19-0459; Rev 0; 1/96 Low-Profile, 5V/12V or A MAXIMA djustable, Step-Up "DC-DC Converters for Flash Memory/PCMCIA Cards General Description The MAX606/MAX607 are the smallest CMOS, step-up DC-DC converters available for flash memory and PC (PCMCIA) cards. They switch at up to 1MHz, permitting the entire circuit to fit in 0.25in2, yet remain under 1.35mm high to fit Type 1, 2, and 3 card standards. These devices operate from a 3V to 5.5V input and pro- vide a +4%-accurate output that is preset to 5V or 12V, or adjustable from Vin to 12.5V. Their guaranteed out- put current is 6OmA at 12V. The MAX606 switches at up to 1MHz and fits Type 1 (thinnest standard) flash memory and PCMCIA cards. It uses a thin, 1.19mm high, 5uH inductor and small, 0.68yF output capacitors. The entire circuit fits in 0.25in? and is less than 1.35mm high. Tne MAX607 switches at up to 500kHz, fitting Type 2 and 3 cards, as well as hand-held devices where height requirements are not as critical, It uses less board area than the MAX606, fitting in 0.16in2, but Features # Lowest-Height Circuit (1.35mm, max) +4% Regulated Output (5V, 12V, or Adjustable) # Guaranteed 60mA Output at 12V # 1MHz Switching Frequency (MAX606) 1pA Logic-Controlled Shutdown 3V to 5.5V Input Voltage Range @ Compact 8-Pin pMAX Package Ordering Information requires 2.5mm of height. It also has a lower no-load PART TEMP. RANGE PIN-PACKAGE supply current than the MAX606. MAX606C/D OC to +70C Dice Both devices use a unique, current-limited pulse-fre- MAX606ESA A0C to +85C 8S0 quency-modulation (PFM) control scheme that optimizes MAXB0BEUA -40C to +85C 8 MAX efficiency over all input and output voltages. Other fea- MAX607C/D OC to +70C Dice* tures include 1pA logic-controlled shutdown and user- MAX607ESA -40C to +85C 8S0 controlled soft-start to minimize inrush currents. MAX607EUA--40C. to 485C 8 pMAX The MAX606/MAX607 come in 8-pin UMAX and SO packages. The HMAX package uses haif the board area of a standard 8-pin SO and has a maximum height of just 1.141mm. Applications PCMCIA Cards Memory Cards Single PCMCIA Slot Programming Digital Cameras Flash Memory Programming * Contact factory for dice specifications. Typical . Operating Circuit INPUT 43V 10 +55V Hand-Held Equipment osaF Lome ont. Pin Configuration => > = __ IN ON/OFF SHON ix OUTPUT TOP VIEW <7 maxaa 12v @ 60mA penn [3 ra) ux ra MAX606- out o.6auF re [2] MAXIAA TF) our x2 _ MAX606 SHON [3] yaxeo7 [6] ss GND pan w [4] 5] GND SO/MAX = PA MKIAA Maxim integrated Products 4.14 For free samples & the latest literature: http:/Awww.maxim-ic.com, or phone 1-800-998-8800 ZO9OXVW/909XVWMAX606/MAX607 Low-Profile, 5V/12V or Adjustable, Step-Up DC-DC Converters for Flash Memory/PCMCIA Cards ABSOLUTE MAXIMUM RATINGS IN to GND ooo cece cceeceeteeneenreassecarsesseceamersereessens -0.3V to +6V LX, OUT to GND. -0.3V to +15V PGND 0 GND...ccesccccesecsssseecsscssssseancsuetecescentssvessessesnecssens +0.3V FB to GND.......... .-0.3V to (Voc + 0.3V) SS, SHDN to GND ooo cssesscsssessesecsseeneesesssenseees -0.3V to +6V Continuous Power Dissipation (Ta = +70C) SO (derate 5.88mW/C above +70C)........ccccncee 471mW UMAX (derate 4.10mW/C above +70C) .. - 830mW Operating Temperature Range ...........0...... C to +85C Storage Temperature 0... ec cescsetscseseceteresseetsseeeees +160C Lead Temperature (soldering, 10sec) . Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the davice. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum tating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (VIN = 3.3V, GND = PGND = FB = OV, SHON = IN, Ta = 0C to +85C, unless otherwise noted. Typical values are at Ta = +25C.) PARAMETER CONDITIONS MIN TYP MAX UNITS Supply Voltage 3.0 5.5 Vv Undervoltage Lockout Threshold 2.4 2.8 Vv 3V < Vin <5.5V |FB=IN, ILoAp = OmA to 90mA 48 5.0 .2 Vv Output Voltage (Note 1) FB=GND, Loap=OnAtw60mA| 115 120 125 FB Regulation Setpoint 0.1V < Veg < (Vin - 0.1V) 1.96 2.00 2.04 v Adjustable Output Voitage Range 0.1V < Veg < (Vin - 0.1V) VIN 12.5. Vv Line Regulation VIN = 3V to 5.5V 0.5 % Switch On-Resistance 0.4 1 Q Switch Off Leakage Vix = 12V 10 pA Switch Current Limit 0.7 14 A VSHON = Vin, Vss = 150mV 30 45 60 SS Resist kQ esistance VaHEN = Veg = OV 05 Qui t Supply Current Ve = 13V MAX606 250 500 A uiescent Supply Curre! OUT = MAXGO? 150 300 u Shutdown Quiescent Current VSHDN = OV, OUT = IN 0.01 10 yA OUT Input Current Vout = 13V 80 HA . . 3V < Vin < 5.5V MAX606 1.9 3.0 43 - K is-V Switch On-Time Constant (K) (ton = K/ Vin) MAX607 38. 60 86 is . . . 2V < (Vout + 0.5V - Vin) < 8V (see Pulse- Switch Off-Time Ratio Frequency-Modulation Control Scheme section) 0.3 0.7 SHON input Low Voltage VIN = 3V 0.25ViN v SHDN Input High Voltage VIN = 5.5V 0.66Vin Vv SHON Input Current VEHDN = OV or Vin +1 pA Vin = 3V to 5.5V. For Veg below this voltage, FB Input Low Voltage output regulates to 12V. 0.1 v . Vin = 3V to 5.5V. For Veg above this voltage, . FB Input High Voltage output regulates to 5V. Vin - 0.1 Vv FB Input Current Ves = 2.05V, Vout = 13V 200 nA 4-12 MAAXILRALow-Profile, 5V/12V or Adjustable, Step-Up DC-DC Converters for Flash Memory/PCMCIA Cards ELECTRICAL CHARACTERISTICS (continued) (Vin = 3.3V, GND = PGND = FB = OV, SHDN = IN, Ta = -40C to +85C, unless otherwise noted.) (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS Supply Voltage 3.0 5.5 v Undervoltage Lockout Threshold 28 Vv 3V < Vin < 5.5V FB = IN, lLoap = OmA to 90mA 4.75 .25 Output Voltage pu g (Note 1) FB = GND, Loan =OmAto60mA| 11.4 12.6 v FB Regulation Setpoint 0.1V < Veg < (Vin -0.1V) 1.94 2.06 v Adjustable Output Voltage Range 0.1V < Veg < (Vin - 0.1V) VIN 12.5 Vv Switch On-Resistance 1 2 Switch Off Leakage Vix = 12V 10 HA Switch Current Limit 0.55 1.25 A Vv = VIN, Vss = 1 Vv SS Resistance SHON = Vin. Vss = 150m 30 60 kQ VSHDN = Vsg = OV 0.5 MAX606 500 Quiescent Supply Current vi = 13V uiescent Supply Curren OUT MAX6O7 300 pA Shutdown Quiescent Current VSHDN = OV, OUT = IN 10 pA OUT Input Current VouT = 13V 85 pA . . 3V < Vin < 5.5V MAX606 1.8 45 h On- t (KC 7 Switch On-Time Constant (K) (ton = K/ViN) MAX607 35 30 ps-V . . . 2V < (Vout + 0.5V - Vin) < 8V (see Pulse- Switch Off-Time Ratio Frequency-Modulation Control Scheme section) 0.3 07 SHDN Input Low Voltage VIN = 3V 0.25ViN v SHON Input High Voltage VIN = 5.5V 0.66ViN Vv SHDN Input Current VSHON = OV or Vin +1 yA VIN = 3V to 5.5V. For Veg below this voltage, FB Input Low Voltage output regulates to 12V. 01 V . VIN = 3V to 5.5V. For Veg above this voltage, . FB Input High Voltage output regulates to 5V. Vin - 0.4 Vv FB Input Current VeB = 2.05V, Vout = 13V 200 nA Note 1: The load specification is guaranteed by DC parametric tests and is not production tested in circuit. Note 2: Specifications to -40C are guaranteed by design, not production tested. FRAAXKLSA 4-13 ZLO9XVW/909XUWMAX606/MAX607 Low-Profile, 5V/12V or Adjustable, Step-Up DC-DC Converters for Flash Memory/PCMCIA Cards Typical Operating Characteristics (Vin = 3.3V, Ta = +25C, unless otherwise noted.) MAXIMUM OUTPUT CURRENT MAX606 MAX607 +00 vs. INPUT VOLTAGE 00 EFFICIENCY vs. OUTPUT CURRENT 100 EFFICIENCY vs. OUTPUT CURRENT = lore ae /) i 90 ort EH Lt ot 90 fone 4 Pel Ml Co Le i Z sw vatN Y Lg Le ei oo hig TT Peer ng z tT _ Ul {ml Ao _ 2 Tan Pitty ail all, = y = ar il il Sy CU a TE UT TT , 4 35 ue CCC 5 Cen TT Uh gE LTP E 40 Le All ST = | L Bo ll LT 90 Bil! PUI HS = Stator, F: oo LLY UIT [aVaur = 12. va = 33 oo LL a A Vout = 12V, Vy = 33M Zo |e imo A TUN Yor=s4 ns AA LIM 1 3 eo = 033 2 aT TNs | 10 ba: Vout = 12, Vin = BV 10 YH bc: Vour = 12V, Vy = SV 0 ours 1 9 CLUE LUM Lo: Vout =v, t= 5 CLUE UIT fo: vaur = 5, y= 5 2 3 4 5 6 oor of 1 10 100 1000 oo of 4 10 100 1000 INPUT VOLTAGE (V) OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) SHUTDOWN QUIESCENT CURRENT SWITCH ON-TIME vs. SWITCH OFF-TIME vs. vs. TEMPERATURE INPUT VOLTAGE OUTPUT VOLTAGE 0 Vin = 3V, 3.3V, AND 5V 3000 4000 A: MAX607, Vin=5V 3 0.9 Ts MINUTE WAIT BEFORE MEASUREMENT 3500 B: MAX606, Vin = 5V i ss x ger ea ae ao : 1 VIN = = 0.7 2000 = 1 3 0.6 S = 2500 E05 2 1500 iE 2000 2 04 5 5 1500 = = 1000 = Oe & % 1000 01 500 500 0 0 0 40 -20 0 2 40 60 80 25 30 35 40 45 50 55 2345678 9 1011 12 TEMPERATURE (C) INPUT VOLTAGE (V) OUTPUT VOLTAGE (V) MAX606 MAX607 NO-LOAD SUPPLY CURRENT NG-LDAD SUPPLY CURRENT naptime vs. TEMPERATURE vs. TEMPERATURE vs. TEMPERA 10,000 RVow 10,000 * 10,000 < B: Vour = 12V, MBROS40 DIODE = = 12V, MBR0540 DIODE 1000 3 C: Vout = 5V, MBA0520 DIODE 3a = 5V, MBR0520 DIODE _ 5 D: Vour = 5V, MBR0540 DIODE 5 = 5V, MBRO540 DIODE = 0 & z iB E 1000 z 1000 c ' wn g 2 0.01 Vout = = 12V 100 100 0.001 hal 40 20 0 2 40 60 80 40 20 0 2 40 60 80 40-20 0 2 40 60 60 TEMPERATURE (C) TEMPERATURE (C) TEMPERATURE (C} 414 PA AXIAALow-Profile, 5V/12V or Adjustable, Step-Up DC-DC Converters for Flash Memory/PCMCIA Cards (VIN = 3.3V, Ta = +25C, unless otherwise noted.) MAX606 MAX607 MAXIMUM OUTPUT CURRENT MAXIMUM GUTPUT CURRENT vs. INDUCTOR VALUE vs. INDUCTOR VALUE 400 = = A: Vout = 5V, Vin = 3 = 350 Vour = 12V, Vin = 5V aad _ C: Vout = 12V, Vin = 3.3V g & = so 3 3 Ee e z = 200 2 2 180 z $ z* = = 100 2 A Vout = 5V, Vin= 3 = B: Vour = 12V, Vin = 5V = 50 C: Vout = 12V, Vin = 3.3V 0 1x100 ixio! 1x10 INDUCTOR VALUE (j1H) INDUCTOR VALUE (2H) MAX606 START-UP DELAY AND INRUSH CURRENT 5Ous/div khoap = 1MA, INPUT = 3.3V, Cos = 10nF, Cour= 2x 0.68aF MRAXLMA Typical Operating Characteristics (continued) SHON 2vidiv OUTPUT 5V/div INPUT 200mAdiv START-UP DELAY vs. SOFT START CAPAGITOR A = B: MAX606 Vout = 12V C: MAX607 Vout = 5V 0: MAX606 =5V LOOXVIN/909XVIN 0 txto! it! xt? txt txto# 1x08 SOFT-START CAPACITOR (pF) MAX607 START-UP DELAY AND INAUSH CURRENT 400mA } i 4 100p,s/div ILoap = 1mA, INPUT = 3.3V, Css = 10nF, Cour = 4.7 pF 4-15Low-Profile, 5V/12V or Adjustable, Step-Up DC-DC Converters for Flash Memory/PCMCIA Cards OUTPUT 20rnA div MAX606/MAX607 OUTPUT 100mV/div INPUT S500mVidiv SOmVidiv EN... 10ps/div ILoap = SmA to 60mA, OUTPUT = 12V, INPUT = 3.3V cep poddveb reper ou ~ 1 ay SOus/div toa = 10mA, OUTPUT 12V, INPUT = 3.3V TO 4.3V 4-16 Typical Operating Characteristics (continued) (VIN = 3.3V, Ta = +25C, unless otherwise noted.) MAX607 LOAD-TRANGIENT RESPONSE ouput FRO ca SomVidiv OUTPUT Fd 20mA/div 20ps/div {Loan = SmA to 60mA, OUTPUT = 12V, INPLT = 3.3 MAXGO7 LINE-TRANSIENT RESPONSE OUTPUT 100mV/div av wet Lit _ 500mv/div settee : hee : bees since {BY 100pys/div ILoap = 10mA, OUTPUT = 12V, INPUT = 3.3V T0.4.3V MAAXLAALow-Profile, 5V/12V or Adjustable, Step-Up DC-DC Converters for Flash Memory/PCMCIA Cards Pin Description PIN NAME FUNCTION 1 PGND | Power Ground. Source of N-channel power MOSFET. 