Analog Devices Inc./Maxim Integrated

The LTC1541/LTC1542 combine a micropower amplifier, comparator and bandgap reference (LTC1541) in an 8-pin package. The part operates from a single 2.5V to 12.6V or dual ±1.25V to ±6.3V supply with a typical supply current of 5µA. Both the op amp and comparator feature a common mode input voltage range that extends from the negative supply to within 1.3V of the positive supply. The op amp output stage swings from rail-to-rail. The comparator's inverting input is internally connected to the reference output (LTC1541).The reference output voltage is 1.2V ±1% over the extended temperature range. The output can drive a bypass capacitor of up to 0.01µF without any oscillations. It can also source up to 2mA and sink up to 20µA.The op amp is internally compensated to be unity-gain stable with typical GBW at 12kHz and slew rate of 8V/ms. The comparator has ±2.25mV of internal hysteresis to ensure clean output switching, even with slow moving input signals.The LTC1541/LTC1542 are available in MSOP and SO-8 packages. For space-limited applications, the LTC1541/LTC1542 are available in a 3mm × 3mm low profile (0.8mm) dual fine-pitch leadless package (DFN).ApplicationsBattery- or Solar-Powered SystemsAutomotive Keyless EntryLow Frequency, Local Area Alarms/DetectorsInfrared Receivers for Remote ControlsSmoke Detectors and Safety SensorsGSM Portable Phones

The LTC1544 is a 4-driver/4-receiver multiprotocol transceiver. The LTC1544 and LTC1543 form the core of a complete software-selectable DTE or DCE interface port that supports the RS232, RS449, EIA530, EIA530-A, V.35, V.36 or X.21 protocols. Cable termination for the LTC1543 may be implemented using the LTC1344A software-selectable cable termination chip or by using existing discrete designs. The LTC1546 includes software-selectable cable termination on-chip.The LTC1544 runs from a 5V supply and the charge pump on the LTC1543 or LTC1546. The part is available in a 28-lead SSOP surface mount package.ApplicationsData NetworkingCSU and DSUData Routers

The LTC1545 is a 5-driver/5-receiver multiprotocol transceiver. The LTC1545 and LTC1543 form the core of a complete software-selectable DTE or DCE interface port that supports the RS232, RS449, EIA530, EIA530-A, V.35, V.36 or X.21 protocols. Cable termination may be implemented using the LTC1344A software-selectable cable termination chip or by using existing discrete designs.The LTC1545 runs from a 5V supply and the charge pump on the LTC1543. The part is available in a 36-lead SSOP surface mount package.ApplicationsData NetworkingCSU and DSUData Routers

The LTC1546 is a 3-driver/3-receiver multiprotocol transceiver with on-chip cable termination. When combined with the LTC1544, this chip set forms a complete software-selectable DTE or DCE interface port that supports the RS232, RS449, EIA530, EIA530-A, V.35, V.36 and X.21 protocols. All necessary cable termination is provided inside the LTC1546. In most applications, the LTC1546 replaces both an LTC1543 and an LTC1344A without any changes to the PC board.The LTC1546 runs from a single 5V supply using an internal charge pump that requires only five space-saving surface mounted capacitors. The LTC1546 is available in a 28-lead SSOP surface mount package.ApplicationsData NetworkingCSU and DSUData Routers

The LTC1550/LTC1551 are switched capacitor charge pump voltage inverters which include internal linear post-regulators to minimize output ripple. Output voltages are fixed at –4.1V, with ripple voltages typically below 1mVP-P. The LTC1550 is also available in an adjustable output voltage version. The LTC1550/LTC1551 are ideal for use as bias voltage generators for GaAs transmitter FETs in portable RF and cellular telephone applications.The LTC1550/LTC1551 operate from single 4.5V to 6.5V supplies and draw typical quiescent currents of 4.25mA with a 5V supply. Each device includes a TTL compatible Shutdown pin which drops supply current to 0.2µA typically. The LTC1550 Shutdown pin is active low (SHDN), while the LTC1551 Shutdown pin is active high (SHDN). Only four external components are required: an input bypass capacitor, two 0.1µF charge pump capacitors and a filter capacitor at the linear regulator output. The adjustable LTC1550 requires two additional resistors to set the output voltage. The LTC1550/LTC1551 will supply up to 10mA output current with a 5V supply, while maintaining guaranteed output regulation of ±5%.The fixed voltage LTC1550/LTC1551 are available in S0-8 plastic packages. The adjustable LTC1550 is available in a 16-pin SSOP.ApplicationsGaAs FET Bias GeneratorsNegative Supply GeneratorsBattery-Powered SystemsSingle Supply Applications

The LTC1550/LTC1551 are switched capacitor charge pump voltage inverters which include internal linear post-regulators to minimize output ripple. Output voltages are fixed at –4.1V, with ripple voltages typically below 1mVP-P. The LTC1550 is also available in an adjustable output voltage version. The LTC1550/LTC1551 are ideal for use as bias voltage generators for GaAs transmitter FETs in portable RF and cellular telephone applications.The LTC1550/LTC1551 operate from single 4.5V to 6.5V supplies and draw typical quiescent currents of 4.25mA with a 5V supply. Each device includes a TTL compatible Shutdown pin which drops supply current to 0.2µA typically. The LTC1550 Shutdown pin is active low (SHDN), while the LTC1551 Shutdown pin is active high (SHDN). Only four external components are required: an input bypass capacitor, two 0.1µF charge pump capacitors and a filter capacitor at the linear regulator output. The adjustable LTC1550 requires two additional resistors to set the output voltage. The LTC1550/LTC1551 will supply up to 10mA output current with a 5V supply, while maintaining guaranteed output regulation of ±5%.The fixed voltage LTC1550/LTC1551 are available in S0-8 plastic packages. The adjustable LTC1550 is available in a 16-pin SSOP.ApplicationsGaAs FET Bias GeneratorsNegative Supply GeneratorsBattery-Powered SystemsSingle Supply Applications