12-Bit Monitor and Control System with Multichannel ADC, DACs, Temperature Sensor, and Current Sense Data Sheet AD7294-2 FEATURES APPLICATIONS 12-bit SAR ADC with 3 s conversion time Cellular base stations 4 uncommitted analog inputs GSM, EDGE, UMTS, CDMA, TD-SCDMA, W-CDMA, WiMAX Differential/single-ended Point-to-multipoint and other RF transmission systems V , 2 V input ranges 12 V, 24 V, 48 V automotive applications REF REF 2 high-side current sense inputs Industrial controls 5 V to 59.4 V operating range GENERAL DESCRIPTION 0.75% maximum gain error The AD7294-2 contains all the functions that are required for 200 mV input range general-purpose monitoring and control of current, voltage, 2 external diode temperature sensor inputs and temperature, integrated into a single-chip solution. The part 55C to +150C measurement range includes low voltage (200 mV) analog input sense amplifiers 2C accuracy for current monitoring across shunt resistors, temperature sense Series resistance cancellation inputs, and four uncommitted analog input channels multiplexed 1 internal temperature sensor: 2C accuracy into a SAR analog-to-digital converter (ADC) with a 3 s Built-in monitoring features conversion time. A high accuracy internal reference is provided Minimum/maximum recorder for each channel to drive both the digital-to-analog converters (DACs) and the Programmable alert thresholds ADC. Four 12-bit DACs provide the outputs for voltage control. Programmable hysteresis The AD7294-2 also includes limit registers for alarm functions. Four 12-bit, monotonic, 15 V DACs The part is designed for high voltage compliance: 59.4 V on the 5 V span, 0 V to 10 V offset 8 s settling time current sense inputs and up to a 15 V DAC output voltage. 10 mA sink and source capability The AD7294-2 is a highly integrated solution that offers all the Power-on reset (POR) to 0 V functionality necessary for precise control of the power amplifier Internal 2.5 V reference in cellular base station applications. In these types of applications, 2 2-wire, fast mode I C interface the DACs provide 12-bit resolution to control the bias currents Temperature range: 40C to +105C of the power transistors. Thermal diode-based temperature sensors Package type: 64-lead TQFP are incorporated to compensate for temperature effects. The ADC Pin compatible with the AD7294 monitors the high-side current and temperature. This functionality is provided in a 64-lead TQFP, which operates over a temperature range of 40C to +105C. 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Technical Support www.analog.com AD7294-2 Data Sheet TABLE OF CONTENTS Command Register .................................................................... 26 Features .............................................................................................. 1 ADC Result Register .................................................................. 26 Applications ....................................................................................... 1 TSENSE1 and TSENSE2 Result Registers ......................................... 27 General Description ......................................................................... 1 TSENSEINT Result Register .......................................................... 27 Revision History ............................................................................... 2 DAC , DAC , DAC , and DAC Value Registers ....................... 27 A B C D Functional Block Diagram .............................................................. 3 Alert Status Register A, Alert Status Register B, and Alert Specifications ..................................................................................... 4 Status Register C ......................................................................... 28 DAC Specifications....................................................................... 4 Channel Sequence Register ....................................................... 28 ADC Specifications ...................................................................... 5 Configuration Register .............................................................. 29 General Specifications ................................................................. 7 Power-Down Register ................................................................ 30 Timing Characteristics ................................................................ 8 DATALOW and DATAHIGH Registers .......................................... 30 Absolute Maximum Ratings ............................................................ 9 Hysteresis Registers .................................................................... 30 Thermal Resistance ...................................................................... 9 Remote Channel T 1 and T 2 Offset Registers ........... 31 SENSE SENSE ESD Caution .................................................................................. 9 2 I C Interface .................................................................................... 32 Pin Configuration and Function Descriptions ........................... 10 2 General I C Timing .................................................................... 32 Typical Performance Characteristics ........................................... 12 Serial Bus Address Byte ............................................................. 32 Terminology .................................................................................... 17 Interface Protocol ....................................................................... 33 DAC Terminology ...................................................................... 17 Modes of Operation ....................................................................... 36 ADC Terminology ...................................................................... 17 Command Mode ........................................................................ 36 Theory of Operation ...................................................................... 18 Autocycle Mode .......................................................................... 37 ADC Overview ........................................................................... 18 Alerts and Limits Theory .............................................................. 38 ADC Transfer Functions ........................................................... 18 ALERT FLAG Bit ....................................................................... 38 Analog Inputs .............................................................................. 19 Alert Status Registers ................................................................. 38 Current Sensor ............................................................................ 20 DATALOW and DATAHIGH Monitoring Features ...................... 38 Analog Comparator Loop ......................................................... 22 Hysteresis ..................................................................................... 39 Temperature Sensor ................................................................... 22 Applications Information .............................................................. 40 DAC Operation ........................................................................... 23 Base Station Power Amplifier Monitor and Control ............. 40 ADC and DAC Reference .......................................................... 24 Gain Control of Power Amplifier ............................................. 41 V Feature .............................................................................. 24 DRIVE Outline Dimensions ....................................................................... 42 Register Settings .............................................................................. 25 Ordering Guide .......................................................................... 42 Address Pointer Register ........................................................... 25 REVISION HISTORY 6/13Revision 0: Initial Version Rev. 0 Page 2 of 44