2 FB Feedback Input. Connect to IN for 5V output, to GND for 12V output, or to a resistive voltage divider between OUT and GND for an adjustable output between IN and 12.5V. 3 SHDN Shutdown Input, active low. Connect to GND to power down, or to IN for normal operation. Output power FET is held off when SHDN is low. 4 IN Supply Voltage Input: 3.0V to 5.5V 5 GND Analog Ground 6 ss Soft-Start Input 7 OUT Output. Always connect directly to the circuit output. 8 LX Drain of N-channel power MOSFET INPUT 43V 10 45.5V ay ON/OFF _IC]SS MAx606 cht ie INPUT +3.3V p BIN on/OFF SHON ix MAAXLAN MAX606 am SS MAx607 OUT ca] 4 een a a 7 OUTPUT 5V @ 120mA PGND Figure 1. 12V Standard Application Circuit Standard Application Circuits This data sheet provides two predesigned standard application circuits. The circuit of Figure 1 produces 12V al 6OmA from a 3V to 5.5V input. Table 1 lists component values and part numbers for both the MAX606 and MAX607 variations of this circuit. The circuit of Figure 2 PAAXAMA Figure 2. 5V Standard Application Circuit produces 5V at a typical output current of 120mA from a 3.3V input. Each application circuit is designed to deliver the full rated output load current over the temperature range listed. Component values and part numbers for this circuit are listed in Table 2. See Table 3 for compo- nent suppliers phone and fax numbers. 4-17 ZLO9XVIW/909XVWMAX606/MAX607 Low-Profile, 5V/12V or Adjustable, Step-Up DC-DC Converters for Flash Memory/PCMCIA Cards Table 1. Suggested Components for 12V Standard Application Circuit of Figure 2 Table 2. Suggested Components for 5V Standard Application Circuit of Figure 1 4-18 DESIGNATION MAX606 MAX607 DESIGNATION MAX606 MAX607 4 5pH inductor 10pH inductor Lt 5yH, 1A inductor JOUH, 0.7A inductor Dale ILS-3825-XX Sumida CLS62-100 Dale ILS-3825-XX Sumida CLS62B- 100 D1 0.5A, 20V diode 0.5A, 20V diode D1 0.5A, 20V diode 0.5A, 20V diode Motorola MBRO520L | Motorola MBRO520L Motorola MBRO520L | Motorola MBROS20L C1 O.1pF ceramic cap. | 0.1pF ceramic cap. C1 0.1pF ceramic cap. | 0.1uF ceramic cap. 2.x 0.68pF ceramic cap.| 2.2uF ceramic cap. 2x 0.68pyF caramic cap.| 2.2yF ceramic cap. c2 Marcon Marcon c2 Marcon Marcon THCR20E1E684Z THCR30E1E225M THCR20E1E684Z THCR30E1E225M 2x 0.68uF ceramic cap.| 2 x 1pF ceramic cap. 4.7uF ceramic cap. | 4.7uF ceramic cap. c3 Marcon Marcon C3 Marcon Marcon THCR20E1 684Z THCR30E1E105M THCR30E1E475M THCR30E1E475M C4 10nF ceramic cap. 10nF ceramic cap. c4 10nF ceramic cap. 10nF ceramic cap. Detailed Description Table 3. Component Suppliers The remainder of this document contains the detailed information you'll need to design a circuit that differs from the two Standard Application Circuits. If you are using one of the predesigned circuits, the following sections are purely informational. The MAX606/MAX607 CMOS, step-up DC-DC convert- ers employ a current-limited pulse-frequency modula- tion (PFM) control scheme. This PFM control scheme regulates a boost topology to convert input voltages between 3V and 5.5V into either a pin-programmable 5V/12V output, or an adjustable output between VIN and 12.5V. It optimizes performance over all input and output voltages, and guarantees output accuracy to 4%. The ultra-high switching frequency (typically 1MHz for the MAX606 