CS209A Datasheet, PDF (1/6 Pages) Cherry Semiconductor Corporation – Proximity Detector

CS209A
Proximity Detector
Description
The CS209A is a bipolar monolithic
integrated circuit for use in metal detec-
tion/proximity sensing applications.
The IC (see block diagram) contains two
on-chip current regulators, oscillator
and low-level feedback circuitry, peak
detection/demodulation circuit, a com-
parator and two complementary output
stages.
The oscillator, along with an external
LC network, provides controlled oscilla-
tions where amplitude is highly depen-
dent on the Q of the LC tank. During
low Q conditions, a variable low-level
feedback circuit provides drive to main-
tain oscillation. The peak demodulator
senses the negative portion of the oscil-
lator envelop and provides a demodu-
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.
A transient suppression circuit is
included to absorb negative transients
at the tank circuit terminal.
Absolute Maximum Ratings
Supply Voltage ................................................................................................24V
Power Dissipation (T_A = 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
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
Block Diagram
OSC
RF
DVBE/R Current
Regulator
300mA
Oscillator
OSC
Feedback
4.8kW 23.6kW
Neg Transient
Suppression
DEMOD
V_CC
VBE/R Current
Regulator
+
COMP
-
V_CC
OUT₁
OUT₂
Features
s Separate Current
Regulator for Oscillator
s Negative Transient
Suppression
s Variable Low-Level
Feedback
s Improved Performance
over Temperature
s 6mA Supply Current
Consumption at
V_CC = 12V
s Output Current Sink
Capability
20mA at 4V_CC
100mA at 24V_CC
Package Options
14L SO
OSC 1
TANK 2
Gnd 3
OUT₁ 4
N.C. 5
OUT₂ 6
N.C. 7
14 N.C.
13 RF
12 V_CC
11 N.C.
10 DEMOD
9 N.C.
8 N.C.
8L PDIP & SO
OSC 1
TANK 2
Gnd 3
OUT₁ 4
8 RF
7 V_CC
6 DEMOD
5 OUT₂
TANK
GND
Rev. 3/11/99
DEMOD
1
Cherry Semiconductor Corporation
2000 South County Trail, East Greenwich, RI 02818
Tel: [phone] Fax: [phone]
Email: [e-mail]
Web Site: www.cherry-semi.com
A
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