MAX1842EEE+T中文资料
MAX1742/MAX1842
Synchronous Rectification and Internal Switches
________________________________________________________________Maxim Integrated Products 1
General Description
The MAX1742/MAX1842 constant-off-time, pulse-width-modulated (PWM) step-down DC-DC converters are ideal for use in 5V and 3.3V to low-voltage conversion neces-sary in notebook and subnotebook computers. These devices feature internal synchronous rectification for high efficiency and reduced component count. They require no external Schottky diode. The internal 90m ΩPMOS power switch and 70m ΩNMOS synchronous-rectifier switch easily deliver continuous load currents up to 1A.The MAX1742/MAX1842 produce a preset 2.5V, 1.8V, or 1.5V output voltage or an adjustable output from 1.1V to V IN . They achieve efficiencies as high as 95%.
The MAX1742/MAX1842 use a unique current-mode,
constant-off-time, PWM control scheme, which includes Idle Mode? to maintain high efficiency during light-load operation. The programmable constant-off-time architec-ture sets switching frequencies up to 1MHz, allowing the user to optimize performance trade-offs between effi-ciency, output switching noise, component size, and cost. Both devices are designed for continuous output currents up to 1A. The MAX1742 uses a peak current limit of 1.3A (min) and is suitable for applications requir-ing small external component size and high efficiency.The MAX1842 has a higher current limit of 3.1A (min)and is intended for applications requiring an occasional burst of output current up to 2.7A. Both devices also fea-ture an adjustable soft-start to limit surge currents during startup, a 100% duty cycle mode for low-dropout opera-tion, and a low-power shutdown mode that disconnects the input from the output and reduces supply current below 1μA. The MAX1742/MAX1842 are available in 16-pin QSOP packages.
For similar devices that provide continuous output cur-rents up to 2A and 3A, refer to the MAX1644 and MAX1623 data sheets.
Applications
5V or 3.3V to Low-Voltage Conversion CPU I/O Ring Chipset Supplies
Notebook and Subnotebook Computers
Features
?±1% Output Accuracy ?95% Efficiency
?Internal PMOS and NMOS Switches
90mΩOn-Resistance at V IN = 4.5V 110mΩOn-Resistance at V IN = 3V ?Output Voltage
2.5V, 1.8V, or 1.5V Pin Selectable 1.1V to V IN Adjustable
?3V to 5.5V Input Voltage Range ?600μA (max) Operating Supply Current ?<1μA Shutdown Supply Current
?Programmable Constant-Off-Time Operation ?1MHz (max) Switching Frequency ?Idle-Mode Operation at Light Loads ?Thermal Shutdown
?Adjustable Soft-Start Inrush Current Limiting ?100% Duty Cycle During Low-Dropout Operation ?Output Short-Circuit Protection ?16-Pin QSOP Package
Ordering Information
Idle Mode is a trademark of Maxim Integrated Products.
Typical Configuration
Pin Configuration appears at end of data sheet.
For pricing, delivery, and ordering information,please contact Maxim/Dallas Direct!at 1-888-629-4642, or visit Maxim’s website at https://www.sodocs.net/doc/039334207.html,.
+ Denotes lead-free package.
M A X 1742/M A X 1842
1A/2.7A, 1MHz, Step-Down Regulators with
Synchronous Rectification and Internal Switches
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. 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 rating conditions for extended periods may affect device reliability.
V CC , IN to GND........................................................-0.3V to +6V IN to V CC .............................................................................±0.3V GND to PGND.....................................................................±0.3V All Other Pins to GND.................................-0.3V to (V CC + 0.3V)
LX Current (Note 1).............................................................±4.7A REF Short Circuit to GND Duration............................Continuous ESD Protection.....................................................................±2kV
Continuous Power Dissipation (T A = +70°C)SSOP (derate 16.7mW/°C above +70°C;part mounted on 1 in.2of 1oz. copper)...............................1W
Operating Temperature Range ...........................-40°C to +85°C Storage Temperature Range.............................-65°C to +150°C Lead Temperature (soldering, 10s)................................+300°C Note 1:LX has internal clamp diodes to PGND and IN. Applications that forward-bias these diodes should take care not to exceed
the IC’s package power dissipation limits.
