FAN5067M

www.fairchildsemi.com FAN5067 ACPI Dual Switch Controller Features Description • Implements ACPI control with PWROK, SLP_S3 and SLP_S5 • Switch and linear regulator controller for 3.3V or 5V Dual • Linear regulator controller and linear regulator for VADJ Dual output adjustable from 2.5V to 3.5V • Break-before-Make • Drives all N-Channel MOSFETs plus NPN • Latched overcurrent protection for outputs • Power-up softstarts for the linear regulators • UVLO guarantees correct operation for all conditions • 16 pin SOIC package The FAN5067 is an ACPI Switch Controller for Pentium IV Platforms. It is controlled by PWROK, SLP_S3 and SLP_S5, and provides 3.3V or 5V Dual and VADJ Dual output for SDRAM or DDR with 200mA minimum base current for an external NPN transistor. An on-board precision low TC reference achieves tight tolerance voltage regulation without expensive external components. The FAN5067 also offers integrated Current Limiting that protects each output, and softstart for the linear regulators. The FAN5067 is available in a 16 pin SOIC. Applications • Willamette Platform ACPI Controller • Northnwood Platform ACPI Controller Block Diagram +12V +5V Standby PWR_OK 9 10 SLP_S3 SLP_S5 3 8 7 Softstart 1 2 16 Osc +5V Main 15 Over Current Main 4 14 VADJ Dual (SDRAM or DDR) 13 +5V Standby + - + - REF 12 REF + + 5 REF 6 +3.3V or 5V Dual 11 REV. 1.0.1 5/2/02 FAN5067 PRODUCT SPECIFICATION Pin Assignments QCAP PUMP 5VSTBY DUALOUT1 DUALOUT2 DUALVFB SLP_S3 SLP_S5 1 2 3 4 5 6 7 8 FAN5067 16 15 14 13 12 11 10 9 VCCP 5VMAIN VADJOUT VADJ VADJFB GND SS PWR_OK Pin Definitions Pin Number 2 Pin Name Pin Function Description 1 QCAP Charge pump cap. Attach flying capacitor between this pin and PUMP to generate high voltage from standby power. 2 PUMP Charge pump switcher. 3 5VSTBY 5V Standby. Apply +5V standby on this pin to run the circuit in standby mode. 4 DUALOUT1 Dual output main gate control. Attach this pin to a transistor powering 3.3V or 5V dual from the main supply. 5 DUALOUT2 Dual output standby gate control. Attach this pin to a transistor powering 3.3V or 5V dual from the 5V standby supply. 6 DUALFB Dual output voltage Feedback. Pin 6 is used as the input for the voltage feedback control loop for 3.3V or 5V dual. 7 SLP_S3 SLP_S3. Control signal governing the Soft Off state S3. Internal current source pulls this line high if left open. 8 SLP_S5 SLP_S5. Control signal governing the Soft Off state S5. Internal current source pulls this line high if left open. 9 PWR_OK PWR_OK. Control signal for switches. Internal current source pulls this line high if left open. 10 SS Softstart. Attach a capacitor to this pin to determine the softstart rate. 11 GND Ground. Connect this pin to ground. 12 VADJFB Adjustable Dual Voltage Feedback. Pin 12 is used as the input for the voltage feedback loop for the adjustable dual voltage. 13 VADJ Adjustable Dual Voltage. Pin 13 sources VADJ during standby. 14 VADJOUT Adjustable Dual Voltage Base Control. Attach this pin to an NPN transistor powering VADJ from the 5V Main. 15 5VMAIN 5V Main. Apply +5V Main on this pin to run the VADJ base drive. 16 VCCP Main Power. Apply +12V through a diode on this pin to run the circuit in normal mode. Bypass with a 0.1µF capacitor. When 12V is not present, this pin produces voltage doubled 5V standby. REV. 1.0.1 5/2/02 PRODUCT SPECIFICATION FAN5067 Absolute Maximum Ratings VCCP 15V All Other Pins 13.5V Junction Temperature, TJ 150°C Storage Temperature -65 to 150°C Lead Soldering Temperature, 10 seconds 300°C Thermal Resistance Junction to Ambient ΘJA 85°C/W Thermal Resistance Junction-to-case, ΘJC 24°C/W Recommended Operating Conditions Parameter Min. Typ. Max. Units +3.3VMAIN 3.135 3.3 3.465 V +5VMAIN 4.75 5 5.25 V +5VSTBY 4.75 5 5.25 V +12V 11.4 12 12.6 V 70 °C Ambient Operating Temperature REV. 1.0.1 5/2/02 