AD7151BRMZ Analog Devices Inc, AD7151BRMZ Datasheet
AD7151BRMZ
Specifications of AD7151BRMZ
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AD7151BRMZ Summary of contents
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FEATURES Ultra-low power 2 3 μA Response time Adaptive environmental compensation 1 capacitance input channel Sensor capacitance ( SENS Sensitivity EMC tested 2 modes ...
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AD7151 TABLE OF CONTENTS Features .............................................................................................. 1 Applications....................................................................................... 1 General Description ......................................................................... 1 Functional Block Diagram .............................................................. 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 Timing Specifications .................................................................. 4 Absolute Maximum Ratings............................................................ 5 ESD Caution.................................................................................. 5 Pin Configuration and Function Descriptions............................. ...
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SPECIFICATIONS 3.6 V; GND = 0 V; –40°C to +85°C, single-ended capacitance mode, unless otherwise noted. DD Table 1. Parameter CAPACITIVE INPUT 2 Conversion Input Range CIN to EXC 3 Resolution 3 Allowed Capacitance CIN ...
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AD7151 Parameter POWER REQUIREMENTS V -to-GND Voltage Current Current Power-Down Mode DD 1 Capacitance units: one picofarad (1 pF × The CAPDAC can be used to shift (offset) the input ...
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ABSOLUTE MAXIMUM RATINGS T = 25°C, unless otherwise noted. A Table 3. Parameter Positive Supply Voltage V to GND DD Voltage on Any Input or Output to GND ESD Rating HBM (ESD Association Human Body Model, S5.1) ESD Rating FICDM ...
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AD7151 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS Table 4. Pin Function Descriptions Pin No. Mnemonic Description 1 GND Ground Pin. 2 VDD Power Supply Voltage. This pin should be decoupled to GND using a low impedance capacitor, for example, 0.1 μF ...
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TYPICAL PERFORMANCE CHARACTERISTICS 300 200 100 0 –100 0 50 100 150 CAPACITANCE CIN TO GND (pF) Figure 4. Capacitance Input Offset Error vs. Capacitance CIN to GND 3.3 V, EXC Pin Open Circuit –2 ...
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AD7151 –5 – RESISTANCE EXC TO GND (MΩ) Figure 10. Capacitance Input Offset Error vs. Resistance EXC to GND 3.3 V, CIN Pin Open Circuit DD 0.50 0.25 0 –0.25 –0.50 ...
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TEMPERATURE (°C) Figure 16. EXC Frequency Error vs. Temperature 3 –1 –2 2.7 3.0 3.3 V (V) DD Figure 17. EXC Frequency Error ...
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AD7151 ARCHITECTURE AND MAIN FEATURES CIN C X EXC The AD7151 core is a high performance capacitance-to-digital converter (CDC) that allows the part to be interfaced directly to a capacitive sensor. The comparator compares the CDC result with thresholds, either ...
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COMPARATOR AND THRESHOLD MODES The AD7151 comparator and its threshold can be programmed to operate in several different modes adaptive mode, the threshold is dynamically adjusted and the comparator output indicates fast changes and ignores slow changes in ...
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AD7151 SENSITIVITY In adaptive threshold mode, the output comparator threshold is set as a defined distance (sensitivity) above the data average, below the data average, or both, depending on the selected threshold mode of operation (see Figure 29). The sensitivity ...
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AUTOCAPDAC ADJUSTMENT In adaptive threshold mode, the part can dynamically adjust the CAPDAC to keep the CDC in an optimal operating capacitive range. When the AutoDAC function is enabled, the CAPDAC value is automatically incremented when the data average exceeds ...
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AD7151 REGISTER DESCRIPTIONS Table 5. Register Summary Pointer Register (Dec) (Hex) R/W Status 0 0x00 R Data High 1 0x01 R Data Low 2 0x02 R – 3 0x03 R – 4 0x04 R Average High 5 0x05 R Average ...