MAX1742/MAX1842
1A/2.7A, 1MHz, Step-Down Regulators with
Synchronous Rectification and Internal Switches
_______________________________________________________________________________________3
ELECTRICAL CHARACTERISTICS (continued)
(V
= V = 3.3V, FBSEL = GND, T = 0°C to +85°C , unless otherwise noted. Typical values are at T = +25°C.)
M A X 1742/M A X 1842
1A/2.7A, 1MHz, Step-Down Regulators with
Synchronous Rectification and Internal Switches 4_______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS
Typical Operating Characteristics
(Circuit of Figure 1, T A = +25°C, unless otherwise noted.)
MAX1742/MAX1842
1A/2.7A, 1MHz, Step-Down Regulators with
Synchronous Rectification and Internal Switches
_______________________________________________________________________________________5
100959085807065605550750.001
0.01
1MAX1742
EFFICIENCY vs. OUTPUT CURRENT
(V IN = 5.0V, L = 6.0μH)
OUTPUT CURRENT (A)E F F I C I E N C Y (%)
0.1
100959085807065605550
750.001
0.01
1
MAX1742
EFFICIENCY vs. OUTPUT CURRENT
(V IN = 3.3V, L = 3.9μH)
OUTPUT CURRENT (A)E F F I C I E N C Y (%)
0.1
100
95908580
706560
55
50750.001
0.011
MAX1742
EFFICIENCY vs.OUTPUT CURRENT
(f PWM = 270kHz)
OUTPUT CURRENT (A)
E F F I C I E N C Y (%)
0.10.50.40.30.20.1-0.1-0.2-0.3-0.4-0.5
00.001
0.01
1
MAX1742
NORMALIZED OUTPUT ERROR vs. OUTPUT CURRENT
OUTPUT CURRENT (A)
N O R M A L I Z E D O U T P U T E R R O R (%)
0.1
3001002006009007001100
100040050080000.20.40.60.8 1.0
MAX1742
SWITCHING FREQUENCY vs. OUTPUT CURRENT
OUTPUT CURRENT (A)
F R E Q U E N C Y (k H z )
M A X 1742/M A X 1842
1A/2.7A, 1MHz, Step-Down Regulators with
Synchronous Rectification and Internal Switches 6_______________________________________________________________________________________
0V 0V 0V 0A MAX1742
STARTUP AND SHUTDOWN
I INPUT 1A/div
V OUTPUT 1V/div V SS
2V/div
MAX1742 toc06
1ms/div
V SHDN 5V/div 0V
MAX1742
LOAD-TRANSIENT RESPONSE
V OUTPUT
AC-COUPLED,50mV/div
I L
0.5A/div
MAX1742 toc07
10μs/div
0V
MAX1742
LINE-TRANSIENT RESPONSE
V INPUT 2V/div V OUTPUT 20mV/div AC-COUPLED
MAX1742 toc08
20μs/div
I OUT = 1A, V OUT = 1.5V, R TOFF = 100k Ω, L = 6μH
0150100502002503003504004505000
302010405060708090
1000
2
1
34
56
SUPPLY CURRENT vs. SUPPLY VOLTAGE
V IN (V)
N O -L O A D S U P P L Y C U R R E N T , I I N + I C C (μA )
S H U T D O W N S U P P L Y C U R R E N T , I I N + I C C (n A )
Typical Operating Characteristics (continued)
(Circuit of Figure 1, T A = +25°C, unless otherwise noted.)
01.00.52.01.53.02.53.54.54.05.0
10015020050250300350450400500
OFF-TIME vs. R TOFF
M A X 1742 t o c 10
R TOFF (k Ω)
t O F F (μs )
MAX1742/MAX1842
1A/2.7A, 1MHz, Step-Down Regulators with
Synchronous Rectification and Internal Switches
_______________________________________________________________________________________7
Typical Operating Characteristics (continued)
(Circuit of Figure 1, T A = +25°C, unless otherwise noted.)
