19-3492; Rev 0; 1/05 Silicon Oscillator with Low-Power Frequency Switching The MAX7383 dual-speed silicon oscillator replaces ceramic resonators, crystals, and crystal-oscillator modules as the primary and secondary clock source for microcontrollers in 3V, 3.3V, and 5V applications. The MAX7383 features a factory-programmed high-speed oscillator, a 32.768kHz oscillator, and a clock-selector input. The clock output can be switched at any time between the high-speed clock and the 32.768kHz clock for low-power operation. Switchover is synchronized internally to provide glitch-free clock switching. Unlike typical crystal and ceramic-resonator oscillator circuits, the MAX7383 is resistant to vibration and EMI. The high-output-drive current and absence of highimpedance nodes makes the oscillator less susceptible to dirty or humid operating conditions. With a wide operating temperature range as standard, the MAX7383 is a good choice for demanding home appliance and automotive environments. The MAX7383 is available with factory-programmed frequencies ranging from 10MHz to 32MHz. See Table 1 for standard frequencies and contact the factory for custom frequencies. Refer to the MAX7377 data sheet for frequencies less than 10MHz. The MAX7383 is available in a 5-pin SOT23 package. The MAX7383 standard operating temperature range is -40°C to +125°C. See the Applications Information section for extended operating temperature range. Applications White Goods Features ♦ 2.7V to 5.5V Operation ♦ High-Speed Oscillator from 10MHz to 32MHz Low-Speed 32kHz Oscillator Glitch-Free Clock-Speed Switching ♦ ±10mA Clock-Output Drive Capability ♦ 2.5% Initial Accuracy ♦ ±50ppm/°C (typ) Frequency Drift ♦ 50% Duty Cycle ♦ 5ns Output Rise and Fall Time ♦ Low Jitter: 80psP-P at 16MHz ♦ 4mA Operating Current at 16MHz ♦ 13µA, 32kHz Operating Current ♦ -40°C to +125°C Temperature Range ♦ Small 5-Pin SOT23 Package Ordering Information PART* TEMP RANGE PINPACKAGE MAX7383AX _ _-T -40°C to +125°C 5 SOT23-5 RESET OUTPUT Active high push-pull *The first two letters are AX. Insert the two-letter code from Table 2 in the remaining two positions for the desired frequency range. Insert the two-letter code from Table 1 in the remaining two positions for the desired frequency range. Table 1 is located at the end of the data sheet. Automotive Consumer Products Typical Operating Circuit Appliances and Controls Handheld Products VCC 2.7V TO 5.5V Portable Equipment 0.1µF Microcontroller Systems VCC CLOCK OSC1 OSC2 MAX7383 E.C. µC I/O PORT SPEED GND Pin Configuration appears at end of data sheet. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX7383 General Description MAX7383 Silicon Oscillator with Low-Power Frequency Switching ABSOLUTE MAXIMUM RATINGS VCC to GND ...........................................................-0.3V to +6.0V All Other Pins to GND...................................-0.3V to (V+ + 0.3V) CLOCK Current ...............................................................±50mA Input Current (SPEED)......................................................±50mA Continuous Power Dissipation (TA = +70°C) 5-Pin SOT23 (derate 7.1mW/°C above +70°C)....571mW (U5-2) Operating Temperature Range .........................