 2 25 30 35 40 45 50 55 60 65 70 75 80 85 AMBIENT TEMPERATURE (°C) 10 9 8 7 6 5 4 3 CONDITIONS VIN = 12V TJMAX = 125°C θJA = 14°C/W 11x10x3mm QFN Heat Sink - Wakefield Thermal Solutions P/N 651-B VOUT = 1.0V VOUT = 1.2V VOUT = 1.8V VOUT = 2.5V VOUT = 3.3V 2 25 30 35 40 45 50 55 60 65 70 75 80 85 AMBIENT TEMPERATURE (°C) www.altera.com/enpirion Page 7 07515 June 2, 2015 Rev D EN2390QI Typical Performance Curves Output Current De-rating w/ Heat Sink and Air Flow (400fpm) MAXIMUM OUTPUT CURRENT (A) MAXIMUM OUTPUT CURRENT (A) Output Current De-rating w/ Heat Sink and Air Flow (200fpm) 10 9 8 CONDITIONS VIN = 12V TJMAX = 125°C θJA = 11.5°C/W 11x10x3mm QFN 7 6 Air Flow (200fpm) Heat Sink - Wakefield Thermal Solutions P/N 651-B 5 4 3 VOUT = 1.0V VOUT = 1.2V VOUT = 1.8V VOUT = 2.5V VOUT = 3.3V 2 10 9 8 CONDITIONS VIN = 12V TJMAX = 125°C θJA = 10°C/W 11x10x3mm QFN 7 6 5 Air Flow (400fpm) Heat Sink - Wakefield Thermal Solutions P/N 651-B 4 3 VOUT = 1.8V VOUT = 2.5V VOUT = 3.3V 2 Output Voltage vs. Output Current Output Voltage vs. Output Current 1.005 1.205 1.004 VIN = 8V 1.003 VIN = 10V 1.002 VIN = 12V OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) VOUT = 1.2V 25 30 35 40 45 50 55 60 65 70 75 80 85 AMBIENT TEMPERATURE (°C) 25 30 35 40 45 50 55 60 65 70 75 80 85 AMBIENT TEMPERATURE (°C) 1.001 1.000 0.999 0.998 0.997 1.204 VIN = 8V 1.203 VIN = 10V 1.202 VIN = 12V 1.201 1.200 1.199 1.198 1.197 CONDITIONS VOUT_NOM = 1.0V 0.996 CONDITIONS VOUT_NOM = 1.2V 1.196 0.995 1.195 0 1 2 3 4 5 6 7 OUTPUT CURRENT (A) 8 9 0 1 2 3 4 5 6 7 OUTPUT CURRENT (A) 8 9 Output Voltage vs. Output Current Output Voltage vs. Output Current 2.505 1.805 VIN = 8V 1.804 1.803 VIN = 10V 1.802 VIN = 12V OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) VOUT = 1.0V 1.801 1.800 1.799 1.798 1.797 VIN = 8V 2.503 VIN = 10V 2.502 VIN = 12V 2.501 2.500 2.499 2.498 2.497 CONDITIONS VOUT_NOM = 1.8V 1.796 2.504 CONDITIONS VOUT_NOM = 2.5V 2.496 2.495 1.795 0 1 2 3 4 5 6 7 OUTPUT CURRENT (A) 8 9 0 1 2 3 4 5 6 7 OUTPUT CURRENT (A) 8 9 www.altera.com/enpirion Page 8 07515 June 2, 2015 Rev D EN2390QI Typical Performance Curves Output Voltage vs. Temperature Output Voltage vs. Temperature 1.204 CONDITIONS VIN = 14V VOUT_NOM = 1.2V 1.203 1.202 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1.204 1.201 1.200 LOAD = 0A 1.199 LOAD = 2A LOAD = 4A 1.198 LOAD = 6A 1.197 CONDITIONS VIN = 12V VOUT_NOM = 1.2V 1.203 1.202 1.201 1.200 LOAD = 0A 1.199 LOAD = 2A LOAD = 4A 1.198 LOAD = 6A 1.197 LOAD = 9A LOAD = 9A 1.196 1.196 -40 35 60 -15 10 AMBIENT TEMPERATURE ( C) -40 85 85 Output Voltage vs. Temperature Output Voltage vs. Temperature 1.204 1.204 CONDITIONS VIN = 10V VOUT_NOM = 1.2V 1.203 1.202 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) -15 10 35 60 AMBIENT TEMPERATURE ( C) 1.201 1.200 LOAD = 0A 1.199 LOAD = 1A LOAD = 2A 1.198 LOAD = 3A 1.197 CONDITIONS VIN = 8V VOUT_NOM = 1.2V 1.203 1.202 1.201 1.200 LOAD = 0A 1.199 LOAD = 1A LOAD = 2A 1.198 LOAD = 3A 1.197 LOAD = 4A LOAD = 4A 1.196 1.196 -40 -15 10 35 60 AMBIENT TEMPERATURE ( C) 85 -40 -15 10 35 60 AMBIENT TEMPERATURE ( C) 85 INDIVIDUAL OUTPUT CURRENT (A) Parallel Current Share Breakdown 10 9 8 MASTER 7 SLAVE 6 IDEAL 5 4 CONDITIONS EN2390QI VIN = 12V VOUT = 1.2V 3 2 1 0 2 4 6 8 10 12 14 TOTAL OUTPUT CURRENT (A) 16 www.altera.com/enpirion Page 9 07515 June 2, 2015 Rev D EN2390QI Typical Performance Characteristics Enable Startup/Shutdown Waveform (0A) Enable Startup/Shutdown Waveform (3A) ENABLE ENABLE VOUT VOUT POK POK LOAD LOAD CONDITIONS VIN = 12V, VOUT = 1.8V, Load = 0A, Css = 47nF CIN = 2x22µF(1206), COUT = 2x47µF(1206)+100µF(1206) CONDITIONS VIN = 12V, VOUT = 1.8V, Load = 3A, Css = 47nF CIN = 2x22µF(1206), COUT = 2x47µF(1206)+100µF(1206) Enable Startup/Shutdown Waveform (6A) Enable Startup/Shutdown Waveform (9A) ENABLE ENABLE VOUT VOUT POK POK LOAD LOAD CONDITIONS VIN = 12V, VOUT = 1.8V, Load = 6A, Css = 47nF CIN = 2x22µF(1206), COUT = 2x47µF(1206)+100µF(1206) CONDITIONS VIN = 12V, VOUT = 1.8V, Load = 9A, Css = 47nF CIN = 2x22µF(1206), COUT = 2x47µF(1206)+100µF(1206) Power