LDC0851 Datasheet, PDF (1/39 Pages) Texas Instruments – Differential Inductive Switch

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LDC0851
SNOSCZ7A – DECEMBER 2015 – REVISED JANUARY 2016
LDC0851 Differential Inductive Switch
1 Features
•1 Threshold tolerance: <1 % of coil diameter
• Temperature stable switching operation
• Average Supply Current: < 20 µA @ 10 sps
• Shutdown Supply Current: 140 nA
• Push-pull output
• Resistor Programmable Threshold
• Insensitive to DC Magnetic Fields
• Contactless Switching Operation
• Sample Rate up to 4 ksps
• Supply Voltage: 1.8 V – 3.3 V
• Operating Temperature Range: -40 to 125 °C
2 Applications
• Open/Close Switches
– Home Security and Tamper Detection
– Printers
– Personal Electronics
• Event Counting
– Fan Speed RPM Detection
– Rotary Encoder
– Flow Meters
– Incremental Knob / Dial
• Simple Buttons
– Industrial Keypads
– Personal Electronics
• Industrial Proximity Switch
3 Description
The LDC0851 is a close range inductive switch ideal
for contactless and robust applications such as
presence detection, event counting, and simple
buttons.
The switch is triggered when a conductive object
comes within close proximity of the sensing coil.
Hysteresis is included to ensure a reliable switching
threshold immune to mechanical vibration. The
differential implementation prevents false triggering
over environmental factors such as temperature
variation or humidity effects.
Inductive sensing technology provides reliable and
accurate sensing even in the presence of dirt, oil, or
moisture making it ideal for use in harsh or dirty
environments. The solid state switching eliminates
the failures due to reed, mechanical, or contact
switching. Unlike competitive products, the LDC0851
does not require magnets, nor is it affected by DC
magnetic fields.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
LDC0851
WSON-8
2mm x 2mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
4 Simplified Schematic
Approaching
Metal Target
dswitch
Sense
Coil
LSENSE
Sensor
Cap
Reference
Coil
1.8 V
LCOM
LREF
R1
ADJ
R2
Differential
LDC Core
Inductance
Converter
LDC0851
LS
+
Inductance
Converter
+
LR _±
±
Output High
(LS > LR)
OUT
Output Low
(LS < LR)
dswitch
Offset Adjust
4-bit ADC
VDD
Power ^EN
Management
GND
1.8 V
CBYP
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.