Conditions 0 3 FAN5067 PRODUCT SPECIFICATION Electrical Specifications (V+5VSTBY = V+5VMAIN =5V, V+3.3V = 3.3V, V+12V = 12V and TA = +25°C using circuit in Figure 4, unless otherwise noted.) The • denotes specifications which apply over the full operating temperature range. Parameter Conditions Min. Typ. Max. Units DUAL Output VOut1, On • 10 VOut1, Off I = 10µA • VOut2, On Standby • 5 DUALOUT2 On • 3.135 100 1 Total Output Voltage Variation Maximum Drive Current DUALOUT1 On • Minimum Load Current DUALOUT2 On • V 200 mV mA 3.3 3.465 V 50 mA mA Overcurrent Limit: Undervoltage 80 %Vout Overcurrent Delay Time 150 µsec Output Driver Deadtime See Figure 2: Main → Standby • 2 6 µsec See Figure 2: Standby → Main • 200 1000 nsec VADJ DUAL IB Total Voltage Variation1 VO > 3.3V • 100 mA VO ≤ 3.3V • 150 mA R1 = R2 = 10KΩ • 2.375 VADJ Output Voltage Range 2.5 1.25 VADJ Current V mA Overcurrent Limit 80 %Vref Overcurrent Delay Time 150 µsec See Figure 2 • 365 V 3.5 400 Output Driver Overlap Time • 2.625 1 5 µsec Common Functions Charge Pump Frequency 250 KHz +5VSTBY UVLO 4.5 V +5VSTBY UVLO Hysteresis 0.5 V +12V UVLO 7.5 V +12V UVLO Hysteresis 800 mV +5VSTBY Current MAIN Power Present +12V Current Input Logic HIGH • Input Logic LOW • Softstart Current Control Line Input Current 10 25 mA 2.5 10 mA 2.0 V 0.8 6 SLP_S5, SLP_S3, PWROK Over Temperature Shutdown • µA 100 150 V µA °C Note: 1. Voltage Regulation includes Initial Voltage Setpoint and Output Temperature Drift. 4 REV. 1.0.1 5/2/02 PRODUCT SPECIFICATION FAN5067 Table 1. Power Descriptors PWROK SLP_S3 SLP_S5 Main Dual Output VADJ State Usage 1 1 1 ON ON, Powered from MAIN ON, Powered from MAIN S0 S0 1 0 1 OFF ON, Powered from STANDBY ON, Powered from STANDBY S3 S0 → S3 0 0 1 OFF ON, Powered from STANDBY ON, Powered from STANDBY S3 S3 0 1 1 OFF ON, Powered from STANDBY ON, Powered from STANDBY S3 S3 → S0 1 0 0 OFF ON, Powered from STANDBY OFF S5 S0 → S5 0 0 0 OFF ON, Powered from STANDBY OFF S5 S5 0 1 0 OFF ON, Powered from STANDBY OFF S5 S5 → S0 1 1 0 ON ON, Powered from MAIN OFF S5 Not Used 0 0 0→1 OFF ON, Powered from STANDBY S5* * OFF *When PWROK = SLP_S3 = 0 and SLP_S5 transitions from 0 to 1, the FAN5067 remains in the S5 state. See Table 2. 101 111 001 000 S0 S3 S5 110 Not Used Blocked 011 100 010 Figure 1. Power State Usage Diagram REV. 1.0.1 5/2/02 5 FAN5067 PRODUCT SPECIFICATION Table 2. State Transition Table Initial Control Signal Initial Control Signal 000 001 010 011 100 101 110 111 000 — x - x — x — S0 001 S5 — S5 - S5 — S5 S0 010 — x - x — x — S0 011 S5 — S5 — S5 — S5 S0 100 — x — x — x — S0 101 S5 — S5 — S5 — S5 S0 110 — x — x — x — S0 111 S5 S3 S5 S3 S5 S3 S5 — Notes: 1. Control Signal order: PWROK, SLP_S3, SLP_S5. 2. Dash (—) signifies that no state change takes place. 3. X signifies that the state transition is blocked, and the FAN5067 remains in the S5 state. OUTPUT OUTPUT 1 2V 2V 2V tOT tDT tDT 2V 2V 2V tOT 2V OUTPUT2 2V OUTPUT2 Figure 2. Deadtime and Overlap Time Measurements STBY STBY SLP_S3# SLP_S3# PWROK PWROK MAIN MAIN SLP_S5# DUAL VADJ Figure 3. Control Logic for Dual Voltages and Memory Voltages 6 REV. 1.0.1 5/2/02 PRODUCT SPECIFICATION FAN5067 Application Circuits +5V Standby 5V Main D1 +12V 3.3V Main C2 C1 Q1 Q2 C3 1 2 3 4 5 6 7 16 15 14 13 12 11 10 U1 FAN5067 9 8 Q3 R1 C4 R2 Adjustable Dual 3.3V Dual (PCI) SLP_S3 C5 SLP_S5 C6 PWR_OK Figure 4. ACPI Selector Table 3. FAN5067 Application Bill of Materials Reference Manufacturer, Part # C1-4 Various 4 100nF, 25V Ceramic C5–6 Various 2 220µF, 6V Tantalum, ESR ~ 0.1Ω R1 Various 1 * *10KΩ for 2.5V, 16.5KΩ for 3.3V R2 Various 1 10KΩ Resistor D1 Fairchild MBR0520L 1 20V, 1/2A Schottky Q1 Fairchild FDS4410DY 1 N-channel MOSFET Rds,on = 20mΩ @ Vgs = 4.5V Q2 Fairchild NDS9956A 1 N-channel MOSFET Rds,on = 110mΩ @ Vgs = 4.5V Q3 Fairchild TIP41A 1 NPN VCE ~0.4V @ IC = 2A, IB = 