MAX1385 Datasheet | Maxim Integrated

19-4456; Rev 0; 2/09 .. KIT ATION EVALU LE B A IL A AV Dual RF LDMOS Bias Controllers with I2C/SPI Interface General Description The MAX1385/MAX1386 set and control bias conditions for dual RF LDMOS power devices found in cellular base stations. Each device includes a high-side current-sense amplifier with programmable gains of 2, 10, and 25 to monitor LDMOS drain current over the 20m A to 5A range. Two external diode-connected transistors monitor LDMOS temperatures while an internal temperature sensor measures the local die temperature of the MAX1385/MAX1386. A 12-bit ADC converts the programmable-gain amplifier (PGA) outputs, external/internal temperature readings, and two auxiliary inputs. The two gate-drive channels, each consisting of 8-bit coarse and 10-bit fine DACs and a gate-drive amplifier, generate a positive gate voltage to bias the LDMOS devices. The MAX1385 includes a gate-drive amplifier with a gain of 2 and the MAX1386 gate-drive amplifier provides a gain of 4. The 8-bit coarse and 10-bit fine DACs allow up to 18 bits of resolution. The MAX1385/ MAX1386 include autocalibration Features to minimize error over time, temperature, and supply voltage. The MAX1385/MAX1386 feature an I2C/SPI™-patible serial interface. Both devices operate from a 4.75V to 5.25V analog supply (3.2m A supply current), a 2.7V to 5.25V digital supply (3.1m A supply current), and a 4.75V to 11.0V gate-drive supply (4.5m A supply current). The MAX1385/MAX1386 are available in a 48-pin thin QFN package. Features - Integrated High-Side Drain Current-Sense PGA with Gain of 2, 10, or 25 - ±0.5% Accuracy for Sense Voltage Between 75m V and 250m V - Full-Scale Sense Voltage of 100m V with Gain of 25 - Full-Scale Sense Voltage of 250m V with Gain of 10 - mon-Mode Range of 5V to 30V Drain Voltage for LDMOS - Adjustable Low Noise 0 to 5V, 0 to 10V Output Gate-Bias Voltage Ranges with ±10m A Gate Drive - Fast Clamp to 0V for LDMOS Protection - 8-Bit DAC Control of...