Up Waveform (0A) Power Up Waveform (4.5A) PVIN PVIN VOUT VOUT POK POK LOAD LOAD CONDITIONS VIN = 12V, VOUT = 1.8V, Load = 9A, Css = 47nF CIN = 2x22µF(1206), COUT = 2x47µF(1206)+100µF(1206) CONDITIONS VIN = 12V, VOUT = 1.8V, Load = 4.5A, Css = 47nF CIN = 2x22µF(1206), COUT = 2x47µF(1206)+100µF(1206) www.altera.com/enpirion Page 10 07515 June 2, 2015 Rev D EN2390QI Typical Performance Characteristics Power Up Waveform (6A) Power Up Waveform (9A) PVIN PVIN VOUT VOUT POK POK LOAD LOAD CONDITIONS VIN = 12V, VOUT = 1.8V, Load = 6A, Css = 47nF CIN = 2x22µF(1206), COUT = 2x47µF(1206)+100µF(1206) CONDITIONS VIN = 12V, VOUT = 1.8V, Load = 9A, Css = 47nF CIN = 2x22µF(1206), COUT = 2x47µF(1206)+100µF(1206) Output Ripple at 20MHz Bandwidth VOUT = 1V (AC Coupled) Output Ripple at 20MHz Bandwidth VOUT = 1V (AC Coupled) LOAD = 0A VOUT = 1.8V (AC Coupled) VOUT = 1.8V (AC Coupled) VOUT = 3.3V (AC Coupled) VOUT = 3.3V (AC Coupled) 20mV / DIV 20mV / DIV CONDITIONS VIN = 12V, CIN = 2x22µF (1206), COUT = 2x47µF + 100µF (1206) CONDITIONS VIN = 12V, CIN = 2x22µF (1206), COUT = 2x47µF + 100µF (1206) Output Ripple at 500MHz Bandwidth VOUT = 1V (AC Coupled) LOAD = 9A Output Ripple at 500MHz Bandwidth VOUT = 1V (AC Coupled) LOAD = 0A VOUT = 1.8V (AC Coupled) VOUT = 1.8V (AC Coupled) VOUT = 3.3V (AC Coupled) VOUT = 3.3V (AC Coupled) 20mV / DIV 20mV / DIV CONDITIONS VIN = 12V, CIN = 2x22µF (1206), COUT = 2x47µF + 100µF (1206) LOAD = 9A CONDITIONS VIN = 12V, CIN = 2x22µF (1206), COUT = 2x47µF + 100µF (1206) www.altera.com/enpirion Page 11 07515 June 2, 2015 Rev D EN2390QI Typical Performance Characteristics Load Transient from 0 to 3A (VOUT =1V) Load Transient from 0 to 4.5A (VOUT =1V) VOUT (AC Coupled) VOUT (AC Coupled) CONDITIONS VIN = 12V, VOUT = 1.0V CIN = 2x22µF (1206) COUT = 2 x 47µF (1206) + 100µF (1206) Using Best Performance Configuration CONDITIONS VIN = 12V, VOUT = 1.0V CIN = 2x22µF (1206) COUT = 2 x 47µF (1206) + 100µF (1206) Using Best Performance Configuration LOAD LOAD Load Transient from 0 to 6A (VOUT =1V) Load Transient from 0 to 9A (VOUT =1V) VOUT (AC Coupled) VOUT (AC Coupled) CONDITIONS VIN = 12V, VOUT = 1.0V CIN = 2x22µF (1206) COUT = 2 x 47µF (1206) + 100µF (1206) Using Best Performance Configuration LOAD LOAD CONDITIONS VIN = 12V, VOUT = 1.0V CIN = 2x22µF (1206) COUT = 2 x 47µF (1206) + 100µF (1206) Using Best Performance Configuration Load Transient from 0 to 3A (VOUT =3.3V) Load Transient from 0 to 4.5A (VOUT =3.3V) VOUT (AC Coupled) VOUT (AC Coupled) CONDITIONS VIN = 12V, VOUT = 3.3V CIN = 2x22µF (1206) COUT = 2 x 47µF (1206) + 100µF (1206) Using Best Performance Configuration CONDITIONS VIN = 12V, VOUT = 3.3V CIN = 2x22µF (1206) COUT = 2 x 47µF (1206) + 100µF (1206) Using Best Performance Configuration LOAD LOAD www.altera.com/enpirion Page 12 07515 June 2, 2015 Rev D EN2390QI Typical Performance Characteristics Load Transient from 0 to 6A (VOUT =3.3V) Load Transient from 0 to 9A (VOUT =3.3V) VOUT (AC Coupled) VOUT (AC Coupled) LOAD CONDITIONS VIN = 12V, VOUT = 3.3V CIN = 2x22µF (1206) COUT = 2 x 47µF (1206) + 100µF (1206) Using Best Performance Configuration LOAD CONDITIONS VIN = 12V, VOUT = 3.3V CIN = 2x22µF (1206) COUT = 2 x 47µF (1206) + 100µF (1206) Using Best Performance Configuration www.altera.com/enpirion Page 13 07515 June 2, 2015 Rev D EN2390QI Functional Block Diagram M/S S_OUT S_IN UVLO Digital I/O BTMP PVIN PG Linear Regulator To PLL AVINO Thermal Limit Short Circuit Protection NC(SW) Gate Drive VOUT 7.5k BGND (-) PWM Comp (+) PGND PLL/Sawtooth Generator FADJ VDDB Compensation Network EAIN Compensation Network (-) Error Amp (+) VFB Power Good Logic ENABLE POK 300k R SS Soft Start Voltage Reference Generator Band Gap Reference EN2390QI AVIN AGND Figure 4: Functional Block Diagram Functional Description small size input and output filter capacitors, as well as a wide loop bandwidth within a small foot print. Synchronous Buck Converter The EN2390QI is a highly integrated synchronous, buck converter with integrated controller, power MOSFET switches and integrated inductor. The nominal input voltage (PVIN) range is 4.5V to 14V and can support up to 9A of continuous output current. The output voltage is programmed using an external resistor divider network. The control loop utilizes a Type IV Voltage-Mode compensation network and maximizes on a low-noise PWM topology. 