100mA U1 Fairchild FAN5067 1 ACPI Dual Switch Controller REV. 1.0.1 5/2/02 Quantity Description Comments 7 PRODUCT SPECIFICATION FAN5067 Vcore 2V/17.4A Synchronous ATX 5Vmain, 18A Conversion Vnb 1.8V/2A RC5058 SO24 Linear Linear/Switch Typedet 5Vstdby 720mA Vagp 3.3V/1.5V/2A Vck 2.5V/600mA Linear Vtt 1.5V/2A RC1587 12V, 6A 3.3Vmain, 14A FAN5067 SO16 Linear Switch 3.3Vdual or 5Vdual 2.4A/500mA/500mA PCI Linear PWROK SLP_S3# SLP_S5# Linear 2.5V DDR or 3.3V SDRAM Figure 5. System Architectural Block Diagram (Power Paths Only) REV. 1.0.1 5/2/02 8 FAN5067 Application Information The FAN5067 Controller The FAN5067 is a fully compliant ACPI controller IC. Used with an ATX power supply, it generates a 3.3V or 5V Dual and power for either SDRAM or DDR, and has a large array of additional protection functions integrated in. Overview of ACPI The Advanced Configuration and Power Interface, or ACPI, is a system for controlling the use of power in a computer. It enables the computer manufacturer and the computer user to determine the computer’s power usage dynamically. For example, when the computer has been unused for a certain time, the monitor and peripherals could be turned off, and their states saved to memory. After a longer period, the processor could be turned off, and the memory saved to disk. A peripheral could then re-awaken the entire system on the occurrence of an event, such as the arrival of a FAX on a modem. As shown in Figure 5, the available power inputs to the computer system from the ATX power supply are +5V main, +12V main, +3.3V main, and +5V standby. “Main” means that these power outputs are available under full-power operation of the system, but can be turned off in some of the powersaving modes. “Standby” means that this power output is always present. The most general ACPI system requires four dual outputs: 5V dual, 3.3V dual, 3.3V SDRAM, and 2.5V dual. “Dual” means that the power can be (but is not necessarily) present whether the main power supplies are present or not. To ensure the presence of these outputs, while not overloading the standby power, they have dual inputs, from both main power and standby. The presence or absence of the dual outputs is determined by the control signals to the FAN5067. ACPI States As shown in Table 1, there are three ACPI states that are of primary concern to the system designer, designated S0, S3 and S5. S0 is the full-power state, the state of the computer when it is being actively used. The other two states are sleep states, reflecting differing levels of power-down. S3 is a state in which the processor is powered down, but its last state is being preserved in IC memory, which is kept on. Since memory is fast, the computer can quickly come back up to full operation. However, this state continues to draw moderate power, due to the memory being kept alive. PRODUCT SPECIFICATION It is anticipated that only the following state transitions will occur: S0 → S3, S0 → S5, S3 → S5, S5 → S0, and S3 → S0; the transition S5 → S3 will occur only as an intermediate state during the transition from S5 → S0. To prevent overcurrent limit from activating, the FAN5067 blocks this transition. For example, when PWROK = SLP_S3 = 0, and SLP_S5 transitions from 0 to 1, the FAN5067 remains in the S5 state. See Table 2. Dual Output The dual output is intended to power subsystems such as the computer’s PCI slots. A typical application that would require the use of 3.3V dual rather than +3.3V main for a PCI slot would be the use of a modem: if the system needs to be able to awaken from sleep when the modem receives incoming data, then that slot must be powered from dual, because main power is off. Other slots not requiring dual power can be configured using the control signals. 