general description t he max7381 is a silicon oscillator intended as a low-cost improvement to ceramic resonators, crystals, and crystal oscillator modules as the clock source for microcon- trollers and uarts in 3v, 3.3v, and 5v applications. the max7381 is an integrated oscillator, supplied at spe- cific frequencies, just like crystals and resonators, and with a rail-to-rail, 50%, duty-cycle square-wave output. the oscillator frequency is generated directly without the use of a phase-locked loop (pll). no additional compo- nents are required for setting or adjusting the frequency. unlike typical crystal and ceramic resonator oscillator cir- cuits, the max7381 is resistant to vibration and emi. the high output-drive current and absence of high-imped- ance nodes make the oscillator invulnerable to dirty or humid operating conditions. with a wide operating tem- perature range as standard, the oscillator is a good choice for demanding appliance and automotive environ- ments. the max7381 is available with frequencies in the 10mhz to 16mhz range. the max7381 is offered in a space-saving 3-pin sc70 package. all ics are guaranteed to operate over the -55? to +135? temperature range and specified from the -40? to +125? temperature range. applications white goods automotive appliances and controls handheld products portable equipment microcontroller systems features ? 2.7v to 5.5v operation ? factory-trimmed oscillator (10mhz to 16mhz) ? no external components required ? ?0ma output-drive current ? 2% initial accuracy ? ?00ppm/? temperature drift ? fast startup time: 5? ? 40% to 60% maximum duty cycle ? 5ns output rise/fall time ? very-low-emi susceptibility (no high-impedance nodes) ? no pll ? low jitter: 180ps p-p at 16mhz ? -40? to +125? temperature range max7381 3-pin silicon oscillator ________________________________________________________________ maxim integrated products 1 ordering information 19-3697; rev 0; 4/05 for pricing, delivery, and ordering information, please contact maxim/dallas direct! at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com. part temp range pin-package max7381axr106-t -40? to +125? 3 sc70-3 MAX7381AXR126-T -40? to +125? 3 sc70-3 max7381axr146-t -40? to +125? 3 sc70-3 max7381axr166-t -40? to +125? 3 sc70-3 osc2 osc1 c clock max7381 v+ gnd 2.7v to 5.5v t ypical operating circuit selector guide appears at end of data sheet. the max7381 is available in factory-set frequencies from 10mhz to 16mhz. there are four standard versions 10mhz, 12mhz, 14mhz, and 16mhz, shown in the selector guide) with a required order increment of 2.5k. nonstandard frequencies are also available with a required order increment of 10k. for nonstandard versions, contact factory for availability and ordering information. all versions are available in tape and reel only. refer to the max7375 data sheet for output frequencies below 10mhz.
max7381 3-pin silicon oscillator 2 _______________________________________________________________________________________ absolute maximum ratings stresses beyond those listed under ?bsolute maximum ratings?may cause permanent damage to the device. these are stress rating s only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specificatio ns is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. v+ to gnd .............................................................-0.3v to +6.0v clk to gnd..................................................-0.3v to (v+ + 0.3v) clk current .....................................................................?0ma continuous power dissipation (t a = + 70?) 3-pin sc70 (derate 2.9mw/? over +70?) ..............235.3mw functional temperature range .........................-55? to +135? junction temperature ......................................................+150? storage temperature range .............................-65? to +150? lead temperature (soldering, 10s) .................................+300? electrical characteristics (v+ = 2.7v to 5.5v, t a = -40? to +125?, unless otherwise noted. typical values are at v+ = 5v, t a = +25?, unless otherwise noted.) (note 1) parameter symbol conditions min typ max units operating supply voltage v+ 2.7 5.5 v max7381axr126 3.7 4.75 operating supply current i+ max7381axr166 4.8 6.50 ma v+ 2.7v, i source = 2.5ma v+ - 0.4 output high voltage v oh v+ 4.5v, i source = 9ma v+ - 0.4 v v+ 2.7v, i sink = 10ma 0.4 output low voltage v ol v+ 4.5v, i sink = 20ma 0.4 v v in = 3v (typ value at t a = +25 c) 0.11 0.17 on-resistance v in = 5v (typ value at t a = +25 c) 0.095 0.15 ? v+ = 5.0v, t a = +25? max7381axr_ _ _ -2% +2% initial clock frequency (note 2) f clock v+ = 2.7v to 5.5v, t a = +25? max7381axr_ _ _ -5% +3% mhz clock frequency temperature sensitivity t a = - 40 c to + 125 c , (note 3) -350 100 +300 ppm/? duty cycle (note 3) 40 50 60 % output jitter observation for 20s using a 12ghz oscilloscope (max7381axr166) 180 ps p - p output rise time t r 5ns output fall time t f 5ns startup time 5 s note 1: all parameters tested at t a = +25?. specifications over temperature are guaranteed by design and characterization. note 2: typical frequencies are nominal values. note 3: guaranteed by design and characterization. not production tested.
