GXCAS GX21M15

GX21M15 is a temperature-to-digital converter that integrates an on-chip bandgap temperature sensor and Sigma-Delta ADC technology, with an overtemperature detection output. The device contains multiple data registers: a configuration register storing device operating mode, OS operating mode, OS polarity, and OS fault queue settings; a temperature register storing digital temperature data; and setpoint registers storing programmable overtemperature shutdown threshold and hysteresis limit settings. These registers communicate with a controller via a two-wire serial I²C bus interface. The device also provides an open-drain output that asserts when the temperature exceeds the programmed threshold. Up to 8 devices can be connected on the same bus without address conflicts using three logic address pins. The GX21M15 can be configured for different operating modes, including normal mode for periodic temperature monitoring and shutdown mode for minimizing power consumption. The OS output can operate in comparator mode or interrupt mode, with its active state configurable as active-high or active-low. Both the fault queue and setpoint thresholds are programmable. The temperature register always stores 11-bit data in two's complement format, providing 0.125°C resolution, suitable for applications requiring precise thermal drift measurement. Accessing the device does not interrupt an ongoing temperature conversion — the I²C bus section and converter section operate independently, allowing continuous access without waiting for conversion to complete, while the temperature register is updated with new conversion results. At power-up, the device is in normal operating mode with OS in comparator mode, temperature threshold preset to 80°C, and hysteresis value of 75°C, allowing it to function as a standalone thermostat with these predefined setpoints.

• Pin-compatible with industry-standard LM75 and LM75A, offering 0.125°C temperature resolution with supply voltage range of 2.8V to 5.5V.
• I²C bus interface support, up to 8 devices on the same bus.
• Supply voltage range: 2.8V to 5.5V.
• Operating temperature range: -55°C to +125°C.
• I²C bus frequency range: 20Hz to 400kHz, with bus fault timeout to prevent bus lockup.
• 11-bit ADC with 0.125°C resolution.
• Temperature accuracy: ±0.5°C from 0°C to +50°C; ±1°C from -25°C to +100°C; ±1.5°C from -55°C to +125°C.
• Programmable alarm temperature threshold and hysteresis.
• Shutdown mode supply current as low as 0.1μA for power saving.
• Standalone thermostat operation after power-up.
• ESD protection exceeding JESD22-A114 (4500V HBM) and JESD22-C101 (1000V CDM).
• Latch-up testing exceeding 100mA per JEDEC standard JESD78.
• Available in compact 8-pin packages: SOP8, MSOP8/TSSOP8.

• System Thermal Management
• Personal Computers
• Electronic Equipment
• Industrial Controllers