3.3V dual can be generated by two MOSFETs, one from +3.3V main, the other from +5V standby, as shown in Figure 4. When main power is present, the MOSFET Q1 is turned on as a switch, so that input and output are connected together. When main power is absent, the MOSFET Q2 is controlled by the FAN5067 as a linear regulator, generating a regulated 3.3V from +5V standby. The MOSFET Q1 must be connected as shown in the figures, to avoid back-feed. The state of the MOSFETs is controlled by the SLP_S3 and PWROK lines, as shown in Figure 3. When both SLP_S3 and PWROK are asserted, the main switch is on, and the linear regulator is off. If either line is de-asserted, the main switch is off and the linear regulator is on. Q1 and Q2 as shown in Table 3 have different RDS,on ratings. In a typical system, it is anticipated that full-power current will be about 2.4A maximum, and standby current will be about 500mA maximum. The difference in maximum currents means that Q2 can be a less expensive device than Q1. The design of the linear regulator for a 3.3V Dual necessitates a minimum load current of 50mA. Furthermore, in order to guarantee stable operation, the output capacitor on the 3.3V Dual must have a minimum ESR as shown in Figure 6. The hatched region shows acceptable values of ESR vs. output capacitance. Values of the output capacitor less than 47µF or greater than 300µF are not recommended. 5V Dual can be generated by applying 5V main to the source of Q1, and placing a resistor divider in the feedback to pin 6. S5 is a state in which memory is off, and the last state of the processor has been written to the hard disk. Since the disk is slow, the computer takes longer to come back to full operation. However, since memory is off, this state draws minimal power. 9 REV. 1.0.1 5/2/02 FAN5067 PRODUCT SPECIFICATION The output voltage of the Adjustable Dual is set with two resistors as shown in Figure 4, according to the equation. 300 R1 + R2 Vadj = 1.25V • ------------------R2 200 ESR (mΩ) 100 Dynamic Change of Adjust Output 47 100 200 C (µF) 300 330 400 There may be circumstances under which it is desired to dynamically change the output of the adjustable dual output. For example, a circuit that switches from 2.5V to 3.3V is shown in Figure 7. Figure 6. Recommended C vs. ESR for Stable Operation of the Dual Output VADJ Adjustable Dual Output The adjustable dual output is intended to provide power to SDRAM or DDR memory. Adjustable dual is generated by one external NPN bipolar acting as a linear regulator from +5V main, and one linear regulator internal to the FAN5067 from +5V standby, as shown in Figure 4, and in the block diagram on the front page. When main power is present, the NPN Q3 linear regulates, and when main power is absent, the internal linear regulator is on. Q3 cannot be substituted with a MOSFET. If used in one direction, the MOSFET’s body diode would permit back-feed; if used in the other direction, it would shortcircuit the linear regulator action. The state of the external MOSFET and the internal linear regulator is controlled by the SLP_S3 and PWROK lines, and additionally the SLP_S5 line, as shown in Figure 3. When SLP_S5 is de-asserted, both the external MOSFET and the internal linear regulator are off, and there is no output voltage on the 3.3V SDRAM line. If the SLP_S5 line is asserted, the adjustable dual output is on. In this condition, if either the SLP_S3 or the PWROK line, or both, are de-asserted, the linear regulator is on and the MOSFET is off. Only in the case if both the SLP_S3 and the PWROK lines are asserted, the MOSFET is on and the linear regulator is off. In a typical system, it is anticipated that standby current will be a maximum of 365mA, and full-power current may be as high as 2A. This places some significant constraints on the selection of Q3. Since its input may be as low as (5V – 5%) = 4.75V, there is only 4.75V – 3.3V = 1.45mV of VCE headroom for its operation as a linear regulator. For this reason the FAN5067 can provide up to 200mA of steady-state base current. The TIP41A device shown has a sufficiently low VCE, sat to guarantee worst-case regulation even at 2A IE with this base current. 