MAX6655/MAX6656 Dual Remote/Local Temperature Sensors and Four-Channel Voltage Monitors General Description Features The MAX6655/MAX6656 are precise voltage and Three Temperature Channels temperature monitors. The digital thermometer reports Two Remote PN Junctions the temperature of two remote sensors and its own die One Local Sensor temperature. The remote sensors are diode-connected Four Voltage Channels transistorstypically a low-cost, easily mounted 2N3906 +12V, +5V, +3.3V, +2.5V PNP typethat replace conventional thermistors or Three External Monitors thermocouples. Remote accuracy is 1C for multiple One Internal Supply Monitor transistor manufacturers with no calibration necessary. 11-Bit, 0.125C Resolution The remote channels can also measure the die High Accuracy: 1C Over +60C to +100C temperature of other ICs, such as microprocessors, Temperature Range that contain a substrate-connected PNP with its collector grounded and its base and emitter available for temperature- Programmable Under/Over-Threshold Alarms sensing purposes. The temperature is digitized with 11-bit Programmable Power-Saving Mode resolution. No Calibration Required The MAX6655/MAX6656 also measure their own supply 2 SMBus/I C-Compatible Interface voltage and three external voltages with 8-bit resolution. Each voltage inputs sensitivity is set to give approximately OVERT Output for Fan Control and System 3/4-scale output code when the input voltage is at its nominal Shutdown value. The MAX6655 operates at +5V supply and its second voltage monitor is 3.3V. The MAX6656 operates on a Ordering Information +3.3V supply and its second voltage monitor is 5V. PIN- PKG PART TEMP RANGE The 2-wire serial interface accepts standard SMBus PACKAGE CODE Write Byte, Read Byte, Send Byte, and Receive Byte MAX6655MEE+ -55C to +125C 16 QSOP E16+5 commands to program the alarm thresholds and to read MAX6656MEE+ -55C to +125C 16 QSOP E16+5 data. The MAX6655/MAX6656 also provide SMBus alert response and timeout functions. The MAX6655/MAX6656 measure automatically and autonomously, with the con- Typical Application Circuit appears at end of data sheet. version rate programmable. The adjustable rate allows the user to control the supply current. Pin Configuration In addition to the SMBus ALERT output, the MAX6655/ MAX6656 feature an OVERT output, which is used as TOP VIEW a temperature reset that remains active only while the V 1 16 STBY CC temperature is above the maximum temperature limit. DXP1 2 15 SMBCLK The OVERT output is optimal for fan control or for DXN1 3 14 OVERT system shutdown. MAX6655 ADD0 4 13 SMBDATA MAX6656 Applications ADD1 5 12 ALERT Notebooks Workstations DXP2 6 11 V IN2 Thin Clients Communication DXN2 7 10 V IN1 Equipment Servers GND 8 9 V IN3 Desktop PC QSOP SMBus is a trademark of Intel Corp. 19-2117 Rev 2 5/17MAX6655/MAX6656 Dual Remote/Local Temperature Sensors and Four-Channel Voltage Monitors Absolute Maximum Ratings V to GND ............................................................-0.3V to +6V DXN Current .....................................................................1mA CC DXN to GND .......................................................-0.3V to +0.8V ESD Protection (all pins, Human Body Model) .................2000V SMBCLK, SMBDATA, ALERT, STBY, Continuous Power Dissipation (T = +70C) A OVERT to GND ...................................................-0.3V to +6V 16-Pin QSOP (derate 8.30mW/C above +70C) .......667mW V to GND ..........................................................-0.3V to +16V Operating Temperature Range ......................... -55C to +125C IN1 V to GND ............................................................-0.3V to +6V Junction Temperature ......................................................+150C IN2 V to GND ............................................................-0.3V to +6V Storage Temperature Range ............................ -65C to +150C IN3 All Other Pins to GND .............................. -0.3V to (V + 0.3V) Lead Temperature (soldering, 10s) .................................+300C CC SMBDATA, ALERT, OVERT Current.................. -1mA to +50mA 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 (V = +3.0V to +3.6V for MAX6656, V = +4.5V to +5.5V for MAX6655, T = -55C to +125C, unless otherwise noted. Typical CC CC A values are at V = +3.3V for MAX6656, V = +5.0V for MAX6655, T = +25C.) CC CC A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Range V 3.0 5.5 V CC +60C T +100C 1.5 A Accuracy (Local Sensor) C 0C T +125C 3 A +60C T +100C 1 RJ Accuracy (Remote Sensor) C 0C T +120C 3 RJ 0.125 C Temperature Measurement Resolution 11 Bits ADC Input Impedance Z V , V , V input resistance 100 k IN IN1 IN2 IN3 V , V , V between 30% and 120% of IN1 IN2 IN3 ADC Total Error 1 1.5 % nominal V ADC Resolution 8 Bits IN V input, disables A/D conversion, CC Undervoltage Lockout Threshold UVLO 2.50 2.70 2.90 V falling edge Undervoltage Lockout Hysteresis 90 mV Power-On Reset (POR) V , falling edge 1 1.7 2.5 V CC Threshold POR Threshold Hysteresis 90 mV Standby Current SMBus static, STBY = GND 3 10 A DXP and DXN Leakage Current In standby mode 2 A Average Operating Current Continuous temperature mode 550 1000 A Conversion Time for Single t From stop bit to conversion completed 95 125 155 ms CON Temperature Measurement Total of 3 temperature plus 4 voltage Monitoring Cycle Time t 625 ms MONI measurements Maxim Integrated 2 www.maximintegrated.com