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 IV compensation network.. The high switching frequency of the EN2390QI enables the use of Protection Features: The power supply has the following protection features: • Short Circuit Protection • Thermal Shutdown with Hysteresis. • AVIN Under-Voltage Lockout Protection Additional Features: • • • Switching Frequency Synchronization. Programmable Soft-Start Power OK Output Monitoring www.altera.com/enpirion Page 14 07515 June 2, 2015 Rev D EN2390QI Power Up Sequence The EN2390QI is designed to be powered by either a single input supply (PVIN) or two separate supplies: one for PVIN and the other for AVIN. The EN2390QI is not “hot pluggable.” Refer to the PVIN Slew Rate specification on page 4. Single Input Supply Application (PVIN): PG BTMP VDDB PVIN 2.26k 1µF 2x 47µF 0805 EAIN ENABLE 2x 22µF 1206 VOUT BGND VOUT EN2390QI 10k 4.75k Dual Input Supply Application (PVIN and AVIN): 0.22µF 47nF VIN AVINO RA 47nF PG CA VFB M/S EN2390QI OFF 2x 22µF 1206 VAVIN AGND RFS RCLX AVIN 47nF RB 100k CA RCA VFB SS M/S CGND PGND PGND FADJ Figure 5: Single Input Supply Schematic AGND RCLX RB 100k Figure 7: Dual Input Supply Schematic The EN2390QI has an internal linear regulator that converts PVIN to 3.4V. The output of the linear regulator is provided on the AVINO pin once the device is enabled. AVINO should be connected to AVIN on the EN2390QI. In this application, the following external components are required: Place a 1µF, X5R/X7R capacitor between AVINO and AGND as close as possible to AVINO. Place a 1µF, X5R/X7R capacitor between AVIN and AGND as close as possible to AVIN. In addition, place a resistor (RVB) between VDDB and AVIN, as shown in Figure 5. Altera recommends RVB=4.75kΩ. In this application, ENABLE cannot be asserted before PVIN. See diagram below for a recommended startup and shutdown sequencing. 12V 0V RA REA RFS PVIN 2x 47µF 0805 EAIN ENABLE AVINO 1µF PGND FADJ VOUT BGND VOUT ON RCA CGND PGND BTMP VDDB PVIN REA SS 0.22µF 47nF VIN AVIN 1µF the device at a programmed PVIN voltage level. The lower resistor (2.26k) can be adjusted to set startup and shutdown at a specific PVIN voltage level. In this operating mode the minimum PVIN is 6.8V due to the ENABLE threshold. See ENABLE and DISABLE thresholds in the Electrical Characteristics table. PVIN slew rate limitations as per datasheet PVIN – Recommended to be ramped down after the Vout softshutdown occurs In this application, place a 1µF, X5R/X7R, capacitor between AVIN and AGND as close as possible to AVIN. Refer to Figure 7 for a recommended schematic for a dual input supply application. For dual input supply applications, the sequencing of the two input supplies, PVIN and AVIN, is very important. There are two common acceptable turnon sequences for the device. AVIN can always come up before PVIN. If PVIN comes up before AVIN, then ENABLE must be toggled last, after AVIN is asserted. Do not turn off AVIN before PVIN and ENABLE during shutdown. Doing so will disable the internal controller while there may still be energy in the system. The device will not softshutdown properly and damage may occur. See diagram below for a recommended startup and shutdown sequencing. 