0.001
0.01
0.1
1
10
MAX1842
EFFICIENCY vs. OUTPUT CURRENT
(V IN = 5.0V, L = 2.5μH)
OUTPUT CURRENT (A)1009590858070656055
5075E F F I C I E N C Y (%)
0.001
0.01
0.1
1
10
MAX1842
EFFICIENCY vs. OUTPUT CURRENT
(V IN = 3.3V, L = 1.5μH)
OUTPUT CURRENT (A)
100
9590858070656055
5075E F F I C I E N C Y (%)
0.001
0.01
0.11
10
MAX1842
EFFICIENCY vs. OUTPUT CURRENT
(f PWM = 270kHz)
I OUT (A)
10095908580706560555075E F F I C I E N C
Y (%)
MAX1842
NORMALIZED OUTPUT ERROR vs. OUTPUT CURRENT
0.001
0.010.1110
OUTPUT CURRENT (A)
0.1
-0.1
-0.2
-0.3
-0.4N O R M A L I Z E D O U T P U T E R R O R (%)
0400
200800600
10001200
1.0
1.5
0.5
2.0
2.5
3.0
MAX1842
SWITCHING FREQUENCY vs. OUTPUT CURRENT
OUTPUT CURRENT (A)
F R E Q U E N C Y (k H z )
MAX1842
STARTUP AND SHUTDOWN
V SS 2V/div
MAX1842 toc16
V SHDN 5V/div R OUT = 0.5Ω, R TOFF = 56k ΩV IN = 3.3V, V OUT = 1.5V
I INPUT 1A/div
V OUTPUT 1V/div 1ms/div
M A X 1742/M A X 1842
1A/2.7A, 1MHz, Step-Down Regulators with
Synchronous Rectification and Internal Switches 8_______________________________________________________________________________________
Pin Description
MAX1842
LOAD-TRANSIENT RESPONSE
V OUTPUT 50mV/div
I L
2A/div
MAX1842 toc17
10μs/div
MAX1842
LINE-TRANSIENT RESPONSE
V INPUT 2V/div
V OUTPUT 20mV/div AC-COUPLED
MAX1842 toc18
20μs/div
I OUT = 2.5A, V OUT = 1.5V, R TOFF = 100k Ω, L = 2.2μH
Typical Operating Characteristics (continued)
(Circuit of Figure 1, T A = +25°C, unless otherwise noted.)
MAX1742/MAX1842
1A/2.7A, 1MHz, Step-Down Regulators with
Synchronous Rectification and Internal Switches
_______________________________________________________________________________________9
_______________Detailed Description
The MAX1742/MAX1842 synchronous, current-mode,constant-off-time, PWM DC-DC converters step down input voltages of 3V to 5.5V to a preset output voltage of 2.5V, 1.8V, or 1.5V, or to an adjustable output voltage from 1.1V to V IN . Both devices deliver up to 1A of contin-uous output current; the MAX1842 delivers bursts of out-put current up to 2.7A (see the Extended Current Limit section). Internal switches composed of a 0.09ΩPMOS power switch and a 0.07ΩNMOS synchronous rectifier switch improve efficiency, reduce component count, and eliminate the need for an external Schottky diode.The MAX1742/MAX1842 optimize efficiency by operat-ing in constant-off-time mode under heavy loads and in Maxim’s proprietary Idle Mode under light loads. A sin-gle resistor-programmable constant-off-time control sets switching frequencies up to 1MH z, allowing the user to optimize performance trade-offs in efficiency,switching noise, component size, and cost. Under low-dropout conditions, the device operates in a 100%duty-cycle mode, where the PMOS switch remains con-tinuously on. Idle Mode enhances light-load efficiency by skipping cycles, thus reducing transition and gate-charge losses.
When power is drawn from a regulated supply, constant-off-time PWM architecture essentially provides constant-frequency operation. This architecture has the inherent advantage of quick response to line and load transients.The MAX1742/MAX1842s’ current-mode, constant-off-time PWM architecture regulates the output voltage by changing the PMOS switch on-time relative to the con-stant off-time. Increasing the on-time increases the peak inductor current and the amount of energy trans-ferred to the load per pulse.
Modes of Operation
The current through the PMOS switch determines the mode of operation: constant-off-time mode (for load currents greater than half the Idle Mode threshold), or Idle Mode (for load currents less than half the Idle Mode threshold). Current sense is achieved through a proprietary architecture that eliminates current-sensing I 2R losses.
