A4231 Datasheet, PDF (1/2 Pages) alpha microelectronics gmbh – proximity sensor integrated circuit to be used with a broad range

a4231 general features
The a4231 is a proximity sensor integrated circuit to be used with a broad range of
inductive single-coiled proximity transducers in proximity detection applications
 Monolithic IC in bipolar technology
 User-adjustable sensing range by means of a single external resistor
 User-adjustable hysteresis (0…15%)
 5.5V…35V broad supply voltage range
 Low-voltage operation possible using stabilised 4.5V…5.5V voltage source
 Internal voltage regulator to improve immunity against fluctuations of supply
voltage
 Broad operating temperature range: -25°C...90°C
 Can work with a broad selection of inductive transducers
 NPN open collector output with guaranteed sink current of 150mA
 Output overload/over current protection
 Integrated power-on and detect LED drivers
 Normally open(NO)/normally closed(NC) select pin
 Broad range of operating frequencies: 100kHz…1MHz
 Output over current and short-circuit protection
 Easy temperature compensation of proximity transducers
 Package – QFN-24
example application schematic
C_F
100nF/6.3V
R_F
10%
Inductive
Transducer
R_F
L
L₁
C_RES
L₂
220nF/6.3V
20%
Rref
91kohm
GND
R_H
Rhyst, 5%
(optional)
NO/NC
NO/NC
VCC
min. 2.2uF/40V
electrolytic
Vcc
220nF/6.3V
20% ceramic
C_B
P_LED
a4231
D_LED
OutN
C_DET
Cdet, 10%
(optional)
C_OVL
Covl, 10%
100nF/6.3V
GND1
RSN
R_S,N
1R6 5%
125mW
OutN
Typical application schematic of a proximity sensor/detector