12V PVIN 0V PVIN slew rate limitations as per datasheet PVIN powered down before AVIN 3.3V ENABLE 0V Delay from ENABLE rising edge to soft start begin ~ 1ms VOUT 3.3V Delay from ENABLE falling edge to soft shutdown begin ~ 1.5ms Soft Start Time ≈ 2ms w/Css=47nF AVIN Soft Shutdown Time ≈ 1.3ms w/Css=47nF AVIN powered up before PVIN 0V 3.3V ENABLE Figure 6: Single Supply Startup/Shutdown Sequence If no external enable signal is used, a resister divider (see Figure 5) from PVIN to ENABLE and then to ground can be used to enable and disable 0V Delay from ENABLE rising edge to soft start begin ~ 1ms VOUT Delay from ENABLE falling edge to soft shutdown begin ~ 1.5ms Soft Start Time ≈ 2ms w/Css=47nF PVIN/AVIN – Recommended to be ramped down after the Vout softshutdown occurs Soft Shutdown Time ≈ 1.3ms w/Css=47nF Figure 8: Dual Supply Startup/Shutdown Sequencing www.altera.com/enpirion Page 15 07515 June 2, 2015 Rev D EN2390QI Enable Operation Pre-Bias Operation The EN2390QI 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 EN2390QI is not pre-biased when the EN2390QI is first enabled. Rfs vs. SW Frequency 1.800 SWITCHING FREQUENCY (MHz) 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 signal has to be low for at least the ENABLE Lockout Time (8ms) in order for the device to be reenabled. To ensure accurate startup sequencing the ENABLE/DISABLE signal should be faster than 1V/100µs. A slower ENABLE/DISABLE signal may result in a delayed startup and shutdown response. Do not leave ENABLE floating. 1.600 1.400 1.200 1.000 0.600 0 2 4 6 8 10 12 14 16 18 20 22 RFS RESISTOR VALUE (kΩ) Figure 9. RFS versus Switching Frequency The efficiency performance of the EN2390QI for various VOUTs can be optimized by adjusting the switching frequency. Table 1 shows recommended RFS values for various VOUTs in order to optimize performance of the EN2390QI. PVIN Frequency Synchronization The switching frequency of the EN2390QI can be phase-locked to an external clock source to move unwanted beat frequencies out of band. The internal switching clock of the EN2390QI can be phase locked to a clock signal applied to the S_IN pin. An activity detector recognizes the presence of an external clock signal and automatically phaselocks the internal oscillator to this external clock. Phase-lock will occur as long as the input clock frequency is in the range of 0.8MHz to 1.8MHz. The external clock frequency must be within ±10% of the nominal switching frequency set by the RFS resistor. It is recommended to use a synchronized clock frequency close to the typical frequency recommendations in Table 1. A 3.01kΩ resistor from FQADJ to ground is recommended for clock frequencies within ±10% of 1MHz. When no clock is present, the device reverts to the free running frequency of the internal oscillator set by the RFS resistor. The efficiency performance of the EN2390QI for various PVIN/VOUT combinations can be optimized by adjusting the switching frequency. Table 1 shows recommended RFS values for various PVIN/VOUT combinations in order to optimize performance of the EN2390QI. CONDITIONS VIN = 6V to 12V VOUT = 0.8V to 3.3V 0.800 12V 5V VOUT 3.3V 2.5V 1.8V 1.5V 1.2V <1.0V 2.5V 1.8V 1.5V 1.2V <1.0V RFS 22k 10k 4.87k 3.01k 1.65k 1.3k 22.1k 10k 6.65k 4.87k 3.01k Typical fsw 1.42 MHz 1.3 MHz 1.15 MHz 1.0 MHz 0.95 MHz 0.8 MHz 1.4 MHz 1.3 MHz 1.25 MHz 1.15 MHz 1.0 MHz Table 1: Recommended RFS Values Soft-Start Operation Soft start is a means to ramp the output voltage gradually upon start-up. The output voltage rise time is controlled by the choice of soft-start capacitor, which is placed between the SS pin and the AGND pin. 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 10µA. The soft-start time is measured from when VIN > VUVLOR and ENABLE pin voltage crosses its logic high threshold to when VOUT reaches its programmed value. The total softstart time can be calculated by: Soft Start Time (ms): T SS ≈ Css [nF] x 0.06 www.altera.com/enpirion Page 16 07515 June 2, 2015 Rev D EN2390QI POK Operation The POK signal is an open drain signal (requires a pull up resistor to AVIN or similar voltage) from the converter indicating the output voltage is within the specified range. Typically, a 100kΩ or lower resistance is used as the pull-up resistor. The POK signal will be logic high (AVIN) when the output voltage is above 90% of the programmed voltage level. If the output voltage is below this point, the POK signal will be a logic low. The POK signal can be used to sequence down-stream converters by tying to their enable pins. Short Circuit Protection The short circuit protection feature will