Analog Devices Inc./Maxim Integrated

The DS3904/DS3905 contain three nonvolatile (NV) low temperature coefficient, variable digital resistors. Each resistor has 128 user-selectable positions. Additionally, the DS3904/DS3905 have a high-impedance setting that allows each resistor to function as a digital switch. The DS3904/DS3905 can operate over a 2.7V to 5.5V supply voltage range, and communication with the device is achieved through a 2-wire serial interface. Address pins allow multiple DS3904/DS3905s to operate on the same two-wire bus. The DS3904 has one address pin, allowing two DS3904s to share the bus, while the DS3905 has three address pins, allowing up to eight DS3905s to share a common bus. The low-cost and small size of the DS3904/DS3905 make them ideal replacements for conventional mechanical trimming resistors.ApplicationsCell Phones/PDAsFibre Optic Transceiver ModulesPortable ElectronicsPower-Supply CalibrationTest Equipment

The DS3911 is a quad, 10-bit delta-sigma output, nonvolatile (NV) controller that features an on-chip temperature sensor and associated analog-to-digital converter (ADC). The integrated temperature sensor indexes the up to 2°C resolution NV lookup tables (LUTs), encompassing a -40°C to +100°C temperature range. The LUT directly drives the delta-sigma digital-to-analog converter (DAC) outputs. This flexible LUT-based architecture allows the device to provide a temperature-compensated DAC output with arbitrary slope. Programming is accomplished by an I²C-compatible interface that operates at speeds of up to 400kHz.ApplicationsActive Optical CablesInstrumentation and Industrial ControlsLinear and Nonlinear CompensationOptical Transceivers

The DS3922 high-speed current mirror integrates high-voltage devices necessary for monitoring the burst mode receive power signal in avalanche photodiode (APD) biasing and OLT applications. The device has two small and one large gain current mirror outputs to monitor the APD current. An adjustable current clamp limits current through the APD. The clamp also features an external shutdown. An integrated FET is also provided that can be used to quickly clamp the high-voltage bias to ground in the case of high optical input power. Integrated low-voltage FET circuits can be used to create buck, boost, and inverting DC-DC converters for efficient laser bias and EML bias applications.The DS3922 is available in a 24-pin TQFN package and operates over an extended -40°C to +95°C temperature range.Applications10G EPON10GPON OLTAvalanche Photodiode (APD) MonitoringEML BiasGPON OLT