-55°C to +135°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C 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. ELECTRICAL CHARACTERISTICS (Typical Operating Circuit, VCC = 2.7V to 5.5V, VL = VCC, TA = -40°C to +125°C. Typical values are at VCC = 5.0V, TA = +25°C, unless otherwise noted.) (Note 1) PARAMETER Operating Supply Voltage Operating Supply Current SYMBOL CONDITIONS VCC ICC MIN TYP 2.7 MAX UNITS 5.5 V fCLOCK = 16MHz, TA = -40°C to +125°C, no load 8.7 fCLOCK = 14.7456MHz, TA = -40°C to +125°C, no load 8.0 fCLOCK = 12MHz, TA = -40°C to +125°C, no load 6.5 fCLOCK = 11.0592MHz, TA = -40°C to +125°C, no load 6.0 fCLOCK = 10MHz, TA = -40°C to +125°C, no load 5.4 fCLOCK = 32.768kHz, TA = -40°C to +125°C, no load 13 25 mA µA LOGIC INPUTS (SPEED) Input High Voltage VIH Input Low Voltage VIL Input Current IIN 0.7 x VCC V 0.3 x VCC VCC SPEED = 5.5V 2 V µA CLOCK OUTPUT Output High Voltage VOH Output Low Voltage VOL Fast Clock Frequency Accuracy Fast Clock Temperature Coefficient 2 fCLOCK VL = 4.5V, ISOURCE = 7.0mA VL = 2.7V, ISOURCE = 2.0mA VL - 0.4 V VL = 4.5V, ISINK = 20mA 0.4 VL = 2.7V, ISINK = 10mA VCC = 5V, TA = +25°C, deviation from selected frequency -2.5 +2.5 VCC = 2.7V to 5.5V, TA = +25°C, deviation from selected frequency -5.0 +3.5 V % TA = -40°C to +125°C ±50 _______________________________________________________________________________________ ±350 ppm/°C Silicon Oscillator with Low-Power Frequency Switching (Typical Operating Circuit, VCC = 2.7V to 5.5V, VL = VCC, TA = -40°C to +125°C. Typical values are at VCC = 5.0V, TA = +25°C, unless otherwise noted.) (Note 1) PARAMETER SYMBOL Slow Clock Frequency fCLOCK Slow Clock Temperature Coefficient MIN TYP MAX VCC = 5V, TA = +25°C CONDITIONS 32.268 32.768 33.268 VCC = 2.7V to 5.5V, TA = +25°C 31.768 32.768 33.768 ±50 ±325 ppm/°C 50 60 % TA = -40°C to +125°C 40 UNITS kHz Duty Cycle (Note 2) Output Jitter Observation of 16MHz for 20s using a 500MHz oscilloscope 80 psP-P ns Output Rise Time tR 10% to 90% 5 Output Fall Time tF 90% to 10% 5 Undervoltage Lockout Threshold VCC rising, deviation from nominal threshold VTH Undervoltage Lockout Hysteresis 2.45 2.55 TA = -40°C to +125°C 2.37 2.63 Difference between rising and falling thresholds HYST ns TA = +25°C % 1 % Note 1: All parameters tested at TA = +25°C. Specifications over temperature are guaranteed by design. Note 2: Guaranteed by design. Not production tested. Typical Operating Characteristics (VCC = VL = 5V, TA = +25°C, frequency = 10MHz, unless otherwise noted.) 49.0 48.5 49 48 47 46 48.0 -17 21 59 TEMPERATURE (°C) 97 135 3.15 3.10 FREQUENCY = 10MHz 3.05 3.00 2.95 2.90 45 -55 3.20 SUPPLY CURRENT (mA) FREQUENCY = 10MHz 3.25 MAX7383 toc02 MAX7383 toc01 FREQUENCY = 11.0592MHz 50 DUTY CYCLE (%) DUTY CYCLE (%) 50.0 49.5 SUPPLY CURRENT vs. TEMPERATURE DUTY CYCLE vs. SUPPLY VOLTAGE 51 MAX7383 toc03 DUTY CYCLE vs. TEMPERATURE 50.5 2.7 3.1 3.5 3.9 4.3 4.7 SUPPLY VOLTAGE (V) 5.1 5.5 -55 -17 21 59 97 135 TEMPERATURE (°C) _______________________________________________________________________________________ 3 MAX7383 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (continued) (VCC = VL = 5V, TA = +25°C, frequency = 10MHz, unless otherwise noted.) 