protect the device if the output is shorted to ground. Short circuit protection is achieved by sensing the current flowing through a sense PFET. When the sensed current exceeds the threshold for more than 32 cycles, both power FETs are turned off for the rest of the switching cycle. If the short circuit condition is removed, the device will reactivate soft-start and resume PWM operation. In the event the short circuit trips consistently in normal operation, the device enters a hiccup mode. While in hiccup mode, the device is disabled for a short while and restarted with a normal soft-start. The hiccup time is approximately 32ms. This cycle can continue indefinitely as long as the short circuit condition persists. Use a resistor value of 100k from the RCLX pin to ground to enable this feature. Thermal Overload Protection Thermal shutdown circuit will disable device operation when the junction temperature exceeds approximately 160°C. After a thermal shutdown event, when the junction temperature drops by approx 35°C, the converter will re-start with a normal soft-start. AVIN Under-Voltage Lock-Out (UVLO) Internal circuits ensure that the converter will not start switching until the AVIN input voltage is above the specified minimum voltage. Hysteresis, input de-glitch and output leading edge blanking ensures Master / Slave (Parallel) Operation: Up to four EN2390QI devices may be connected in a Master/Slave configuration to handle larger load currents. The maximum output current for each parallel device will need to be de-rated by 20 percent so that no devices will over current due to current mis-match. The Master device’s switching clock may be phase-locked to an external clock source via the S_IN pin or left open and use its default switching frequency. The device is placed in Master mode by pulling the M/S pin low or in Slave mode by pulling M/S pin high. Note that the M/S pin is also pulled low for standalone mode. In Master mode, the internal PWM signal is output on the S_OUT pin. This PWM signal from the Master is fed to the Slave device at its S_IN input. The Slave device acts like an extension of the power FETs in the Master. The inductor in the Slave prevents crow-bar currents from Master to Slave due to timing delays. Parallel operation in dual supply mode is shown in Figure 11. Single supply mode operation may also be implemented similarly. Note that only critical components are shown. The red text and red lines indicate the important parallel operation connections and care should be taken in layout to ensure low impedance between those paths. The parallel current matching is illustrated in Figure 10. Parallel Current Share Breakdown INDIVIDUAL OUTPUT CURRENT (A) Typical soft-start time is approximately 2.8ms with SS capacitor value of 47nF. high noise immunity and prevents false UVLO triggers. 10 9 8 MASTER 7 SLAVE 6 IDEAL 5 4 CONDITIONS EN2390QI VIN = 12V VOUT = 1.2V 3 2 1 0 2 4 6 8 10 12 14 TOTAL OUTPUT CURRENT (A) 16 Figure 10. Parallel Current Matching www.altera.com/enpirion Page 17 07515 June 2, 2015 Rev D EN2390QI Note 2: The Master and Slave VOUTs should be connected with very low iµpedance as shown by the double red line connections in parallel. Note 1: The Master and Slave VINs should be connected with very low iµpedance as shown by the double red line connections in parallel. VIN PVIN ENA 2x 22µF 1206 AVIN AVIN 2x 47µF 1206 EN2390QI (MASTER) SS 47nF VOUT VOUT RA CA VFB R1 M/S PGND PGND S_OUT AGND RB FQADJ S_IN PVIN AVIN 2x 22µF 1206 VOUT ENA AVIN 15k 2x 47µF 1206 EN2390QI (SLAVE) VFB M/S open SS PGND PGND FQADJ AGND 47nF Slave #1 Note 4: Up to 3 Slaves µay be used in parallel with the Master Note 3: The Master and Slave PGNDs should be connected with very low iµpedance as shown by the double red line connections in parallel. Figure 11. Parallel Operation Illustration www.altera.com/enpirion Page 18 07515 June 2, 2015 Rev D EN2390QI Application Information Output Voltage Programming and Loop Compensation The EN2390QI uses a Type IV Voltage Mode compensation network. Type IV