Complete Current Share 10A DC/DC Power Module ISL8200AM Features The ISL8200AM is a simple and easy to use high power, current-sharing DC/DC power module for Datacom/Telecom/ FPGA power hungry applications. All that is needed is the ISL8200AM, a few passive components and one VOUT setting resistor to have a complete 10A design ready for market. • Complete Switch Mode Power Supply in One Package • Input Voltage Range +3.0V to +20V at 10A, Current Share up to 60A • A Single Resistor Sets VOUT from +0.6V to +6V Need more output current? Parallel up to six ISL8200AM modules to scale up to a 60A solution (see Figure 6 on page 10). • Output Overvoltage, Overcurrent and Over-Temperature Protection and Undervoltage Indication The simplicity of the ISL8200AM is in its "Off The Shelf", unassisted implementation versus a discrete implementation. Patented current sharing in multi-phase operation greatly reduces ripple currents, BOM cost and complexity. For example, parallel 2 for 20A and up to 6 for 60A. The output voltage can be precisely regulated to as low as 0.6V with ±1% output voltage regulation over line, load, and temperature variations. The ISL8200AM’s thermally enhanced, compact QFN package, operates at full load and over-temperature, without requiring forced air cooling. It's so thin it can even fit on the back side of the PCB. Easy access to all pins with few external components, reduces the PCB design to a component layer and a simple ground layer. Complete Functional Schematic • RoHS Compliant Applications • Servers, Telecom and Datacom Applications • Industrial and Medical Equipment • Point of Load Regulation Related Literature • AN1738 “ISL8200AMEVAL1PHZ Evaluation Board User’s Guide” • iSim Model - (See respective Device Information page at www.intersil.com) ISL8200AM Package VOUT RANGE 0.6V TO 6.0V PVIN ISL8200AM POWER MODULE RSET 330μF VOUT VIN 2.2mm VOUT_SET EN VSEN_REM- ISHARE PGND ISET FF PVCC 22μF R1 R2 VEN • Programmable Phase Shift (1 to 6 Phase) • Extremely Low Profile (2.2mm Height) The ease of use virtually eliminates the design and manufacturing risks while dramatically improving time to market. VIN RANGE 3V TO 20V • Patented Current Share Architecture Reduces Layout Sensitivity when Modules are Paralleled PGND1 15 10μF m 15 5kΩ FIGURE 1. COMPLETE 10A DESIGN, JUST SELECT R SET FOR THE DESIRED VOUT September 13, 2012 FN8271.2 m 1 mm FIGURE 2. THE 2.2mm HEIGHT IS IDEAL FOR THE BACKSIDE OF PCBS WHEN SPACE AND HEIGHT IS A PREMIUM CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas Inc. 2012. All Rights Reserved Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries. All other trademarks mentioned are the property of their respective owners. ISL8200AM Ordering Information PART NUMBER (Notes 1, 2, 3) TEMP. RANGE (°C) PART MARKING ISL8200AMIRZ ISL8200AM PACKAGE (RoHS Compliant) -40°C to +85°C PKG. DWG. # 23 Ld QFN L23.15x15 NOTES: 1. Add “-T” suffix for tape and reel. Please refer to TB347 for details on reel specifications. 2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020 3. For Moisture Sensitivity Level (MSL), please see device information page for ISL8200AM. For more information on MSL please see techbrief TB363. Pinout Internal Circuit VCC PVCC PVIN 14 17 21 RCC CF2 BOOT1 LDO VIN 13 ISL8200AM MODULE 5 CF1 UGATE1 CBOOT1 Q1 EN 12 LOUT1 PHASE1 FF 11 330nH 19 VOUT VCC PGOOD 22 RPG 10k VCC LGATE1 INTERNAL PGOOD RCLK 10k CLKOUT 8 PH_CNTRL 9 Q2 ISEN1A 18 PGND VCC RPHC 10k RISEN-IN CONTROLLER 16 PHASE 2.2k ISEN1B ISET 5 CF3 ISHARE 20 OCSET 1 VOUT_SET 2 VSEN_REM- COMP ZCOMP1 6 CF4 FB1 ISHARE_BUS 10 VMON1 ISFETDRV 3 FSYNC_IN 7 ZCOMP2 VSEN1+ RFS 59k 2 VSEN1- 15 4 PGND1 PGND1 RCSR CVSEN ROS1 2.2k FN8271.2 September 13, 2012 ISL8200AM Pin Configuration (1) VOUT_SET (2) VSEN_REM- (3) ISFETDRV (4) PGND1 (5) ISET (6) ISHARE (7) FSYNC_IN (8) CLKOUT (9) PH_CNTRL (10) ISHARE_BUS (11) FF ISL8200AM (23 LD QFN) TOP VIEW (12) EN (23) N.C. (13) VIN (22) PGOOD (21) VCC (14) PVCC (20) OCSET (15) PGND1 (16) PHASE PD1 (17) PVIN PD2 PD3 (18) PGND PD4 (19) VOUT Pin Descriptions PIN # PIN NAME PIN DESCRIPTION 1 VOUT_SET 2 VSEN_REM- 3 ISFETDRV 4, 15 PGND1 Normal Ground - All voltage levels are referenced to this pad. This pad provides a return path for the low side MOSFET drives and internal power circuitries as well as all analog signals. PGND and PGND1 should be connected together with a ground plane. 5 ISET Analog Current Output - This pin sources a 15µA offset current plus Channel 1’s average current. The voltage (VISET) set by an external resistor (RISET) represents the average current level of the local active module. For full-scale current, RISET should be ~10kΩ. The output current range is 15µA to 126µA typ. The ISET and ISHARE pins are used for current sharing purposes with multiple ISL8200AM modules. In the single module configuration, this pin can be tied to the ISHARE pin. In multi-phase operation, if noise is a concern, add an additional 10pF capacitor to the ISET line. Analog Voltage Input - Used with VOUT to program the regulator output voltage. The typical input impedance of VOUT_SET with respect to VSEN_REM- is 500kΩ. The voltage input typ. is 0.6V. Analog Voltage Input - This pin is the negative input of standard unity gain operational amplifier for differential remote sense for the regulator, and should connect to the negative rail of the load/processor. This pin can be used for VOUT trimming by connecting a resistor from this pin to the VOUT_SET pin. Digital Output - This pin is used to drive an optional NFET, which will connect ISHARE with the system ISHARE bus upon completing a pre-bias startup. The voltage output range is 0V to 5V. 3 FN8271.2 September 13, 2012 ISL8200AM Pin Descriptions (Continued) PIN # PIN NAME PIN DESCRIPTION 6 ISHARE Analog Current Output - Cascaded system level overcurrent shutdown pin. This pin is used where you have multiple modules configured for current sharing and is used with a common current share bus. The bus sums each of the modules' average current contribution to the load to protect for a overcurrent condition at the load. The pin sources 15µA plus average module's output current. The shared bus voltage (VISHARE) is developed across an external resistor (RISHARE). VISHARE represents the average current of all active channel(s) that are connected together. The ISHARE bus voltage is compared with each module's internal reference voltage set by each module's RISET resistor. This will generate an individual current share error signal in each cascaded controller. The share bus impedance RISHARE should be set as RISET/NCTRL, RISET divided by the number of active current sharing controllers. The output current from this pin generates a voltage across the external resistor. This voltage, VISHARE, is compared to an internal 1.2V threshold for average overcurrent protection. For full-scale current, RISHARE should be ~10kΩ. Typically 10kΩ is used for RSHARE and RSET. The output current range is 15µA to 126µA typ. 7 FSYNC_IN Analog Input Control Pin - An optional external resistor (RFS-ext) connected to this pin and ground will increase the oscillator switching frequency. It has an internal 59kΩ resistor for a default frequency of 700kHz. The internal oscillator will lock to an external frequency source when connected to a square waveform. The external source is typically the CLKOUT signal from another ISL8200AM or an external clock. The internal oscillator synchronizes with the leading positive edge of the input signal. The input voltage range for the external source is 0V to 5V Square Wave. When not synchronized to an external clock, a 100pF capacitor between FSYNC_IN and PGND1 is recommended. 