12-Bit Monitor and Control System with Multichannel ADC, DACs, Temperature Sensor, and Current Sense Data Sheet AD7294 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 0.5% max gain error The AD7294 contains all the functions required for general- 200 mV input range purpose monitoring and control of current, voltage, and 2 external diode temperature sensor inputs temperature integrated into a single-chip solution. The device 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 into a SAR analog-to-digital converter (ADC) with a 3 s conver- 2C accuracy sion time. A high accuracy internal reference is provided to drive Built-in monitoring features both the digital-to-analog converter (DAC) and ADC. Four 12-bit Minimum/maximum recorder for each channel DACs provide the outputs for voltage control. The AD7294 also Programmable alert thresholds includes limit registers for alarm functions. The device is designed Programmable hysteresis on Analog Devices, Inc., high voltage DMOS process for high Four 12-bit monotonic 15 V DACs 5 V span, 0 V to 10 V offset voltage compliance, 59.4 V on the current sense inputs, and up 8 s settling time to a 15 V DAC output voltage. 10 mA sink and source capability The AD7294 is a highly integrated solution that offers all the Power-on resets (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 or 56-lead LFCSP are incorporated to compensate for temperature effects. The ADC monitors the high-side current and temperature. All this function- ality is provided in a 64-lead TQFP or a 56-lead LFCSP operating over a temperature range of 40C to +105C. Rev. I Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 20082016 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. AD7294 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 TSENSE1, TSENSE2 Result Registers (0x02 and 0x03) ........ 29 Applications ....................................................................................... 1 TSENSEINT Result Register (0x04) ........................................ 29 General Description ......................................................................... 1 DACA, DACB, DACC, DACD, Registers (0x01 to 0x04) ............... 30 Revision History ............................................................................... 3 Alert Status Register A (0x05), Register B (0x06), and Register C (0x07) ........................................................................ 30 Functional Block Diagram .............................................................. 4 Channel Sequence Register (0x08) .......................................... 30 Specifications ..................................................................................... 5 Configuration Register (0x09) .................................................. 31 DAC Specifications....................................................................... 5 Power-Down Register (0x0A) ................................................... 32 ADC Specifications ...................................................................... 6 DATAHIGH/DATALOW Registers: 0x0B, 0x0C (VIN0) 0x0E, 0x0F General Specifications ................................................................. 8 (VIN1) 0x11, 0x12 (VIN2) 0x14, 0x15 (VIN3) .............................. 32 Timing Characteristics ................................................................ 9 Hysteresis Registers: 0x0D (VIN0), 0x10 (VIN1), 0x13 Absolute Maximum Ratings .......................................................... 10 (VIN2), 0x16 (VIN3) ................................................................. 32 Thermal Resistance .................................................................... 10 T Offset Registers (0x26 and 0x27) ................................... 33 SENSE ESD Caution ................................................................................ 10 2 I C Interface .................................................................................... 34 Pin Configurations and Function Descriptions ......................... 11 2 General I C Timing .................................................................... 34 Typical Performance Characteristics ........................................... 14 Serial Bus Address Byte ............................................................. 35 Terminology .................................................................................... 19 Interface Protocol ....................................................................... 35 DAC Terminology ...................................................................... 19 Modes of Operation ....................................................................... 39 ADC Terminology ...................................................................... 19 Command Mode ........................................................................ 39 Theory of Operation ...................................................................... 20 Autocycle Mode .......................................................................... 40 ADC Overview ........................................................................... 20 Alerts and Limits Theory .............................................................. 41 ADC Transfer Functions ........................................................... 20 Alert Flag Bit .............................................................................. 41 Analog Inputs .............................................................................. 20 Alert Status Registers ................................................................. 41 Current Sensor ............................................................................ 22 Data and Data Monitoring Features ............................ 41 HIGH LOW Analog Comparator Loop ......................................................... 23 Hysteresis ..................................................................................... 42 Temperature Sensor ................................................................... 24 Applications Information .............................................................. 43 DAC Operation ........................................................................... 25 Base Station Power Amplifier Monitor and Control ............. 43 ADC and DAC Reference .......................................................... 25 Gain Control of Power Amplifier............................................. 44 V Feature .............................................................................. 26 DRIVE Layout and Configuration ............................................................. 45 Register Setting ............................................................................... 27 Power Supply Bypassing and Grounding ................................ 45 Address Pointer Register ........................................................... 27 Outline Dimensions ....................................................................... 46 Command Register (0x00) ........................................................ 28 Ordering Guide .......................................................................... 46 Result Register (0x01) ................................................................ 28 Rev. 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