LTC1840IGN#PBF

LTC1840 is a fan controller with two 8bit current output DACs, two tachometer interfaces, and four general purpose I/O (GPIO) pins. A current output DAC is used to control an external switching regulator, which controls the fan speed. A current output DAC and tachometer allow a controller to form a closed control loop on fan velocity. The GPIO pins can be used as digital inputs or open drain pull-down outputs. The part features a simple 2-wire I²C and SMBus compatible serial interface that allows communication between many devices. The interface includes a fault status register that reflects the state of the part and which can be polled to find the cause of a fault condition. Other operational characteristics of the part, such as DAC output currents, GPIO modes, and tachometer frequency, are also programmed through the serial interface. Two address pins provide nine possible device addresses. It is used in application like servers, desktop computers, power supplies, cooling systems.

• DACs guaranteed monotonic, known IC state on power-up
• Serial interface watchdog timer with disable
• 4 programmable general purpose I/Os
• Single supply operation is 2.7V to 5.75V
• Fault output signal, status register
• Fan blasting function, nine addresses using two programming lines
• Differential nonlinearity is ±0.9LSB max, integral nonlinearity is ± 4LSB max
• Supply current is 400µA typical at (VCC = 3V, A0 and A1 Floating)
• Oscillator frequency is 50KHz typical
• Operating temperature is -40°C to 85°C, package style is 16-lead plastic SSOP

Notes

ADI products are only authorized (and sold) for use by the customer and are not to be resold or otherwise passed on to any third party