8 CLKOUT Digital Voltage Output - This pin provides a clock signal to synchronize with other ISL8200AM(s). When there is more than one ISL8200AM in the system, the two independent regulators can be programmed via PH_CNTRL for different degrees of phase delay. 9 PH_CNTRL Analog Input - The voltage level on this pin is used to program the phase shift of the CLKOUT clock signal to synchronize with other module(s). 10 ISHARE_BUS Open pin until first PWM pulse is generated. Then, via an internal FET, this pin connects the module’s ISHARE to the system’s ISHARE bus after pre-bias is complete and soft-start is initiated. 11 FF Analog Voltage Input - The voltage on this pin is fed into the controller, adjusting the sawtooth amplitude to generate the feed-forward function. The input voltage range is 0.8 to VCC. Typically, FF is connected to EN. 12 EN This is a double function pin: Analog Input Voltage - The input voltage to this pin is compared with a precision 0.8V reference and enables the digital soft-start. The input voltage range is 0V to VCC or VIN through a pull-up resistor maintaining a typical current of 5mA. Analog Voltage Output - This pin can be used as a voltage monitor for input bus undervoltage lockout. The hysteresis levels of the lockout can be programmed via this pin using a resistor divider network. Furthermore, during fault conditions (such as overvoltage, overcurrent, and over-temperature), this pin is used to communicate the information to other cascaded modules by pulling the wired OR low as it is an Open Drain. The output voltage range is 0V to VCC. 13 VIN Analog Voltage Input - This pin should be tied directly to the input rail when using the internal linear regulator. It provides power to the internal linear drive circuitry. When used with an external 5V supply, this pin should be tied directly to PVCC. The internal linear device is protected against the reversed bias generated by the remaining charge of the decoupling capacitor at VCC when losing the input rail. The input voltage range is 4.5V to 20V. 14 PVCC Analog Output - This pin is the output of the internal series linear regulator. It provides the bias for both low-side and high-side drives. Its operational voltage range is 4.5V to 5.5V. The decoupling ceramic capacitor in the PVCC pin is 10µF. 16 PHASE 17 PVIN Analog Input - This input voltage is applied to the power FETs with the FET’s ground being the PGND pin. It is recommended to place input decoupling capacitance, 22µF, directly between the PVIN pin and the PGND pin as close as possible to the module. The input voltage range is 3V to 20V. 18 PGND All voltage levels are referenced to this pad. This is the low side MOSFET ground. PGND and PGND1 should be connected together with a ground plane. 19 VOUT Output voltage from the module. The output voltage range is 0.6V to 6V. 20 OCSET Analog Input - This pin is used with the PHASE pin to set the current limit of the module. The input voltage range is 0V to 30V. 21 VCC Analog Input - This pin provides bias power for the analog circuitry. It’s operational range is 4.5V to 5.5V. In 3.3V applications, VCC, PVCC and VIN should be shorted to allow operation at the low end input as it relates to the VCC falling threshold limit. This pin can be powered either by the internal linear regulator or by an external voltage source. 22 PGOOD Analog Output - This pin, pulled up to VCC via an internal 10kΩ resistor, provides a Power Good signal when the output is within 9% of nominal output regulation point with 4% hysteresis (13%/9%), and soft-start is complete. An external pull-up is not required. PGOOD monitors the outputs (VMON1) of the internal differential amplifiers. The output voltage range is 0V to VCC. Analog Output - This pin is the phase node of the regulator. The output voltage range is 0V to 30V. 4 FN8271.2 September 13, 2012 ISL8200AM Pin Descriptions (Continued) PIN # PIN NAME 23 NC PIN DESCRIPTION Not internal connected PD1 Phase Thermal Pad Used for both the PHASE pin (Pin # 16) and for heat removal connecting to heat dissipation layers using vias. Connect this pad to a copper island on the PCB board with the same shape as the pad; this is electrically connected to PHASE pin 16. PD2 PVIN Thermal Pad Used for both the PVIN pin (Pin # 17) and for heat removal connecting to heat dissipation layers using vias. Connect this pad to a copper island on the PCB board with the same shape as the pad; this is electrically connected to PVIN pin 17. PD3 PGND Thermal Pad Used for both the PGND pin (Pin # 18) and for heat removal connecting to heat dissipation layers using vias. Connect this pad to a copper island on the PCB board with the same shape as the pad; this is electrically connected to PGND pin 18. PD4 VOUT Thermal Pad Used for both the VOUT pin (Pin # 19) and for heat removal connecting to heat dissipation layers using vias. Connect this pad to a copper island on the PCB board with the same shape as the pad; this is electrically connected to VOUT pin 19. Typical Application Circuits VIN RSET VOUT_SET FF 2.2k ISL8200AM FSYNC_IN PGOOD CLKOUT VCC PVCC VCC RSET CAN CHANGE VOUT REFER TO TABLE 1 10µF PGND PHASE OCSET ISET PGND1 C209 RISHARE1 5k ISHARE ISFETDRV SET R1 AND R2 SUCH THAT 0.8V ≤ VEN ≤ 5.0V PGOOD PH_CNTRL ISHARE_BUS DO NOT TIE EN DIRECTLY TO A POWER SOURCE GROUND VSEN_REM- EN ISFETDRV1 VOUT 330µF VOUT VOUT C9 22µF PVIN 1nF R2 2.05k GROUND C211 R1 8.25k C203 270µF C3 PVIN FIGURE 3. SINGLE PHASE 10A 1.2V OUTPUT CIRCUIT 5 FN8271.2 September 13, 2012 Typical Application Circuits (continued) 22µF C203 R1 PVIN 26.7k 270µF C3 PVIN VOUT RSET1 VIN 1nF C211 R2 2.61k 100µF (x6) 10k GROUND VSEN_REM- EN ISL8200AM FSYNC_IN 6 CLKOUT PGOOD PGOOD 2.2nF PH_CNTRL ISHARE_BUS VCC VCC1 PVCC PGND1 PGND PHASE ISET OCSET ISFETDRV ISHARE ISFETDRV1 C9 VOUT_SET FF GROUND VOUT VOUT 22µF C303 10µF C209 10k RISET1 PVIN VOUT VIN VOUT RSET2 VOUT_SET 1nF C311 FF 10k VSEN_REM- EN ISL8200AM FSYNC_IN CLKOUT PGOOD PH_CNTRL ISHARE_BUS VCC VCC2 PVCC PGND1 PGND PHASE ISET OCSET ISFETDRV ISHARE ISFETDRV2 PGOOD 10µF C309 10k RISET2 ISHARE FN8271.2 September 13, 2012 FIGURE 4. TWO PHASE 20A 3.3V OUTPUT CIRCUIT 2.2nF ISL8200AM RISHARE1 5k ISHARE ISL8200AM Absolute Maximum Ratings Thermal Information Input Voltage, PVIN, VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +27V Driver Bias Voltage, PVCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +6.0V Signal Bias Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +6.5V BOOT/UGATE Voltage, VBOOT . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +36V Phase Voltage, VPHASE . . . . . . . . . . . . . . . . . . . VBOOT - 7V to VBOOT + 0.3V BOOT to PHASE Voltage, VBOOT - VPHASE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to VCC + 0.3V Input, Output or I/O Voltage . . . . . . . . . . . . . . . . . . . . . . -0.3V to VCC + 0.3V ESD Rating Human Body Model (Tested per JESD22-A114E) . . . . . . . . . . . . . . . . 2kV Machine Model (Tested per JESD22-A115-A) . . . . . . . . . . . . . . . . . 200V Charge Device Model (Tested per JESD22-C101C). . . . . . . . . . . . . . . 1kV Latch Up (Tested per JESD-78B; Class 2, Level A) . . . . . . . . . . . . . . 100mA Thermal Resistance (Typical) θJA (°C/W) θJC (°C/W) QFN Package (Notes 4, 5) . . . . . . . . . . . . . . 13 2.0 Maximum Storage Temperature Range . . . . . . . . . . . . . .-55°C to +150°C Recommended Operating Conditions Input Voltage, PVIN, VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3V to 20V Driver Bias Voltage, PVCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3V to 5.6V Signal Bias Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3V to 5.6V Boot to Phase Voltage VBOOT - VPHASE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <6V Industrial Ambient Temperature Range . . . . . . . . . . . . . . . -40°C to +85°C Junction Temperature Range . . . . . . . . . . . . . . . . . . . . . . .-40°C to +125°C CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and result in failures not covered by warranty. NOTES: 4. θJA is measured in free air with the component mounted on a high effective thermal conductivity test board (i.e., 4-layer type without thermal vias see tech brief TB379) per JEDEC standards except that the top and bottom layers assume solid plains. 5. For θJC, the “case temp” location is the center of the exposed metal pad on the package underside. Electrical Specifications PARAMETER Boldface limits apply over the operating temperature range, -40°C to +85°C. SYMBOL TEST CONDITIONS MIN (Note 7) TYP (Note 6) MAX (Note 7) UNITS VCC SUPPLY CURRENT Nominal Supply VIN Current IQ_VIN PVIN = VIN = 20V; No Load; FSW = 700kHz 36 mA Nominal Supply VIN Current IQ_VIN Shutdown Supply VCC Current PVIN = VIN = 4.5V; No Load; FSW = 700kHz 27 mA IVCC EN = 0V, VCC = 2.97V 9 mA IPVCC PVCC = 4V to 5.6V 320 mA INTERNAL LINEAR REGULATOR Maximum Current Saturated Equivalent Impedance RLDO P-Channel MOSFET (VIN = 5V) PVCC Voltage Level (Note 7) PVCC IPVCC = 0mA, VIN = 12V 1 5.15 5.4 Ω 5.60 V POWER-ON RESET (Note 7) Rising VCC Threshold 2.85 2.97 V Falling VCC Threshold 2.65 2.75 V Rising PVCC Threshold 2.85 2.97 V 2.65 2.75 Falling PVCC Threshold System Soft-start Delay tSS_DLY After PLL, VCC, and PVCC PORs, and EN above their thresholds 384 V Cycles ENABLE (Note 7) Turn-On Threshold Voltage Hysteresis Sink Current IEN_HYS Undervoltage Lockout Hysteresis VEN_HYS 0.75 0.8 0.86 V 21 30 35 µA VEN_RTH = 10.6V; VEN_FTH = 9V 1.6 RUP = 53.6kΩ, RDOWN = 5.23kΩ Sink Current IEN_SINK VEN = 1V Sink Impedance REN_SINK VEN = 1V V 15.4 mA 64 Ω OSCILLATOR Oscillator Frequency FOSC Total Variation (Note 7) RFS = 59kΩ; Figure 34 VCC = 5V; 7 700 -9 kHz +9 % FN8271.2 September 13, 2012 ISL8200AM Electrical Specifications PARAMETER Boldface limits apply over the operating temperature range, -40°C to +85°C. (Continued) SYMBOL TEST CONDITIONS MIN (Note 7) TYP (Note 6) MAX (Note 7) UNITS 1500 kHz FREQUENCY SYNCHRONIZATION AND PHASE LOCK LOOP (Note 7) Synchronization Frequency VCC = 5.4V PLL Locking Time VCC = 5.4V; FSW = 700kHz Input Signal Duty Cycle Range FOSC 210 10 µs 90 % 410 ns PWM (Note 7) Minimum PWM OFF Time tMIN_OFF Current Sampling Blanking Time tBLANKING 310 345 175 ns OUTPUT CHARACTERISTICS Output Continuous Current Range IOUT(DC) PVIN = VIN = 12V, VOUT = 1.2V 0 10 A Line Regulation Accuracy ΔVOUT/ΔVIN VOUT = 1.2V, IOUT = 0A, PVIN = VIN = 3.5V to 20V 0.15 % VOUT = 1.2V, IOUT = 10A, PVIN = VIN = 5V to 20V 0.15 % Load Regulation Accuracy ΔVOUT/ΔIOUT IOUT = 0A to 10A, VOUT = 1.2V, PVIN = VIN = 12V 0.1 % IOUT = 10A, VOUT = 1.2V, PVIN = VIN = 12V 27 mVP-P IOUT = 0A, VOUT = 1.2V, PVIN = VIN = 12V 19 mVP-P ΔVOUT Output Ripple Voltage DYNAMIC CHARACTERISTICS Voltage Change For Positive Load Step ΔVOUT-DP IOUT = 0A to 5A. Current slew rate = 2.5A/µs, PVIN = VIN = 12V, VOUT = 1.2V 45 mVP-P Voltage Change For Negative Load Step ΔVOUT-DN IOUT = 5A to 0A. Current slew rate = 2.5A/µs, PVIN = VIN = 12V, VOUT = 1.2V 55 mVP-P 0.6 V REFERENCE (Note 7) Reference Voltage (Include Error and Differential Amplifiers’ Offsets) VREF -0.75 0.75 % DIFFERENTIAL AMPLIFIER (Note 7) DC Gain UG_DA Unity Gain Bandwidth Unity Gain Amplifier UGBW_DA VSEN+ Pins Input Current IVSEN+ Maximum Source Current for Current Sharing IVSEN1- RVSEN+_to _VSEN- Input Impedance 0.2 VSEN1- Source Current for Current Sharing when parallel multiple modules each of which has its own voltage loop VVSEN+/IVSEN+, VVSEN+ = 0.6V Output Voltage Swing Input Common Mode Range Disable Threshold VVSEN- 0 dB 5 MHz 1.16 2.5 µA 350 µA -500 kΩ 0 VCC - 1.8 V -0.2 VCC - 1.8 V VMON1 = Tri-State VCC - 0.4 V 111 µA OVERCURRENT PROTECTION (Note 7) Channel Overcurrent Limit Channel Overcurrent Limit Share Pin OC Threshold ISOURCE VCC = 2.97V to 5.6V ISOURCE VCC = 5V; VOC_ISHARE Comparator offset included 89 111 129 µA 1.16 1.20 1.22 V CURRENT SHARE External Current Share Accuracy Up to 3 phases ±10 % POWER GOOD MONITOR (Note 7) Undervoltage Falling Trip Point VUVF Undervoltage Rising Hysteresis VUVR_HYS Overvoltage Rising Trip Point VOVR 8 Percentage Below Reference Point -15 Percentage Above UV Trip Point Percentage Above Reference Point -13 -11 4 11 13 % % 15 % FN8271.2 September 13, 2012 ISL8200AM Electrical Specifications PARAMETER Boldface limits apply over the operating temperature range, -40°C to +85°C. (Continued) SYMBOL Overvoltage Falling Hysteresis VOVF_HYS TEST CONDITIONS MIN (Note 7) Percentage below OV Trip Point TYP (Note 6) MAX (Note 7) 4 UNITS % PGOOD Low Output Voltage IPGOOD = 2mA 0.35 V Sinking Impedance IPGOOD = 2mA 70 Ω Maximum Sinking Current VPGOOD < 0.8V 10 mA OVERVOLTAGE PROTECTION (Note 7) OV Latching Trip Point EN = UGATE = LATCH Low, LGATE = High OV Non-Latching Trip Point EN = Low, UGATE = Low, LGATE = High LGATE Release Trip Point EN = Low/HIGH, UGATE = Low, LGATE = Low 118 120 122 % 113 % 87 % Over-Temperature Trip 150 °C Over-Temperature Release Threshold 125 °C RCC 5 Ω Internal Resistor Between PHASE and OCSET Pins RISEN-IN 2.2k Ω Internal Resistor Between FSYNC_IN and PGND1 Pins RFS 59k Ω Internal Resistor Between PGOOD and VCC Pins RPG 10k Ω Internal Resistor Between CLKOUT and VCC Pins RCLK 10k Ω Internal Resistor Between PH_CNTRL and VCC Pins RPHC 10k Ω Internal Resistor Between VOUT_SET and VSEN_REM- pin ROS1 2.2k Ω OVER-TEMPERATURE PROTECTION CONTROLLER JUNCTION TEMPERATURE INTERNAL COMPONENT VALUES Internal Resistor Between PVCC and VCC pin NOTES: 6. Parameters with TYP limits are not production tested, unless otherwise specified. 