and 0.5MHz for the MAX607) permits the use of extremely small external components, making these converters ideal for use in Types 1, 2, and 3 flash memory and PCMCIA applications. Pulse-Frequency-Modulation Control Scheme The MAX606/MAX607 employ a proprietary, current- limited PFM control scheme that combines the ultra-low supply current of traditional pulse-skipping PFM con- verters with the high full-load efficiency of current-mode pulse-width-modulation (PWM) converters. This particu- lar control scheme is similar to the one used in previous current-limited PFM devices, which governed the SUPPLIER PHONE FAX Dale Inductors (605) 668-4131 (605) 665-1627 Motorola (602) 244-3576 | (602) 244-4015 Sumida USA (708) 956-0666 | (708) 956-0702 Sumida Japan (03) 607-5111 (03) 607-5144 Marconfunted | (708) 696-2000 | (708) 518-9985 switching current via maximum on-time, minimum off- time, and current limit, except it varies the on and off times according to the input and output voltages. This important feature enables the MAX606/MAX607 to achieve ultra-high switching frequencies while main- taining high output accuracy, low output ripple, and high efficiency over a wide range of loads and input/output voltages. Figure 3 shows the functional diagram of the MAX606/ MAX607. The internal power MOSFET is turned on when the error comparator senses that the output is out of reg- ulation. The power switch stays on until either the timing circuit turns it off at the end of the on-time, or the switch current reaches the current limit. Once off, the switch remains off during the off-time. Subsequently, if the out- put is still out of regulation, another switching cycle is ini- tiated. Otherwise, the switch remains turned off as long as the output is in regulation. PAAXNMALow-Profile, 5V/12V or Adjustable, Step-Up DC-DC Converters for Flash Memory/PCMCIA Cards UNDER- VOLTAGE LOCKOUT SHON TIMING CIRCUIT ton torr LX INTERNAL POWER 12 SWITCH CURRENT-LIMIT COMPARATOR f PGND < 88 ouT ERROR COMPARATOR f Figure 3. Functional Diagram The on/off times are determined by the input and output voltages: ton = K/VIN torr = 0.5 x K / (VouT + VDIODE - VIN) K is typically 3ys-V for the MAX606 and 6ys-V for the MAX607. This factor is chosen to seat the optimum switching frequency and the one-cycle current limit, which determines the no-load output ripple at low out- put-to-input voltage differentials. The factor of 0.5 in the off-time equation is the typical switch off-time ratio. This ratio guarantees high efficiency under a heavy load by allowing the inductor to operate in continuous-conduc- tion mode. For example, a switch off-time ratio of 1 would cause the device to operate on the edge of dis- continuous-conduction mode. To determine the actual switch off-time ratio for a par- ticular device, measure ton, toFF, Vin, and Vout, and MAAXIAA then solve for the ratio by substituting these values into the off-time equation. Unlike PWM converters, the MAX606/MAX607 generate variable-frequency switching noise. However, the amplitude of this noise does not exceed the product of the switch current limit and the output capacitor equiva- lent series resistance (ESR). Traditional clocked-PFM or pulse-skipping converters cannot make this claim. Output Voltage Selection The MAX606/MAX607 output voltage is pin-program- mable to 5V and 12V, and also adjustable to voltages between VIN and 12.5V. Connect FB to IN for a 5V out- put, to GND for a 12V output, or to