CS209A
Proximity Detector
Description
Features
The CS209A is a bipolar monolithic
integrated circuit for use in metal detec-
tion/proximity sensing applications.
feedback circuit provides drive to main-
tain oscillation. The peak demodulator
senses the negative portion of the oscil-
■ Separate Current
Regulator for Oscillator
■ Negative Transient
The IC (see block diagram) contains two lator envelop and provides a demodu-
on-chip current regulators, oscillator
and low-level feedback circuitry, peak
detection/demodulation circuit, a com-
parator and two complementary output
stages.
lated waveform as input to the com-
parator. The comparator sets the states
of the complementary outputs by com-
paring the input from the demodulator
to an internal reference. External loads
are required for the output pins.
Suppression
■ Variable Low-Level
Feedback
■ Improved Performance
over Temperature
The oscillator, along with an external
LC network, provides controlled oscilla- A transient suppression circuit is
tions where amplitude is highly depen-
dent on the Q of the LC tank. During
low Q conditions, a variable low-level
■ 6mA Supply Current
included to absorb negative transients
at the tank circuit terminal.
Consumption at
VCC = 12V
■ Output Current Sink
Capability
Absolute Maximum Ratings
20mA at 4VCC
100mA at 24VCC
Supply Voltage................................................................................................24V
Power Dissipation (TA = 125¡C).............................................................200mW
Storage Temperature Range....................................................Ð55¡C to +165¡C
Junction Temperature...............................................................Ð40¡C to +150¡C
Electrostatic Discharge (except TANK pin)................................................2kV
Lead Temperature Soldering
Package Options
14L SO
Wave Solder(through hole styles only)...........10 sec. max, 260¡C peak
Reflow (SMD styles only)...........60 sec. max above 183¡C, 230¡C peak
1
2
3
4
5
6
7
14
13
12
11
10
9
OSC
TANK
Gnd
N.C.
RF
VCC
Block Diagram
OUT1
N.C.
N.C.
DEMOD
N.C.
N.C.
OUT2
N.C.
DVBE/R Current
Regulator
8
VBE/R Current
Regulator
V
CC
300mA
Oscillator
OSC
RF
4.8kW
23.6kW
8L PDIP & SO
OSC
Feedback
OUT
OUT
1
2
8
7
6
5
1
2
3
4
OSC
TANK
Gnd
RF
V
CC
Neg Transient
Suppression
VCC
+
COMP
DEMOD
OUT2
-
DEMOD
OUT1
TANK
GND
DEMOD
Cherry Semiconductor Corporation
2000 South County Trail, East Greenwich, RI 02818
Tel: (401)885-3600 Fax: (401)885-5786
Email: info@cherry-semi.com
Web Site: www.cherry-semi.com
Rev. 3/11/99
1
A
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Company