Voltage Mode control is a proprietary Altera Enpirion control scheme that maximizes control loop bandwidth to deliver excellent load transient responses and maintain output regulation with pin point accuracy. For ease of use, most of this network has been customized and is integrated within the device package. The EN2390QI output voltage is programmed using a simple resistor divider network (RA and RB). The feedback voltage at VFB is nominally 0.6V. RA is predetermined based on Table 4 and RB can be calculated based on Figure 12. The values recommended for COUT, CA, RCA and REA make up the external compensation of the EN2390QI. It will vary with each PVIN and VOUT combination to optimize on performance. The EN2390QI solution can be optimized for either smallest size or highest performance. Please see Table 4 for a list of recommended RA, CA, RCA, REA and COUT values for each solution. Since VFB is a sensitive node, do not touch the VFB node while the device is in operation as doing so may introduce parasitic capacitance into the control loop that causes the device to behave abnormally and damage may occur. VOUT VOUT COUT EAIN RA CA capacitors are needed in parallel with the larger, capacitors in order to provide high frequency decoupling. Table 2 contains a list of recommended input capacitors. Recommended Input Capacitors Description MFG 22µF, 16V, X5R, 10%, 1206 Murata GRM31CR61C226ME15 22µF, 16V, X5R, 20%, 1206 Taiyo Yuden EMK316ABJ226ML- T Table 2: Recommended Input Capacitors Output Capacitor Selection As seen from Table 4, the EN2390QI has been optimized for use with one 100µF/1206 plus two 47µF/1206 output capacitors for best performance. For smallest solution size, various combinations of output capacitance may be used. See Table 4 for details. 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. Table 4 contains a list of recommended output capacitors Output ripple voltage is determined by the aggregate output capacitor impedance. Capacitor impedance, denoted as Z, is comprised of capacitive reactance, effective series resistance, ESR, and effective series inductance, ESL reactance. Placing output capacitors in parallel reduces the impedance and will hence result in lower ripple voltage. REA RCA VFB VFB = 0.6V PGND RB = EN2390QI P/N 1 VFB x RA Z Total VOUT - VFB Figure 12: VOUT Resistor Divider & Compensation Components. See Table 4 for details. Input Capacitor Selection The EN2390QI requires two 22µF/1206 input capacitors. 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. In some applications, lower value = 1 1 1 + + ... + Z1 Z 2 Zn Recommended Output Capacitors Description 47µF, 6.3V, X5R, 20%, 1206 47µF, 10V, X5R, 20%, 1206 22µF, 10V, X5R, 20%, 0805 22µF, 10V, X5R, 20%, 0805 100µF, 6.3V, X5R, 20%, 1206 MFG P/N Murata GRM31CR60J476ME19L Taiyo Yuden LMK316BJ476ML- T Panasonic ECJ-2FB1A226M Taiyo Yuden LMK212BJ226MG- T Murata GRM31CR60J107ME39L Taiyo Yuden JMK316BJ107ML-T Table 3: Recommended Output Capacitors www.altera.com/enpirion Page 19 07515 June 2, 2015 Rev D EN2390QI Best Performance Smallest Solution Size CIN = 2x22µF/1206 CIN = 2x22µF/1206 V OUT ≤ 1.8V, COUT = 2x47µF/0805 1.8V < V OUT ≤ 3.3V, COUT = 2x47µF/1206 COUT = 2x47µF/1206 + 100µF/1206 RA = 200 kΩ PVIN (V) 14V 12V 10V 8V 6.6V 5V RA = 75k VOUT (V) CA (pF) RCA (kΩ) REA (kΩ) Ripple (m V) Deviation (m V) 0.9V 15 18 0 5.83 1.2V 15 22 0 1.5V 18 22 1.8V 15 22 2.5V 27 3.3V 0.9V 1.2V PVIN (V) VOUT (V) CA (pF) RCA (kΩ) REA (kΩ) Ripple (m V) Deviation (m V) 44 0.9V 18 8.2 Open 15 93 7.22 48 1.2V 18 8.2 Open 21 104 0 8.63 38 1.5V 18 8.2 Open 27 110 0 10.8 50 1.8V 18 8.2 Open 35 120 5.1 33 14.6 72 2.5V 15 8.2 Open 54 150 22 8.2 33 26.1 76 3.3V 10 8.2 Open 81 215 27 18 0 5.21 40 0.9V 27 5.1 Open 15 96 22 22 0 6.7 36 1.2V 27 5.1 Open 21 104 1.5V 18 22 0 8.98 44 1.5V 27 5.1 Open 27 112 1.8V 18 22 0 10 50 1.8V 27 5.1 Open 34 130 2.5V 27 5.1 33 12.6 76 2.5V 22 5.1 Open 52 162 3.3V 22 8.2 33 23.6 72 3.3V 15 5.1 Open 77 221 0.9V 27 18 0 5.01 44 0.9V 56 2 Open 15 99 1.2V 22 22 0 6.28 40 1.2V 56 2 Open 20 107 1.5V 18 22 0 8.57 54 1.5V 