The MAX6627/MAX6628 precise digital temperature sensors report the temperature of a remote sensor. The remote sensor is a diode-connected transistor, typically a low-cost, easily mounted 2N3904 NPN type that replaces conventional thermistors or thermocouples. The MAX6627/MAX6628 can also measure the die temperature of other ICs, such as microprocessors (µPs) or microcontrollers (µCs) that contain an on-chip, diode-connected transistor. Remote accuracy is ±1°C when the temperature of the remote diode is between 0°C and +125°C and the temperature of the MAX6627/MAX6628 is +30°C. The temperature is converted to a 12-bit + sign word with 0.0625°C resolution. The architecture of the device is capable of interpreting data as high as +145°C from the remote sensor. The MAX6627/MAX6628 temperature should never exceed +125°C. These sensors are 3-wire serial interface SPI compatible, allowing the MAX6627/MAX6628 to be readily connected to a variety of µCs. The MAX6627/MAX6628 are read-only devices, simplifying their use in systems where only temperature data is required. Two conversion rates are available, one that continuously converts data every 0.5s (MAX6627), and one that converts data every 8s (MAX6628). The slower version provides minimal power consumption under all operating conditions (30µA, typ). Either device can be read at any time and provide the data from the last conversion.
The MAX6627 and MAX6628 are precise digital temperature sensors that read a remote diode‑connected transistor (commonly a 2N3904) or the die temperature of other ICs. They provide ±1 °C accuracy from 0 °C to +125 °C when the device itself is at +30 °C, and output a 12‑bit signed word with 0.0625 °C resolution. Applications include hard‑disk drives, smart battery packs, automotive systems, industrial control, and PCs.
Both devices operate from a 3.0 V to 5.5 V supply, work over –55 °C to +125 °C, and are offered in 8‑pin SOT23 or lead‑free TDFN packages. The MAX6627 updates every 0.5 s, while the MAX6628 updates every 8 s, delivering low typical supply currents of 200 µA and 30 µA respectively. The sensors use a 3‑wire SPI‑compatible serial interface and include detailed guidelines for PCB layout, cable routing, and noise filtering.
| Accuracy | ±1 °C (0 °C‑+125 °C, device at +30 °C) |
|---|---|
| Resolution | 0.0625 °C (12‑bit) |
| Supply Voltage Range | +3.0 V to +5.5 V |
| Operating Temperature Range | -55 °C to +125 °C |
| Conversion Rate | 0.5 s (MAX6627) / 8 s (MAX6628) |
| Package Types | 8‑pin SOT23 and lead‑free TDFN |
| Interface | 3‑wire SPI‑compatible serial interface |
The MAX6627 updates every 0.5 seconds, while the MAX6628 updates every 8 seconds.
They operate from 3.0 V up to 5.5 V.
The sensors provide ±1 °C accuracy when the remote diode is between 0 °C and +125 °C and the device is at +30 °C.