7. Parameters with MIN and/or MAX limits are 100% tested for internal IC prior to module assembly, unless otherwise specified. Temperature limits established by characterization and are not production tested. 9 FN8271.2 September 13, 2012 ISL8200AM RSET 2.2k VOUT_SET VSEN_REMISL8200AM FSYNC_IN VCC VOUT = 1.2V for RSET = 2.2k Refer to Table 1 for RSET vs. VOUT VCC PVCC PGND1 10µF 5k C209 PGND PHASE ISET OCSET ISFETDRV ISHARE GROUND 10nF PH_CNTRL ISHARE_BUS RISHARE1 47µF (x8) PGOOD CLKOUT ISFETDRV1 C9 C205 FF EN VOUT VOUT VOUT VIN 1nF 4.12k C211 GROUND R2 PVIN 22µF C203 R1 16.5k C3 270µF PVIN FIGURE 5. TEST CIRCUIT FOR ALL PERFORMANCE AND DERATING GRAPHS Typical Performance Characteristics TA = +25°C, PVIN = VIN, CIN = 220µFx1, 10µF/Ceramic x 2, COUT = 47µF/Ceramic x 8. 100 100 95 95 90 90 EFFICIENCY (%) EFFICIENCY (%) Efficiency Performance 85 80 3.3V 75 2.5V 1.5V 70 1.2V 65 60 0 2 4 6 0.8V 8 85 80 75 70 65 10 60 0 3.3V 1.5V 1.2V 5.0V 2 LOAD CURRENT (A) FIGURE 6. EFFICIENCY vs LOAD CURRENT (5VIN) 2.5V 0.8V 4 6 LOAD CURRENT (A) 8 10 FIGURE 7. EFFICIENCY vs LOAD CURRENT (12VIN) VOUT 100 3.3V EFFICIENCY (%) 95 2.5V 5.0V 90 VIN = 12V VOUT = 1.2V IOUT = 0A TO 5A 85 80 75 70 1.5V 65 60 0 2 4 6 1.2V 8 10 LOAD CURRENT (A) FIGURE 8. EFFICIENCY vs LOAD CURRENT (20VIN) 10 FIGURE 9. 1.2V TRANSIENT RESPONSE FN8271.2 September 13, 2012 ISL8200AM Typical Performance Characteristics (Continued) Transient Response Performance TA = +25°C, PVIN = VIN = 12V, CIN = 220µFx1, 10µF/Ceramic x 2, COUT = 47µF/Ceramic x 8 IOUT = 0A to 5A, Current slew rate = 2.5A/µs VOUT VOUT VIN = 12V VOUT = 1.8V IOUT = 0A TO 5A VIN = 12V VOUT = 1.5V IOUT = 0A TO 5A FIGURE 10. 1.5V TRANSIENT RESPONSE FIGURE 11. 1.8V TRANSIENT RESPONSE VOUT VOUT VIN = 12V VOUT = 2.5V IOUT = 0A TO 5A VIN = 12V VOUT = 1.8V IOUT = 0A TO 5A FIGURE 12. 2.5V TRANSIENT RESPONSE FIGURE 13. 3.3V TRANSIENT RESPONSE PHASE1-M PHASE2-M PHASE3-M PHASE4-S FIGURE 14. FOUR MODULE CLOCK SYNC (V IN = 12V) 11 FN8271.2 September 13, 2012 ISL8200AM Typical Performance Characteristics (Continued) Output Ripple Performance TA = +25°C, PVIN = VIN = 12V, CIN = 220µFx1, 10µF/Ceramic x 2, COUT = 100µF/Ceramic x 6 IOUT = No Load, 5, 10A VIN = 0V TO 18V VOUT = 1.2V IOUT = NO LOAD VOUT EN PGOOD VOUT PHASE FIGURE 15. OVERCURRENT PROTECTION VOUT NO LOAD VOUT 5A VOUT 10A FIGURE 17. 1.2V OUTPUT RIPPLE VOUT NO LOAD VOUT 5A VOUT 10A FIGURE 19. 2.5V OUTPUT RIPPLE 12 PVIN PHASE FIGURE 16. 50% PRE-BIAS START UP VOUT NO LOAD VOUT 5A VOUT 10A FIGURE 18. 1.5V OUTPUT RIPPLE VOUT NO LOAD VOUT 5A VOUT 10A FIGURE 20. 3.3V OUTPUT RIPPLE FN8271.2 September 13, 2012 ISL8200AM VOUT VEN VOUT 0.6V 0.8V 1.0V 1.2V RSET 0Ω 732Ω 1.47kΩ 2.2kΩ VOUT 1.5V 1.8V 2.0V 2.5V RSET 3.32kΩ 4.42kΩ 5.11kΩ 6.98kΩ COUT PVIN ISL8200AM POWER MODULE RSET VOUT_SET EN VSEN_REM- FF ISHARE PVCC TABLE 1. VOUT - RSET VOUT VIN R2 Note: ISL8200AM has integrated 2.2kΩ resistances into the module dividing resistor for the bottom side (ROS). The resistances for different output voltages in single phase operation are listed in Table 1. For a parallel setup, please refer to the current sharing application note (Coming Soon). PVIN = 3.3V VIN = 5.0V PGND (EQ. 1) ISET R SET⎞ ⎛ V OUT = 0.6 × ⎜ 1 + -------------⎟ R OS ⎠ ⎝ The circuit shown in Figure 24 ensures proper startup by injecting current into the ISHARE line until all phases are ready to start regulating. CIN1 The ISL8200AM has an internal 0.6V ± 0.7% reference voltage. Programming the output voltage requires a dividing resistor (RSET) between the VOUT_SET pin and the VOUT regulation point. The output voltage can be calculated as shown in Equation 1: CIN2 Programming the Output Voltage (RSET) power stage is at a 5.0V rail. It is imperative to not cross 5.5V in this setup as that is the voltage limit on the PVCC pin. Figure 23 is a more general setup and can accommodate VIN ranges up to 20V; PVCC is not tied to VIN and hence the control circuitry is powered by the internal LDO. R1 Applications Information PGND1 PVCC = 5.0V 10µF 5k PVIN VEN RSET VOUT_SET EN VSEN_REM- FF The module has a minimum input voltage at a given output voltage, which needs to be a minimum of 1.43 times the output voltage if operating at FSW = 700kHz switching frequency. This is due to the Minimum PWM OFF Time (tMIN-OFF). ISHARE PGND1 PVCC = VIN 10µF 5k The equation to determine the minimum PVIN to support the required VOUT is given by Equations 2 and 3; it is recommended to add 0.5V to the result to account for temperature variations. V OUT × t SW PV IN_MIN = --------------------------------------t SW – t MIN_OFF ISL8200AM POWER MODULE PVCC The output voltage accuracy can be improved by maintaining the impedance at VOUTSET (internal VSEN1+) at or below 1kΩ effective impedance. Note: the impedance between VSEN1+ and VSEN1- is about 500kΩ. VOUT VOUT VIN COUT VIN = 5.0V DO NOT CROSS 5.5V PGND 20kΩ ISET 6.0V 16.2kΩ CIN 5.0V 10kΩ R1 3.3V RSET R2 VOUT FIGURE 21. 3.3V OPERATION FIGURE 22. 5.0V OPERATION (EQ. 2) VIN is the input to the internal LDO that powers the control circuitry while PVCC is the output of the aforementioned LDO. PVIN is the power input to the power stage. Figure 21 shows a scenario where the power stage is running at 3.3V and the control circuitry is running at 5.0V; keep in mind that the PVCC pin is also at 5.0V to ensure that the LDO is not functioning. Figure 22 shows a setup where both the control circuitry and the VEN R2 For 3.3V input voltage operation, the VIN voltage is recommended to be 5V for sufficient gate drive voltage. This can be accomplished by using a voltage greater than or equal to 5V on VIN, or directly connecting the 5V source to both VIN and PVCC. RSET COUT ISL8200AM POWER MODULE VOUT_SET EN VSEN_REM- FF ISHARE PVCC (EQ. 3) 13 PVIN CIN PV IN_MIN = 1.43 × V OUT R1 for the 700kHz switching frequency = 1428ns VOUT VOUT VIN PGND VIN = 5V-20V ISET tSW = switching period = 1/FSW PGND1 10µF 5k FIGURE 23. 5V TO 20V OPERATION FN8271.2 September 13, 2012 ISL8200AM Selection of the Input Capacitor VCC (PHASE 1) The input filter capacitor should be based on how much ripple the supply can tolerate on the DC input line. The larger the capacitor, the less ripple expected, but consideration should be taken for the higher surge current during power-up. The ISL8200AM provides the soft-start function that controls and limits the current surge. The value of the input capacitor can be calculated by Equation 4: D • (1 – D) C IN ( MIN ) = I O • --------------------------------------•F V P-P ( MAX ) RINC RPH1 ISFETDRV (PHASE 1) QSHR DPH2 (EQ. 4) ISFETDRV (PHASE 2) CG S DPH2 Where: ISFETDRV (PHASE 3) ISHARE CIN(MIN) is the minimum input capacitance (µF) required ADD ADDITIONAL DIODES PER PHASE IO is the output current (A) FIGURE 24. STARTUP CIRCUITRY D is the duty cycle (VO/VIN) VP-P(MAX) is the maximum peak-to-peak voltage (V) Functional Description FS is the switching frequency (Hz) Initialization In addition to the bulk capacitance, some low Equivalent Series Inductance (ESL) ceramic capacitance is recommended to decouple between the drain terminal of the high side MOSFET and the source