The MAX6655/MAX6656 are precise voltage and temperature monitors. The digital thermometer reports the temperature of two remote sensors and its own die temperature. The remote sensors are diode-connected transistors—typically a low-cost, easily mounted 2N3906 PNP type—that replace conventional thermistors or thermocouples. Remote accuracy is ±1°C for multiple transistor manufacturers with no calibration necessary. The remote channels can also measure the die temperature of other ICs, such as microprocessors, that contain a substrate-connected PNP with its collector grounded and its base and emitter available for temperature-sensing purposes. The temperature is digitized with 11-bit resolution. The MAX6655/MAX6656 also measure their own supply voltage and three external voltages with 8-bit resolution. Each voltage input’s sensitivity is set to give approximately 3/4-scale output code when the input voltage is at its nominal value. The MAX6655 operates at +5V supply and its second voltage monitor is 3.3V. The MAX6656 operates on a +3.3V supply and its second voltage monitor is 5V. The 2-wire serial interface accepts standard SMBus™ Write Byte, Read Byte, Send Byte, and Receive Byte commands to program the alarm thresholds and to read data. The MAX6655/MAX6656 also provide SMBus alert response and timeout functions. The MAX6655/MAX6656 measure automatically and autonomously, with the conversion rate programmable. The adjustable rate allows the u
The MAX6655 and MAX6656 provide precise temperature monitoring for two remote diode‑connected sensors and an internal sensor, plus four voltage monitoring channels. They communicate via a standard SMBus/I²C‑compatible 2‑wire interface, offering programmable alarm thresholds, OVERT fan‑control output, and low‑power standby mode.
The devices feature 11‑bit temperature resolution (0.125 °C), 8‑bit voltage resolution, and operate from +5 V (MAX6655) or +3.3 V (MAX6656) supplies. Typical applications include notebooks, workstations, thin clients, and other computer systems requiring thermal management and voltage monitoring.
| Supply Voltage Range (Voc) | 3.0 V to 5.5 V |
|---|---|
| Temperature Resolution | 0.125 °C (11‑bit) |
| Temperature Accuracy (Remote Sensor) | ±1 °C |
| Number of Temperature Channels | 3 (2 remote, 1 local) |
| Number of Voltage Channels | 4 |
| Standby Current | 3 µA (typ) |
| Operating Temperature Range | -55 °C to +125 °C |
| SMBus Alert Output | Open‑drain, active‑low |
The devices operate from –55 °C to +125 °C.
It provides three temperature channels: two remote PN‑junction sensors and one local sensor.
Standby current is typically 3 µA.
The MAX6655 operates from a +5 V supply, with a second voltage monitor at 3.3 V.