3.0 2.5 1.0 0.5 0 -0.5 -1.0 4 MAX7383 toc06 FREQUENCY = 11.0592MHz 1.5 FREQUENCY = 10MHz 3 FREQUENCY DEVIATION (%) 3.5 2.0 MAX7383 toc05 FREQUENCY = 11.0592MHz FREQUENCY DEVIATION (%) MAX7383 toc04 4.0 FREQUENCY DEVIATION vs. TEMPERATURE FREQUENCY DEVIATION vs. SUPPLY VOLTAGE SUPPLY CURRENT vs. SUPPLY VOLTAGE SUPPLY CURRENT (mA) 2 1 0 -1 -2 2.0 1.5 2.7 3.1 3.5 3.9 4.3 4.7 5.1 -1.5 -3 -2.0 -4 2.7 5.5 3.1 3.5 3.9 4.3 4.7 5.1 5.5 CLOCK OUTPUT WAVEFORM (CL = 10pF) SETTLING TIME FROM START MAX7383 toc07 -55 -17 21 59 97 135 TEMPERATURE (°C) SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) CLOCK OUTPUT WAVEFORM (CL = 10pF) MAX7383 toc08 MAX7383 toc09 CH1 FREQ 9.992MHz LOW RESOLUTION 10µs/div 20ns/div 20ns/div SUPPLY CURRENT vs. FREQUENCY HIGH-SPEED TO LOW-SPEED TRANSITION CHANNEL 1 = CLOCK, CHANNEL 2 = VCC CLOCK OUTPUT WAVEFORM (CL = 100pF) MAX7383 toc10 MAX7383 toc12 MAX7383 toc11 5 SUPPLY CURRENT (mA) MAX7383 Silicon Oscillator with Low-Power Frequency Switching 4 3 2 1 20ns/div 10 11 12 13 14 FREQUENCY (MHz) 4 15 16 10µs/div CHANNEL 1 = CLOCK, CHANNEL 2 = SPEED _______________________________________________________________________________________ Silicon Oscillator with Low-Power Frequency Switching HIGH-SPEED TO LOW-SPEED TRANSITION (DETAIL ZOOM) LOW-SPEED TO HIGH-SPEED TRANSITION MAX7383 toc13 LOW-SPEED TO HIGH-SPEED TRANSITION (DETAIL ZOOM) MAX7383 toc14 40ns/div MAX7383 toc15 10µs/div CHANNEL 1 = CLOCK, CHANNEL 2 = SPEED 100ns/div CHANNEL 1 = CLOCK, CHANNEL 2 = SPEED CHANNEL 1 = CLOCK, CHANNEL 2 = SPEED Pin Description PIN NAME 1 CLOCK FUNCTION 2 GND 3 SPEED 4 VCC Positive Supply Voltage. Bypass VCC to GND with a 0.1µF capacitor. 5 E.C. Externally Connected. Connect to Vcc. Push-Pull Clock Output Ground Clock Speed Select Input. Drive SPEED low to select the 32kHz fixed frequency. Drive SPEED high to select the factory-trimmed frequency. _______________________________________________________________________________________ 5 MAX7383 Typical Operating Characteristics (continued) (VCC = VL = 5V, TA = +25°C, frequency = 10MHz, unless otherwise noted.) MAX7383 Silicon Oscillator with Low-Power Frequency Switching Detailed Description The MAX7383 is a dual-speed clock generator for microcontrollers (µCs) and UARTs in 3V, 3.3V, and 5V applications. The MAX7383 is a replacement for two crystal-oscillator modules, crystals, or ceramic resonators. The high-speed clock frequency is factory trimmed to specific values. A variety of popular standard frequencies are available. The low-speed clock frequency is fixed at 32.768kHz. See Table 1. No external components are required for setting or adjusting the frequency. Oscillator The push-pull clock output drives a load to within 400mV of either supply rail. The clock output remains stable over the full operating voltage range and does not generate short output cycles during either power-on or changing of the frequency. A typical oscillating startup is shown in the Typical Operating Characteristics. Clock-Speed Selection Drive SPEED low to select slow clock speed (nominally 32.768kHz) or high to select full clock speed. SPEED can be connected to VCC or to GND to select fast or slow clock speed, or connected to a logic output (such as a µP GPIO port) used to change clock speed on the fly. If SPEED is connected to a µP GPIO port, connect a pullup or pulldown resistor to set the clock to the preferred speed on power-up. SPEED input bias current is 2µA max, so a resistor value as high as 500kΩ can be used. SUFFIX STANDARD FREQUENCY (MHz) UK 10 UT 11.0592 VB 12 VT 14.7456 WB 16 YN 32 For all other frequency options, contact factory. Table 2. Standard