terminal of the low side MOSFET. This is used to reduce the voltage ringing created by the switching current across parasitic circuit elements. The ISL8200AM requires VCC and PVCC to be biased by a single supply. Power-On Reset (POR) circuits continually monitor the bias voltages (PVCC and VCC) and the voltage at the EN pin. The POR function initiates soft-start operation 384 clock cycles after the EN pin voltage is pulled to be above 0.8V; all input supplies exceed their POR thresholds and the PLL locking time expires. The enable pin can be used as a voltage monitor and to set desired hysteresis with an internal 30µA sinking current going through an external resistor divider. The sinking current is disengaged after the system is enabled. This feature is especially designed for applications that require higher input rail POR for better undervoltage protection. For example, in 12V applications, RUP = 53.6k and RDOWN = 5.23k will set the turn-on threshold (VEN_RTH) to 10.6V and turn-off threshold (VEN_FTH) to 9V, with 1.6V hysteresis (VEN_HYS). These numbers are explained in Figure 29 on page 15. Output Capacitors The ISL8200AM is designed for low output voltage ripple. The output voltage ripple and transient requirements can be met with bulk output capacitors (COUT) with low enough Equivalent Series Resistance (ESR); the recommended ESR is <10mΩ. When the total ESR is below 4mΩ, a capacitor (CFF) between 2.2nF-10nF is recommended; CFF is placed in parallel with RSET, in between the VOUT and VOUT_SET pin. COUT can be a low ESR tantalum capacitor, a low ESR polymer capacitor or a ceramic capacitor. The typical capacitance is 330µF and decoupled ceramic output capacitors are used per phase. The internally optimized loop compensation provides sufficient stability margins for all ceramic capacitor applications with a recommended total value of 300µF per phase. Additional output filtering may be needed if further reduction of output ripple or dynamic transient spike is required. During shutdown or fault conditions, the soft-start is quickly reset while UGATE and LGATE immediately change state (<100ns) upon the input dropping below POR. HIGH = ABOVE POR; LOW = BELOW POR VCC POR PVCC POR Using Multiple Phases The ISL8200AM can be easily connected in parallel with other ISL8200AM modules and current share providing an additional 10A per phase. For 2 phases, simply follow the schematic shown in Figure 4. A rough summary shows that the modules share VIN, VOUT, GND and have their ISHARE pins tied together with a 10kΩ resistor to ground (per phase). When using 3 phases or more, it is recommended that you add the following circuitry (see Figure 24) to ensure proper startup. The circuit shown in Figure 24 ensures proper startup by injecting current into the ISHARE line until all phases are ready to start regulating. For additional phases, the RC time constant, using RINC and CG, might have to be adjusted to increase the turn on time of the PFET (QSHR). For 3-4 phases, these are the values, RINC = 243k, RPH1 = 15k, QSHR = Small Signal PFET, CG = 22nF). 14 EN POR AND 384 CYCLES SOFT-START OF MODULE PLL LOCKING FIGURE 25. SOFT-START INITIALIZATION LOGIC Soft-Start The ISL8200AM has an internal digital pre-charged soft-start circuitry, which has a rise time inversely proportional to the switching frequency and is determined by a digital counter that increments with every pulse of the phase clock. The full soft-start time from 0V to 0.6V can be estimated by Equation 5. 2560 t SS = -------------f SW (EQ. 5) FN8271.2 September 13, 2012 ISL8200AM The ISL8200AM has the ability to work under a pre-charged output. The PWM outputs will not be fed to the drivers until the first PWM pulse is seen. The low side MOSFET is held low for the first clock cycle to provide charge for the bootstrap capacitor. If the pre-charged output voltage is greater than the final target level but less than the 113% setpoint, switching will not start until the output voltage is reduced to the target voltage and the first PWM pulse is generated. The maximum allowable pre-charged level is 113%. If the pre-charged level is above 113% but below 120%, the output will hiccup between 113% (LGATE turns on) and 87% (LGATE turns off) while EN is pulled low. If the pre-charged load voltage is above 120% of the targeted output voltage, then the controller will be latched off and not be able to power-up. OV = 113% FIRST PWM PULSE VOUT TARGET VOLTAGE FIGURE 28. SOFT-START WITH VOUT BELOW OV BUT ABOVE FINAL TARGET VOLTAGE Voltage Feedforward The voltage applied to the FF pin is fed to adjust the sawtooth amplitude of the channel. The amplitude the sawtooth is set to is 1.25 times the corresponding FF voltage when the module is enabled. This configuration helps to maintain a constant gain (GM = VIN • DMAX/ΔVRAMP) and input voltage to achieve optimum loop response over a wide input voltage range. The sawtooth ramp offset voltage is 1V (equal to 0.8V*1.25), and the peak of the sawtooth is limited to VCC - 1.4V. With VCC = 5.4V, the ramp has a maximum peak-to-peak amplitude of VCC - 2.4V (equal to 3V); so the feed-forward voltage effective range is typically 3x as the ramp amplitude ranges from 1V to 3V. SS SETTLING AT VREF + 100mV FIRST PWM PULSE VOUT TARGET VOLTAGE 0.0V 2560 t ss ≈ -------------f SW -100mV 384 t ss_DLY ≈ ---------f SW A 384 cycle delay is added after the system reaches its rising POR and prior to the soft-start. The RC timing at the FF pin should be sufficiently small to ensure that the input bus reaches its static state and the internal ramp circuitry stabilizes before soft-start. A large RC could cause the internal ramp amplitude not to synchronize with the input bus voltage during output start-up or when recovering from faults. A 1nF capacitor is recommended as a starting value for typical applications. The voltage on the FF pin needs to be above 0.8V prior to soft-start and during PWM switching to ensure reliable regulation. In a typical application, FF pin can be shorted to the EN pin. FIGURE 26. SOFT-START WITH VOUT = 0V FIRST PWM PULSE SS SETTLING AT VREF + 100mV VOUT TARGET VOLTAGE INIT. VOUT -100mV FIGURE 27. SOFT-START WITH VOUT < TARGET VOLTAGE R V EN_HYS = -----------------------------UP NxI EN_HYS R VCC R UP • V EN_REF = ------------------------------------------------------DOWN V –V EN_FTH EN_REF GRAMP = 1.25 where N is number of EN pins connected together VCC - 1.4V ∑ V EN_FTH = V EN_RTH – V EN_HYS 0.8V ΔV RAMP = max(V CC_FF × G RAMP , VCC - 1.4V - V RAMP_OFFSET ) V CC_FF = max(0.8V, V FF ) VCC_FF UPPER LIMIT LIMITER SAWTOOTH AMPLITUDE (ΔVRAMP) VIN VRAMP_OFFSET = 1.0V FF LOWER LIMIT (RAMP OFFSET) 0.8V RUP SYSTEM DELAY RDOWN EN EN_POR IEN_HYS = 30µA OV, OT, OC, AND PLL LOCKING FAULTS FIGURE 29. SIMPLIFIED ENABLE AND VOLTAGE FEEDFORWARD CIRCUIT 15 FN8271.2 September 13, 2012 ISL8200AM Power Good Overvoltage Protection (OVP) The Power-Good comparators monitor the voltage on the internal VMON1 pin. The trip points are shown in Figure 30. PGOOD will not be asserted until after