19-3475; Rev 0; 10/04 Silicon Oscillator with Reset Output Applications White Goods Automotive Consumer Products Appliances and Controls Handheld Products Features ♦ 2.7V to 5.5V Operation ♦ Accurate Oscillator: 600kHz to 10MHz or 32kHz ♦ Reset Output Holds the µC in Reset for 100µs After Clock Startup ♦ ±10mA Clock Output Drive Capability ♦ 2% Initial Accuracy ♦ ±50ppm/°C Temperature Coefficient ♦ 50% Duty Cycle ♦ 5ns Output Rise and Fall Time ♦ Low Jitter: 160psP-P) at 8MHz (No PLL) ♦ 3mA Operating Current (8MHz) ♦ 13µA Operating Current (32kHz) ♦ -40°C to +125°C Temperature Range Ordering Information PART TEMP RANGE PINPACKAGE RESET OUTPUT MAX7376C_ _ _-T -40°C to +125°C 5 SOT23-5 Open drain MAX7376A_ _ _-T -40°C to +125°C 5 SOT23-5 Active high push-pull MAX7376B_ _ _-T -40°C to +125°C 5 SOT23-5 Active low push-pull Standard version is shown in bold. The first letter after the part number designates the reset output option. Insert the letter corresponding to the desired reset threshold level from Table 1 in the next position. Insert the twoletter code from Table 2 in the remaining two positions for the desired frequency range. See Table 3 for standard part numbers. Portable Equipment Pin Configuration Microcontroller (µC) Systems TOP VIEW CLOCK 1 5 E.C. 4 VCC Typical Application Circuit appears at end of data sheet. GND 2 MAX7376 RST/RST 3 SOT23 ________________________________________________________________ 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 MAX7376 General Description The MAX7376 silicon oscillator with reset, is a replacement for ceramic resonators, crystals, crystal oscillator modules, and discrete reset circuits. The MAX7376 provides the primary clock source and reset function for microcontrollers in 3V, 3.3V, and 5V applications. The MAX7376 features a factory-programmed high-speed oscillator and a microprocessor (µP) power-on-reset (POR) supervisor. Unlike typical crystal and ceramic resonator oscillator circuits, the MAX7376 is resistant to vibration and EMI. The high-output-drive current and absence of highimpedance nodes make the oscillator less susceptible to dirty or humid operating conditions. With a wide operating temperature range as standard, the MAX7376 is a good choice for demanding home appliance, industrial, and automotive environments. The MAX7376 is available in factory-programmed frequencies from 32.768kHz to 10MHz. See Table 2 for standard frequencies and contact the factory for custom frequencies. The MAX7376 is available in a 5-pin SOT23 package. Refer to the MAX7382 data sheet for frequencies ≥10MHz. The MAX7376 standard operating temperature range is -40°C to +125°C. See the Applications Information section for the extended operating temperature range. MAX7376 Silicon Oscillator with Reset Output ABSOLUTE MAXIMUM RATINGS VCC to GND .............................................................-0.3V to +6V All Other Pins to GND ................................-0.3V to (VCC + 0.3V) CLOCK Current ................................................................±10mA Continuous Power Dissipation (TA = +70°C) 5-Pin SOT23 (derate 7.1mW/°C above +70°C) ...................571mW (U5 - 2) Operating Temperature Range .........................-40°C to +135°C Junction Temperature .....................................................+150°C Storage Temperature Range.............................-60°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 (VCC = 2.7V to 5.5V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VCC = 5V and TA = +25°C.) (Note 1) PARAMETER SYMBOL Operating Supply Voltage VCC Operating Supply Current ICC CONDITIONS MIN TYP 2.7 MAX UNITS 5.5 V fCLOCK = 8MHz, no load 3 5 mA fCLOCK = 32.768kHz, no load 13 25 µA CLOCK OUTPUT Minimum Operating Voltage Output High Voltage Output Low Voltage Initial Frequency Accuracy 1.65 VCC = 2.7V, ISOURCE = 2.5mA VCC - 0.4 VOL fCLOCK VCC = 4.5V, ISINK = 20mA 0.4 VCC = 2.7V, ISINK = 10mA 0.4 VCC = 5V, TA = +25°C (Note 2) -2 +2 VCC = 2.7V to 5.5V, TA = +25°C -4 +4 (Note 3) fCLOCK Frequency Temperature Sensitivity VCC = 5V, TA = +25°C (Note 2) 32.440 VCC = 2.7V to 5.5V, TA = +25°C 31.785 32.768kHz (Note 3) CLOCK Output Duty Cycle 43 Observation of 8MHz output for 20s using a 500MHz oscilloscope CLOCK Output Jitter V V VOH Frequency Temperature Sensitivity Initial Frequency