39 2 Open 26 122 1.8V 18 22 0 9.44 60 1.8V 39 2 Open 33 126 2.5V 33 5.1 33 11 64 2.5V 33 2 Open 50 169 3.3V 27 8.2 33 21.6 68 3.3V 22 2 Open 71 241 0.9V 27 18 0 4.9 44 0.9V 100 0 Open 15 108 1.2V 22 22 0 5.82 48 1.2V 100 0 Open 20 113 1.5V 22 22 0 7.48 56 1.5V 82 0 Open 25 122 14V 12V 10V 8V 1.8V 22 22 0 8.01 54 1.8V 68 0 Open 31 136 2.5V 33 5.1 33 10.7 76 2.5V 47 0 Open 46 183 3.3V 27 8.2 33 20.5 84 3.3V 33 0 Open 62 253 0.9V 33 18 0 4.58 46 0.9V 100 0 Open 14 121 1.2V 27 22 0 5.28 54 1.2V 100 0 Open 19 128 1.5V 27 22 0 6.44 54 1.5V 100 0 Open 24 138 1.8V 22 22 0 7.2 58 1.8V 100 0 Open 29 149 2.5V 3.3V 0.9V 33 33 39 5.1 8.2 18 33 33 0 11.4 18.4 4.1 84 96 54 2.5V 3.3V 0.9V 68 47 100 0 0 0 Open Open Open 41 53 13 188 239 152 1.2V 33 22 0 5.1 62 1.2V 100 0 Open 18 161 1.5V 27 22 0 6.2 66 1.5V 100 0 Open 22 177 1.8V 2.5V 27 39 22 5.1 0 33 7.02 9.84 68 104 1.8V 2.5V 100 100 0 0 Open Open 25 33 183 216 6.6V 5V Table 4: RA, CA, RCA and REA Values for Various PVIN/VOUT Combinations: Best Performance vs. Smallest Solution Size. Use the equations in Figure 12 to calculate RB. Output ripple is measured at no load and nominal deviation is for a 9A load transient step. For a voltage in between the specified output voltages, choose compensation values of the lower output voltage setting. www.altera.com/enpirion Page 20 07515 June 2, 2015 Rev D EN2390QI Thermal Considerations 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. The Altera Enpirion PowerSoC helps alleviate some of those concerns. The Altera Enpirion EN2390QI DC-DC converter is packaged in a 10x11x3mm 76-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 125°C. Continuous operation above 125°C 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 160°C. The following example and calculations illustrate the thermal performance of the EN2390QI. Example: VIN = 12V VOUT = 1.2V PIN ≈ 10.8W / 0.8 ≈ 13.17W The power dissipation (PD ) is the power loss in the system and can be calculated by subtracting the output power from the input power. PD = PIN – POUT ≈ 13.17W – 10.8W ≈ 2.37W With the power dissipation known, the temperature rise in the device may be estimated based on the theta JA value (θJA). The θJA parameter estimates how much the temperature will rise in the device for every watt of power dissipation. The EN2390QI has a θJA value of 15 ºC/W without airflow. Determine the change in temperature (ΔT) based on PD and θJA. ΔT = PD x θJA ΔT ≈ 2.37W x 15°C/W = 35.56°C ≈ 36°C 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 25°C. T J ≈ 25°C + 36°C ≈ 61°C First calculate the output power. POUT = 1.2V x 9A = 10.8W Next, determine the input power based on the efficiency (η) shown in Figure 13. Efficiency vs. Output Current 100 80 70 60 50 VOUT = 3.3V 40 VOUT = 2.5V 30 VOUT = 1.8V 20 VOUT = 1.2V VOUT = 1.0V The maximum operating junction temperature (T JMAX) of the device is 125°C, so the device can operate at a higher ambient temperature. The maximum ambient temperature (T AMAX) allowed can be calculated. T AMAX = T JMAX – PD x θJA ≈ 125°C – 36°C ≈ 89°C The maximum ambient temperature the device can reach is 89°C given the input and output conditions. Note that the efficiency will be slightly lower at higher temperatures and this calculation is an estimate. Check De-rating Curves for guaranteed maximum output current over temperature. 90 EFFICIENCY (%) PIN = POUT / η T J = T A + ΔT IOUT = 9A 10 η = POUT / PIN = 82% = 0.82 CONDITIONS VIN = 12.0V AVIN = 3.3V Dual Supply 0 0 1 2 3 4 5 6 OUTPUT CURRENT (A) 7 8 9 Figure 13: Efficiency vs. Output Current For VIN = 12V, VOUT = 1.2V at 9A, η ≈ 82% www.altera.com/enpirion Page 21 07515 June 2, 2015 Rev D EN2390QI Engineering Schematic A single through-hole test point connects the AGND M/S must be tied to ground pin to the GND plane. for stand-alone operation. Optional EAIN test point used for loop optimization purposes. Do not connect a voltage probe to this test point. Css 47n 0402 Rclx Rfs values chosen for 12Vin/3.3Vout. 100k 0402 Rf s 15k 0402 Enable can also be driven with an external logic