the completion of the soft-start cycle. The PGOOD pulls low upon both EN’s disabling it or the internal VMON1 pin’s voltage is out of the threshold window. PGOOD will not be asserted until after the completion of the soft-start cycle. PGOOD will not pull low until the fault is present for three consecutive clock cycles. The Overvoltage (OV) protection indication circuitry monitors the voltage on the internal VMON1 pin. The UV indication is not enabled until the end of soft-start. In a UV event, if the output drops below -13% of the target level due to some reason (cases when EN is not pulled low) other than OV, OC, OT, and PLL faults, PGOOD will be pulled low. Current Share The IAVG_CS is the current of the module. ISHARE and ISET pins source a copy of IAVG_CS with 15µA offset, i.e., the full scale will be 126µA. The share bus voltage (VISHARE) set by an external resistor (RISHARE = RISET/NCTRL) represents the average current of all active modules. The voltage (VISET) set by RISET represents the average current of the corresponding module and is compared with the share bus (VISHARE). The current share error signal (ICSH_ER) is then fed into the current correction block to adjust each module’s PWM pulse accordingly. The current share function provides at least 10% overall accuracy between ICs, up to 3 phases. The current share bus works for up to 6-phase. Figure 4 further illustrates the current sharing aspects of the ISL8200AM. CHANNEL 1 UV/OV AND PGOOD END OF SS1 +20% +13% VMON1 +9% VREF -9% -13% PGOOD LATCH OFF AFTER 120% OV PGOOD FIGURE 30. POWER-GOOD THRESHOLD WINDOW When there is only one module in the system, the ISET and ISHARE pins can be shorted together and grounded via a single resistor to ensure zero share error - a resistor value of 5k (paralleling 10k on ISET and ISHARE) will allow operation up to the OCP level. 16 OV protection is active from the beginning of soft-start. An OV condition (>120%) would latch the IC off (the high-side MOSFET to latch off permanently; the low-side MOSFET turns on immediately at the time of OV trip and then turns off permanently after the output voltage drops below 87%). The EN and PGOOD are also latched low at OV event. The latch condition can be reset only by recycling VCC. There is another non-latch OV protection (113% of target level). At the condition of EN low and the output over 113% OV, the lower side MOSFET will turn on until the output drops below 87%. This is to protect the overall power trains in case of a single channel of a multi-module system detecting OV. The low-side MOSFET always turns on at the conditions of EN = LOW and the output voltage above 113% (all EN pins are tied together) and turns off after the output drops below 87%. Thus, in a high phase count application (multi-module mode), all cascaded modules can latch off simultaneously via the EN pins (EN pins are tied together in multiphase mode), and each IC shares the same sink current to reduce the stress and eliminate the bouncing among phases. Over-Temperature Protection (OTP) When the junction temperature of the IC is greater than +150°C (typically), EN pin will be pulled low to inform other cascaded channels via their EN pins. All connected ENs stay low and release after the IC’s junction temperature drops below +125°C (typically), a +25°C hysteresis (typically). Overcurrent Protection (OCP) The OCP function is enabled at startup. The load current sampling ICS1 is sensed by sampling the voltage across Q2 MOSFET rDS(ON) during turn on through the resistor between OCSET and PHASE pin. IC1 is compared with the Channel Overcurrent Limit ‘111µA OCP’ comparator, and waits 7-cycles before OCP condition is declared. The module’s output current (ICS1) plus a fixed internal 15µA offset forms a voltage (VISHARE) across the external resistor, RISHARE. VISHARE is compared with a precision internal 1.2V threshold for a second method to detect OCP condition. Multi-module operation can be achieved by connecting the ISHARE pin of two or more modules together. In multi-module operation the voltage on the ISHARE pin correlates to the average current of all active channels. The output current of each module in multi-module operation is compared to a precise 1.2V threshold to determine the overcurrent condition. Additionally, each module has an overcurrent trip point of 111µA with 7-cycle delay. Note that it is not necessary for the RISHARE to be scaled to trip at the same level as the 111µA OCP comparator. Typically the ISHARE pin average current protection level should be higher than the phase current protection level. With an internal RISEN-IN of 2.2kΩ, the OCP level is set to the default value. To lower the OCP level, an external RISEN-EX is connected between OCSET and PHASE pin. The relationships between the external RISEN-EX values and the typical output current IOUT(MAX) OCP levels for ISL8200AM are shown in FN8271.2 September 13, 2012 ISL8200AM Figures 31 through 33. It is important to note that the OCP level shown in these graphs is the average output current and not the inductor ripple current. 16 1.8VOUT 14 OCP (A) When OCP is triggered, the controller pulls EN low immediately to turn off UGATE and LGATE. 2.5VOUT 12 10 1.2VOUT 8 6 4 2 0 0 5 10 RSEN (kΩ) 15 20 FIGURE 31. 5VIN 16 5.0VOUT In a multi-module system, with the EN pins wired OR’ed together, all modules can immediately turn off, at one time, when a fault condition occurs in one or more modules. A fault would pull the EN pin low, disabling all the modules and therefore not creating current bounce. Thus, no single channel would be over stressed when a fault occurs. OCP (A) 12 1.8VOUT 10 8 6 2.5VOUT 4 2 0 0 10 20 30 40 50 The Oscillator is a sawtooth waveform, providing for leading edge modulation with 350ns minimum dead time. The oscillator (Sawtooth) waveform has a DC offset of 1.0V. Each channel’s peak-to-peak of the ramp amplitude is set to be proportional to the voltage applied to its corresponding FF pin. FIGURE 32. 12VIN 16 1.8VOUT Frequency Synchronization and Phase Lock Loop OCP (A) 12 1.2VOUT 10 8 2.5VOUT 6 5.0VOUT 4 2 0 0 20 Since the EN pins are pulled down under fault conditions, the pull-up resistor (RUP) should be scaled to sink no more than 5mA current from EN pin. Essentially, the EN pins cannot be directly connected to VCC. Oscillator RSEN (kΩ) 14 For overload and hard short conditions, the overcurrent protection reduces the regulator RMS output current much less than full load by putting the controller into hiccup mode. A delay time, equal to 3 soft-start intervals, is entered to allow the disturbance to be cleared out. After the delay time, the controller then initiates a soft-start interval. If the output voltage comes up and returns to the regulation, PGOOD transitions high. If the OC trip is exceeded during the soft-start interval, the controller pulls EN low again. The PGOOD signal will remain low and the soft-start interval will be allowed to expire. Another soft-start interval will be initiated after the delay interval. If an overcurrent trip occurs again, this same cycle repeats until the fault is removed. Fault Handshake 1.2VOUT 14 In a high input voltage, high output voltage application, such as 20V input to 5V output, the inductor ripple becomes excessive due to the fixed internal inductor value. In such applications, the output current will be limited from the rating to approximately 70% of the module’s rated current. 