Accuracy (32.768kHz) VCC = 4.5V, ISOURCE = 9mA VCC - 0.4 ±50 ±325 32.768 33.096 33.751 V % ppm/oC kHz ±50 ±325 ppm/oC 50 57 % 160 psP-P CLOCK Output Rise Time tR 10% to 90% 5 ns CLOCK Output Fall Time tF 90% to 10% 5 ns 2 _______________________________________________________________________________________ Silicon Oscillator with Reset Output MAX7376 ELECTRICAL CHARACTERISTICS (continued) (VCC = 2.7V to 5.5V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VCC = 5V and TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX TA = +25°C VTH 2% VTH + 2% TA = -40°C to +125°C VTH 5% VTH + 5% UNITS RST/RST OUTPUT Reset Threshold VTH+ Reset Hysteresis VTHYS POR Delay Output High Voltage VOH Output Low Voltage VOL Leakage Current V VCC rising ILEAK VHYST = {(VTH+) - ( VTH-)}/(VTH-) x 100% 2.0 % VCC rising from 0V to (VTH + 200mV) in 1µs 100 µs VCC = 4.5V, ISOURCE = 9mA VCC - 0.4 VCC = 2.7V, ISOURCE = 2.5mA VCC - 0.4 V VCC = 4.5V, ISINK = 20mA 0.4 VCC = 2.7V, ISINK = 10mA 0.4 VCC = 5.5V, VRST = 5.5V, open drain V 1 µA Note 1: All parameters are tested at TA = +25°C. Specifications over temperature are guaranteed by design. Note 2: The frequency is determined by part number selection. See Table 3. Note 3: Guaranteed by design. Not production tested. Typical Operating Characteristics (VCC = 5V, TA = +25°C, unless otherwise noted.) DUTY CYCLE vs. SUPPLY VOLTAGE 51 CLOCK = 4MHz 50 53 DUTY CYCLE (%) 52 54 49 52 51 CLOCK = 4MHz 50 1.4 1.3 SUPPLY CURRENT (mA) 53 1.5 MAX7376 toc02 54 DUTY CYCLE (%) 55 MAX7376 toc01 55 SUPPLY CURRENT vs. TEMPERATURE 49 1.2 1.1 1.0 48 47 47 0.7 46 46 0.6 45 45 -30 -5 20 45 70 TEMPERATURE (°C) 95 120 4.3 4.6 4.9 5.2 SUPPLY VOLTAGE (V) 5.5 CLOCK = 4MHz 0.9 48 -55 MAX7376 toc03 DUTY CYCLE vs. TEMPERATURE 0.8 0.5 -55 -30 -5 20 45 70 95 120 TEMPERATURE (°C) _______________________________________________________________________________________ 3 Typical Operating Characteristics (continued) (VCC = 5V, TA = +25°C, unless otherwise noted.) SUPPLY CURRENT vs. SUPPLY VOLTAGE FREQUENCY vs. SUPPLY VOLTAGE 1.1 1.0 0.9 4.04 CLOCK = 4MHz 0.8 4.02 CLOCK = 4MHz 4.00 3.98 4.08 4.06 4.04 4.02 3.98 3.96 0.7 3.94 3.94 0.6 3.92 3.92 0.5 3.90 4.9 5.2 5.5 3.90 4.3 4.6 4.9 5.2 SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) CLOCK OUTPUT WAVEFORM (CL = 10pF) CLOCK OUTPUT WAVEFORM (CL = 50pF) 5.5 -55 -30 -5 20 45 70 95 120 TEMPERATURE (°C) MAX7376 toc08 MAX7376 toc07 CLOCK OUTPUT WAVEFORM (CL = 100pF) MAX7376 toc09 4.6 CLOCK = 4MHz 4.00 3.96 4.3 MAX7376 toc06 4.06 FREQUENCY (MHz) 1.2 4.08 FREQUENCY (MHz) 1.3 4.10 MAX7376 toc05 1.4 FREQUENCY vs. TEMPERATURE 4.10 MAX7376 toc04 1.5 SUPPLY CURRENT (mA) CLOCK CLOCK CLOCK f = 4MHz, CL = 10pF f = 4MHz, CL = 50pF f = 4MHz, CL = 100pF 40ns/div 40ns/div 40ns/div MAXIMUM TRANSIENT DURATION vs. RESET THRESHOLD MAX7376 toc10 1000 MAXIMUM TRANSIENT DURATION (µs) MAX7376 Silicon Oscillator with Reset Output RESET OCCURS ABOVE THE CURVE 100 RESET = 4.29V 10 0 200 400 600 800 1000 RESET THRESHOLD OVERDRIVE (mV) 4 _______________________________________________________________________________________ Silicon Oscillator with Reset Output PIN NAME FUNCTION 1 CLOCK 2 GND Push-Pull Clock Output Ground 3 RST Reset Output. See the RST Reset Output Options section for more details. 4 VCC Positive Supply Voltage. Bypass VCC to GND with a 0.1µF capacitor. 5 E.C. Must Be Externally Connected to VCC Detailed Description The MAX7376 is a clock generator with integrated reset for µCs and UARTs in 3V, 3.3V, and 5V applications (Figure 1). The MAX7376 is a replacement for crystal oscillator modules, crystals, or ceramic resonators and a system-reset IC. The clock frequency is factory trimmed to specific values. A variety of popular standard frequencies are available (Table 2). No external components are required for setting or adjusting the frequency. Supply Voltage The MAX7376 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. See the Absolute Maximum Ratings section for limit values of power-supply and pin voltages. VCC Oscillator The clock output is a push-pull configuration and is capable of driving a ground-connected 500Ω or a positive-supply-connected 250Ω 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 power-off. A typical startup characteristic is shown in the Typical Operating Characteristics. Applications