Part Numbers FREQUENCY (MHz) TOP MARK MAX7383AXUK 10 AEVN MAX7383AXUT 11.0592 AEVO MAX7383AXVB 12 AEVP MAX7383AXVT 14.7456 AEVQ MAX7383AXWB 16 AEVT MAX7383AXYN* 32 AEVS PART *Contact factory for availability. Applications Information Interfacing to a Microcontroller Clock Input The MAX7383 clock output is a push-pull, CMOS, logic output that directly drives a µP or µC clock input. There are no impedance-matching issues when using the MAX7383. Refer to the microcontroller data sheet for clock input compatibility with external clock signals. The MAX7383 requires no biasing components or load capacitance. When using the MAX7383 to retrofit a crystal oscillator, remove all biasing components from the oscillator input. VCC UVLO MAX7383 Table 1. Standard Frequencies 32kHz (LF OSCILLATOR) Output Jitter SPEED MUX LOGIC 10MHz TO 32MHz (HF OSCILLATOR) GND Figure 1. Functional Diagram 6 CLOCK The MAX7383’s jitter performance is given in the Electrical Characteristics table as a peak-to-peak value obtained by observing the output of the MAX7383 for 20s with a 12GHz oscilloscope. Jitter measurements are approximately proportional to the period of the output of the device. Thus, a 10MHz device has approximately twice the jitter value of a 20MHz device. The jitter performance of all clock sources degrades in the presence of mechanical and electrical interference. The MAX7383 is relatively immune to vibration, shock, and EMI influences and thus provides a considerably _______________________________________________________________________________________ Silicon Oscillator with Low-Power Frequency Switching Initial Power-Up and Operation An internal-undervoltage lockout function holds the clock output low until the supply voltage has risen above 2.5V. The clock output then starts at the frequency selected by SPEED. Extended Temperature Operation The MAX7383 was tested to +135°C during product characterization and shown to function normally at this temperature (see the Typical Operating Characteristics). However, production test and qualification is only performed from -40°C to +125°C at this time. Contact the factory if operation outside this range is required. TOP VIEW CLOCK 1 GND 2 5 E.C. 4 VCC MAX7383 SPEED 3 SOT23 Power-Supply Considerations The MAX7383 operates with power-supply voltages from 2.7V and 5.5V. Good power-supply decoupling is needed to maintain the power-supply rejection performance of the MAX7383. Bypass VCC to GND with a 0.1µF surface-mount ceramic capacitor. Mount the bypassing capacitor as close to the device as possible. Use a larger value of bypass capacitor recommended if the MAX7383 is to operate with a large capacitive load. Use a bypass capacitor value of at least 1000 times that of the output load capacitance. Chip Information TRANSISTOR COUNT: 2937 PROCESS: BiCMOS _______________________________________________________________________________________ 7 MAX7383 Pin Configuration more robust clock source than crystal or ceramic resonator-based oscillator circuits. Silicon Oscillator with Low-Power Frequency Switching SOT-23 5L .EPS PACKAGE OUTLINE, SOT-23, 5L 21-0057 E 1 1 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. 8 _____________________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. MAX7383 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 www.maxim-ic.com/packages.)