40 60 RSEN (kΩ) FIGURE 33. 20VIN 17 80 100 The FSYNC_IN pin has two primary capabilities: fixed frequency operation and synchronized frequency operation. By tying a resistor (RFS) to PGND1 from the FSYNC_IN pin, the switching frequency can be set at any frequency between 700kHz and 1.5MHz. The ISL8200AM has an integrated 59kΩ resistor between FSYNC_IN and PGND1, which sets the default frequency to 700kHz. The frequency setting curve shown in Figure 34 is provided to assist in selecting an externally connected resistor RFS-ext between FSYNC_IN and PGND1 to increase the switching frequency. FN8271.2 September 13, 2012 ISL8200AM • Place a high frequency ceramic capacitor between (1) PVIN and PGND (pin 18) and (2) a 10µF between PVCC and PGND1 (pin 15) as close to the module as possible to minimize high frequency noise. High frequency ceramic capacitors close to the module between VOUT and PGND will help to minimize noise at the output ripple. SWITCHING FREQUENCY (kHz) 1500 1400 1300 1200 • Use large copper areas for power path (PVIN, PGND, VOUT) to minimize conduction loss and thermal stress. Also, use multiple vias to connect the power planes in different layers. 1100 1000 • Keep the trace connection to the feedback resistor short. 900 800 700 0 100 200 300 400 RFS-ext (kΩ) FIGURE 34. RFS-ext vs SWITCHING FREQUENCY By connecting the FSYNC_IN pin to an external square pulse waveform (such as the CLKOUT signal, typically 50% duty cycle from another ISL8200AM), the ISL8200AM will synchronize its switching frequency to the fundamental frequency of the input waveform. The voltage range on the FSYNC_IN pin is VCC/2 to VCC. The Frequency Synchronization feature will synchronize the leading edge of the CLKOUT signal with the falling edge of Channel 1’s PWM clock signal. CLKOUT is not available until the PLL locks. The locking time is typically 210µs for FSW = 700kHz. EN is not released for a soft-start cycle until FSYNC_IN is stabilized and the PLL is in locking. It is recommended to connect all EN pins together in multiphase configuration. The loss of a synchronization signal for 13 clock cycles causes the IC to be disabled until the PLL returns locking, at which point a soft-start cycle is initiated and normal operation resumes. Holding FSYNC_IN low will disable the IC. • Use remote sensed traces to the regulation point to achieve a tight output voltage regulation, and keep them in parallel. Route a trace from VSEN_REM- to a location near the load ground, and a trace from feedback resistor to the point-of-load where the tight output voltage is desire. • Avoid routing any sensitive signal traces, such as the VOUT and VSENREM- sensing point near the PHASE pin or any other noise-prone areas. • FSYNC_IN is a sensitive pin. If it is not used for receiving an external synchronization signal, then keep the trace connecting to the pin short. A bypass capacitor value of 100pF, connecting between FSYNC_IN pin and GND1, can help to bypass the noise sensitivity on the pin. To Load GND To VOUT RFBT CEN CPVCC Setting Relative Phase-Shift on CLKOUT Depending upon the voltage level at PH_CNTRL, set by the VCC resistor divider output, the ISL8200AM operates with CLKOUT phase shifted, as shown in Table 2. The phase shift is latched as VCC raises above POR so it cannot be changed on the fly. TABLE 2. DECODING PH_CNTRL RANGE PHASE FOR CLKOUT WRT CHANNEL 1 REQUIRED PH_CNTRL <29% of VCC -60° 15% VCC 29% to 45% of VCC 90° 37% VCC 45% to 62% of VCC 120° 53% VCC 62% to VCC 180° VCC Layout Guide To achieve stable operation, low losses, and good thermal performance, some layout considerations are necessary, which are illustrated in Figures 35 and 36. • The ground connection between PGND1 (pin 15) and PGND (pin 18) should be a solid ground plane under the module. 18 PVIN CIN COUT PGND VOUT FIGURE 35. RECOMMENDED LAYOUT FOR SINGLE PHASE SETUP The recommended layout considerations for operating multiple modules in parallel follows the single-phase guidelines as well as these additional points: • Orient VOUT towards the load on the same layer and connect with thick direct copper etch directly to minimize the loss. • Place modules such that pins 1-11 point away from power pads (PD1-4) so that signal busses (EN, ISHARE, CLKOUT-to-FSYNCIN) can be routed without going under the module. Run them along the perimeter as in Figure 36. • Keep remote sensing traces separate, and connect only at the regulation point. Four separate traces for VSEN_REM- and RFBT (which stands for remote feedback) as in the example in Figure 36. FN8271.2 September 13, 2012 ISL8200AM CLKOUT to FSYNC_IN EN ISHARE TO LOAD GND TO VOUT TO LOAD GND TO VOUT RFBT RFBT CEN CEN CPVCC CPVCC CIN COUT CIN COUT FIGURE 36. RECOMMENDED LAYOUT FOR DUAL PHASE SETUP 19 FN8271.2 September 13, 2012 ISL8200AM 3.5 12 LOSS (W) 2.5 MAX LOAD CURRENT (A) 3.0 3.3V 2.0 1.5V 1.5 0.8V 1.0 0.5 0.0 10 8 2 6 4 8 1.5V 0.8V 4 2 0 0 3.3V 6 10 60 70 FIGURE 37. POWER LOSS vs LOAD CURRENT (5V IN) 0 LFM FOR VARIOUS OUTPUT VOLTAGES 90 100 110 FIGURE 38. DERATING CURVE (5VIN) 0 LFM FOR VARIOUS OUTPUT VOLTAGES 12 5.0 MAX LOAD CURRENT (A) 4.5 5.0V 4.0 3.5 LOSS (W) 80 AMBIENT TEMPERATURE (°C) LOAD CURRENT (A) 3.3V 3.0 2.5 0.8V 2.0 1.5V 2.5V 1.5 1.0 0.5 0.0 10 8 2 4 6 8 10 3.3V 6 Thermal Considerations Empirical power loss curves, shown in Figures 37 to 40, along with θJA from thermal modeling analysis can be used to evaluate the thermal consideration for the module. The derating curves are derived from the maximum power allowed while maintaining the temperature below the maximum junction temperature of +125°C. In actual application, other heat sources and design margin should be considered. Package Description The structure of the ISL8200AM belongs to the Quad Flat-pack No-lead package (QFN). This kind of package has advantages, such as good thermal and electrical conductivity, low weight and small size. The QFN package is applicable for surface mounting technology and is being more readily used in the industry. The ISL8200AM contains several types of devices, including resistors, capacitors, inductors and control ICs. The ISL8200AM is a copper lead-frame based package with exposed copper thermal pads, which have good electrical and thermal conductivity. The copper lead frame and multi component assembly is overmolded with polymer mold compound to protect these devices. 