Information Interfacing to a µC Clock Input The MAX7376 clock output is a push-pull, CMOS, logic output that directly drives any µP or µC clock input. There are no impedance-matching issues when using the MAX7376. The MAX7376 is not sensitive to its position on the board and it does not need to be placed right next to the µP. Refer to the µC data sheet for clock-input compatibility with external clock signals. The MAX7376 requires no biasing components or load capacitance. When using the MAX7376 to retrofit a crystal oscillator, remove all biasing components from the oscillator input. RST Reset Output Options BIAS_V RST/RST POR LOGIC MUX 600kHz TO 10MHz MAX7376 Figure 1. Functional Diagram CLOCK The MAX7376 is available with three reset output stage options: push-pull with active-low output, push-pull with active-high output, and open drain with active-low output. The RST output is asserted when the monitored input (VCC) drops below the internal VTH- threshold and remains asserted for 100µs after the monitored input exceeds the internal VTH+ threshold. The open-drain RST output requires an external pullup resistor. Output Jitter The MAX7376’s jitter performance is given in the Electrical Characteristics table as a peak-to-peak value obtained by observing the output of the MAX7376 for 20s with a 500MHz oscilloscope. Jitter values are approximately proportional to the period of the output frequency of the device. Thus, a 4MHz part has approximately twice the jitter value of an 8MHz part. The jitter performance of clock sources degrades in the presence of mechanical and electrical interference. _______________________________________________________________________________________ 5 MAX7376 Pin Description MAX7376 Silicon Oscillator with Reset Output The MAX7376 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. Initial Power-Up and Operation The clock starts up within 30µs (typ) after VCC has risen above the reset threshold. The reset output remains asserted for 100µs after the reset threshold is reached. Extended Temperature Operation The MAX7376 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. Power-Supply Considerations The MAX7376 operates with a 2.7V and 5.5V powersupply voltage. Good power-supply decoupling is needed to maintain the power-supply rejection performance of the MAX7376. Bypass VCC to GND with a 0.1µF surface-mount ceramic capacitor. Mount the bypass capacitor as close to the device as possible. If possible, mount the MAX7376 close to the µC’s decoupling capacitor so that additional decoupling is not required. A larger value bypass capacitor is recommended if the MAX7376 is to operate with a large capacitive load. Use a bypass capacitor value of at least 1000 times that of the output load capacitance. Typical Application Circuit Table 1. Standard Reset Threshold Levels SUFFIX RESET THRESHOLD (V) R 2.57 M 4.29 SUPPLY VOLTAGE For all other reset threshold options, contact factory. VCC Table 2. Standard Frequencies SUFFIX STANDARD FREQUENCY (MHz) AA 32.768kHz MG 1 OK 1.8432 QT 3.39545 QW 3.6864 RD 4 RH 4.1943 TP 8 OSC1 CLOCK E.C. OSC2 MAX7376 RST RST/RST For all other reset threshold options, contact factory. 6 _______________________________________________________________________________________ µC Silicon Oscillator with Reset Output MAX7376 Table 3. Standard Part Numbers PART MAX7376CRAA PIN-PACKAGE RESET THRESHOLD (V) FREQUENCY (Hz) TOP MARK 5 SOT23 2.57 32.768k AEUZ MAX7376CRMG 5 SOT23 2.57 1M AEUN MAX7376CROK 5 SOT23 2.57 1.8432M AEUJ MAX7376CRQT 5 SOT23 2.57 3.39545M AETT MAX7376CRQW 5 SOT23 2.57 3.6864M AETU MAX7376CRRD 5 SOT23 2.57 4M AETV MAX7376CRRH 5 SOT23 2.57 4.1943M AETW MAX7376CRTP 5 SOT23 2.57 8M AESF AEUM MAX7376CMMG 5 SOT23 4.29 1M MAX7376CMOK 5 SOT23 4.29 1.8432M AEUI MAX7376CMQT 5 SOT23 4.29 3.39545M AESH MAX7376CMQW 5 SOT23 4.29 3.6864M AETP MAX7376CMRD 5 SOT23 4.29 4M AESJ MAX7376CMRH 5 SOT23 4.29 4.1943M AETR MAX7376CMTP 5 SOT23 4.29 8M AETS Chip Information TRANSISTOR COUNT: 2027 PROCESS: BiCMOS _______________________________________________________________________________________ 7 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.) SOT-23 5L .EPS MAX7376 Silicon Oscillator with Reset Output 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 © 2004 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.