signal depending on the application. Cav in 1u 0402 EAIN PVIN PVIN NC15 PVIN NC16 PVIN NC17 PVIN PGND NC14 NC18 100k 0402 57 POK 58 59 AVIN ENABLE AGND 60 61 M/S 62 VFB 64 65 63 EAIN SS FADJ RCLX 66 67 NC67 68 CGND 70 69 NC(SW)69 72 71 NC(SW)71 NC(SW)70 NC73 NC72 74 NC13 PVIN 56 Cb 0.22u 0402 55 54 53 52 Cpg 47n 0402 51 Rv b 4.75k 0402 50 49 48 Cav ino 1u 0402 47 46 45 44 43 42 41 40 39 PVIN = 12 VDC Cout1 47u 1206 Cout2 47u 1206 38 37 36 35 33 34 32 31 30 29 27 28 26 25 24 23 21 22 20 PVIN 19 VOUT 73 PVIN 0402 Rb 16.5k NC74 NC76 NC12 PGND 0201 5.1k 18 PVIN PGND Rca PVIN NC11 PGND 0402 17 NC10 PGND 16 PVIN PGND Ra 75k PVIN EN2390 NC(SW)32 0402 15 U1 NC9 NC(SW)31 Ca 15p NC8 NC29 14 AVINO NC30 13 NC7 VOUT 12 PG VOUT 11 NC6 VOUT 10 BTMP VOUT 9 VDDB NC5 VOUT 8 NC4 VOUT 7 S_IN BGND VOUT 6 S_OUT NC3 VOUT 5 NC75 76 4 NC2 NC19 3 NC1 VOUT 2 75 RPOK 1 Choose RPOK so that max sink current is not exceeded. POK AGND Cin1 22u 1206 Cin2 22u 1206 Connect input and output cap grounds to the GND plane through multiple vias (See the Gerber files). Output capacitors & compensation network optimized for 12Vin to 3.3Vout. See datasheet for other Vin/Vout cases. Figure 14: Engineering Schematic for Smallest Solution Size www.altera.com/enpirion Page 22 07515 June 2, 2015 Rev D EN2390QI Layout Recommendation Figure 15: Critical Component Layout for Minimum Footprint (Top Layer). See Figure 14 for schematic. This layout only shows the critical components and top layer traces for minimum footprint in single-supply, master 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 EN2390QI 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 EN2390QI 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. 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. If vias cannot be placed under the capacitors, then place them on both sides of the slit in the top layer PGND copper. Recommendation 6: AVIN is the power supply for the small-signal control circuits. AVINO powers AVIN in single supply mode. AVIN and AVINO should have a decoupling capacitor close to each of their pins. Refer to Figure 15. Recommendation 7: The layer 1 metal under the device must not be more than shown in Figure13. 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. Contact Altera MySupport for any remote sensing applications. Recommendation 9: Keep RA, CA, RB, and RCA close to the VFB pin (Refer to Figure 15). 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 instead of going through the GND plane. Recommendation 10: Follow all the layout recommendations as close as possible to optimize performance. Altera provides schematic and layout reviews for all customer designs. Contact Altera MySupport for detailed support (www.altera.com/mysupport). www.altera.com/enpirion Page 23 07515 June 2, 2015 Rev D EN2390QI 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 16. 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 EN2390QI should be clear of any metal (copper pours, traces, or vias) except for the thermal pad. The “shaded-out” area in Figure 16 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 the EN2390QI QFN Package Soldering Guidelines for more details and recommendations. Figure 16: Lead-Frame exposed metal (Bottom View) Shaded area highlights exposed metal that is not to be mechanically or electrically connected to the PCB. www.altera.com/enpirion Page 24 07515 June 2, 2015 Rev D EN2390QI Recommended PCB Footprint Figure 17: EN2390QI PCB Footprint (Top View) The solder stencil aperture for the thermal pad (shown in blue) is based on Altera’s manufacturing recommendations. www.altera.com/enpirion Page 25 07515 June 2, 2015 Rev D EN2390QI Package and Mechanical Figure 18: EN2390QI Package Dimensions (Bottom View) Packing and Marking Information: www.altera.com/support/reliability/packing/rel-packing-and-marking.html Contact Information Altera Corporation 101 Innovation Drive San Jose, CA 95134 Phone: 408-544-7000 www.altera.com © 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. www.altera.com/enpirion Page 26 07515 June 2, 2015 Rev D