20 1.5V 0.8V 2 60 70 80 90 100 110 AMBIENT TEMPERATURE (°C) LOAD CURRENT (A) FIGURE 39. POWER LOSS vs LOAD CURRENT (12VIN) 0 LFM FOR VARIOUS OUTPUT VOLTAGES 2.5V 4 0 0 5.0V FIGURE 40. DERATING CURVE (12VIN) 0 LFM FOR VARIOUS OUTPUT VOLTAGES The package outline and typical PCB layout pattern design and typical stencil pattern design are shown in the package outline drawing L23.15x15 on page 23. The module has a small size of 15mm x 15mm x 2.2mm. Figure 41 shows typical reflow profile parameters. These guidelines are general design rules. Users could modify parameters according to their application. PCB Layout Pattern Design The bottom of ISL8200AM is a lead-frame footprint, which is attached to the PCB by surface mounting process. The PCB layout pattern is shown in the Package Outline Drawing L23.15x15 on page 23. The PCB layout pattern is essentially 1:1 with the QFN exposed pad and I/O termination dimensions, except for the PCB lands being a slightly extended distance of 0.2mm (0.4mm max) longer than the QFN terminations, which allows for solder filleting around the periphery of the package. This ensures a more complete and inspectable solder joint. The thermal lands on the PCB layout should match 1:1 with the package exposed die pads. Thermal Vias A grid of 1.0mm to 1.2mm pitch thermal vias, which drops down and connects to buried copper plane(s), should be placed under the thermal land. The vias should be from 0.3mm to 0.33mm in diameter with the barrel plated with 1.0 ounce copper. Although adding more vias (by decreasing via pitch) will improve the thermal performance, diminishing returns will be seen as more FN8271.2 September 13, 2012 ISL8200AM Stencil Pattern Design Reflowed solder joints on the perimeter I/O lands should have about a 50µm to 75µm (2mil to 3mil) standoff height. The solder paste stencil design is the first step in developing optimized, reliable solder joins. Stencil aperture size to land size ratio should typically be 1:1. The aperture width may be reduced slightly to help prevent solder bridging between adjacent I/O lands. To reduce solder paste volume on the larger thermal lands, it is recommended that an array of smaller apertures be used instead of one large aperture. It is recommended that the stencil printing area cover 50% to 80% of the PCB layout pattern. A typical solder stencil pattern is shown in the Package Outline Drawing L23.15x15 on page 24. The gap width between pad to pad is 0.6mm. The user should consider the symmetry of the whole stencil pattern when designing its pads. A laser cut, stainless steel stencil with electropolished trapezoidal walls is recommended. Electropolishing “smooths” the aperture walls resulting in reduced surface friction and better paste release, which reduces voids. Using a trapezoidal section aperture (TSA) also promotes paste release and forms a "brick like" paste deposit that assists in firm component placement. A 0.1mm to 0.15mm stencil thickness is recommended for this large pitch (1.3mm) QFN. Reflow Parameters Due to the low mount height of the QFN, "No Clean" Type 3 solder paste per ANSI/J-STD-005 is recommended. Nitrogen purge is also recommended during reflow. A system board reflow profile depends on the thermal mass of the entire populated board, so it is not practical to define a specific soldering profile just for the QFN. The profile given in Figure 41 is provided as a guideline, to be customized for varying manufacturing practices and applications. 300 PEAK TEMPERATURE +230°C~+245°C; TYPICALLY 60s-70s ABOVE +220°C KEEP LESS THAN 30s WITHIN 5°C OF PEAK TEMP. 250 TEMPERATURE (°C) and more vias are added. Simply use as many vias as practical for the thermal land size and your board design rules allow. 200 SLOW RAMP (3°C/s MAX) AND SOAK FROM +100°C TO +180°C FOR 90s~120s 150 100 RAMP RATE ≤1.5°C FROM +70°C TO +90°C 50 0 0 100 150 200 250 300 350 DURATION (s) FIGURE 41. TYPICAL REFLOW PROFILE 21 FN8271.2 September 13, 2012 ISL8200AM Revision History The revision history provided is for informational purposes only and is believed to be accurate, but not warranted. Please go to web to make sure you have the latest Rev. DATE REVISION September 13, 2012 FN8271.2 CHANGE Initial Release. Products Intersil Corporation is a leader in the design and manufacture of high-performance analog semiconductors. The Company's products address some of the industry's fastest growing markets, such as, flat panel displays, cell phones, handheld products, and notebooks. Intersil's product families address power management and analog signal processing functions. Go to www.intersil.com/products for a complete list of Intersil product families. For a complete listing of Applications, Related Documentation and Related Parts, please see the respective device information page on intersil.com: ISL8200AM To report errors or suggestions for this datasheet, please go to www.intersil.com/askourstaff FITs are available from our website at http://rel.intersil.com/reports/search.php For additional products, see www.intersil.com/product_tree Intersil products are manufactured, assembled and tested utilizing ISO9000 quality systems as noted in the quality certifications found at www.intersil.com/design/quality Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see www.intersil.com 22 FN8271.2 September 13, 2012 Package Outline Drawing L23.15x15 23 LEAD QUAD FLAT NO-LEAD PLASTIC PACKAGE (PUNCH QFN) Rev 3, 10/10 A 3.22 23 2.2 0.2 H AB 1.02 23 22 21 20 20 21 22 0.05 M H AB 1 2 3 4 5 19 9.9 13.8 4.7 4.26 2.36 1.34 18 3.4 4.38 X4 17 0.8 2.28 16 0.2 H AB 17 15.0±0.2 3.4 18 15.0±0.2 15.8±0.2 16 1 2 4.7 19 35x 0.5 0.82 4.8 (35x 0.40) 15.8±0.2 7x 1.9 ±0.05 23 18x 0.75 3 4 B 5 6 7 8 10x 1.1 ±0.1 9 10 11 15 11x 0.7 0.90 14 13 12 2.0 5.82 11x 1.85 ±0.05 7x 0.8 TOP VIEW BOTTOM VIEW 8° ALL AROUND 2.2 ±0.2 NOTES: S 0.2 S FN8271.2 September 13, 2012 SIDE VIEW 0.25 S 0.05 1. Dimensions are in millimeters. 2. Unless otherwise specified, tolerance : Decimal ± 0.2; Body Tolerance ±0.2mm 3. The configuration of the pin #1 identifier is optional, but must be located within the zone indicated. The pin #1 identifier may be either a mold or mark feature. ISL8200AM 6 7 8 9 10 11 12 13 14 15 18x 1.3 ±0.1 X4 3x 2.6 5.18 4.73 4.68 4.03 4.08 3.63 8.15 3.58 2.93 6.88 2.98 5.58 2.48 23 1 0.00 0.00 3.02 4.13 2.13 2.83 3.43 0.83 1.53 1.07 0.00 1.77 1.47 3.52 1.92 4.64 4.13 6.03 6.73 6.78 8.09 6.11 5.67 4.97 4.37 3.67 3.07 2.37 1.77 1.07 0.60 6.48 4.88 5.68 6.88 8.14 5.53 5.03 2.08 1.58 0.78 0.18 1.82 0.65 0.00 2.32 4.12 4.72 5.22 5.82 6.07 3.12 4.07 4.77 5.17 5.87 6.02 3.62 3.02 3.62 STENCIL PATTERN WITH SQUARE PADS-1 TYPICAL RECOMMENDED LAND PATTERN 6.73 6.23 4.18 4.68 4.38 3.88 1.83 2.33 1.53 1.53 0.00 0.52 0.82 2.87 3.17 4.69 4.99 6.52 0.00 0.52 0.82 2.82 3.67 6.48 4.58 4.28 2.23 1.48 0.88 0.13 0.00 0.60 FN8271.2 September 13, 2012 5.50 5.80 6.52 STENCIL PATTERN WITH SQUARE PADS-2 ISL8200AM 8.15 3.67 3.43 5.62 2.97 2.92 3.62 4.22 4.92 5.52 6.82 8.10 2.52 0.00 2.57 2.83 1.87 2.13 1.47 4.42 2.37 0.32 0.77 1.48 0.37 0.77 0.78 0.28 0.88 0.00 1.68 0.13 0.33 4.92 3.07 1.38 2.18 6.06 5.72 3.67 1.88 1.43 0.73 0.93 2.75 3.05 4.03 4.83 24 8.10 6.48 5.48 4.88 4.18 3.58 2.88 2.28 1.58 0.98 0.28 0.00 0.32 1.02 1.62 2.32 0.00 2.53 1.83 4.37 5.78 5.13 4.97 6.03 tag 5.72 8.14 6.88 4.68 4.18 0.78 1.02 0.00 1.82 2.32 3.12 3.62 4.42 4.92 5.83 5.72 5.98