10 VADJFB 3.3V Figure 7. Circuit for Dynamic Change of Output Voltage of the Adjustable A potential problem arises when using this circuit, however: When the transistor is turned on, the voltage on the VADJFB pin abruptly drops, until the output of the linear regulator can charge up the output caps. If the voltage to which it drops is less than about 80% of 1.25V, or 1.00V, the OC limit will trip and shut down the IC. This happens in this example because ( R 2 || R 3 ) 2.5V • ----------------------------------------- = 0.94V [ ( R 2 || R 3 ) + R1 ] To avoide this problem, systems that intended to dynamically change the output voltage of the adjustable dual output should disable the OC protection with the circuit shown in Figure 8. +5V_SB + 1µF 2N3906 1N4148 SS CSS 500K Figure 8. Circuit to Disable OC Protection REV. 1.0.1 5/2/02 PRODUCT SPECIFICATION FAN5067 FAN5067 ACPI Control Lines Softstart As already discussed, the FAN5067 outputs are controlled by the three ACPI control lines, SLP_S3, SLP_S5 and PWROK, as summarized in Tables 1 and 2. System designers must in particular be careful to ensure that their system is designed with SLP_S5, not SLP_S5; if SLP_S5 is used, it must be inverted before being used with the FAN5067. Pin 10 of the FAN5067 functions as a softstart. When power is first applied to the chip, a constant current is applied from the pin into an external capacitor, linearly ramping up the voltage. This ramp in turn controls the internal reference of the FAN5067. providing a softstart for the linear regulators. The actual state of the FAN5067 on power up will be determined by the state of its control lines. The control lines have internal pull-ups of approximately 40µA, and so can be controlled by open collector drivers if desired. In a noisy system, it may be desirable to filter these lines, which can be done with a 1KΩ resistor and a small capacitor. FAN5067 Dynamic Operation The FAN5067 is designed to minimize the output capacitance required to hold up the various output lines during transitions between different states. Thus in particular, the adjustable dual output has guaranteed minimum overlap time, the time (as shown in Figure 2) during a state transition during which both main and standby are connected to the output. This overlap time guarantees that a power source is always connected to the output, so that there will be no dip in the output voltage during state transitions. There is also a maximum overlap time, to ensure that the standby power doesn’t have to source main power very long, thus minimizing thermal stress on the standby device. The dual output is different because it is powered by both a linear regulator and a switch. If the linear regulator were to turn on while the switch is on (or vice versa) the linear regulator would supply power to the main line through the switch. For this reason, the linear regulator must be off before the switch is on, and vice versa. Thus, this output has guaranteed minimum deadtime when both linear regulator and switch are off. During this time, the output capacitor must hold up the load, and so there is also a specified maximum deadtime, allowing a maximum necessary capacitance to be selected, see below. Stability As with all linear regulators, the FAN5067’s linear regulators require a minimum load. With the exception of the 3.3V dual output, however, all of these minimum loads are internal to the FAN5067. The dual output requires a minimum load of 50mA; if a situation may occur in which the load is less than 50mA, additional steps may be