a resistive divider between the output and GND for an adjustable output. Always connect OUT to the output. When FB is connected to IN or GND, an internal volt- age divider is configured to produce a predetermined 4-19 ZLO9OXVW/S09XVWMAX606/MAX607 Low-Profile, 5V/12V or Adjustable, Step-Up DC-DC Converters for Flash Memory/PCMCIA Cards OUTPUT GND PGND Vout = Vrer a +1) = = Vper = 2V Figure 4. Adjustable Output Voltage output. However, when the voltage at FB is between 0.1V above ground and 0.1V below Vin, the device is in the adjustable output mode. In this mode, the MAX606/MAX607 output voltage is set by two external resistors, R1 and R2 (Figure 4), which form a voltage divider between the output and FB. Use the following equation to determine the output voltage: Vout = VREF (R1/R2 + 1) where VREF = 2V. To simplify the resistor selection: R1 = R2 [(Vout/ VREF) - 1] Since the input current at FB is 200nA maximum, large values (up to 100kQ) can be used for R2 with no signifi- cant loss of accuracy. For 1% error, the current through R2 should be at least 100 times the FB input bias current. Soft-Start Connecting a capacitor to the Soft-Start (SS) pin ensures a gradually increasing current limit during power-up or when exiting shutdown, thereby reducing initial inrush currents. This feature can be useful, for example, when an old batterys increased series resis- tance limits initial inrush currents. Using the soft-start feature in a situation like this minimizes the risk of over- loading the incoming supply. Soft-start timing is controlled by the value of the SS capacitor. On power-up, the SS capacitor is charged by the 2V reference through an internal, 45kQ pull-up resis- tor. As the voltage on the SS pin increases, the voltage at the SS clamp output also increases, which in turn raises the current-limit threshold. The Start-Up Delay vs. SS Capacitor graph in the Typical Operating Characteristics shows typical timing characteristics for 4-20 selected capacitor values and circuit conditions. The soft-start capacitor is discharged each time the MAX606 or MAX607 is put into shutdown, including during under- voltage lockout and when powering down at IN. If the circuit is required to start up with no foad, as in flash memory programming supplies, soft-start is not required. Omitting the soft-start capacitor permits a minimum output voltage rise time from the shutdown state, improving flash memory access time. Undervoltage Lockout The MAX606/MAX607 monitor the supply voltage at IN and operate for supply voltages greater than 2.8V. When an undervoltage condition is detected, control logic turns off the output power FET and discharges the soft-start capacitor to ground. The control logic holds the output power FET in an off state until the supply voltage rises above the undervoltage threshold, at which time a soft-start cycle begins. Shutdown Mode Connecting SHDN to GND will hold the MAX606/ MAX607 in shutdown mode. !n shutdown, the output power FET is off, but there is still an external path from IN to the load via the inductor and diode. The internal reference also turns off, which causes the soft-start capacitor to discharge. Typical device standby current in shutdown mode is 0.01pA. For normal operation, connect SHDN to IN. A soft-start cycle is initiated when the MAX606/MAX607 exit shutdown. Applications Information Inductor Selection Use a 5yH inductor for the MAX606 and a 10uH induc- tor for the MAX607. See Table 3 for