LTC1840IGN#TR

Product Summary

The LTC1840IGN#TR is a fan controller with two 8-bit current output DAC, two tachometer interfaces, and four general purpose I/O (GPIO) pins. It operates from a single supply with a range of 2.7V to 5.75V. 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 of the LTC1840IGN#TR 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 LTC1840IGN#TR, 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. Applications are servers, desktop computers, power supplies, cooling systems.

Parametrics

LTC1840IGN#TR absolute maximum ratings: (1)VCC to GND : –0.3 to 6V, A0, A1 : –0.3 to (VCC + 0.3V); (2)IDACOUTA, IDACOUTB : –0.3 to (VCC + 0.75V); (3)All other pins : –0.3 to 6V; (4)Operating Temperature: –40℃ to 85℃; (5)Storage Temperature Range : –65℃ to 125℃; (6)Lead Temperature (Soldering, 10 sec): 300℃; (7)fOSC Oscillator Frequency: 47 to 53 kHz.

Features

LTC1840IGN#TR features: (1)Two 8-Bit Current DACs; (2)DACs Guaranteed Monotonic; (3)KnowIC State oPower-Up; (4)Serial Interface Watchdog Timer with Disable; (5)2-Wire Serial Interface Compatible with I2CTM and SMBus; (6)2 Programmable FaTachometer Interfaces; (7)4 Programmable General Purpose I/Os; (8)Small 16-PiSSOP Package; (9)Single 2.7V to 5.75V Supply Operation; (10)Fault Output Signal; (11)Status Register; (12)FaBlasting Function; (13)Nine Addresses Using Two Programming Lines.

Diagrams