necessary to ensure stability. Furthermore, depending on location, it may be necessary to bypass the drain (or collector) of the linear regulator with a low ESR capacitor for stability. As a rule of thumb, if the pass element is more than 1” from its power source, it should have a bypass. The switches in the system must be either on or off, and so softstart has no effect on their characteristics: if the appropriate control signals are asserted, they will turn on at once. The softstart is effective only during power on. During a transition between states, such as from S5 → S0, the linear regulators are not softstarted. It is important to note that the softstart pin is not an enable; pulling it low will not necessarily turn off all outputs. Charge Pump In main power operation, the FAN5067 is run from the +12V main supply. This supply also provides voltage to the various MOSFET gates. However, during standby, this supply is off. To provide power to the chip and the appropriate gates, the FAN5067 incorporates a free-running charge pump. As shown in Figure 4, and in the block diagram on the front page, a capacitor attached between pins 1 and 2 of the FAN5067 acts as a charge pump with internal diodes. The charge pump output is internally diode or’red with the 12V input. The 12V input must have a series diode to prevent back-feeding the charge pump to the + 12V main when in standby. The 12V input line needs a bypass capacitor for high-frequency noise rejection. If desired, the system may be operated without the 12V or the diode; however, the bypass capacitor must still be present. Overcurrent The FAN5067 does not directly detect current through the devices that power its outputs. Instead, it monitors the output voltages. In the event of a hard short, the voltage drops below 80% of nominal, and all outputs are latched off, and remain off until 5V standby power is recycled. The overcurrent latch off is delayed by 150µsec to prevent nuisance trips. During softstart, the overcurrent voltage monitors are kept proportional to the reference, to avoid tripping overcurrent during startup. In the S5 state, when the memory outputs are off, the voltage monitors on the memory lines are disabled, to prevent tripping the overcurrent. When turning these lines back on from the S5 state, overcurrent is prevented from tripping because the S3 state is blocked. See Table 2. If the adjustable dual is not used, its feedback line, pin 12, must be connected to 5V STBY, to prevent an overcurrent trip. REV. 1.0.1 5/2/02 11 FAN5067 PRODUCT SPECIFICATION UVLO If the +5V standby is below approximately 4.5V, the FAN5067 will leave off or turn off all outputs. Similar comments apply to the +12V main at 7.5V. The +5V standby UVLO has approximately 0.5V hysteresis, the +12V main UVLO 1V. Over Temperature The FAN5067 is capable of sourcing substantial current, 200mA minimum to the adjustable voltage transistor’s base during S0 and 144mA to the line during S3. As a result, there can be heavy power dissipation in the IC. While the FAN5067 is designed to accept this power dissipation, any overloading of outputs can cause excessive heating. If the FAN5067 die temperature exceeds about 150°, all outputs are shut off. Outputs remain off until the die temperature returns to its safe area. Transistor Selection External transistor selection depends on usage, differing for the linear regulators and the switches. The MOSFET switches, should be sized based on regulation requirements and power dissipation. Since the ATX outputs are ±5%, the outputs driven from them must be wider. As an example, if we want to hold 3.3V PCI to -10%, we can drop only 5% = 165mV across Q1. At 2.4A, this means Ql must have a maximum RDS,on of 165mV/2.7A = 68mΩ, including tolerance and self-heating effects. We thus choose a Fairchild FDC633N, which has 72mΩ maximum RDS, on at 4.5V VGS at 25°C. We can estimate power dissipation as (2.4A)2 * 42mΩ = 270mW, which should be acceptable for this package. Q2 is a MOSFET functioning as a linear regulator. Since it delivers only 500mA, it is easy to select a MOSFET, it need only be able to handle 500mA * (5V + 5% – 3.3V) = 1W. We select the Fairchild FDS6630A in an SO-8 package. Q3 is an NPN bipolar functioning as a linear regulator. As already discussed, it must have a VCE,sat lower than 1.45V at IE = 2A and IB = 200mA. Its power dissipation can be as high as (5V + 5%–3.3V) * 2A = 3.9W. Alternate for Adjustable Dual Instead of the bipolar transistor shown in Figure 4 for Q3, the linear pass element for the adjustable dual, a MOSFET and schottky diode can be used as shown in Figure 9. 12 5V Main FAN5067 14 12 Adjustable Dual Figure 9. Adjustable Dual with MOSFET The schottky should be chosen to have a low Vf at the specified adjustable voltage and current. The MOSFET’s RDS,on must then be lower than (5V -5% -VADJ -Vf)/IDual including temperature. An additional constraint is that the MOSFET must have a gate threshold voltage lower than 1.5V. For example, for 2.8A @3.3V, choose the diode to be an MBR835, and the MOSFET a Fairchild FDC653M. This same technique can then also be used for adjustable currents higher than can be achieved with the bipolar transistor. Output Capacitor Selection Output capacitor selection depends on whether the line has overlap time or not. For both the adjustable dual, there is guaranteed overlap time between when one source is turned on and the other source turned off. For this output, the output capacitor is not needed to hold up the supply, but only for noise filtering and to respond to transient loading. The dual output has deadtime between when one source is turned off and the other source turned on. During the time when both are off, the output current must be supplied by the output capacitor. Mitigating this, it must be realized that the system will be designed in such a way that the current has gone to its sleep value before the transition occurs. For example, the dual has a sleep current of 500mA maximum. Maximum deadtime is 6µsec, and so charge depletion is 500mA * 6µsec = 3µC. Suppose that we have a total of 8% drop due to the source tolerance and the MOSFET drop, and we are trying to hold 10% regulation. The remaining 2% = 66mV implies a minimum capacitance of 3µC/66m V = 45µF. REV. 1.0.1 5/2/02 PRODUCT SPECIFICATION FAN5067 Mechanical Dimensions 16 Lead SOIC Inches Symbol Min. A A1 B C D E e H h L N α ccc Millimeters Max. Min. 1.35 1.75 0.10 0.25 0.33 0.51 0.19 0.25 9.80 10.00 3.81 4.00 1.27 BSC .228 .010 .016 5.80 0.25 0.40 16 6.20 0.50 1.27 16 0° 8° 0° 8° — .004 — 0.10 16 1. Dimensioning and tolerancing per ANSI Y14.5M-1982. Max. .053 .069 .004 .010 .013 .020 .0075 .010 .386 .394 .150 .158 .050 BSC .244 .020 .050 Notes: Notes 2. "D" and "E" do not include mold flash. Mold flash or protrusions shall not exceed .010 inch (0.25mm). 3. "L" is the length of terminal for soldering to a substrate. 4. Terminal numbers are shown for reference only. 5 2 2 5. "C" dimension does not include solder finish thickness. 6. Symbol "N" is the maximum number of terminals. 3 6 9 E 1 H 8 h x 45° D C A1 A e B SEATING PLANE –C– LEAD COPLANARITY α L ccc C REV. 1.0.1 5/2/02 13 FAN5067 PRODUCT SPECIFICATION Ordering Information Product Number Package FAN5067M 16 pin SOIC FAN5067MX 16 pin SOIC in Tape & Reel DISCLAIMER FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. LIFE SUPPORT POLICY FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, or (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in significant injury to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. www.fairchildsemi.com 5/2/02 0.0m 006 Stock#DS30005067  2002 Fairchild Semiconductor Corporation