max7381 3-pin silicon oscillator _______________________________________________________________________________________ 3 duty cycle vs. temperature max7381 toc01 temperature ( c) duty cycle (%) 110 95 65 80 -10 5 20 35 50 -25 46 47 48 49 50 51 52 53 54 55 45 -40 125 duty cycle vs. supply voltage supply voltage (v) 5.0 4.5 4.0 3.5 3.0 47 49 51 53 55 45 2.5 5.5 max7381 toc02 duty cycle (%) supply current vs. temperature max7381 toc03 supply current (ma) 1 2 3 4 5 6 0 temperature ( c) 110 95 65 80 -10 5 20 35 50 -25 -40 125 v+ = 5v v+ = 3.3v v+ = 2.7v supply voltage (v) 5.0 4.5 4.0 3.5 3.0 2.5 5.5 supply current vs. supply voltage max7381 toc04 supply current (ma) 1 2 3 4 5 6 0 supply voltage (v) 5.0 4.5 4.0 3.5 3.0 2.5 5.5 frequency vs. supply voltage max7381 toc05 normalized frequency 0.985 0.990 0.995 1.000 1.005 1.010 0.980 frequency vs. temperature max7381 toc06 normalized frequency 0.985 0.995 1.005 1.015 1.025 1.035 0.975 temperature ( c) 110 95 65 80 -10 5 20 35 50 -25 -40 125 frequency (mhz) 15 14 13 12 11 10 16 supply current vs. frequency max7381 toc07 supply current (ma) 1 2 3 4 5 6 0 v+ = 5v t ypical operating characteristics (v+ = 5v, c l = 10pf, 16mhz output, t a = +25?, unless otherwise noted.) settling time from start max7381 toc08 clock 2v/div v+ 2v/div 100ns/div v+ = 3.3v clock output waveform with c l = 10pf max7381 toc09 clock 1v/div 20ns/div v+ = 3.3v
max7381 3-pin silicon oscillator 4 _______________________________________________________________________________________ t ypical operating characteristics (continued) (v+ = 5v, c l = 10pf, 16mhz output, t a = +25?, unless otherwise noted.) detailed description the max7381 is a replacement for ceramic resonators, crystals, and crystal-oscillator modules as the clock source for microcontrollers and uarts in 3v, 3.3v, and 5v applications. the max7381 is an integrated oscilla- tor, supplied at specific frequencies just like crystals and resonators. a variety of popular standard frequen- cies are available. no external components are required for setting or adjusting the frequency. supply voltages the max7381 has been designed for use in systems with nominal supply voltages of 3v, 3.3v, or 5v and is specified for operation with supply voltages in the 2.7v to 5.5v range. operation outside this range is not guar- anteed. see the absolute maximum ratings for limit values of power-supply and pin voltages. oscillator the clock output is a push-pull configuration and is capable of driving a ground-connected 1k ? load or a positive-supply-connected 500 ? load to within 400mv of either supply rail. the clock output remains stable over the full operating voltage range. a typical startup characteristic is shown in the typical operating characteristics section. output jitter the max7381? jitter performance is given in the electrical characteristics table as a peak-to-peak value obtained by observing the output of the max7381 for 20s with a 500mhz oscilloscope. jitter measurements are approximately proportional to the period of the out- put frequency of the device. the jitter performance of all clock sources degrades in the presence of mechanical and electrical interference. the max7381 is relatively immune to vibration, shock, and emi influences, and thus provides a considerably more robust clock source than crystal- or ceramic- resonator-based oscillator circuits. applications information interfacing to a microcontroller clock input the max7381 clock output is a push-pull, cmos, logic output, which directly drives any microprocessor ( p) or microcontroller (?) clock input. there are no imped- ance-matching issues when using the max7381. operate the max7381 and microcontroller (or other clock-input device) from the same supply voltage. refer to the microcontroller data sheet for clock-input compatibility with external clock signals. pin description pin name function 1v+ positive supply voltage. bypass v+ to gnd with a 0.1? surface-mount ceramic capacitor. 2 clock clock output. clock is a push- pull output. 3 gnd ground clock output waveform with c l = 50pf max7381 toc10 clock 1v/div 20ns/div v+ = 3.3v clock output waveform with c l = 100pf max7381 toc11 clock 1v/div 20ns/div v+ = 3.3v
the max7381 requires no biasing components or load capacitance. when using the max7381 to retrofit a crystal oscillator, remove all biasing components from the oscillator input. startup performance the max7381 oscillator output stabilizes within a few cycles of operation after v+ rises to a sufficient voltage to start the oscillator, typically 1.65v at +25?. use a reset or similar voltage-detection circuit to disable devices connected to the max7381 until 20? after the voltage on v+ has risen above 2.7v. power-supply considerations the max7381 operates with power-supply voltages in the 2.7v to 5.5v range. power-supply decoupling is needed to maintain the power-supply rejection perfor- mance of the max7381. use a 0.1? surface-mount ceramic capacitor connected between v+ and gnd and mounted as close to the device as possible. if pos- sible, mount the max7381 close to the microcontroller? decoupling capacitor so that additional decoupling is not required. a larger value bypass capacitor is recommended if the max7381 is driving a large capacitive load. use a bypass capacitor value of at least 1000 times the out- put-load capacitance. max7381 3-pin silicon oscillator _______________________________________________________________________________________ 5 part frequency (mhz) top mark max7381axr106 10 ape max7381axr126 12 apg max7381axr146 14 arc max7381axr166 16 aph selector guide chip information process: bicmos clock 1 3 gnd v+ max7381 sc70 top view 2 pin configuration
max7381 3-pin silicon oscillator maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim product. no circu it patent licenses are implied. maxim reserves the right to change the circuitry and specifications without notice at any time. maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 _____________________ 6 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 info rmation, go to www.maxim-ic.com/packages .) sc70, 3l.eps package outline, 3l sc70 21-0075 1 1 c
|