a list of component suppliers. Higher inductor values allow greater load currents due to operation in continuous-conduction mode, while lower inductor values lead to smaller phys- ical size due to lower energy-storage requirements and lower output-filter-capacitor requirements. Potential drawbacks of using lower inductor values are increased output ripple, lower efficiency, and lower out- put-current capability due to operation in discontinu- ous-conduction mode. (See the Maximum Output Current vs. Inductor Value graph in the Typical! Operating Characteristics.) The inductor must have a saturation (incremental) cur- rent rating equal to the peak switch-current limit, which is 1.1A. For highest efficiency, minimize the inductor's DC resistance. MAAKXIIMALow-Profile, 5V/12V or Adjustable, Step-Up DC-DC Converters for Flash Memory/PCMCIA Cards Diode Selection The MAX606/MAX607's high switching frequency demands a high-speed rectifier. Use a Schottky diode with at least a 0.5A average current rating and a 1.2A peak current rating, such as an MBRO520L. See Table 3 for a list of component suppliers. Capacitor Selection Output Filter Capacitor The output voltage ripple is a function of the output capacitors equivalent series resistance (ESR) and capacitance. For best performance, use ceramic capacitors. Higher-ESR capacitors, such as tantalums, will cause excessive ripple. See Table 3 for a list of component suppliers. The output voitage ripple is approximately 100mVp-p for the 12V Standard Application Circuit (Figure 1) and 50mV for the 5V circuit (Figure 2). To further reduce this ripple, or to reduce the ripple on a different application circuit, increase the value of the output filter capacitor. If this capacitor is low ESR (e.g., ceramic), the output voltage ripple will be dominated by this capacitance. input Bypass Capacitors For applications where the MAX606/MAX607 are physi- cally close to the input supplys filter capacitor (e.g., in PCMCIA drivers from the host computer), the input bypass capacitor may not be necessary. PAAKXLAA In other applications where the MAX606/MAX607 are more than a few inches a away from the supply (such as memory cards), the input bypass capacitor is need- ed to reduce reflected current ripple to the supply and improve efficiency by creating a low-impedance path for the ripple current. Under these circumstances, the associated high Q and iow ESR of ceramic capacitors do not diminish the problem. Therefore, include some low-Q, moderate-ESR capacitance (e.g., tantalum) at the input in order to reduce ringing. See Table 3 for a list of component suppliers. Layout The MAX606/MAX607s high-frequency operation and high peak currents make PC board layout critical to minimize ground bounce and noise. Locate input bypass and output filter capacitors as close to the device pins as possible. Ali connections to OUT (and to FB when operating in adjustable-output mode) should also be kept as short as possible. A ground plane is recommended. Solder GND and PGND directly to the ground plane. Refer to the MAX606/MAX607 evaluation kit manual for a suggested surface-mount layout. 4-21 ZLO9XVW/909XVWMAX606/MAX607 Low-Profile, 5V/12V or Adjustable, Step-Up DC-DC Converters for Flash Memory/PCMCIA Cards 4-22 Chip Topography POND +i] ie wel, Pann Bi | mt ix POND Tm, ~ X 9 opa a (2.134mm) se. a 2 Bout SHON i fit ss V+ i - * ae -- GND v 0.058" , {1.473mm) TRANSISTOR COUNT: 613 SUBSTRATE CONNECTED TO GND. MAXIMA