Constant-Off-Time Mode
Constant-off-time operation occurs when the current through the PMOS switch is greater than the Idle Mode threshold current (which corresponds to a load current of half the Idle Mode threshold). In this mode, the regu-lation comparator turns the PMOS switch on at the end of each off-time, keeping the device in continuous-con-duction mode. The PMOS switch remains on until the
output is in regulation or the current limit is reached.When the PMOS switch turns off, it remains off for the programmed off-time (t OFF ). To control the current under short-circuit conditions, the PMOS switch remains off for approximately 4 x t OFF when V OUT Idle Mode Under light loads, the devices improve efficiency by switching to a pulse-skipping Idle Mode. Idle Mode operation occurs when the current through the PMOS switch is less than the Idle Mode threshold current. Idle Mode forces the PMOS to remain on until the current through the switch reaches the Idle Mode threshold,thus minimizing the unnecessary switching that degrades efficiency under light loads. In Idle Mode, the device operates in discontinuous conduction. Current-sense circuitry monitors the current through the NMOS synchronous switch, turning it off before the current reverses. This prevents current from being pulled from the output filter through the inductor and NMOS switch to ground. As the device switches between operating modes, no major shift in circuit behavior occurs. 100% Duty-Cycle Operation When the input voltage drops near the output voltage,the duty cycle increases until the PMOS MOSFET is on continuously. The dropout voltage in 100% duty cycle is the output current multiplied by the on-resistance of the internal PMOS switch and parasitic resistance in the inductor. The PMOS switch remains on continuously as long as the current limit is not reached. Shutdown Drive SHDN to a logic-level low to place the MAX1742/MAX1842 in low-power shutdown mode and reduce supply current to less than 1μA. In shutdown, all circuitry and internal MOSFETs turn off, and the LX node becomes high impedance. Drive SHDN to a logic-level high or connect to V CC for normal operation. Summing Comparator Three signals are added together at the input of the summing comparator (Figure 2): an output voltage error signal relative to the reference voltage, an integrated output voltage error correction signal, and the sensed PMOS switch current. The integrated error signal is pro-vided by a transconductance amplifier with an external capacitor at COMP. This integrator provides high DC accuracy without the need for a high-gain amplifier.Connecting a capacitor at COMP modifies the overall loop response (see the Integrator Amplifier section). M A X 1742/M A X 1842 1A/2.7A, 1MHz, Step-Down Regulators with Synchronous Rectification and Internal Switches 10 ______________________________________________________________________________________ Synchronous Rectification In a step-down regulator without synchronous rectifica-tion, an external Schottky diode provides a path for cur-rent to flow when the inductor is discharging. Replacing the Schottky diode with a low-resistance NMOS syn-chronous switch reduces conduction losses and improves efficiency. The NMOS synchronous-rectifier switch turns on follow-ing a short delay after the PMOS power switch turns off,thus preventing cross conduction or “shoot through.” In MAX1742/MAX1842 1A/2.7A, 1MHz, Step-Down Regulators with Synchronous Rectification and Internal Switches ______________________________________________________________________________________11 constant-off-time mode, the synchronous-rectifier switch turns off just prior to the PMOS power switch turning on. While both switches are off, inductor current flows through the internal body diode of the NMOS switch. The internal body diode’s forward voltage is rel-atively high. Thermal Resistance Junction-to-ambient thermal resistance, θJA , is highly dependent on the amount of copper area immediately surrounding the IC leads. The MAX1742 evaluation kit has 0.5in 2of copper area and a thermal resistance of 80°C/W with no forced airflow. Airflow over the board significantly reduces the junction-to-ambient thermal resistance. For heatsinking purposes, evenly distribute the copper area connected at the IC among the high-current pins. Power Dissipation Power dissipation in the MAX1742/MAX1842 is domi-nated by conduction losses in the two internal power switches. Power dissipation due to supply current in the control section and average current used to charge and discharge the gate capacitance of the internal switches (i.e., switching losses) is approximately: P DS = C x V IN 2x f PWM where C = 2.5nF and f PWM is the switching frequen-cy in PWM mode. This number is reduced when the switching frequency decreases as the part enters Idle Mode. Combined con-duction losses in the two power switches