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STATUS REGISTER Address Pointer 0x00 8 Bits, Read-Only, Default Value 0x53 Before Conversion, 0x52 After Conversion The status register indicates the status of the part. The register can be read via the 2-wire serial interface to query the status of ...
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AD7151 DATA REGISTER Address Pointer 0x01, 0x02 16 Bits, Read-Only, Default Value 0x0000 Data from the last complete capacitance-to-digital conversion reflects the capacitance on the input. Only the 12 MSBs (most significant bits) of the data register are used for ...
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TIMEOUT REGISTER Address Pointer 0x0A 8 Bits, Read/Write, Factory Preset 0x86 Table 9. Timeout Register Bit Map Bit Bits [7:4] Mnemonic TimeOutApr Default 0x08 The register sets timeouts for the adaptive threshold mode. The approaching timeout starts when the CDC ...
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AD7151 SETUP REGISTER Address Pointer 0x0B 8 Bits, Read/Write, Factory Preset 0x0B Table 10. Setup Register Bit Map Bit Bit 7 Mnemonic RngH Default 0 Table 11. Setup Register Bit Descriptions Bit Mnemonic Description 7 RngH Range bits set the ...
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CONFIGURATION REGISTER Address Pointer 0x0F 8 Bits, Read/Write, Factory Preset 0x19 Table 12. Configuration Register Bit Map Bit Bit 7 Mnemonic ThrFixed Default 0 Table 13.Configuration Register Bit Descriptions Bit Mnemonic Description 7 ThrFixed ThrFixed = 1 sets the fixed ...
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AD7151 POWER-DOWN TIMER REGISTER Address Pointer 0x10 8 Bits, Read/Write, Factory Preset 0x00 Table 14. Power-Down Timer Register Bit Map Bit Bit 7 Mnemonic – Default 0 Table 15. Power-Down Timer Register Bit Descriptions Bit Mnemonic Description [7:6] - These ...
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SERIAL INTERFACE 2 The AD7151 supports an I C-compatible 2-wire serial interface. The two wires on the serial bus (interface) are called SCL (clock) and SDA (data). These two wires carry all addressing, control, and data information one bit at ...
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AD7151 If a repeated start condition is encountered after the address pointer byte, all peripherals connected to the bus respond exactly as outlined previously for a start condition; that is, a repeated start condition is treated the same as a ...
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HARDWARE DESIGN CONSIDERATIONS OVERVIEW The AD7151 is an interface to capacitive sensors. On the input side, the sensor (C ) can be connected directly X between the AD7151 EXC and CIN pins. The way it is connected and the electrical ...
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AD7151 PARASITIC SERIAL RESISTANCE R S1 CIN EXC Figure 45. Parasitic Serial Resistance The AD7151 CDC result is affected by a resistance in series with the measured capacitance. The total serial resistance ( Figure ...
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APPLICATION EXAMPLES C SENS C SENS 39kΩ 82kΩ 68pF 22pF C SENS 10kΩ 47pF Figure 51. AD7151 Standalone Operation with EMC Protection and Optional Serial Interface 0.1µF 10kΩ VDD AD7151 CIN SDA SCL EXC OUT GND Figure 49. AD7151 Standalone ...
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... AD7151 OUTLINE DIMENSIONS ORDERING GUIDE Model Temperature Range 1 AD7151BRMZ −40°C to +85°C AD7151BRMZ-REEL 1 −40°C to +85° RoHS Compliant Part. 3.10 3.00 2. 5.15 3.10 4.90 3.00 4.65 2. PIN 1 0.50 BSC 0.95 0.85 1.10 MAX 0.75 0.15 0.33 SEATING 0.23 0.05 PLANE 0 ...
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NOTES Rev Page AD7151 ...
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AD7151 NOTES Purchase of licensed components of Analog Devices or one of its sublicensed Associated Companies conveys a license for the purchaser under the Philips I 2 Rights to use these components system, ...