are approxi-mated by: P D = I OUT 2x R PMOS where R PMOS is the on-resistance of the PMOS switch.The junction-to-ambient thermal resistance required to dissipate this amount of power is calculated by: θJA = (T J,MAX - T A,MAX ) / P D(T OT ) where: θJA = junction-to-ambient thermal resistance T J,MAX = maximum junction temperature T A,MAX = maximum ambient temperature P D(TOT)= total losses __________________Design Procedure For typical applications, use the recommended compo-nent values in Tables 1 or 2. For other applications,take the following steps: 1)Select the desired PWM-mode switching frequency;1MHz is a good starting point. See Figure 3 for maxi-mum operating frequency. M A X 1742/M A X 1842 1A/2.7A, 1MHz, Step-Down Regulators with Synchronous Rectification and Internal Switches 12______________________________________________________________________________________ 2)Select the constant off-time as a function of input voltage, output voltage, and switching frequency.3)Select R TOFF as a function of off-time. 4)Select the inductor as a function of output voltage,off-time, and peak-to-peak inductor current. Setting the Output Voltage The output of the MAX1742/MAX1842 is selectable between one of three preset output voltages: 2.5V,1.8V, and 1.5V. For a preset output voltage, connect FB to the output voltage and connect FBSEL as indicated in Table 3. For an adjustable output voltage, connect FBSEL to GND and connect FB to a resistive divider between the output voltage and ground (Figure 4).Regulation is maintained for adjustable output voltages when V FB = V REF . Use 50k Ωfor R1. R2 is given by the equation: where V REF is typically 1.1V. Programming the Switching Frequency and Off-Time The MAX1742/MAX1842 features a programmable PWM mode switching frequency, which is set by the input and output voltage and the value of R TOFF , con-nected from TOFF to GND. R TOFF sets the PMOS power switch off-time in PWM mode. Use the following equation to select the off-time according to your desired switching frequency in PWM mode: where: t OFF = the programmed off-time V IN = the input voltage V OUT = the output voltage V PMOS = the voltage drop across the internal PMOS power switch V NMOS = the voltage drop across the internal NMOS synchronous-rectifier switch f PWM = switchin g frequency in PWM mode Select R TOFF according to the formula: R TOFF = (t OFF - 0.07μs) (110k Ω/ 1.00μs) Recommended values for R TOFF range from 36k Ωto 430k Ωfor off-times of 0.4μs to 4μs. Inductor Selection The key inductor parameters must be specified: inductor value (L) and peak current (I PEAK ). The following equa-tion includes a constant, denoted as LIR, which is the ratio of peak-to-peak inductor AC current (ripple current)to maximum DC load current. A higher value of LIR allows smaller inductance but results in higher losses and ripple.A good compromise between size and losses is found at approximately a 25% ripple-current to load-current ratio (LIR = 0.25), which corresponds to a peak inductor cur- where:I OUT = maximum DC load current LIR = ratio of peak-to-peak AC inductor current to DC load current, typically 0.25 Figure 4. Adjustable Output Voltage MAX1742/MAX1842 1A/2.7A, 1MHz, Step-Down Regulators with Synchronous Rectification and Internal Switches ______________________________________________________________________________________13 The peak inductor current at full load is 1.125 x I OUT if the above equation is used; otherwise, the peak current Choose an inductor with a saturation current at least as high as the peak inductor current. The inductor you select should exhibit low losses at your chosen operat-ing frequency. Capacitor Selection The input filter capacitor reduces peak currents and noise at the voltage source. Use a low-ESR and low-ESL capacitor located no further than 5mm from IN.Select the input capacitor according to the RMS input ripple-current requirements and voltage rating: where I RIPPLE = input RMS current ripple. The output filter capacitor affects the output voltage rip-ple, output load-transient response, and feedback loop stability. For stable operation, the MAX1742/MAX1842requires a minimum output ripple voltage of V RIPPLE ≥1% x V OUT . The minimum ESR of the output capacitor should be: Stable operation requires the correct output filter capaci-tor. When choosing the output capacitor, ensure that: Integrator Amplifier An internal transconductance amplifier fine tunes the output DC accuracy. A capacitor, C COMP , from COMP to V CC compensates the transconductance amplifier.For stability, choose C COMP = 470pF. A large capacitor value maintains a constant average output voltage but slows the loop response to changes in output voltage. A small capacitor value speeds up the loop response to changes in output voltage but decreases stability. Choose the capacitor values that result in optimal performance. Soft-Start Soft-start allows a gradual increase of the internal cur-rent limit to reduce input surge currents at startup and at exit from shutdown. A timing capacitor, C SS , placed from SS to GND sets the rate at which the internal cur-rent limit is changed. Upon power-up, when the device comes out of undervoltage lockout (2.6V typ) or after the SHDN pin is pulled high, a 4μA constant-current source charges the soft-start capacitor and the voltage on SS increases. When the voltage on SS is less than approximately 0.7V, the current limit is set to zero. As the voltage increases from 0.7V to approximately 1.8V,the current limit is adjusted from 0 to the current-limit threshold (see the Electrical Characteristics ).The volt-age across the soft-start capacitor changes with time according to the equation: The soft-start current limit varies with the voltage on the soft-start pin, SS, according to the equation: where I LIMIT is the current threshold from the Electrical Characteristics . M A X 1742/M A X 1842 1A/2.7A, 1MHz, Step-Down Regulators with Synchronous Rectification and Internal Switches 14______________________________________________________________________________________ The constant-current source stops charging once the voltage across the soft-start capacitor reaches 1.8V (Figure 5). Extended Current Limit (MAX1842) For applications requiring occasional short bursts of high output current (up to 2.7A), the MAX1842 provides a higher current-limit threshold. When using the MAX1842, choose external components capable of withstanding its higher peak current limit. The MAX1842 is capable of delivering large output cur-rents for limited durations, and its thermal characteris-tics allow it to operate at continuously higher output currents. Figure 6 shows its maximum recommended continuous output current versus ambient temperature.Figure 7 shows the maximum recommended burst cur-rent versus the output current duty cycle at high tem-peratures. Figure 7 assumes that the output current is a square wave with a 100H z frequency. The duty cycle is defined as the duration of the burst current divided by the period of the square wave. This figure shows the limitations for continuous bursts of output current.Note that if the thermal limitations of the MAX1842 are exceeded, it will enter thermal shutdown to prevent destructive failure. Frequency Variation with Output Current The operating frequency of the MAX1742/MAX1842 is determined primarily by t OFF (set by R TOFF ), V IN , and V OUT as shown in the following formula: f PWM = (V IN - V OUT - V PMOS ) / [t OFF (V IN - V PMOS +V NMOS )] H owever, as the output current increases, the voltage drop across the NMOS and PMOS switches increases and the voltage across the inductor decreases. This causes the frequency to drop. The change in frequency can be approximated with the following formula: Δf PWM = -I OUT x R PMOS / (V IN x t OFF ) where R PMOS is the resistance of the internal MOSFETs (90m Ωtyp). Circuit Layout and Grounding Good layout is necessary to achieve the MAX1742/MAX1842s’ intended output power level, high efficiency,and low noise. Good layout includes the use of a ground plane, careful component placement, and correct rout-ing of traces using appropriate trace widths. The follow-ing points are in order of decreasing importance: 1)Minimize switched-current and high-current ground loops. Connect the input capacitor’s ground, the out-put capacitor’s ground, and PGND. Connect the resulting island to GND at only one point. 2)Connect the input filter capacitor less than 5mm away from IN. The connecting copper trace carries large currents and must be at least 1mm wide,preferably 2.5mm. Figure 7. MAX1842 Maximum Recommended Burst Current vs.Burst Current Duty Cycle MAX1742/MAX1842 1A/2.7A, 1MHz, Step-Down Regulators with Synchronous Rectification and Internal Switches ______________________________________________________________________________________15 3)Place the LX node components as close together and as near to the device as possible. This reduces resistive and switching losses as well as noise. 4)A ground plane is essential for optimum perfor-mance. In most applications, the circuit is located on a multilayer board, and full use of the four or more layers is recommended. Use the top and bottom lay-ers for interconnections and the inner layers for an uninterrupted ground plane. Avoid large AC currents through the ground plane. Chip Information TRANSISTOR COUNT: 3662 Pin Configuration M A X 1742/M A X 1842 1A/2.7A, 1MHz, Step-Down Regulators with Synchronous Rectification and Internal Switches Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 16____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600?2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc. Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,go to https://www.sodocs.net/doc/039334207.html,/packages .)